WO2022109960A1 - Three-dimensional carbon nanotube cluster and method for preparation thereof and application thereof - Google Patents

Three-dimensional carbon nanotube cluster and method for preparation thereof and application thereof Download PDF

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WO2022109960A1
WO2022109960A1 PCT/CN2020/131966 CN2020131966W WO2022109960A1 WO 2022109960 A1 WO2022109960 A1 WO 2022109960A1 CN 2020131966 W CN2020131966 W CN 2020131966W WO 2022109960 A1 WO2022109960 A1 WO 2022109960A1
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precursor
carbon nanotube
jungle
dimensional carbon
sintering container
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PCT/CN2020/131966
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Chinese (zh)
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杨瑞枝
郑祥俊
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苏州大学
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    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/05—Preparation or purification of carbon not covered by groups C01B32/15, C01B32/20, C01B32/25, C01B32/30
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
    • H01M4/90—Selection of catalytic material

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  • the invention relates to a novel preparation method of a three-dimensional carbon nanotube jungle and its application in the technical field of electrocatalysis, which can be used as an electrocatalyst for zinc-air batteries.
  • Zinc-air batteries are considered as promising next-generation energy storage sources due to their high theoretical energy density, environmental friendliness, high safety, and low cost.
  • ORR oxygen reduction reaction
  • OER oxygen evolution reaction
  • both ORR and OER involve slow kinetic processes of multiple electron transfer reactions, there is an urgent need to develop stable and efficient bifunctional oxygen catalysts for rechargeable ZABs.
  • platinum-based materials are currently commercialized as ORR catalysts and iridium/ruthenium-based materials as OER catalysts, these noble metal catalysts only exhibit a single catalytic activity, and their high cost and poor stability greatly limit their potential applications.
  • Application of charging ZAB Therefore, there is an urgent need to explore efficient and low-cost reversible bifunctional oxygen electrocatalysts.
  • transition metal alloy nanoparticles encapsulated in nitrogen-doped carbon nanotubes (N-CNTs) can effectively improve the active sites of electrocatalysts.
  • the strong bonding between TMA-NPs and N-CNTs can effectively improve the electronic structure of the carbon framework, thereby lowering the adsorption energy barrier of oxygen and its intermediates on the catalyst, which is favorable for the bonding between them.
  • the invention discloses a three-dimensional carbon nanotube jungle (FeNi@NCNT-CP) electrocatalyst inlaid with FeNi alloy, which has low preparation cost and uniform diameter of the grown CNT, which is suitable for zinc-air battery electrode catalysis.
  • the present invention adopts the following technical scheme: three-dimensional carbon nanotube jungle, the preparation method is as follows: nitrogen precursor, iron precursor, nickel precursor and water are mixed and then frozen to obtain precursor mixture powder; and then the precursor mixture powder is put into Inside the small sintering container, the small sintering container is inverted on the large sintering container, and cotton cloth is placed on the large sintering container and outside the small sintering container, and then calcined in nitrogen to obtain a three-dimensional carbon nanotube jungle.
  • the creativity of the present invention lies in changing the calcination method of the existing metal hybrid carbon nanotubes, and beyond imagination, FeNi@NCNT-CP electrocatalyst can be obtained.
  • the network structure shows relatively strong carbon peaks and weak metal peaks.
  • This hierarchical three-dimensional porous network structure provides abundant three-phase reaction interfaces and material transport channels for the electrochemical process, which is conducive to the adsorption and reaction of oxygen. .
  • the nitrogen precursor, the iron precursor and the nickel precursor are all water-soluble compounds, for example, the nitrogen precursor is urea, the iron precursor is ferric nitrate nonahydrate, and the nickel precursor is nickel nitrate hexahydrate; the obtained three-dimensional carbon In the nanotube jungle, the top of the CNT is wrapped with the catalyst metal particles necessary for its growth, which is a core-shell structure, and its outer layer is 3-4 layers of highly graphitized layered carbon with a layer spacing of 0.35 nm corresponds to the C(002) crystal plane, while the inner metal part shows lattice fringes with good resolution with a lattice spacing of 0.209 nm, which corresponds to the (111) crystal plane of FeNi alloy.
  • the nitrogen precursor is urea
  • the iron precursor is ferric nitrate nonahydrate
  • the nickel precursor is nickel nitrate hexahydrate
  • the obtained three-dimensional carbon In the nanotube jungle the top of the CNT is wrapped with the catalyst metal particles necessary for its growth,
  • the mixed powder obtained by freeze-drying in the present invention can keep all components well It is as uniformly dispersed as in the aqueous solution, and iron and nickel are not easily oxidized, which solves the problem that the precursors of iron and nickel cannot be heated and dried due to their strong reducing properties.
  • the XRD pattern of FeNi@NCNT-CP shows weak carbon diffraction peaks at 2 ⁇ 26°, corresponding to the C(002) crystal plane; at 2 ⁇ 43.5°, 50.8° and There are strong metal diffraction peaks at 74.6°, corresponding to the (111), (200) and (220) crystal planes of FeNi alloy, respectively; this confirms the existence of carbon and the formation of FeNi alloy, and compared with FeNi@
  • the outer layer CNTs of NCNT and FeNi@NCNT-CP have a higher degree of graphitization, while the metal in the inner layer is more finely and uniformly wrapped inside the CNTs.
  • the invention discloses the application of the above-mentioned three-dimensional carbon nanotube jungle as a battery electrocatalyst and the application in the preparation of the battery; it can be used as an oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) electrocatalyst in the preparation of a zinc-air battery (ZAB). application in.
  • ORR oxygen reduction reaction
  • OER oxygen evolution reaction
  • the electrocatalyst of the present invention separates the C, N and metal precursor mixture from the carbon nanotube (CNT) growth substrate by designing an inverted corundum boat pattern, and controls the rapid heating rate so that the precursor mixture can be rapidly decomposed
  • the 3D carbon nanotube jungle (FeNi@NCNT-CP) composites studded with FeNi alloys were prepared by this simple one-step pyrolysis method, and exhibited excellent ORR and OER electrical properties. catalytic performance.
  • the advantages of the CNT-based bifunctional oxygen electrocatalyst disclosed in the present invention are: unique preparation method, novel material structure, close separation of precursor material and growth substrate, and porous growth substrate.
  • the diameter of the CNT and the particle size of the embedded metal particles are fine, uniform and evenly dispersed, with a large specific surface area and abundant micro/nano-hole channels, which are conducive to exposing more active sites and material transport. It exhibited minimal overpotential and excellent stability during ORR and OER, and was successfully applied to ZAB as a cathode catalyst showing good cycling stability and small potential polarization.
  • the present invention improves the existing pyrolysis method, separates and places the precursor mixture (urea, hexahydrate ferric nitrate, hexahydrate nickel nitrate) and the CNT growth substrate (cotton cloth) by inverting large and small corundum boats, and proposes a novel , and controllably synthesized FeNi alloy-embedded homogeneous carbon nanotube jungle (FeNi@NCNT-CP) composites with a three-dimensional network structure, which exhibited efficient catalytic performance and excellent stability in ORR and OER. And can be successfully applied to rechargeable ZAB as a cathode catalyst.
  • the preparation process is novel and simple, the source of raw materials is abundant, and the cost is low, showing broad application prospects.
  • Figure 3 (a) X-ray diffraction patterns of FeNi@NCNT-CP and FeNi@NCNT and PDF card of Fe 0.64 Ni 0.36 , (b) N adsorption and desorption isotherms of FeNi@ NCNT -CP and FeNi@NCNT, ( c) and the corresponding pore size distribution.
  • Preparation of precursor mixture 3 g urea (CO(NH 2 ) 2 ), 0.105 g ferric nitrate nonahydrate (Fe(NO 3 ) 3 9H 2 O), 0.075 g nickel nitrate hexahydrate (Ni(NO 3 ) 2 6H 2 O) and 20 mL of ultrapure water were added to the beaker, and the beaker was dissolved under normal stirring at room temperature; then the beaker was transferred to a refrigerator at -18 °C for 12 h, and then freeze-dried at -50 °C in a freeze dryer. After 24 h, the precursor mixture powder containing C, N, Fe, and Ni was obtained.
  • Figure 3a is the X-ray diffraction (XRD) patterns of FeNi@NCNT-CP and FeNi@NCNT.
