CN115055199B - Sulfur-doped honeycomb nano sheet g-C 3 N 4 Preparation method and application thereof - Google Patents

Sulfur-doped honeycomb nano sheet g-C 3 N 4 Preparation method and application thereof Download PDF

Info

Publication number
CN115055199B
CN115055199B CN202210495378.8A CN202210495378A CN115055199B CN 115055199 B CN115055199 B CN 115055199B CN 202210495378 A CN202210495378 A CN 202210495378A CN 115055199 B CN115055199 B CN 115055199B
Authority
CN
China
Prior art keywords
thiourea
sulfur
pdcn
melamine
doped
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202210495378.8A
Other languages
Chinese (zh)
Other versions
CN115055199A (en
Inventor
关荣锋
田亚西
王新霖
石文艳
邵荣
丁成
杨秀丽
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Yancheng Institute of Technology
Original Assignee
Yancheng Institute of Technology
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Yancheng Institute of Technology filed Critical Yancheng Institute of Technology
Priority to CN202210495378.8A priority Critical patent/CN115055199B/en
Publication of CN115055199A publication Critical patent/CN115055199A/en
Application granted granted Critical
Publication of CN115055199B publication Critical patent/CN115055199B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
    • B01J27/24—Nitrogen compounds
    • B01J35/39—
    • B01J35/40—
    • B01J35/56—
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/30—Treatment of water, waste water, or sewage by irradiation
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2101/00—Nature of the contaminant
    • C02F2101/30—Organic compounds
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2305/00—Use of specific compounds during water treatment
    • C02F2305/10—Photocatalysts
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/36—Hydrogen production from non-carbon containing sources, e.g. by water electrolysis

Abstract

The application belongs to the technical field of photocatalytic materials, and particularly relates to a sulfur-doped honeycomb nano sheet g-C 3 N 4 And a preparation method and application thereof. The sulfur-doped honeycomb nano sheet g-C of the application 3 N 4 The preparation method of (2) comprises the following steps: (1) Mixing melamine, cyanuric acid and water, and stirring while maintaining the temperature; (2) Adding thiourea into the mixed solution obtained in the step (1) to obtain melamine-cyanuric acid-thiourea supermolecule liquid; (3) Dewatering and drying the melamine-cyanuric acid-thiourea supermolecule liquid obtained in the step (2) to obtain a thiourea modified precursor; (4) Calcining the thiourea modified precursor obtained in the step (3) to obtain the sulfur-doped honeycomb nano sheet g-C 3 N 4 . The sulfur-doped honeycomb nano sheet g-C prepared by the application 3 N 4 Has excellent photocatalytic performance.