  • XRD X-ray diffraction
  • Preparation of precursor mixture 3 g urea (CO(NH 2 ) 2 ), 0.105 g ferric nitrate nonahydrate (Fe(NO 3 ) 3 9H 2 O), 0.075 g nickel nitrate hexahydrate (Ni(NO 3 ) 2 6H 2 O) and 20 mL of ultrapure water were added to the beaker, and the beaker was dissolved under normal stirring at room temperature; then the beaker was transferred to a refrigerator at -18 °C for 12 h, and then freeze-dried at -50 °C in a freeze dryer. After 24 h, the precursor mixture powder containing C, N, Fe, and Ni was obtained.
  • Preparation of precursor mixture 3 g urea (CO(NH 2 ) 2 ), 0.105 g ferric nitrate nonahydrate (Fe(NO 3 ) 3 9H 2 O), 0.075 g nickel nitrate hexahydrate (Ni(NO 3 ) 2 6H 2 O) and 20 mL of ultrapure water were added to the beaker, and the beaker was dissolved under normal stirring at room temperature; then the beaker was transferred to a refrigerator at -18 °C for 12 h, and then freeze-dried at -50 °C in a freeze dryer. After 24 h, the precursor mixture powder containing C, N, Fe, and Ni was obtained.
  • the combination of the above-mentioned inverted corundum boat with cotton cloth was transferred to the middle of the tube furnace, and calcined at 10 °C/min in a nitrogen atmosphere to the design temperature for 1 h, and then naturally cooled to room temperature to obtain three-dimensional carbon.
  • Nanotube jungle FeNi@NCNT-CP the design temperatures are 600°C, 700°C, 900°C, and 1000°C, respectively.

Abstract

The present invention belongs to the technical field of electrocatalysis, and specifically discloses a three-dimensional carbon nanotube (CNT) cluster and method for preparation thereof and application thereof, which can be used as an oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) electrocatalyst in a zinc-air battery (ZAB). A nitrogen precursor, iron precursor, and nickel precursor are mixed with water and then frozen to obtain a precursor mixture powder; the precursor mixture powder is placed in a small sintering container, then the small sintering container is inverted on a large sintering container, and cotton cloth is placed on the large sintering container and on the outside of the small sintering container, then calcining is done in nitrogen to obtain a three-dimensional carbon nanotube cluster. The present invention provides a new way to prepare highly effective and controllable three-dimensional CNTs by means of a one-step pyrolysis gas chromatography method.

Description

三维碳纳米管丛林及其制备方法与应用Three-dimensional carbon nanotube jungle and its preparation method and application 技术领域technical field
本发明涉及一类三维碳纳米管丛林的新型制备方法及其在电催化技术领域的应用，可作为锌空气电池电催化剂。The invention relates to a novel preparation method of a three-dimensional carbon nanotube jungle and its application in the technical field of electrocatalysis, which can be used as an electrocatalyst for zinc-air batteries.
背景技术Background technique
锌-空气电池（ZAB）由于具有较高的理论能量密度、环境友好性、高安全性以及低成本，从而被认为是极具潜力的下一代储能电源。其中，放电过程中涉及的氧气还原反应（ORR）和充电过程中的氧气析出反应（OER）是可充电ZAB的两个关键电化学过程。由于ORR和OER都涉及到缓慢的多电子转移反应动力学过程，因此迫切需要开发稳定且高效的双功能氧气催化剂并用于可充电ZAB。尽管目前铂基材料作为ORR催化剂和铱/钌基材料作为OER催化剂被商业化应用，但是这些贵金属催化剂仅表现出单一的催化活性，并且它们的成本高、稳定性差，极大地限制了其在可充电ZAB中的应用。因此，急需探索高效、低成本的可逆双功能氧气电催化剂。Zinc-air batteries (ZABs) are considered as promising next-generation energy storage sources due to their high theoretical energy density, environmental friendliness, high safety, and low cost. Among them, the oxygen reduction reaction (ORR) involved in the discharge process and the oxygen evolution reaction (OER) during the charging process are the two key electrochemical processes of rechargeable ZABs. Since both ORR and OER involve slow kinetic processes of multiple electron transfer reactions, there is an urgent need to develop stable and efficient bifunctional oxygen catalysts for rechargeable ZABs. Although platinum-based materials are currently commercialized as ORR catalysts and iridium/ruthenium-based materials as OER catalysts, these noble metal catalysts only exhibit a single catalytic activity, and their high cost and poor stability greatly limit their potential applications. Application of charging ZAB. Therefore, there is an urgent need to explore efficient and low-cost reversible bifunctional oxygen electrocatalysts.
近年来，大量的研究报道表明，封装在氮掺杂碳纳米管（N-CNT）中的过渡金属合金纳米颗粒（TMA-NP）可有效改善电催化剂的活性位。TMA-NP和N-CNT之间的强结合可以有效改善碳骨架的电子结构，从而降低了氧气及其中间体在催化剂上的吸附能垒，有利于它们之间的键合。对于N-CNT材料中镶嵌TMA-NP的这类复合材料，一种简单的类似化学气相沉积（CVD）的直接热解法引起了人们的广泛关注，涉及在管式炉中直接加热金属盐（例如硝酸盐、盐酸盐和醋酸盐等）和N/C前体（例如双氰胺，三聚氰胺，谷氨酸等）。然而，通过这种方法合成的核/壳结构的TMA-NP/N-CNT复合材料会存在一些不可忽视的问题：前体混合物的直接分解会导致金属颗粒的团聚和不均匀分散，从而导致生长的CNT的管径粗细不一。因此，需要研发新的方法制备可逆双功能氧气电催化剂，适用于锌-空气电池。In recent years, numerous research reports have demonstrated that transition metal alloy nanoparticles (TMA-NPs) encapsulated in nitrogen-doped carbon nanotubes (N-CNTs) can effectively improve the active sites of electrocatalysts. The strong bonding between TMA-NPs and N-CNTs can effectively improve the electronic structure of the carbon framework, thereby lowering the adsorption energy barrier of oxygen and its intermediates on the catalyst, which is favorable for the bonding between them. For this class of composites in which TMA-NPs are embedded in N-CNT materials, a simple chemical vapor deposition (CVD)-like direct pyrolysis method has attracted much attention, involving the direct heating of metal salts in a tube furnace ( such as nitrates, hydrochlorides and acetates, etc.) and N/C precursors (such as dicyandiamide, melamine, glutamic acid, etc.). However, the core/shell structured TMA-NP/N-CNT composites synthesized by this method suffer from some non-negligible problems: the direct decomposition of the precursor mixture can lead to agglomeration and uneven dispersion of metal particles, leading to growth The diameter and thickness of the CNTs vary. Therefore, it is necessary to develop new methods to prepare reversible bifunctional oxygen electrocatalysts suitable for zinc-air batteries.
技术问题technical problem
本发明公开了一种镶嵌FeNi合金的三维碳纳米管丛林（FeNi@NCNT-CP）电催化剂，制备成本低，生长的CNT的管径粗细均匀，适用于锌-空气电池电极催化。The invention discloses a three-dimensional carbon nanotube jungle (FeNi@NCNT-CP) electrocatalyst inlaid with FeNi alloy, which has low preparation cost and uniform diameter of the grown CNT, which is suitable for zinc-air battery electrode catalysis.
技术解决方案technical solutions
本发明采用如下技术方案：三维碳纳米管丛林，其制备方法为，将氮前驱体、铁前驱体、镍前驱体与水混合后冷冻，得到前驱体混合物粉末；再将前驱体混合物粉末置入小烧结容器内，然后将小烧结容器倒扣在大烧结容器上，并在大烧结容器上、小烧结容器外侧放置棉布，再于氮气中煅烧，得到三维碳纳米管丛林。The present invention adopts the following technical scheme: three-dimensional carbon nanotube jungle, the preparation method is as follows: nitrogen precursor, iron precursor, nickel precursor and water are mixed and then frozen to obtain precursor mixture powder; and then the precursor mixture powder is put into Inside the small sintering container, the small sintering container is inverted on the large sintering container, and cotton cloth is placed on the large sintering container and outside the small sintering container, and then calcined in nitrogen to obtain a three-dimensional carbon nanotube jungle.
本发明的创造性在于改变现有金属杂化碳纳米管的煅烧方法，超出想象的得到FeNi@NCNT-CP电催化剂，由管径细小且均一的CNT组成的一簇簇分散均匀的三维丛林状的网络结构，显示相对较强的碳峰和较弱的金属峰，这种分级的三维多孔网络结构为电化学过程提供了丰富的三相反应界面和物质传输的通道，有利于氧气的吸附和反应。The creativity of the present invention lies in changing the calcination method of the existing metal hybrid carbon nanotubes, and beyond imagination, FeNi@NCNT-CP electrocatalyst can be obtained. The network structure shows relatively strong carbon peaks and weak metal peaks. This hierarchical three-dimensional porous network structure provides abundant three-phase reaction interfaces and material transport channels for the electrochemical process, which is conducive to the adsorption and reaction of oxygen. .