Description

Sulfur-doped honeycomb nano sheet g-C 3 N 4 Preparation method and application thereof
Technical Field
The application belongs to the technical field of photocatalytic materials, and particularly relates to a sulfur-doped honeycomb nano sheet g-C 3 N 4 And preparation thereofMethods and applications.
Background
With the excessive use of conventional energy sources such as coal, petroleum, natural gas and the like, increasingly serious environmental problems and energy shortage form a major obstacle to the world development. Development of new energy sources is one of means for solving the problems. With the intensive research of new energy, solar energy, biomass energy, wind energy, water energy, ocean current energy, geothermal energy, wave energy, tidal energy, thermal cycling between the ocean surface and the deep layer, and the like are gradually appeared in the line of sight of people. Such new energy sources are gaining more and more attention due to their low carbon, environmental protection and renewable characteristics. The hydrogen energy is used as a novel clean energy source, has wide source, wide application range, no smell and toxicity, and has excellent combustibility, thermal conductivity and extremely high utilization efficiency. Compared with other fuels, the combustion product is only water, and has no pollution to the environment.
C 3 N 4 Is one of the first few compositions, reported for the first time by Berzelius and Liebig, 1834. In 2006, g-C 3 N 4 And is beginning to be applied to the field of heterogeneous catalysis. Research of X-ray crystallography proves that g-C 3 N 4 The graphene-like planar two-dimensional lamellar structure comprises a polymer taking triazine rings and 3-s-triazine rings as basic units. The C, N atoms in the structure are hybridized with sp2 to form pi bond. g-C 3 N 4 The good thermal stability and chemical stability make it a research hot spot of hydrogen evolution photocatalysts. But g-C 3 N 4 The defects of higher photo-generated electron-hole recombination rate, low quantum efficiency, low conductivity, low solar utilization rate and the like also exist, and the former overcomes the g-C by morphology regulation, element doping, defect and heterojunction construction 3 N 4 There are problems of its own, but the desired level of application is not achieved at present. Therefore, the development of the environment-friendly and efficient photocatalyst has great practical significance.
Accordingly, there is a need to provide an improved solution to the above-mentioned deficiencies of the prior art.
Disclosure of Invention
The application aims to provide a sulfur-doped honeycomb nano-meterRice flake g-C 3 N 4 And a preparation method and application thereof, so as to solve the problem of g-C in the prior art 3 N 4 At least one of the problems of higher photo-generated electron-hole recombination rate, low quantum efficiency, low conductivity and low solar utilization rate exists, and the g-C is improved 3 N 4 Is used for producing hydrogen by photocatalysis.
In order to achieve the above object, the present application provides the following technical solutions: sulfur-doped honeycomb nano sheet g-C 3 N 4 The preparation method of (2) comprises the following steps: (1) Mixing melamine, cyanuric acid and water, and stirring while maintaining the temperature; (2) Adding thiourea into the mixed solution obtained in the step (1) to obtain melamine-cyanuric acid-thiourea supermolecule liquid; (3) Dewatering and drying the melamine-cyanuric acid-thiourea supermolecule liquid obtained in the step (2) to obtain a thiourea modified precursor; (4) Calcining the thiourea modified precursor obtained in the step (3) to obtain the sulfur-doped honeycomb nano sheet g-C 3 N 4 。
Preferably, the thiourea is used in a proportion of n (thiourea)/[ n (melamine) +n (cyanuric acid) ]=0.8-7%.
Preferably, the molar ratio of melamine to cyanuric acid is 1 (0.5-3).
Preferably, the calcining temperature is 500-600 ℃, the heating rate is 3-20 ℃/min, and the heat preservation time is 4-6h.
Preferably, the calcination is performed under air conditions.
Preferably, step (1) comprises: placing melamine and cyanuric acid into a container, adding deionized water, and stirring vigorously at 60-80deg.C water bath for 0.5-2 hr to obtain uniformly dispersed mixed solution.
Preferably, in step (3), the water removal is specifically: stirring under the condition of heat preservation to evaporate water in the melamine-cyanuric acid-thiourea supermolecule liquid; the drying is specifically as follows: and (5) drying the product obtained after the water removal in a drying oven.
Preferably, the drying is completed further comprising a step of grinding the obtained solid.
The application also providesProvides a sulfur doped honeycomb nano sheet g-C 3 N 4 The technical scheme is as follows: sulfur-doped honeycomb nano sheet g-C 3 N 4 The sulfur-doped honeycomb nano-sheet g-C 3 N 4 Prepared by the method described above.
The application also provides a sulfur-doped honeycomb nano sheet g-C 3 N 4 The application of the (2) adopts the following technical scheme: sulfur-doped cellular nanoflakes g-C as described above 3 N 4 The method is applied to photocatalytic hydrogen production and organic matter degradation.
The beneficial effects are that:
(1) The application takes melamine-cyanuric acid-thiourea supermolecule liquid as a precursor and a template for the first time, and the sulfur-doped honeycomb nano-sheet g-C is successfully prepared by selective volatilization during high-temperature calcination 3 N 4 。
(2) The sulfur-doped honeycomb nano sheet g-C prepared by the application 3 N 4 g-C with the bulk phase 3 N 4 Compared with the method, the method has larger specific surface area, faster electron transfer rate and increased reaction sites due to introduction of carbon defects, improves visible light response capability, widens the photoresponse range, accelerates the separation and transfer of photogenerated carriers, and effectively improves photocatalytic performance.
(3) The sulfur-doped honeycomb nano sheet g-C prepared by the application 3 N 4 The hydrogen production rate of (C) can reach 23780 mu mol/g/h, and the phase g-C is 3 N 4 The hydrogen production rate is only 250 mu mol/g/h, and compared with the hydrogen production rate, the hydrogen production rate has excellent photocatalytic performance. The hydrogen production rate of the former is 95 times that of the latter, namely the application has excellent visible light catalytic performance; in addition, the sulfur-doped cellular nano-sheet g-C of the present application 3 N 4 Can also be used for degrading organic pollutants.
(4) The sulfur-doped honeycomb nano sheet g-C prepared by the application 3 N 4 The preparation process is simple and easy to operate, the synthetic material is cheap and easy to obtain, the repeatability is good, the safety and pollution-free are realized, and the environment is protected.
Drawings
The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the application. Wherein:
FIG. 1 shows sulfur-doped cellular nanoflakes g-C according to example 1 of the present application 3 N 4 (S-PDCN-3) Scanning Electron Microscope (SEM) images;
FIG. 2 shows sulfur-doped cellular nanoflakes g-C according to example 1 of the present application 3 N 4 A Transmission Electron Microscope (TEM) image of (S-PDCN-3);
FIG. 3 shows the bulk phase g-C provided in comparative example 1 of the present application 3 N 4 Scanning Electron Microscope (SEM) images of (BCN);