 本发明中，氮前驱体、铁前驱体、镍前驱体都为水溶性化合物，比如氮前驱体为尿素，铁前驱体为九水合硝酸铁，镍前驱体为六水合硝酸镍；得到的三维碳纳米管丛林中，CNT的顶端包裹着其生长必须的催化剂金属颗粒，是一种核壳结构，其外层是3-4层的高石墨化层状碳，层间距为0.35 nm对应着C（002）晶面，而内部的金属部分显示出分辨率良好的晶格条纹，晶格间距为0.209 nm，对应着FeNi合金的（111）晶面。In the present invention, the nitrogen precursor, the iron precursor and the nickel precursor are all water-soluble compounds, for example, the nitrogen precursor is urea, the iron precursor is ferric nitrate nonahydrate, and the nickel precursor is nickel nitrate hexahydrate; the obtained three-dimensional carbon In the nanotube jungle, the top of the CNT is wrapped with the catalyst metal particles necessary for its growth, which is a core-shell structure, and its outer layer is 3-4 layers of highly graphitized layered carbon with a layer spacing of 0.35 nm corresponds to the C(002) crystal plane, while the inner metal part shows lattice fringes with good resolution with a lattice spacing of 0.209 nm, which corresponds to the (111) crystal plane of FeNi alloy.
 本发明中，冷冻为-18℃冷冻12小时，然后-50℃冷冻干燥24小时；与其他得到混合粉末的方法相比，本发明通过冷冻干燥得到的混合粉末，其各个成分可以很好的保持像水溶液中一样的均匀分散，并且铁和镍也不易氧化，解决了因为铁和镍的前驱体均为强还原性无法加热干燥的问题。In the present invention, freezing is -18°C for 12 hours, and then freeze-drying at -50°C for 24 hours; compared with other methods for obtaining mixed powder, the mixed powder obtained by freeze-drying in the present invention can keep all components well It is as uniformly dispersed as in the aqueous solution, and iron and nickel are not easily oxidized, which solves the problem that the precursors of iron and nickel cannot be heated and dried due to their strong reducing properties.
 本发明中，将前驱体混合物粉末装满小烧结容器，然后将小烧结容器倒扣在大烧结容器上，之间存在空隙；小烧结容器、大烧结容器相对而言，可以为小刚玉舟、大刚玉舟，作为常识，小烧结容器、大烧结容器的大小使得小烧结容器可以倒扣在大烧结容器底面即可。棉布的放置位置没有特别限定，在小烧结容器外侧即可，可与其接触。In the present invention, the small sintering container is filled with the precursor mixture powder, and then the small sintering container is upside down on the large sintering container, and there is a gap between them; As for the big corundum boat, as common sense, the size of the small sintering container and the large sintering container can make the small sintering container upside down on the bottom of the large sintering container. The placement position of the cotton cloth is not particularly limited, and it may be on the outside of the small sintering container and may be in contact therewith.
 本发明中，煅烧为800 ℃煅烧1 h，然后自然冷却到室温，升温速率为10 ℃/min。得到的三维碳纳米管丛林中，在2θ≈26°处，FeNi@NCNT-CP的XRD图谱显示较弱的碳衍射峰，对应着C（002）晶面；在2θ≈43.5°, 50.8°和74.6°处则显示较强的金属衍射峰，分别对应着FeNi合金的（111），（200）和（220）晶面；这证实了碳的存在以及FeNi合金的生成，并且相比于FeNi@NCNT，FeNi@NCNT-CP的外层CNT石墨化程度更高，而内层的金属更加细小均匀地被包裹在CNT的内部。In the present invention, calcination is calcined at 800 °C for 1 h, then naturally cooled to room temperature, and the heating rate is 10 °C/min. In the obtained 3D carbon nanotube jungle, the XRD pattern of FeNi@NCNT-CP shows weak carbon diffraction peaks at 2θ≈26°, corresponding to the C(002) crystal plane; at 2θ≈43.5°, 50.8° and There are strong metal diffraction peaks at 74.6°, corresponding to the (111), (200) and (220) crystal planes of FeNi alloy, respectively; this confirms the existence of carbon and the formation of FeNi alloy, and compared with FeNi@ The outer layer CNTs of NCNT and FeNi@NCNT-CP have a higher degree of graphitization, while the metal in the inner layer is more finely and uniformly wrapped inside the CNTs.
 本发明公开了上述三维碳纳米管丛林作为电池电催化剂的应用，在制备电池中的应用；可作为氧气还原反应（ORR）和氧气析出反应（OER）电催化剂在制备锌-空气电池（ZAB）中应用。本发明的电催化剂是通过设计倒扣的大小刚玉舟的模式将C、N以及金属前驱体混合物与碳纳米管（CNT）生长的基底分开，并控制快速的升温速率从而使前驱体混合物迅速分解形成气流喷射到多孔的棉布基底上，通过这种简单的一步热解法制备得到了镶嵌FeNi合金的三维碳纳米管丛林（FeNi@NCNT-CP）复合材料，并表现出优异的ORR和OER电催化性能。与普通的直接热解法制备得到的CNT相比，本发明公布的CNT基双功能氧气电催化剂的优点是：制备方法独特、材料结构新颖、前驱体材料和生长基底近距离分离、生长基底多孔、CNT的管径和内嵌的金属颗粒的粒径细小均一且分散均匀、拥有较大的比表面积和丰富的微/纳孔洞通道有利于暴露更多的活性位点以及物质的传输，从而在ORR和OER过程中表现出极小的过电势和优异的稳定性，并成功应用于ZAB作为正极催化剂表现出良好的循环稳定性和较小的电势极化。The invention discloses the application of the above-mentioned three-dimensional carbon nanotube jungle as a battery electrocatalyst and the application in the preparation of the battery; it can be used as an oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) electrocatalyst in the preparation of a zinc-air battery (ZAB). application in. The electrocatalyst of the present invention separates the C, N and metal precursor mixture from the carbon nanotube (CNT) growth substrate by designing an inverted corundum boat pattern, and controls the rapid heating rate so that the precursor mixture can be rapidly decomposed The 3D carbon nanotube jungle (FeNi@NCNT-CP) composites studded with FeNi alloys were prepared by this simple one-step pyrolysis method, and exhibited excellent ORR and OER electrical properties. catalytic performance. Compared with CNTs prepared by ordinary direct pyrolysis, the advantages of the CNT-based bifunctional oxygen electrocatalyst disclosed in the present invention are: unique preparation method, novel material structure, close separation of precursor material and growth substrate, and porous growth substrate. , The diameter of the CNT and the particle size of the embedded metal particles are fine, uniform and evenly dispersed, with a large specific surface area and abundant micro/nano-hole channels, which are conducive to exposing more active sites and material transport. It exhibited minimal overpotential and excellent stability during ORR and OER, and was successfully applied to ZAB as a cathode catalyst showing good cycling stability and small potential polarization.
有益效果beneficial effect
本发明对现有热解方法进行改进，通过倒置的大小刚玉舟将前驱体混合物（尿素、六水合硝酸铁、六水合硝酸镍）和CNT的生长基底（棉布）分离放置，提出了一种新颖的制备方法，可控地合成了镶嵌FeNi合金的具有三维网络结构的均一碳纳米管丛林（FeNi@NCNT-CP）复合材料，在ORR和OER中表现出高效的催化性能和优异的稳定性，并可成功应用于可充电ZAB作为正极催化剂。该制备工艺新颖、简单，原料来源丰富、成本低廉，展现出了广阔的应用前景。The present invention improves the existing pyrolysis method, separates and places the precursor mixture (urea, hexahydrate ferric nitrate, hexahydrate nickel nitrate) and the CNT growth substrate (cotton cloth) by inverting large and small corundum boats, and proposes a novel , and controllably synthesized FeNi alloy-embedded homogeneous carbon nanotube jungle (FeNi@NCNT-CP) composites with a three-dimensional network structure, which exhibited efficient catalytic performance and excellent stability in ORR and OER. And can be successfully applied to rechargeable ZAB as a cathode catalyst. The preparation process is novel and simple, the source of raw materials is abundant, and the cost is low, showing broad application prospects.
附图说明Description of drawings
图1a-c为FeNi@NCNT-CP的不同放大倍率的SEM图、(d)TEM和HRTEM图。Figure 1a–c are SEM images, (d) TEM and HRTEM images of FeNi@NCNT-CP at different magnifications.
图2a、b分别为FeNi@NCNT的不同放大倍率的SEM图。Figure 2a and b are SEM images of FeNi@NCNT at different magnifications, respectively.
图3 (a) FeNi@NCNT-CP和FeNi@NCNT的X射线衍射图以及Fe 0.64Ni 0.36的PDF卡片，(b) FeNi@NCNT-CP和FeNi@NCNT的N 2吸附和解吸等温线，(c)以及相应的孔径分布。 Figure 3 (a) X-ray diffraction patterns of FeNi@NCNT-CP and FeNi@NCNT and PDF card of Fe 0.64 Ni 0.36 , (b) N adsorption and desorption isotherms of FeNi@ NCNT -CP and FeNi@NCNT, ( c) and the corresponding pore size distribution.
图4(a) FeNi@NCNT-CP, FeNi@NCNT和商业化Pt/C的ORR电化学性能；(b) FeNi@NCNT-CP, FeNi@NCNT和商业化IrO 2的OER电化学性能；FeNi@NCNT-CP的ORR (c)和OER (d)电化学稳定性。 Fig. 4(a) ORR electrochemical properties of FeNi@NCNT-CP, FeNi@NCNT and commercialized Pt/C; (b) OER electrochemical properties of FeNi@NCNT-CP, FeNi@NCNT and commercialized IrO2 ; FeNi ORR (c) and OER (d) electrochemical stability of @NCNT-CP.
图5为基于FeNi@NCNT-CP和商业化Pt/C的ZAB的放电极化曲线及其功率密度(a)和恒流放电的倍率性能(b)；(c)基于FeNi@NCNT-CP和商业化Pt/C-IrO 2的可充电ZAB的充-放电循环曲线。 Figure 5 shows the discharge polarization curves of ZAB based on FeNi@NCNT-CP and commercialized Pt/C and its power density (a) and rate capability of constant current discharge (b); (c) based on FeNi@NCNT-CP and Charge-discharge cycling curves of rechargeable ZABs of commercial Pt/C- IrO2 .
图6为本发明带有棉布的倒扣大小刚玉舟组合图。FIG. 6 is a combined view of an upside-down corundum boat with cotton cloth according to the present invention.
图7为对比例倒扣大小刚玉舟组合图，a为煅烧后组合状态，b为煅烧后分离状态。Fig. 7 is the combination diagram of the inverted corundum boat of the comparative example, a is the combined state after calcination, and b is the separated state after calcination.
图8中，a、b分别为前驱体混合物与棉布一起混合煅烧所得产物不同放大倍率的SEM图。In Fig. 8, a and b are SEM images of different magnifications of the product obtained by mixing and calcining the precursor mixture with the cotton cloth, respectively.
图9中，a、b分别为FeNi@NCNT-CP在2.5 ℃ min -1不同放大倍率的SEM图。 In Figure 9, a and b are the SEM images of FeNi@NCNT-CP at 2.5 ℃ min -1 at different magnifications, respectively.
图10中，a、b分别为FeNi@NCNT-CP在不同煅烧温度下的ORR和OER电化学性能。In Figure 10, a and b are the ORR and OER electrochemical properties of FeNi@NCNT-CP at different calcination temperatures, respectively.
本发明的实施方式Embodiments of the present invention
本发明涉及的原料都为现有常规市售产品，棉布为纯棉织物，给出来源；本发明采用的具体操作方法以及测试方法为本领域常规方法，如无特殊说明，涉及的实验操作在常规环境下进行。The raw materials involved in the present invention are all existing conventional commercial products, and the cotton cloth is pure cotton fabric, and the source is given; the specific operation method and test method adopted in the present invention are conventional methods in the field. Unless otherwise specified, the experimental operations involved are in under normal circumstances.
本发明将氮前驱体、铁前驱体、镍前驱体与水混合后冷冻，得到前驱体混合物粉末；再将前驱体混合物粉末置入小烧结容器内，然后将小烧结容器倒扣在大烧结容器上，并在大烧结容器上、小烧结容器外侧放置棉布，再于氮气中煅烧，得到三维碳纳米管丛林。In the present invention, nitrogen precursor, iron precursor and nickel precursor are mixed with water and then frozen to obtain precursor mixture powder; the precursor mixture powder is then placed in a small sintering container, and then the small sintering container is inverted on the large sintering container On top of the large sintering container and outside the small sintering container, cotton cloth is placed, and then calcined in nitrogen to obtain a three-dimensional carbon nanotube jungle.
本发明无需其他试剂以及额外的制备步骤，得到的产物FeNi@NCNT-CP具有优异的ORR和OER性能，基于其的ZAB在截止电流密度为300 mA cm -2时的峰值功率密度为200 mW cm -2，达到了基于商业化Pt/C的ZAB（130 mW cm -2）的154 %，并且其循环寿命也远远超过了基于商业化Pt/C+IrO 2的ZAB。 The present invention does not require other reagents and additional preparation steps, and the obtained product FeNi@NCNT-CP has excellent ORR and OER properties, and the ZAB based on it has a peak power density of 200 mW cm when the cut-off current density is 300 mA cm -2 -2 , reaching 154% of the commercialized Pt/C-based ZAB (130 mW cm -2 ), and its cycle life is also much longer than that of the commercialized Pt/C+ IrO2 -based ZAB.
电化学性能是在美国Pine公司的三电极体系旋转圆盘（玻碳盘：面积为0.196 cm2）和电化学工作站上进行测试的。其中三电极体系主要是以玻碳棒为对电极、Ag/AgCl-饱和KCl电极为参比电极（所有电压已经校准到相对于标准氢电极）、滴加催化剂的玻碳电极为工作电极（催化剂的负载量为0.4 mg cm -2）。在电化学工作站上通过线性扫描测试可以得到材料的ORR和OER极化曲线，ORR的测试电压区间为0.1-1.1 V，OER的测试电压区间为1-2 V。通过加速老化测试可以得到材料的稳定性，分别将长时间多圈数的线性扫描测试前后得到的极化曲线进行对比。 The electrochemical performance was tested on a three-electrode system rotating disk (glassy carbon disk: area of 0.196 cm2) and an electrochemical workstation of Pine Corporation in the United States. Among them, the three-electrode system mainly uses a glassy carbon rod as the counter electrode, the Ag/AgCl-saturated KCl electrode as the reference electrode (all voltages have been calibrated to be relative to the standard hydrogen electrode), and the glassy carbon electrode with the catalyst added as the working electrode (catalyst). The loading is 0.4 mg cm -2 ). The ORR and OER polarization curves of the material can be obtained by linear scanning test on the electrochemical workstation. The test voltage range of ORR is 0.1-1.1 V, and the test voltage range of OER is 1-2 V. The stability of the material can be obtained through the accelerated aging test, and the polarization curves obtained before and after the long-term multi-turn linear scan test are compared.
液态锌-空气电池是用负载有电催化剂的碳纸作为空气电极，金属Zn片作为负极，含有0.2 M的乙酸锌的6.0 M KOH作为电解液来组成的。电催化剂是通过滴加到碳纸上的，负载量为1.0 mg cm -2。将两电极片用三块不同的亚克力板以及螺丝组装成一个液态-箱式电池。锌-空气电池性能主要是在蓝电LAND CT2001A上进行的，在恒定的电流密度下测试电压和时间的关系可以得到恒流放电曲线，在固定的容量下进行反复的充电和放电可以得到充-放电循环曲线。电池的放电极化曲线则是在ZAHNER电化学工作站上测试的，设定电压逐渐降低，得到电流随电压的变化曲线。 The liquid zinc-air battery is composed of carbon paper loaded with electrocatalyst as the air electrode, metal Zn sheet as the negative electrode, and 6.0 M KOH containing 0.2 M zinc acetate as the electrolyte. The electrocatalyst was added dropwise onto carbon paper with a loading of 1.0 mg cm -2 . The two electrode sheets were assembled into a liquid-box battery with three different acrylic sheets and screws. The performance of the zinc-air battery is mainly carried out on the LAND CT2001A. The constant current discharge curve can be obtained by testing the relationship between the voltage and time at a constant current density. Discharge cycle curve. The discharge polarization curve of the battery was tested on the ZAHNER electrochemical workstation, and the set voltage was gradually decreased to obtain the curve of current versus voltage.