FIG. 4 is a sulfur-doped g-C provided in comparative example 2 of the present application 3 N 4 (S-CN) Scanning Electron Microscope (SEM) images;
FIG. 5 is a graph showing the g-C ratio provided in comparative example 3 of the present application 3 N 4 A Scanning Electron Microscope (SEM) image of (PDCN);
FIG. 6 is a graph showing the EDS element content of S-PDCN-3 provided in example 1 of the present application;
FIG. 7 shows XPS total spectra of BCN, S-CN, PDCN and S-PDCN-3 (a) of the present application; high resolution spectra of BCN, S-CN, PDCN and S-PDCN-3 (b) C1S; (c) N1s; (d) S2p of S-CN and S-PDCN-3;
FIG. 8 is a fluorescence spectrum of products prepared in example 1 (S-PDCN-3), comparative example 1 (BCN), comparative example 2 (S-CN) and comparative example 3 (PDCN) of the present application; wherein, the samples corresponding from top to bottom according to the peak positions in FIG. 8 are BCN, S-CN, PDCN and S-PDCN-3 in sequence;
FIG. 9 is an ultraviolet-visible absorption spectrum of the products prepared in example 1 (S-PDCN-3), comparative example 1 (BCN), comparative example 2 (S-CN) and comparative example 3 (PDCN) of the present application;
FIG. 10 is a graph showing the results of continuous hydrogen production test of the products prepared in example 1 (S-PDCN-3), example 2 (S-PDCN-0.8), example 3 (S-PDCN-1), example 4 (S-PDCN-5), example 5 (S-PDCN-7), comparative example 1 (BCN), comparative example 2 (S-CN) and comparative example 3 (PDCN) according to the present application; the corresponding samples are ordered in the top-bottom order of the curve in fig. 10, and the samples corresponding in the bottom-up order are: BCN, S-CN, PDCN, S-PDCN-0.8, S-PDCN-1, S-PDCN-7, S-PDCN-5 and S-PDCN-3;
FIG. 11 is a graph of hydrogen production rates for BCN, S-CN, PDCN and S-PDCN-x of the present application;
FIG. 12 is a graph showing hydrogen production rates of example 1 (S-PDCN-3), comparative example 9 (S-PDCN-L), and comparative example 10 (S-PDCN-M) of the present application;
FIG. 13 is a graph showing the results of cyclic stability tests of hydrogen generating properties of the products prepared in example 1 (S-PDCN-3), comparative example 1 (BCN), comparative example 2 (S-CN) and comparative example 3 (PDCN) according to the present application; the corresponding samples are ordered in the top-bottom order of the curve in fig. 13, and the samples corresponding in the bottom-up order are: BCN, S-CN, PDCN and S-PDCN-3;
FIG. 14 is a graph showing the results of specific surface area tests of products prepared in example 1 (S-PDCN-3), comparative example 1 (BCN), comparative example 2 (S-CN) and comparative example 3 (PDCN) according to the present application;
FIG. 15 is a graph showing degradation efficiency test results of RhB on products prepared in example 1 (S-PDCN-3), comparative example 1 (BCN), comparative example 4 (CN-MCT), comparative example 5 (CN-MCT-Order) and comparative example 6 (S-PDCN-3-2) according to the present application; the corresponding samples are ordered in the top-to-bottom order of the curve in fig. 15, and the samples corresponding in sequence from top to bottom are: BCN, CN-MCT, S-PDCN-3-2, CN-MCT-Order and S-PDCN-3.
Detailed Description
The following description of the technical solutions in the embodiments of the present application will be clear and complete, and it is obvious that the described embodiments are only some embodiments of the present application, but not all embodiments. All other embodiments, which are derived by a person skilled in the art based on the embodiments of the application, fall within the scope of protection of the application.
The present application will be described in detail with reference to examples. It should be noted that, without conflict, the embodiments of the present application and features of the embodiments may be combined with each other.
The present application is directed to the present g-C 3 N 4 There is a problem of providing a sulfur-doped cellular nano-sheet g-C 3 N 4 To solve the problems ofBlock g-C 3 N 4 At least one of the problems of high photo-generated electron-hole recombination rate, low quantum efficiency, low conductivity and low solar utilization rate exists.
The sulfur-doped honeycomb nano sheet g-C of the application 3 N 4 The preparation method of (2) comprises the following steps:
(1) Mixing melamine, cyanuric acid and water, and stirring while maintaining the temperature;
(2) Adding thiourea into the mixed solution obtained in the step (1) to obtain melamine-cyanuric acid-thiourea supermolecule liquid;
(3) Dewatering and drying the melamine-cyanuric acid-thiourea supermolecule liquid obtained in the step (2) to obtain a thiourea modified precursor;
(4) Calcining the thiourea modified precursor obtained in the step (3) to obtain sulfur-doped honeycomb nano-sheet g-C 3 N 4 。
In the nano-sheets with different dimensions, the state of binding electrons can be influenced due to the different shapes and sizes of materials. Electrons are limited by different dimensions, and can generate different electron transfer properties, specific surface area, mechanical flexibility and stability. Thus the morphology is regulated to be improved g-C 3 N 4 One of the most effective approaches to photocatalytic activity. 2D g-C 3 N 4 The ultra-thin thickness and hollow structure of the nano-sheet greatly enhance the photocatalytic activity of the material, and are considered to be ideal photocatalysts. In addition to morphology control, doping of elements, such as nonmetallic element B, C, O, S, also improves g-C 3 N 4 An effective method of photocatalytic activity. Wherein S is doped with g-C 3 N 4 Is believed to be more capable of enhancing photocatalytic activity, has more favorable redox properties and prolonged visible light absorption, and widens the photoresponse range. In addition, since the ionic radius and electronegativity of S element are similar to those of N element, S replaces g-C 3 N 4 Is feasible.
The application designs a molecular frame from the source by using a defect construction method, utilizes intermolecular forces of raw materials to connect into a long chain, and selectively volatilizes at high temperaturePreparing sulfur doped honeycomb g-C 3 N 4 A nano-sheet. The nanoplatelets change the morphology of the carbon nitride to nanocrystallize the carbon nitride, and are commonly used for increasing g-C 3 N 4 So that it can provide more active sites and increase the photocatalytic activity. The application takes melamine-cyanuric acid-thiourea supermolecule liquid as a precursor and a template for the first time, and then prepares S doped honeycomb g-C successfully through selective volatilization during calcination 3 N 4 The nano-sheet and the porous structure not only can obviously improve the charge transport efficiency in the photocatalysis process, but also can greatly reduce the composite aggregation of electron holes through interaction sites, thereby greatly improving the g-C 3 N 4 Is effective to overcome the bulk phase g-C 3 N 4 Is not enough. The application provides a brand new g-C 3 N 4 Preparation method for improving g-C 3 N 4 Has important practical significance in the photocatalytic activity of the catalyst.
The preparation method can combine morphology change and element doping to form a synergistic effect, thereby greatly increasing the photocatalytic activity. The defect structure and doping S act as electron transport medium as a result of spin and charge density redistribution caused by S doping, which can provide a new photocatalytic path, promote separation efficiency of the support and alter the bandgap structure of the photocatalyst.
Furthermore, the inventors found in the study that: due to the special property of thiourea, nitrogen and sulfur compounds are released due to the fact that the thiourea is easy to volatilize in the heating process, if the thiourea is mixed with melamine and cyanuric acid, sulfur in the thiourea is possibly lost, and doping of sulfur elements is not easy to achieve. According to the application, the melamine and the cyanuric acid are mixed firstly, and then the thiourea is added, so that the doping of sulfur can be effectively realized. In addition, by mixing cyanuric acid and melamine, adding thiourea after stirring uniformly, a regular supermolecule long chain can be formed, selective volatilization is carried out during calcination, a porous structure is finally formed, and sulfur element is doped into the structure of carbon nitride. Wherein, the above-mentioned "regular supermolecule long chain" is made up of a plurality of supermolecule units, the structure of the supermolecule unit is as follows:
in a preferred embodiment of the application, the thiourea is used in a ratio of n (thiourea)/[ n (melamine) +n (cyanuric acid) ] =0.8-7% (i.e. the number of moles of thiourea is 0.8-7% of the sum of the number of moles of melamine and the number of moles of cyanuric acid; e.g. 0.8%, 1%, 2%, 3%, 4%, 5%, 6% or 7%). According to the application, when the consumption of thiourea is larger or smaller, the photocatalytic performance of the product is adversely affected, so that the photocatalytic performance of the product is greatly reduced. Preferably, the ratio of thiourea is n (thiourea)/[ n (melamine) +n (cyanuric acid) ]=3%
In a preferred embodiment of the application, the molar ratio of melamine to cyanuric acid is 1 (0.5-3) (e.g., the molar ratio of melamine to cyanuric acid is 1:0.5, 1:1, 1:2 or 1:3). When the molar ratio of melamine to cyanuric acid is larger or smaller, the hydrogen-producing property of the produced product is lowered. Preferably, the molar ratio of melamine to cyanuric acid is 1:1.
In a preferred embodiment of the application, the calcination temperature is 500-600deg.C (e.g., 500 deg.C, 520 deg.C, 540 deg.C, 560 deg.C, 580 deg.C, or 600 deg.C), the temperature rise rate is 3-20deg.C/min (e.g., 3 deg.C/min, 6 deg.C/min, 9 deg.C/min, 12 deg.C/min, 15 deg.C/min, 18 deg.C/min, or 20 deg.C/min), and the incubation time is 4-6h (e.g., 4.5h, 5h, 5.5h, or 6 h). The difference of the calcination process (calcination temperature, heat preservation time and heating rate) has great influence on the generated products; the calcining temperature, the heat preservation time or the heating rate are too low, so that the carbon nitride cannot be calcined completely, the specific surface area of the carbon nitride is influenced, and the self-stripping process is influenced, namely whether the nano-sheets can be formed or not is an important factor; of course, excessive calcination will volatilize most of the carbon nitride, but rather will reduce the performance of the carbon nitride.
In a preferred embodiment of the application, the calcination is carried out under air conditions.
In a preferred embodiment of the present application, step (1) comprises: placing melamine and cyanuric acid in a container, adding deionized water, and stirring vigorously under water bath at 60-80deg.C (e.g., 60deg.C, 65deg.C, 70deg.C, 75deg.C or 80deg.C) for 0.5-2 hr (e.g., 0.5 hr, 1 hr, 1.5 hr or 2 hr) to obtain uniformly dispersed mixed solution.
In a preferred embodiment of the present application, in step (3), the water removal is specifically: stirring under the condition of heat preservation to evaporate water in the melamine-cyanuric acid-thiourea supermolecule liquid; the drying is specifically as follows: and (5) drying the product obtained after the water removal in a drying oven. Further preferably, the drying time is 12-24 hours (e.g., 12 hours, 16, 20 hours, or 24 hours).
In a preferred embodiment of the application, the drying is completed with a further step of grinding the solid obtained.
The application also provides a sulfur-doped honeycomb nano sheet g-C 3 N 4 The sulfur-doped honeycomb nano-sheet g-C 3 N 4 Prepared by the method described above.
The application also provides a sulfur-doped honeycomb nano sheet g-C 3 N 4 Is the application of the sulfur-doped honeycomb nano-sheet g-C 3 N 4 The method is applied to photocatalytic hydrogen production and organic matter degradation.
The sulfur-doped cellular nanoflakes g-C of the present application are described below by way of specific examples 3 N 4 And a preparation method and application thereof are described in detail.
Example 1
The sulfur-doped cellular nanoflakes of this example g-C 3 N 4 The preparation method of (2) comprises the following steps:
(1) 3g (0.0238 mol) melamine and 3g (0.0232 mol) cyanuric acid powder are respectively weighed and placed in a 50ml beaker, 40ml deionized water is added, and the mixture is vigorously stirred for 30min under 75 ℃ water bath, so that the mixture is uniformly dispersed, and a mixed solution is obtained;
(2) Pouring 0.1g (0.0013 mol) of thiourea aqueous solution (the thiourea dosage is n (thiourea)/[ n (melamine) +n (cyanuric acid) ]=3%) into the mixed solution obtained in the step (1) to obtain a white suspension (melamine-cyanuric acid-thiourea supermolecular liquid), then continuing stirring to a dry state (a state which is achieved after most of water is removed under a water bath at 75 ℃), and finally continuously drying in a drying oven for 12 hours;
(3) After being completely dried, the mixture is ground into powder by using an agate mortar to obtain a precursor modified by thiourea;
(4) The obtained precursor is directly put into a covered crucible, heated to 550 ℃ at a heating temperature of 5 ℃/min under the air condition, and kept for 4 hours. The obtained fluffy porous powder is the sulfur-doped honeycomb nano-sheet g-C of the embodiment 3 N 4 Labeled S-PDCN-3.
Example 2
The sulfur-doped cellular nanoflakes of this example g-C 3 N 4 The preparation process of (2) differs from example 1 only in that: the amount of thiourea used in step (2) is (n (thiourea)/[ n (melamine) +n (cyanuric acid))]=0.8%) other steps and process parameters were kept consistent with example 1;
the obtained fluffy porous powder is sulfur-doped honeycomb nano-sheet g-C of the embodiment 3 N 4 Labeled S-PDCN-0.8.
Example 3
The sulfur-doped cellular nanoflakes of this example g-C 3 N 4 The preparation process of (2) differs from example 1 only in that: the amount of thiourea used in step (2) is (n (thiourea)/[ n (melamine) +n (cyanuric acid))]=1%, other steps and process parameters were kept identical to example 1;
the obtained fluffy porous powder is sulfur-doped honeycomb nano-sheet g-C of the embodiment 3 N 4 Labeled S-PDCN-1.
Example 4
The sulfur-doped cellular nanoflakes of this example g-C 3 N 4 The preparation process of (2) differs from example 1 only in that: the amount of thiourea used in step (2) is (n (thiourea)/[ n (melamine) +n (cyanuric acid))]=5%, other steps and process parameters were kept identical to example 1;
the obtained fluffy porous powder is sulfur-doped honeycomb nano-sheet g-C of the embodiment 3 N 4 Labeled S-PDCN-5.
Example 5
The sulfur-doped cellular nanoflakes of this example g-C 3 N 4 The preparation process of (2) differs from example 1 only in that: the amount of thiourea used in step (2) is (n (thiourea)/[ n (melamine) +n (cyanuric acid))]=7%, other steps and process parameters were kept identical to example 1;
the obtained fluffy porous powder is sulfur-doped honeycomb nano-sheet g-C of the embodiment 3 N 4 Labeled S-PDCN-7.