实施例。Example.
前驱体混合物的准备：将3 g尿素（CO(NH 2) 2）、0.105 g九水合硝酸铁（Fe(NO 3) 3·9H 2O）、0.075 g六水合硝酸镍（Ni(NO 3) 2·6H 2O）和20 mL超纯水加入到烧杯中，在室温下常规搅拌溶解；之后将烧杯转移到冰箱中-18℃冷冻12 h，然后在冷冻干燥机中-50℃进行冷冻干燥24 h，获得含有C、N、Fe、Ni的前驱体混合物粉末。 Preparation of precursor mixture: 3 g urea (CO(NH 2 ) 2 ), 0.105 g ferric nitrate nonahydrate (Fe(NO 3 ) 3 9H 2 O), 0.075 g nickel nitrate hexahydrate (Ni(NO 3 ) 2 6H 2 O) and 20 mL of ultrapure water were added to the beaker, and the beaker was dissolved under normal stirring at room temperature; then the beaker was transferred to a refrigerator at -18 °C for 12 h, and then freeze-dried at -50 °C in a freeze dryer. After 24 h, the precursor mixture powder containing C, N, Fe, and Ni was obtained.
将上述前驱体混合物粉末装满小刚玉舟，并将其倒置扣在大刚玉舟中间；然后将两片洁净的2*5 cm 2的棉片分别放置在两端的大刚玉舟的空余部分，与小刚玉舟的外侧接触。 Fill the small corundum boat with the above precursor mixture powder, and buckle it upside down in the middle of the large corundum boat; then place two clean 2 *5 cm The outside of the small corundum boat contacts.
室温下，将上述带有棉布的倒扣大小刚玉舟组合转移到管式炉内中部，并在氮气气氛中10 ℃/min升温到800 ℃煅烧1 h，然后自然冷却到室温，即获得三维碳纳米管丛林FeNi@NCNT-CP。At room temperature, the combination of the above-mentioned inverted corundum boat with cotton cloth was transferred to the middle of the tube furnace, and calcined at 10 °C/min to 800 °C for 1 h in a nitrogen atmosphere, and then naturally cooled to room temperature to obtain three-dimensional carbon. Nanotube jungle FeNi@NCNT-CP.
对比例一：前驱体混合物的准备：将3 g尿素（CO(NH 2) 2）、0.105 g九水合硝酸铁（Fe(NO 3) 3·9H 2O）、0.075 g六水合硝酸镍（Ni(NO 3) 2·6H 2O）和20 mL超纯水加入到烧杯中，在室温下常规搅拌溶解；之后将烧杯转移到冰箱中-18℃冷冻12 h，然后在冷冻干燥机中-50℃进行冷冻干燥24 h，获得含有C、N、Fe、Ni的前驱体混合物粉末。 Comparative Example 1: Preparation of the precursor mixture: 3 g urea (CO(NH 2 ) 2 ), 0.105 g ferric nitrate nonahydrate (Fe(NO 3 ) 3 9H 2 O), 0.075 g nickel nitrate hexahydrate (Ni (NO 3 ) 2 ·6H 2 O) and 20 mL of ultrapure water were added to the beaker, and dissolved with regular stirring at room temperature; then the beaker was transferred to a refrigerator at -18 °C for 12 h, and then in a freeze dryer at -50 Freeze-drying was carried out at ℃ for 24 h to obtain precursor mixture powder containing C, N, Fe, and Ni.
将上述前驱体混合物粉末装满小刚玉舟，并将其倒置扣在大刚玉舟中间，一起转移到管式炉内中部，并在氮气气氛中10 ℃/min升温到800 ℃煅烧1 h，然后自然冷却到室温，即获得镶嵌FeNi合金的碳纳米管FeNi@NCNT；上述前驱体混合物粉末的用量以及大小刚玉舟与实施例一样，区别在于不放置棉布。Fill the small corundum boat with the above-mentioned precursor mixture powder, buckle it upside down in the middle of the large corundum boat, transfer it to the middle of the tube furnace together, and heat it up to 800 ℃ for 1 h in a nitrogen atmosphere at 10 °C/min. Naturally cooled to room temperature to obtain FeNi alloy-embedded carbon nanotubes FeNi@NCNT; the amount of the above precursor mixture powder and the size of the corundum boat are the same as those in the embodiment, the difference is that no cotton cloth is placed.
性能分析：图1a和b的SEM图显示所制备的FeNi@NCNT-CP电催化剂是由管径细小且均一的CNT组成的一簇簇分散均匀的三维丛林状的网络结构。图1c为FeNi@NCNT-CP进一步放大的SEM图，这些CNT相互缠绕组成了网络结构，CNT是直径约为20 nm，壁厚约为5 nm的竹节状结构。通过图1d展示的TEM和HRTEM图可以看出，CNT的顶端包裹着其生长必须的催化剂金属颗粒，是一种核壳结构。其外层是3-4层的高石墨化层状碳，层间距为0.35 nm对应着C（002）晶面。而内部的金属部分显示出分辨率良好的晶格条纹，晶格间距为0.209 nm对应着FeNi（111）晶面。Performance analysis: The SEM images of Figures 1a and b show that the as-prepared FeNi@NCNT-CP electrocatalyst is a three-dimensional jungle-like network structure composed of uniformly dispersed clusters of CNTs with small diameters. Figure 1c is a further enlarged SEM image of FeNi@NCNT-CP. These CNTs are intertwined to form a network structure. The CNTs are bamboo-like structures with a diameter of about 20 nm and a wall thickness of about 5 nm. From the TEM and HRTEM images shown in Figure 1d, it can be seen that the top of the CNT is wrapped with the catalyst metal particles necessary for its growth, which is a core-shell structure. The outer layer is 3-4 layers of highly graphitized layered carbon with a layer spacing of 0.35 nm corresponding to the C(002) crystal plane. While the inner metal part shows lattice fringes with good resolution with a lattice spacing of 0.209 nm corresponds to the FeNi (111) crystal plane.
图2a和b 显示没有棉布直接煅烧得到的CNT是杂乱的粉末状，CNT的直径超过了50 nm。并且金属颗粒的团聚非常严重并且大小不一，部分甚至团聚成大颗粒，直径超过了100 nm。另外，直接将前驱体粉末直接放在敞口的大刚玉舟或者小刚玉舟内直接煅烧，几乎得不到催化剂产物。Figures 2a and b show that the CNTs obtained by direct calcination without cotton cloth are disorganized powders, and the diameters of CNTs exceed 50 nm. And the agglomeration of metal particles is very serious and different in size, and some even agglomerate into large particles with a diameter of more than 100 mm. nm. In addition, if the precursor powder is directly calcined in an open large corundum boat or a small corundum boat, almost no catalyst product can be obtained.
图3a是FeNi@NCNT-CP和FeNi@NCNT的X射线衍射（XRD）图谱，在2θ≈26°处，FeNi@NCNT-CP和FeNi@NCNT的XRD图谱都显示较弱的碳衍射峰，对应着C（002）晶面。在2θ≈43.5°, 50.8°和74.6°处则显示较强的金属衍射峰，分别对应着FeNi合金的（111），（200）和（220）晶面。这证实了碳的存在以及FeNi合金的生成，并与图1和2的结果一致。并且相比于FeNi@NCNT，FeNi@NCNT-CP的外层CNT石墨化程度更高，而内层的金属更加细小均匀地被包裹在CNT的内部，因此FeNi@NCNT-CP的XRD图谱显示相对较强的碳峰和较弱的金属峰。Figure 3a is the X-ray diffraction (XRD) patterns of FeNi@NCNT-CP and FeNi@NCNT. At 2θ≈26°, the XRD patterns of FeNi@NCNT-CP and FeNi@NCNT both show weaker carbon diffraction peaks, corresponding to with the C(002) crystal plane. Strong metal diffraction peaks are displayed at 2θ≈43.5°, 50.8° and 74.6°, corresponding to the (111), (200) and (220) crystal planes of FeNi alloy, respectively. This confirms the presence of carbon and the formation of FeNi alloys and is consistent with the results in Figures 1 and 2. And compared with FeNi@NCNT, the outer layer CNT of FeNi@NCNT-CP has a higher degree of graphitization, and the metal in the inner layer is more finely and uniformly wrapped inside the CNT, so the XRD pattern of FeNi@NCNT-CP shows relatively Stronger carbon peaks and weaker metal peaks.