Comparative example 1
The g-C of the bulk phase was prepared as follows 3 N 4 The method comprises the following specific steps: the melamine is directly put into a covered crucible, heated to 550 ℃ at a temperature rising of 5 ℃/min under the air condition, and kept for 4 hours. The obtained product is the bulk phase g-C of the comparative example 3 N 4 Labeled BCN.
Comparative example 2
This comparative example differs from example 1 only in that: the step of adding cyanuric acid in step (1) was omitted, and the remainder was the same as in example 1. The product obtained is marked as S-CN.
Comparative example 3
This comparative example differs from example 1 only in that: the step of adding thiourea in step (2) was omitted and the remainder remained the same as in example 1. The product prepared is labeled PDCN.
Comparative example 4
The carbon nitride of this comparative example was prepared as follows:
(1) 1.9g of melamine (0.015 mol), 2.6g of cyanuric acid (0.02 mol) and 3.8g of thiourea (0.05 mol) are added to a beaker containing 50mL of deionized water to form a suspension, and the suspension is heated and stirred until the water is completely evaporated to form a supramolecular precursor;
(2) The supramolecular precursor was thoroughly ground and then heated to 550 ℃ in a muffle furnace at a heating rate of 2 ℃/min and held at 550 ℃ for 2h. Taken out and cooled to room temperature, and ground to obtain a white solid, which is denoted as CN-MCT.
Comparative example 5
The carbon nitride of this comparative example was prepared as follows:
(1) 1.9g (0.015 mol) melamine and 2.6g (0.02 mol) cyanuric acid are added to a beaker containing 50mL deionized water and stirred for 30min;
(2) Adding 3.8g (0.05 mol) of thiourea into the beaker to form a suspension, and heating and stirring the suspension until water is completely evaporated to form a supermolecule precursor;
(3) The supramolecular precursor was thoroughly ground and then heated to 550 ℃ in a muffle furnace at a heating rate of 2 ℃/min and held at 550 ℃ for 2h. Taken out and cooled to room temperature, and ground to obtain a white solid, which is denoted as CN-MCT-Order.
Comparative example 6
The only difference from example 1 is that: the conditions for calcination are: heating to 550 ℃ at a heating rate of 2 ℃/min, and keeping at 550 ℃ for 2h; the remainder remained the same as in example 1.
The sample prepared in this comparative example was designated S-PDCN-3-2.
Comparative example 7
The only difference from example 1 is that: in the step (1), adding deionized water, and then adding thiourea aqueous solution; the remainder remained the same as in example 1.
The sample prepared in this comparative example was designated S-PDCN-3-Disorder.
Comparative example 8
The only difference from example 1 is that: the dosage of melamine is 1.9g, the dosage of cyanuric acid is 2.6g, and the dosage of thiourea is 3.8g; the remainder remained the same as in example 1.
The sample prepared in this comparative example was designated S-PDCN-142.
Comparative example 9
The only difference from example 1 is that: the amount of cyanuric acid was 1g, the remainder being identical to example 1.
The sample prepared in this comparative example was designated S-PDCN-L.
Comparative example 10
The only difference from example 1 is that: the amount of cyanuric acid was 6g, the remainder being identical to example 1.
The sample prepared in this comparative example was designated S-PDCN-M.
Experimental example
1. The SEM, TEM image and EDS element content image of the product (S-PDCN-3) obtained in example 1 were measured as test samples; and the SEM image, XPS total spectrum and high resolution spectrum were measured using the products (BCN, S-CN and PDCN) obtained in comparative examples 1 to 3 as test samples, respectively:
test results: an SEM image of the S-PDCN-3 test sample is shown in detail in figure 1 of the drawings of the specification, and a TEM image is shown in detail in figure 2; the SEM of BCN is shown in FIG. 3, the SEM of S-CN is shown in FIG. 4, and the SEM of PDCN is shown in FIG. 5; EDS element content diagram of the S-PDCN-3 test sample is shown in FIG. 6; FIG. 7 (a) is a C1S plot of S-PDCN-3, BCN, S-CN, and PDCN; FIG. 7 (b) is an N1S plot of S-PDCN-3, BCN, S-CN, and PDCN; FIG. 7 (c) is an S2p diagram of S-PDCN-3, BCN, S-CN and PDCN; .
Comparing the test results of S-PDCN-3 (sample of example 1) with that of BCN (sample of comparative example 1), it is apparent that the SEM image of S-PDCN-3 is a nano-platelet structure, the TEM image shows a porous structure (pore diameter of about 40-120 nm) on the nano-platelet, the photograph is marked as 200nm (the electron microscope photograph is taken at 200nm size), and the g-C can be seen from SEM and TEM 3 N 4 The thickness is very thin and there is no massive aggregation.
As can be seen from fig. 6-7: the S-PDCN-3 of the embodiment 1 successfully realizes the doping of the S element.
FIG. 6 is an EDS spectrum illustrating the presence of C, N, O, S in the S-PDCN-3 sample and a uniform distribution, and also demonstrating that the S element was successfully doped into g-C 3 N 4 In the structure of (a).
The surface composition, chemical valence and configuration were further observed by detecting XPS spectra of BCN, S-CN, PDCN and S-PDCN-3, and the test results are shown in FIG. 7. As can be seen from FIG. 7 (a), all samples contained C, N, O element, while no characteristic peak of S element was found in S-PDCN-3, probably due to S dopingToo little content. FIG. 7 (b) is a C1s high resolution spectrum of all samples, SP in standard carbon and N-C=N bonds of the C-C bonds adsorbed at the corresponding surfaces of the characteristic peaks at 284.90eV and 288.34eV, respectively 2 And (3) hybridized carbon. For N1s (fig. 7 (c)), the spectrum can be peak-fitted to four peaks. Peaks at 398.80eV, 400.70eV, 401.67eV and 404.42eV are from c=n-C, N- (C), respectively 3 And C-NH x And an N signal conjugated with pi electrons. As shown in FIG. 7 (d), the S element high resolution spectrum has lower characteristic peak intensity due to lower sulfur content in the sample S-CN and S-PDCN-3, but has a distinct characteristic peak at 163.26eV, and the peak signal is due to C-S bond formed by S substituting N in lattice, which indicates that S of thiourea is successfully doped into g-C 3 N 4 At the same time, the ratio of C/N ratio of S-PDCN-3 compared with BCN is reduced, which proves that the C defect structure exists, and the C defect structure is consistent with the apparent morphology result of S-PDCN-3, and the defect structure is successfully constructed by the method. Among the many doping systems, S doping is widely used due to its relatively suitable atomic radius and electronegativity, and according to the density functional theory, S occupies N-bits more easily, and can adjust the conformation and optimize the electronic structure.
2. The products obtained in example 1 and comparative example 1, comparative example 2 and comparative example 3 were used as test samples, respectively, and fluorescence spectra of the samples were measured:
the test was performed using a Cary Eclipse fluorescence spectrometer, and the specific test results are shown in FIG. 8.
As can be seen from FIG. 8, the sample of example 1, S-PDCN-3, had the weakest peak in the PL spectrum, the BCN peak was much higher than that of S-PDCN-3, and the peaks of S-CN and PDCN were also much higher than that of S-PDCN-3, indicating that the sulfur-doped cellular nanoflakes g-C 3 N 4 The separation of electron hole pairs is effectively promoted.
3. The products obtained in example 1 and comparative examples 1 and 2 were used as test samples, respectively, and ultraviolet-visible absorption spectra of the samples were tested:
the band gap value was calculated according to the formula of Kubelka-Munk after testing using an ultraviolet-visible spectrophotometer UV-2600, and the specific results are shown in fig. 9.
As can be seen from FIG. 9, the sample S-PDCN-3 of example 1 has a bandgap of 2.63eV, BCN has a bandgap of 2.70eV, S-CN has a bandgap of 2.66eV, and PDCN has a bandgap of 2.53eV. Obviously, the S-PDCN-3 has a smaller band gap structure and a wider absorption spectrum band, the separation efficiency and the transfer speed of electron hole pairs are greatly improved, the porous structure and the nano-sheet provide more reaction sites, and the photocatalytic activity of the carbon nitride is remarkably improved.
4. The samples were tested for hydrogen production performance using the products obtained in examples 1 to 5 and comparative examples 1, 2, 3 and 9 to 10, respectively, as test samples:
the parallel light reaction instrument is adopted for reaction, and the gas chromatograph is used for testing the hydrogen yield, and the specific testing method is as follows:
the hydrogen production experiment is carried out in a photocatalysis reactor, 10mg of photocatalyst is dispersed in an aqueous solution containing 10vol% of triethanolamine, and the ultrasonic treatment is carried out for 20min; then, add H again 2 PtCl 6 . Experiments were performed under irradiation of visible light (300W xenon lamp). Analysis of the H produced using a gas chromatograph (SP-7890) 2 . The test results are shown in FIGS. 10-11.
FIG. 10 is a graph showing the hydrogen production amount obtained by plotting experimental data obtained by continuously conducting hydrogen production experiments for 9 hours;
FIGS. 11-12 are averages of hydrogen production rates measured by performing multiple hydrogen production experiments (each hydrogen production experiment duration 1 h);
as can be seen from fig. 11: example 1 the hydrogen yield of sample S-PDCN-3 was much greater than that of BCN, S-CN, PDCN samples. Specifically, the hydrogen production rate of BCN is: hydrogen production rate of S-CN at 250 μmol/g/h) is: 1780. Mu. Mol/g/h, the hydrogen production rate of PDCN is: the hydrogen production rate of S-PDCN-0.8 is 2580 mu mol/g/h: the hydrogen production rate of S-PDCN-1 is 3830 mu mol/g/h: 5250. Mu. Mol/g/h, the hydrogen production rate of S-PDCN-3 is: 23780 mu mol/g/h, the hydrogen production rate of S-PDCN-5 is: the hydrogen production rate of S-PDCN-7 was 9700. Mu. Mol/g/h: 6740. Mu. Mol/g/h;
as can be seen from fig. 12: the hydrogen production rate of the S-PDCN-M is 4905 mu mol/g/h, and the hydrogen production rate of the S-PDCN-L is 1275 mu mol/g/h.
Wherein the method comprises the steps ofThe hydrogen production rate of S-PDCN-3 can reach 23780 mu mol/g/h, while BCN (bulk phase g-C 3 N 4 ) The hydrogen production rate is only 250 mu mol/g/h, and the hydrogen production rate of S-PDCN-3 is 95 times that of BCN.
Experimental results show that the sulfur-doped honeycomb nano-sheet g-C prepared by the application 3 N 4 Has remarkable photocatalysis hydrogen production effect.
5. The products obtained in example 1 and comparative example 1, comparative example 2 and comparative example 3 were used as test samples, respectively, and the cyclic stability of the samples was tested:
the test results are shown in fig. 13.
The method for testing the circulation stability comprises the following steps: in the photocatalysis hydrogen production system, after each continuous illumination for 3 hours, the sample is collected and dried, and then the same illumination hydrogen production experiment is carried out, and the continuous circulation is carried out for 3 times each time for 3 hours. Thus obtaining the cyclic stable hydrogen production experiment.
The stability and the recoverability of the photocatalyst are one of key parameters for evaluating the photocatalytic performance, and a cycle stability experiment of a sample shows that the optimal sample S-PDCN-3 has good stability and hydrogen production durability, and the hydrogen production amount does not change greatly in the process of continuously circulating for 3 times, so that the S-PDCN-3 shows excellent photocatalytic performance and has good recoverability.
6. The products obtained in example 1 and comparative example 1, comparative example 2 and comparative example 3 were used as test samples, respectively, and their specific surface areas BET were measured:
the BET test is determined by an instrument model Beckman Coulter SA3100, manufactured by Beckmann Kort, U.S.A. The powder sample to be measured is arranged in a section of closed test tube-shaped sample tube with a certain volume, the adsorbent gas with a certain pressure is injected into the sample tube, and the adsorption molecule (N 2 ) Is used as the adsorption amount of the catalyst. And (3) taking the relative pressure P/Po as an X axis and the absorption volume as a Y axis, drawing a BET equation to perform linear fitting to obtain the slope and intercept of a straight line, and obtaining the Vm value to calculate the specific surface area of the measured sample.
The test results are shown in fig. 14.
As can be seen from fig. 14, the present applicationThe specific surface area of the product S-PDCN-3 obtained in inventive example 1 was 356.60m 2 g -1 Is significantly larger than BCN (specific surface area is 18.97m 2 g -1 ) SCN (specific surface area 21.50 m) 2 g -1 ) And PDCN (specific surface area of 145.06 m) 2 g -1 )。
The above experimental data indicate that: the sulfur-doped cellular nano-sheet g-C prepared by the method of the application 3 N 4 The porous structure is formed, the surface area is obviously increased, more reaction sites and electron traps can be provided for photocatalytic hydrogen production, so that the separation efficiency of photogenerated carriers is greatly increased, and the photocatalytic activity of the carbon nitride is effectively improved.
7. The degradation efficiency for RhB was tested using the products obtained in example 1 and comparative examples 4 to 8 as test samples, respectively:
the subject of photocatalytic degradation is a 10mg/L aqueous rhodamine (RhB) solution. First, 10mg of sample g-C 3 N 4 The photocatalyst is placed in a double glass beaker with a cooling water circulation system, and the mixed solution is stirred for 30min in a dark environment, so as to reach adsorption-desorption equilibrium. Thereafter, a 300W xenon lamp and a filter (lambda)>420 nm) simulates a visible light source. The degradation products were taken out every 5min under irradiation of visible light for 30min, and their degradation efficiency was measured with an ultraviolet-visible spectrophotometer.
The test results are shown in fig. 15.
As can be seen from FIG. 15, after 30min of degradation, the degradation efficiencies of BCN (comparative example 1), CN-MCT (comparative example 4), S-PDCN-3-2 (comparative example 6), CN-MCT-Order (comparative example 5), S-PDCN-dispenser (comparative example 7), S-PDCN-142 (comparative example 8) and S-PDCN-3 (example 1) were 16.47%, 25.89%, 31.40%, 46.79%, 54.5%, 59.2% and 98.06% in this Order.
The above description is only of the preferred embodiments of the present application and is not intended to limit the present application, but various modifications and variations can be made to the present application by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims (4)