图3b和c分别显示为FeNi@NCNT-CP和FeNi@NCNT样品的N 2吸脱附曲线以及孔径分布。由于大的金属颗粒以及不均匀的碳团簇的存在，使得FeNi@NCNT的表面积仅为34 m 2 g -1。相比而言，本发明三维网络结构的FeNi@NCNT-CP则表现出较高的比表面积（275 m 2 g -1），并且同时具有明显的微孔和介孔。这种分级的三维多孔网络结构为电化学过程提供了丰富的三相反应界面和物质传输的通道，有利于氧气的吸附和反应。 Figure 3b and c are shown as N adsorption and desorption curves and pore size distributions of FeNi@NCNT-CP and FeNi@NCNT samples, respectively. The surface area of FeNi@NCNT is only 34 m 2 g -1 due to the presence of large metal particles and inhomogeneous carbon clusters. In contrast, the FeNi@NCNT-CP with the three-dimensional network structure of the present invention exhibits a higher specific surface area (275 m 2 g -1 ), and has obvious micropores and mesopores at the same time. This hierarchical three-dimensional porous network structure provides abundant three-phase reaction interfaces and material transport channels for electrochemical processes, which are beneficial to the adsorption and reaction of oxygen.
图4a显示，FeNi@NCNT-CP拥有更加优异的ORR电化学性能，表现出更高的ORR半波电位（E 1/2=0.851 V），不仅远远高于FeNi@NCNT的（E 1/2=0.71 V），而且可以与商业化Pt/C的ORR性能相比肩（E 1/2=0.851 V）。除此之外，图4b显示FeNi@NCNT-CP的OER电化学性能也非常优异，在10 mA cm -2处的电位为1.596 V，远远低于FeNi@NCNT的OER电位（E j =10=1.683 V）,甚至已经超过了商业化IrO 2的OER性能（E j =10=1.598 V）。图4c显示，在长达10 000圈循环之后，FeNi@NCNT-CP的ORR电势仅产生可忽略的4 mV衰减。并且图4d也显示，在连续20 000圈循环之后，FeNi@NCNT-CP的OER电势没有明显的衰减。以上结果表明，FeNi@NCNT-CP丛林是一种同时具有优异ORR和OER催化性能和稳定性的双功能氧气电催化剂。 Figure 4a shows that FeNi@NCNT-CP has more excellent ORR electrochemical performance, showing a higher ORR half-wave potential (E 1/2 = 0.851 V), which is not only much higher than that of FeNi@NCNT (E 1/ 2 = 0.71 V) and comparable to the ORR performance of commercial Pt/C (E 1/2 = 0.851 V). Besides, Figure 4b shows that the OER electrochemical performance of FeNi@NCNT-CP is also very excellent, with a potential of 1.596 V at 10 mA cm -2 , which is much lower than the OER potential of FeNi@NCNT (E j = 10 = 1.683 V), even surpassing the OER performance of commercial IrO 2 (E j = 10 = 1.598 V). Figure 4c shows that the ORR potential of FeNi@NCNT-CP yields only a negligible 4 mV decay after up to 10 000 cycles. And Fig. 4d also shows that the OER potential of FeNi@NCNT-CP has no obvious decay after 20 000 consecutive cycles. The above results demonstrate that the FeNi@NCNT-CP jungle is a bifunctional oxygen electrocatalyst with excellent catalytic performance and stability for both ORR and OER.
图5a显示，由于FeNi@NCNT-CP优异的ORR性能，基于其的ZAB在截止电流密度为300 mA cm -2时的峰值功率密度为200 mW cm -2，达到了基于商业化Pt/C的ZAB（130 mW cm -2）的154%。另外如图5b所示，其开路电压经测量高达1.551 V，同时也表现出良好的倍率性能。无论是在10 mA cm -2的电流密度下还是在20 mA cm -2的大电流密度下，长时间的放电电压均没有明显降低。基于其优异的ORR活性和稳定性，当FeNi@NCNT-CP作为可充电ZAB正极催化剂时，图5c显示，即使与商业化Pt/C-IrO 2的混合物相比，基于FeNi@NCNT-CP的可充电ZAB具有更小的充-放电电势差。并且在10 mA cm -2的电流密度下经历250 h的连续循环后，仅有0.12V的电势降低，显示出良好的电池寿命。 Figure 5a shows that due to the excellent ORR performance of FeNi@NCNT-CP, the peak power density of ZAB based on FeNi@NCNT-CP is 200 mW cm-2 at a cut-off current density of 300 mA cm -2 , reaching the commercialized Pt/C-based peak power density of 200 mW cm -2 . 154% of ZAB (130 mW cm -2 ). In addition, as shown in Figure 5b, its open-circuit voltage was measured as high as 1.551 V, and it also showed good rate performance. The long-term discharge voltage did not decrease significantly either at a current density of 10 mA cm -2 or at a large current density of 20 mA cm -2 . Based on its excellent ORR activity and stability, when FeNi@NCNT-CP is used as a rechargeable ZAB cathode catalyst, Figure 5c shows that even compared with the commercial Pt/C - IrO mixture, the FeNi@NCNT-CP-based The rechargeable ZAB has a smaller charge-discharge potential difference. And after 250 h of continuous cycling at a current density of 10 mA cm -2 , there is only a 0.12 V potential decrease, showing a good battery life.
本发明将前驱体混合物粉末装满小刚玉舟，并将其倒置扣在大刚玉舟中间，存在空隙；然后将两片洁净的2*5 cm 2的棉片分别放置在两端的大刚玉舟的空余部分，与小刚玉舟的外侧接触，参见图6。作为对比，使用相似的合成方法，将前驱体混合物放在一个小刚玉舟内并倒扣在大刚玉舟内进行煅烧，在小刚玉舟和大刚玉舟的空隙部分可以得到的是杂乱的镶嵌FeNi合金的碳纳米管（FeNi@NCNT）电催化剂，在小刚玉舟内部则没有催化剂产物残留（见图7）。 The present invention fills the small corundum boat with the powder of the precursor mixture, and buckles it upside down in the middle of the large corundum boat, so that there is a gap; then two clean 2*5 cm 2 cotton pieces are respectively placed on the two ends of the large corundum boat. The spare part is in contact with the outside of the small corundum boat, see Figure 6. As a comparison, using a similar synthesis method, the precursor mixture was placed in a small corundum boat and calcined upside down in the large corundum boat. The interstitial parts of the small corundum boat and the large corundum boat were chaotic inlaid FeNi. Alloyed carbon nanotubes (FeNi@NCNT) electrocatalyst, no catalyst product remains inside the small corundum boat (see Figure 7).
对比例二。Comparative example two.
将3 g尿素（CO(NH 2) 2）、0.105 g九水合硝酸铁（Fe(NO 3) 3·9H 2O）、0.075 g六水合硝酸镍（Ni(NO 3) 2·6H 2O）和20 mL超纯水加入到烧杯中，在室温下常规搅拌溶解；将实施例一的棉布浸入上述烧杯中，溶液被全部吸附，到冰箱中-18℃冷冻12 h，然后在冷冻干燥机中-50℃进行冷冻干燥24 h，后放在一个刚玉舟中转移到管式炉内中部，并在氮气气氛中10 ℃/min升温到800 ℃煅烧1 h，然后自然冷却到室温，煅烧得到的产物并不能形成碳纳米管丛林的形貌。如扫描电镜图8所示，可以清楚地看到此时的棉纤维上并没有形成明显的碳纳米管，而是镶嵌着许多金属大颗粒，不适合做催化剂。 3 g urea (CO(NH 2 ) 2 ), 0.105 g ferric nitrate nonahydrate (Fe(NO 3 ) 3 9H 2 O), 0.075 g nickel nitrate hexahydrate (Ni(NO 3 ) 2 6H 2 O) and 20 mL of ultrapure water were added to the beaker, and dissolved under normal stirring at room temperature; the cotton cloth of Example 1 was immersed in the above beaker, the solution was completely adsorbed, and it was frozen at -18 °C for 12 h in the refrigerator, and then placed in a freeze dryer. Freeze-dried at -50 °C for 24 h, then placed in a corundum boat and transferred to the middle of the tube furnace, heated to 800 °C for 1 h at 10 °C/min in a nitrogen atmosphere, and then naturally cooled to room temperature. The product did not form the morphology of the carbon nanotube jungle. As shown in Fig. 8 of the scanning electron microscope, it can be clearly seen that there are no obvious carbon nanotubes formed on the cotton fibers at this time, but many large metal particles are embedded, which is not suitable for catalysts.