1. Sulfur-doped honeycomb nano sheet g-C 3 N 4 Is characterized by comprising the following steps:
(1) Mixing melamine, cyanuric acid and water, and stirring while maintaining the temperature;
(2) Adding thiourea into the mixed solution obtained in the step (1) to obtain melamine-cyanuric acid-thiourea supermolecule liquid;
(3) Dewatering and drying the melamine-cyanuric acid-thiourea supermolecule liquid obtained in the step (2) to obtain a thiourea modified precursor;
(4) Calcining the thiourea modified precursor obtained in the step (3) to obtain the sulfur-doped honeycomb nano sheet g-C 3 N 4 ；
The step (1) comprises: placing melamine and cyanuric acid into a container, adding deionized water, and vigorously stirring for 0.5-2h in a water bath at 60-80 ℃ to obtain a uniformly dispersed mixed solution;
the mole number of the thiourea is 0.8-7% of the sum of the mole number of the melamine and the mole number of the cyanuric acid, and the mole ratio of the melamine to the cyanuric acid is 1 (0.5-3);
the calcining temperature is 500-600 ℃, the heating rate is 3-20 ℃/min, the heat preservation time is 4-6h, and the calcining is carried out under the air condition;
in the step (3), the water removal is specifically: stirring under the condition of heat preservation to evaporate water in the melamine-cyanuric acid-thiourea supermolecule liquid; the drying is specifically as follows: and (5) drying the product obtained after the water removal in a drying oven.
2. Sulfur-doped cellular nanoflakes of claim 1 g-C 3 N 4 The preparation method is characterized by further comprising the step of grinding the obtained solid after the drying is finished.
3. Sulfur-doped honeycomb nano sheet g-C 3 N 4 Characterized in that the following stepsSulfur doped cellular nanoflakes g-C 3 N 4 Prepared by the method of claim 1 or 2.
4. A sulfur-doped cellular nanoflakes g-C as defined in claim 3 3 N 4 The method is applied to photocatalytic hydrogen production and organic matter degradation.
CN202210495378.8A 2022-05-07 2022-05-07 Sulfur-doped honeycomb nano sheet g-C 3 N 4 Preparation method and application thereof Active CN115055199B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210495378.8A CN115055199B (en) 2022-05-07 2022-05-07 Sulfur-doped honeycomb nano sheet g-C 3 N 4 Preparation method and application thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210495378.8A CN115055199B (en) 2022-05-07 2022-05-07 Sulfur-doped honeycomb nano sheet g-C 3 N 4 Preparation method and application thereof