进一步的，在实施例一的基础上，将棉布更换为同样大小的碳布，其余不变，煅烧后，碳布表面光滑，没有金属粒子和碳纳米管的生成。Further, on the basis of Example 1, the cotton cloth was replaced with a carbon cloth of the same size, and the rest remained unchanged. After calcination, the surface of the carbon cloth was smooth, and no metal particles and carbon nanotubes were formed.
实施例二。Example two.
前驱体混合物的准备：将3 g尿素（CO(NH 2) 2）、0.105 g九水合硝酸铁（Fe(NO 3) 3·9H 2O）、0.075 g六水合硝酸镍（Ni(NO 3) 2·6H 2O）和20 mL超纯水加入到烧杯中，在室温下常规搅拌溶解；之后将烧杯转移到冰箱中-18℃冷冻12 h，然后在冷冻干燥机中-50℃进行冷冻干燥24 h，获得含有C、N、Fe、Ni的前驱体混合物粉末。 Preparation of precursor mixture: 3 g urea (CO(NH 2 ) 2 ), 0.105 g ferric nitrate nonahydrate (Fe(NO 3 ) 3 9H 2 O), 0.075 g nickel nitrate hexahydrate (Ni(NO 3 ) 2 6H 2 O) and 20 mL of ultrapure water were added to the beaker, and the beaker was dissolved under normal stirring at room temperature; then the beaker was transferred to a refrigerator at -18 °C for 12 h, and then freeze-dried at -50 °C in a freeze dryer. After 24 h, the precursor mixture powder containing C, N, Fe, and Ni was obtained.
将上述前驱体混合物粉末装满小刚玉舟，并将其倒置扣在大刚玉舟中间；然后将两片洁净的2*5 cm 2的棉片分别放置在两端的大刚玉舟的空余部分，与小刚玉舟的外侧接触。 Fill the small corundum boat with the above precursor mixture powder, and buckle it upside down in the middle of the large corundum boat; then place two clean 2 *5 cm The outside of the small corundum boat contacts.
室温下，将上述带有棉布的倒扣大小刚玉舟组合转移到管式炉内中部，并在氮气气氛中2.5 ℃/min升温到800 ℃煅烧1 h，然后自然冷却到室温，即获得三维碳纳米管丛林FeNi@NCNT-CP。At room temperature, the combination of the above-mentioned inverted corundum boat with cotton cloth was transferred to the middle of the tube furnace, and calcined at 2.5 °C/min to 800 °C for 1 h in a nitrogen atmosphere, and then naturally cooled to room temperature to obtain three-dimensional carbon. Nanotube jungle FeNi@NCNT-CP.
当煅烧的升温速率降低到2.5 ℃ min -1时，通过产物的SEM图可以观察到，相比于FeNi@NCNT-CP在10 ℃ min -1的产物形貌，在2.5 ℃ min -1的低升温速率下得到的产物形貌明显较差。图9a显示此时没有形成完整的碳纳米管丛林的形貌，部分区域没有形成茂密的碳纳米管。并且通过放大的SEM图（图9b）可以看到碳纳米管的分布相对较大比较稀疏，管径也相对较大，这说明升温速率对材料具有较大的影响，本发明限定的升温速率利于碳纳米管丛林的生长。 When the heating rate of calcination is reduced to 2.5 ℃ min -1 , it can be observed from the SEM image of the product that the morphology of the product at 2.5 ℃ min -1 is lower than that of FeNi@NCNT-CP at 10 ℃ min -1 The morphology of the product obtained at the heating rate is obviously poor. Fig. 9a shows the morphology of the complete carbon nanotube jungle that is not formed at this time, and dense carbon nanotubes are not formed in some areas. And through the enlarged SEM image (Fig. 9b), it can be seen that the distribution of carbon nanotubes is relatively large and sparse, and the tube diameter is relatively large, which shows that the heating rate has a great influence on the material, and the heating rate defined in the present invention is beneficial to Growth of carbon nanotube jungles.
实施例三。Example three.
前驱体混合物的准备：将3 g尿素（CO(NH 2) 2）、0.105 g九水合硝酸铁（Fe(NO 3) 3·9H 2O）、0.075 g六水合硝酸镍（Ni(NO 3) 2·6H 2O）和20 mL超纯水加入到烧杯中，在室温下常规搅拌溶解；之后将烧杯转移到冰箱中-18℃冷冻12 h，然后在冷冻干燥机中-50℃进行冷冻干燥24 h，获得含有C、N、Fe、Ni的前驱体混合物粉末。 Preparation of precursor mixture: 3 g urea (CO(NH 2 ) 2 ), 0.105 g ferric nitrate nonahydrate (Fe(NO 3 ) 3 9H 2 O), 0.075 g nickel nitrate hexahydrate (Ni(NO 3 ) 2 6H 2 O) and 20 mL of ultrapure water were added to the beaker, and the beaker was dissolved under normal stirring at room temperature; then the beaker was transferred to a refrigerator at -18 °C for 12 h, and then freeze-dried at -50 °C in a freeze dryer. After 24 h, the precursor mixture powder containing C, N, Fe, and Ni was obtained.
将上述前驱体混合物粉末装满小刚玉舟，并将其倒置扣在大刚玉舟中间；然后将两片洁净的2*5 cm 2的棉片分别放置在两端的大刚玉舟的空余部分，与小刚玉舟的外侧接触。 Fill the small corundum boat with the above precursor mixture powder, and buckle it upside down in the middle of the large corundum boat; then place two clean 2 *5 cm The outside of the small corundum boat contacts.
室温下，将上述带有棉布的倒扣大小刚玉舟组合转移到管式炉内中部，并在氮气气氛中10 ℃/min升温到设计温度煅烧1 h，然后自然冷却到室温，即获得三维碳纳米管丛林FeNi@NCNT-CP；其中设计温度分别为600℃、700℃、900℃、1000℃。At room temperature, the combination of the above-mentioned inverted corundum boat with cotton cloth was transferred to the middle of the tube furnace, and calcined at 10 °C/min in a nitrogen atmosphere to the design temperature for 1 h, and then naturally cooled to room temperature to obtain three-dimensional carbon. Nanotube jungle FeNi@NCNT-CP; the design temperatures are 600°C, 700°C, 900°C, and 1000°C, respectively.
如10图所示，当控制煅烧的温度分别为600 ℃、700 ℃、800 ℃、900 ℃、1000 ℃时，可以观察到材料的ORR和OER性能都有比较大的变化。当煅烧的温度从600 ℃到800 ℃时，可以观察到FeNi@NCNT-CP的ORR极化曲线的半波电位在逐渐正移，并且OER极化曲线在10 mA cm -2电流密度下的电位在逐渐负移。而当煅烧温度从800 ℃继续增加到1000 ℃时，ORR和OER的极化曲线的变化却呈现相反的趋势。这说明煅烧温度对材料的性能影响较大，并且FeNi@NCNT-CP在800 ℃的煅烧温度下具有最佳的ORR和OER电化学性能。 As shown in Figure 10, when the controlled calcination temperature is 600 °C, 700 °C, 800 °C, 900 °C, and 1000 °C, it can be observed that the ORR and OER properties of the material have relatively large changes. When the calcination temperature is from 600 °C to 800 °C, it can be observed that the half-wave potential of the ORR polarization curve of FeNi@NCNT-CP gradually shifts positively, and the potential of the OER polarization curve at a current density of 10 mA cm -2 can be observed. in a gradual negative shift. However, when the calcination temperature continued to increase from 800 ℃ to 1000 ℃, the changes of the polarization curves of ORR and OER showed the opposite trend. This indicates that the calcination temperature has a great influence on the properties of the material, and FeNi@NCNT-CP has the best ORR and OER electrochemical performance at the calcination temperature of 800 °C.
综上所述，本发明报道了一种低成本、简单的合成CNT的方法，采用多孔的棉布作为生长基底，通过特殊的刚玉舟组合形成自喷射气相法，规模化合成了镶嵌FeNi合金的三维碳纳米管丛林（FeNi@NCNT-CP）电催化剂，并在氧气还原和析出反应以及可充电ZAB中表现出了潜在的商用价值。进而为制备价格低廉、形貌均一、高效的CNT基电催化剂提供了一种简单新颖的方法，同时也证明了其在储能和转换***中的广阔应用前景。To sum up, the present invention reports a low-cost and simple method for synthesizing CNTs. Using porous cotton cloth as a growth substrate, a special corundum boat is combined to form a self-jet gas phase method, and a three-dimensional FeNi alloy-inlaid alloy is synthesized on a large scale. carbon nanotube jungle (FeNi@NCNT-CP) electrocatalysts and showed potential commercial value in oxygen reduction and evolution reactions and rechargeable ZABs. This provides a simple and novel method for the preparation of inexpensive, uniform, and efficient CNT-based electrocatalysts, and also demonstrates its broad application prospects in energy storage and conversion systems.

Claims (10)

  1. 三维碳纳米管丛林，其特征在于，所述三维碳纳米管丛林的制备方法为，将氮前驱体、铁前驱体、镍前驱体与水混合后冷冻，得到前驱体混合物粉末；再将前驱体混合物粉末置入小烧结容器内，然后将小烧结容器倒扣在大烧结容器上，并在大烧结容器上、小烧结容器外侧放置棉布，再于氮气中煅烧，得到三维碳纳米管丛林。The three-dimensional carbon nanotube jungle is characterized in that the preparation method of the three-dimensional carbon nanotube jungle is as follows: the nitrogen precursor, the iron precursor, the nickel precursor and the water are mixed and then frozen to obtain the precursor mixture powder; The mixture powder is placed in a small sintering container, then the small sintering container is upside down on the large sintering container, and cotton cloth is placed on the large sintering container and outside the small sintering container, and then calcined in nitrogen to obtain a three-dimensional carbon nanotube jungle.
  2. 根据权利要求1所述三维碳纳米管丛林，其特征在于，氮前驱体、铁前驱体、镍前驱体都为水溶性化合物。The three-dimensional carbon nanotube jungle of claim 1, wherein the nitrogen precursor, the iron precursor, and the nickel precursor are all water-soluble compounds.
  3. 根据权利要求2所述三维碳纳米管丛林，其特征在于，氮前驱体为尿素，铁前驱体为九水合硝酸铁，镍前驱体为六水合硝酸镍。The three-dimensional carbon nanotube jungle of claim 2, wherein the nitrogen precursor is urea, the iron precursor is ferric nitrate nonahydrate, and the nickel precursor is nickel nitrate hexahydrate.
  4. 根据权利要求1所述三维碳纳米管丛林，其特征在于，冷冻为-18℃冷冻12小时，然后-50℃冷冻干燥24小时。The three-dimensional carbon nanotube jungle according to claim 1, wherein the freezing is -18°C for 12 hours, and then freeze-drying at -50°C for 24 hours.
  5. 根据权利要求1所述三维碳纳米管丛林，其特征在于，烧结容器为刚玉舟。The three-dimensional carbon nanotube jungle of claim 1, wherein the sintering vessel is a corundum boat.
  6. 根据权利要求1所述三维碳纳米管丛林，其特征在于，煅烧为800 ℃煅烧1 h，然后自然冷却到室温。The three-dimensional carbon nanotube jungle according to claim 1, wherein the calcination is calcined at 800 °C for 1 h, and then naturally cooled to room temperature.
  7. 根据权利要求1所述三维碳纳米管丛林，其特征在于，煅烧的升温速率为10 ℃/min。The three-dimensional carbon nanotube jungle of claim 1, wherein the heating rate of the calcination is 10°C/min.
  8. 权利要求1所述三维碳纳米管丛林的制备方法，其特征在于，包括以下步骤，将氮前驱体、铁前驱体、镍前驱体与水混合后冷冻，得到前驱体混合物粉末；再将前驱体混合物粉末置入小烧结容器内，然后将小烧结容器倒扣在大烧结容器上，并在大烧结容器上、小烧结容器外侧放置棉布，再于氮气中煅烧，得到三维碳纳米管丛林。The preparation method of the three-dimensional carbon nanotube jungle of claim 1, characterized in that it comprises the following steps: mixing nitrogen precursor, iron precursor, nickel precursor with water and freezing to obtain precursor mixture powder; The mixture powder is placed in a small sintering container, then the small sintering container is upside down on the large sintering container, and cotton cloth is placed on the large sintering container and outside the small sintering container, and then calcined in nitrogen to obtain a three-dimensional carbon nanotube jungle.
  9. 权利要求1所述三维碳纳米管丛林作为电池电催化剂的应用。Application of the three-dimensional carbon nanotube jungle as claimed in claim 1 as a battery electrocatalyst.
  10. 权利要求1所述三维碳纳米管丛林在制备电池中的应用。The application of the three-dimensional carbon nanotube jungle of claim 1 in the preparation of batteries.
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Cited By (1)

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Publication number Priority date Publication date Assignee Title
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Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20120058136A (en) * 2010-11-29 2012-06-07 엠케이전자 주식회사 Metal-carbon nanotube composite powder, metal-carbon nanotube composite paste, and field emission device using the same
CN105883732A (en) * 2016-04-08 2016-08-24 山东大学 Carbon nitride nanotube and preparation method thereof
CN108543545A (en) * 2018-04-26 2018-09-18 大连理工大学 A kind of tri- doped carbon nanometer pipe cladded type FeNi@NCNT catalyst of Fe, Ni, N, preparation method and applications
CN110142058A (en) * 2019-05-21 2019-08-20 大连理工大学 A kind of three-dimensional porous FeNi-NC bifunctional electrocatalyst and preparation method thereof of F127 induction
US20190276915A1 (en) * 2016-09-22 2019-09-12 Pukyong National University Industry-University Cooperation Foundation Discharge plasma sintering method for manufacturing single-walled carbon nanotube reinforced metal matrix composite and composite material produced thereby
CN110860303A (en) * 2019-11-21 2020-03-06 青岛科技大学 Preparation method and application of metal and metal carbide reinforced transition metal-nitrogen active site carbon-based electrocatalyst
CN111977635A (en) * 2020-09-04 2020-11-24 中南大学 Carbon nano tube and preparation method thereof
CN112436156A (en) * 2020-11-23 2021-03-02 苏州大学 Zinc-air battery and preparation method and application thereof
CN112436157A (en) * 2020-11-23 2021-03-02 苏州大学 Three-dimensional carbon nanotube jungle and preparation method and application thereof

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20120058136A (en) * 2010-11-29 2012-06-07 엠케이전자 주식회사 Metal-carbon nanotube composite powder, metal-carbon nanotube composite paste, and field emission device using the same
CN105883732A (en) * 2016-04-08 2016-08-24 山东大学 Carbon nitride nanotube and preparation method thereof
US20190276915A1 (en) * 2016-09-22 2019-09-12 Pukyong National University Industry-University Cooperation Foundation Discharge plasma sintering method for manufacturing single-walled carbon nanotube reinforced metal matrix composite and composite material produced thereby
CN108543545A (en) * 2018-04-26 2018-09-18 大连理工大学 A kind of tri- doped carbon nanometer pipe cladded type FeNi@NCNT catalyst of Fe, Ni, N, preparation method and applications
CN110142058A (en) * 2019-05-21 2019-08-20 大连理工大学 A kind of three-dimensional porous FeNi-NC bifunctional electrocatalyst and preparation method thereof of F127 induction
CN110860303A (en) * 2019-11-21 2020-03-06 青岛科技大学 Preparation method and application of metal and metal carbide reinforced transition metal-nitrogen active site carbon-based electrocatalyst
CN111977635A (en) * 2020-09-04 2020-11-24 中南大学 Carbon nano tube and preparation method thereof
CN112436156A (en) * 2020-11-23 2021-03-02 苏州大学 Zinc-air battery and preparation method and application thereof
CN112436157A (en) * 2020-11-23 2021-03-02 苏州大学 Three-dimensional carbon nanotube jungle and preparation method and application thereof

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
LI ZHAO; CAI LIANG; SONG MING; SHEN YANCHAO; WANG XIANG; LI JING; WANG JU; WANG PENG; TIAN LIN: "Ternary FeCoNi alloy nanoparticles embedded in N-doped carbon nanotubes for efficient oxygen evolution reaction electrocatalysis", ELECTROCHIMICA ACTA, vol. 339, 19 February 2020 (2020-02-19), AMSTERDAM, NL , pages 1 - 9, XP086125455, ISSN: 0013-4686, DOI: 10.1016/j.electacta.2020.135886 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115224293A (en) * 2022-08-17 2022-10-21 郑州大学 ORR and OER bifunctional catalyst, and preparation method and application thereof
CN115224293B (en) * 2022-08-17 2024-01-16 郑州大学 ORR and OER dual-function catalyst and preparation method and application thereof

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