Publications (2)

Publication Number Publication Date
CN115055199A CN115055199A (en) 2022-09-16
CN115055199B true CN115055199B (en) 2023-11-03

Family

ID=83197259

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210495378.8A Active CN115055199B (en) 2022-05-07 2022-05-07 Sulfur-doped honeycomb nano sheet g-C 3 N 4 Preparation method and application thereof

Country Status (1)

Country Link
CN (1) CN115055199B (en)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103861632A (en) * 2014-04-07 2014-06-18 吉林大学 Preparation method for multi-hole carbon nitride photocatalytic material doped with sulphur
CN104722323A (en) * 2015-01-21 2015-06-24 辽宁石油化工大学 Sulfur doped graphite phase carbon nitride pholocatalyst and application thereof in photocatalysis TCP (2,4,6-trichlorophenol) degradation reaction and photocatalysis hydrogen preparation reaction
CN109364977A (en) * 2018-12-06 2019-02-22 辽宁大学 Sulfur doping graphite phase carbon nitride nanosheet photocatalyst and the preparation method and application thereof
WO2019109597A1 (en) * 2017-12-05 2019-06-13 宿州学院 Sulfur-doped s-c3n4 ammonia synthesis catalyst with graphene-like structure and preparation method therefor
CN110064429A (en) * 2019-05-31 2019-07-30 上海纳米技术及应用国家工程研究中心有限公司 Preparation method of sulfur doping azotized carbon nano piece and products thereof and application
CN114367299A (en) * 2022-01-12 2022-04-19 西安交通大学 Graphite phase carbon nitride photocatalyst for photocatalytic hydrogen production and preparation method thereof

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103861632A (en) * 2014-04-07 2014-06-18 吉林大学 Preparation method for multi-hole carbon nitride photocatalytic material doped with sulphur
CN104722323A (en) * 2015-01-21 2015-06-24 辽宁石油化工大学 Sulfur doped graphite phase carbon nitride pholocatalyst and application thereof in photocatalysis TCP (2,4,6-trichlorophenol) degradation reaction and photocatalysis hydrogen preparation reaction
WO2019109597A1 (en) * 2017-12-05 2019-06-13 宿州学院 Sulfur-doped s-c3n4 ammonia synthesis catalyst with graphene-like structure and preparation method therefor
CN109364977A (en) * 2018-12-06 2019-02-22 辽宁大学 Sulfur doping graphite phase carbon nitride nanosheet photocatalyst and the preparation method and application thereof
CN110064429A (en) * 2019-05-31 2019-07-30 上海纳米技术及应用国家工程研究中心有限公司 Preparation method of sulfur doping azotized carbon nano piece and products thereof and application
CN114367299A (en) * 2022-01-12 2022-04-19 西安交通大学 Graphite phase carbon nitride photocatalyst for photocatalytic hydrogen production and preparation method thereof

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Milad Jourshabani et al..An efficient and unique route for the fabrication of highly condensed oxygen-doped carbon nitride for the photodegradation of synchronous pollutants and H2O2 production under ambient conditions.《Applied Catalysis B:Environmental》.2021,第第302卷卷第120839(1-14)页. *

Also Published As

Publication number Publication date
CN115055199A (en) 2022-09-16

Similar Documents

Publication Publication Date Title
Li et al. Controllable design of Zn-Ni-P on g-C3N4 for efficient photocatalytic hydrogen production
CN107297217B (en) Porous thin-layer graphite-phase carbon nitride-supported platinum photocatalyst and preparation method and application thereof
CN106964339B (en) Carbon-doped ultrathin bismuth tungstate nanosheet photocatalytic material and preparation method thereof
Liu et al. Carbon doped honeycomb-like graphitic carbon nitride for photocatalytic hydrogen production
CN106362774B (en) A kind of 1D/2D vertical configuration CdS/MoS2Produce the preparation method of hydrogen catalyst
CN110560105B (en) Preparation of nickel phosphide-loaded sulfur indium zinc nano microsphere composite material and application of composite material in photocatalytic hydrogen production
CN109046425A (en) Composite photo-catalyst TiO derived from a kind of MOF base2/g-C3N4Preparation method
CN112427045A (en) CdS/g-C synthesized by hydrothermal method and having Z-shaped heterojunction3N4Preparation method of composite photocatalyst material
Sun et al. Synthesis of g-C3N4/NiO-carbon microsphere composites for Co-reduction of CO2 by photocatalytic hydrogen production from water decomposition
CN113145138B (en) Thermal response type composite photocatalyst and preparation method and application thereof
Zhu et al. Fabrication of ZnS/CdS heterojunction by using bimetallic MOFs template for photocatalytic hydrogen generation
CN110876953A (en) P and S co-doped carbon nitride homotype heterojunction composite photocatalyst
CN112023974B (en) P-CeO2/g-C3N4Heterojunction material, preparation method and application thereof
CN110813347B (en) Molecular doping modified graphite phase carbon nitride photocatalyst with three-dimensional loose structure and preparation method and application thereof
CN111203234A (en) CdIn2S4Nanoblock/SnIn4S8Preparation method of difunctional composite photocatalyst with sheet stacking structure
CN108927197B (en) g-C with high catalytic performance3N4Preparation method and use of
CN114054066A (en) Doped g-C3N4Nanotube photocatalyst, preparation method and application
CN115055199B (en) Sulfur-doped honeycomb nano sheet g-C 3 N 4 Preparation method and application thereof
CN113663715B (en) P-doped g-C 3 N 4 Sheet photocatalyst, and preparation method and application thereof
CN113441165B (en) VN/g-C 3 N 4 Composite photocatalyst and preparation method thereof
Xu et al. Enhanced photocatalytic hydrogen production from Co-MOF/CN by nitrogen and sulfur co-doped coal-based carbon quantum dots
CN109092344B (en) Multistage eggshell structure g-C3N4/TiO2Composite material and preparation method and application thereof
CN108654673B (en) Novel photocatalytic material and preparation method and application thereof
CN113398966A (en) Photocatalyst with porous nitrogen-doped carbon nanofiber dispersed nickel and molybdenum phosphide, and preparation and application thereof
CN111889124A (en) Cobalt sulfide/two-dimensional graphite phase carbon nitride composite photocatalyst and preparation method thereof

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant