CN114471655A - 可见光下不加牺牲剂高效生成过氧化氢的复合光催化剂的制备方法 - Google Patents
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- 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
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- 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
- B01J21/00—Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
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- 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
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- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B15/00—Peroxides; Peroxyhydrates; Peroxyacids or salts thereof; Superoxides; Ozonides
- C01B15/01—Hydrogen peroxide
- C01B15/027—Preparation from water
Abstract
g‑C3N4利用水和氧气进行光催化生产过氧化氢是一种很有前途且可持续的方法。然而,由于有限的光吸收,快速的光生电子‑空穴复合和差的表面电子迁移,纯的g‑C3N4生产H2O2的产量不理想。因此,采用高温煅烧和水热方法通过掺入磷和负载碳量子点来改性多孔g‑C3N4合成p‑P1CN/CQDs25复合光催化剂。磷作为电子转移的桥梁,诱导电子进入CQDs,CQDs作为电子捕获材料,捕获和稳定光生的电子。由于CQDs具有独特的光学特性,同时也可以增强光吸收。p‑P1CN/CQDs25在可见光下,不添加牺牲剂和通氧的条件下,呈现出高度提升的H2O2生成活性,反应5 h后H2O2的生成量高达494μM/L,生成速率常数Kf为238μM h‑1。
Description
技术领域
本发明涉及一种光催化剂的制备技术,具体为可见光下不加牺牲剂高效生成过氧化氢的复合光催化剂的制备方法。
背景技术
随着人类社会对环境污染和新能源的日益关注,过氧化氢(H2O2)作为一种重要的绿色氧化剂和有前途的未来燃料,被认为是解决环境问题和能源危机的理想资源[1-3]。H2O2甚至拥有比压缩H2气体更高的能量密度,有望在未来取代传统的化石燃料[3, 4-6]。然而,现阶段大规模H2O2的生成仍然依赖于传统的基于蒽醌的方法,此类传统方法存在着工艺复杂、能耗大、有机溶剂投入多、副产品有毒和***危险等诸多缺点[7-9]。目前,作为替代传统方法的新兴方法,电催化和光催化生成H2O2已经引起了许多科研人员的极大兴趣[10-13]。与电催化法的严重能耗相比,光催化过程是一种节能、环保和可持续的方法,它是在温和的条件下捕获太阳光并驱动半导体催化剂来产生H2O2[14-16]。
一般来说,光催化生成H2O2的机理过程主要是在光照下,通过适当导带位置上的电子与氧气发生还原反应生成的。生成途径主要是通过直接的双电子反应(公式1)[17-20]或以超氧自由基(·O2 -)为中间物的连续两步单电子反应(公式2和3)[21-23]。基于以上生成过程,H2O2的光催化生成主要由良好的光吸收、合适的导带位置、理想的光生载流子分离及表面电子转移、光催化剂表面一定的吸附氧浓度等决定的。
近年来,石墨相氮化碳(g-C3N4)作为一类新兴的无金属聚合物光催化剂,基于其稳定的理化性质、合适的能带结构、易于制备、无毒和低成本的优势,已经成为光催化生成H2O2的一个理想的候选者[24-27]。值得注意的是,其优越的导带位置(约-1.3 eV)可以催化公式1-3中的所有反应[28]。然而,块体g-C3N4产生的光催化H2O2的产量仍然远远不能令人满意[29-32]。为了提高光催化生成H2O2的效率,需要解决g-C3N4光催化生成H2O2过程中的一些关键问题:有限的光吸收、快速的光生电子-空穴复合以及差的表面电子迁移。因为这些问题会使光生电子在与氧气反应之前,与空穴复合或失去活性。
为了克服上述问题,研究人员提出了各种方法对纯的g-C3N4进行改性,包括构建异质结和Z形体系(g-C3N4-CoWO,AgBr-Br/g-C3N4,CuO/g-C3N4,Cu2(OH)2CO3/g-C3N4,Ni-CAT/g-C3N4,Bi4O5Br2/g-C3N4)[17, 20, 33-36]或引入缺陷[26, 31, 37-40]以扩大光吸收范围,提高光生电子空穴的分离;或者通过负载贵金属(Au/g-C3N4)[41],单原子(Co1/g-C3N4)[42]或碳材料(g-C3N4-CNTs)[43]以加速光生电子的表面迁移率。然而,如果分离和迁移的光生电子和空穴没有被捕获固定,它们仍然有很大机会可以复合,从而减少光生电子与氧气的反应机会。所以有研究学者也加入牺牲剂作为空穴捕获剂来抑制光生电子-空穴的复合,同时用连续通入氧气来增加氧在光催化剂表面的扩散,促进电子与氧的反应[44]。然而,加入牺牲剂和鼓入氧气增加了成本,并需要额外的过程来去除牺牲剂的副产物[45]。
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发明内容
本发明为解决目前g-C3N4光催化生成H2O2存在有限的光吸收、快速的光生电子-空穴复合以及差的表面电子迁移,进而导致H2O2产量低的技术问题,提供一种可见光下不加牺牲剂高效生成过氧化氢的复合光催化剂的制备方法。
本发明是采用如下技术方案实现的:一种可见光下不加牺牲剂高效生成过氧化氢的复合光催化剂的制备方法,包括如下步骤:
1)掺磷的多孔g-C3N4的合成
采用热聚合方法合成掺磷的多孔g-C3N4:将盐酸三聚氰胺与六氯三聚磷氰均匀混合,二者质量比为10:x,其中x取0.5~1.5;将混合物放在带盖的坩埚中,利用马弗炉在530~560℃下以3-10℃/min的加热速度煅烧3~5小时,得到的黄色粉末是磷掺杂的多孔g-C3N4,简称为p-PxCN,x代表六氯三聚磷氰的添加量;
2)碳量子点的合成
碱辅助超声法制备碳量子点:将葡萄糖均匀地溶解在去离子水中,然后加入浓度为1mol/L的氨水超声1.5~3小时,然后再持续搅拌6~9小时,葡萄糖溶液的浓度与氨水浓度比为0.5~1.5:1,且葡萄糖溶液和氨水体积比为2:1~1:2;加入盐酸将混合溶液调节到pH=7,并通过MWCO 3000半透膜进行透析,最后得到透明的棕色溶液,称为CQDs水溶液,储存在4℃的冰箱中备用;
3)复合光催化剂p-PxCN/CQDsy的合成
通过水热法将CQDs负载于p-PxCN上:在30~80ml去离子水中加入p-PxCN和CQDs溶液,比例关系为每克p-PxCN中加入20~30ml的CQDs溶液,在室温下搅拌4~10小时,之后将混合溶液转移到聚四氟乙烯内衬不锈钢高压釜中,在170~190℃下反应6~9小时,得到的样品简称为p-PxCN/CQDsy,其中y是CQDs溶液的添加量。
本发明希望引入一种电子捕获材料来捕集和固定光生电子,从而增加电子和氧气之间的反应机会,提高光催化生产H2O2的产率。同时还要解决如何使光生电子可以被诱导到电子捕集材料中。
为了实现上述构想,发明人设计采用高温煅烧和水热方法通过掺有磷(P)和负载碳量子点(CQDs)去改性多孔g-C3N4(p-CN),合成p-P1CN/CQDs25复合光催化剂。掺杂的P一方面作为一个电子转移的桥梁,诱导光生电子进入CQDs,促进光生电子空穴的分离;另一方面,它也可以增加对氧气的吸附,促进光生电子和吸附的氧气之间的还原反应。而对于CQDs来说,由于其具有捕捉、转移和储存电子的独特特性,因此选择它作为电子捕获材料,以进一步增强光生电子孔的分离,稳定光生电子,加速电子与氧气的高效反应。同时,CQDs还具有独特的光学特性,可以提高复合物光吸收能力并拓宽光响应范围。总而言之,掺杂的P和负载的CQDs可以同时优化光学吸收、光生电子-空穴的分离、表面电子迁移和电子与氧气的还原反应。步骤2中,碱辅助超声法中氨水碱液的使用可以制备得到具有更好晶相的CQDs,其晶格条纹为0.34nm,负载这样的CQDs可以更好地提升复合物光催化产H2O2,结果如图6所示。步骤3通过水热法将p-PxCN和CQD复合,可以得到两者紧密连接的复合光催化材料p-PxCN/CQDsy,如图2c和d。
进一步的,步骤(1)中x取1;步骤(3)中y取值为20ml、25ml、30ml,最终得到p-P1CN/CQDs20、p-P1CN/CQDs25和p-P1CN/CQDs30。
p-P1CN/CQDs25复合光催化剂在可见光下,不添加牺牲剂和不曝氧的情况下就能获得高的H2O2产量。以反应5 h后H2O2的生成量高达494μM/L(分别是p-CN和p-P1CN的21倍和14倍),生成速率常数Kf为238μM h-1(分别是p-CN和p-P1CN的34倍和22倍)。本发明为设计高效生成H2O2的新型光催化剂提供了一个新的思路。
本发明的有益效果:1、本发明设计并合成的复合光催化剂p-PxCN/CQDsy,其中掺杂的P作为电子转移的桥梁,诱导电子进入CQDs,同时CQDs作为电子捕获材料,捕获和稳定光生的电子。此外,由于CQDs具有独特的光学特性,同时也可以增强光吸收。由此,掺杂的磷和负载的碳点可以同时解决提出的问题:有限的光吸收,快速的光生电子-空穴复合和差的表面电子迁移。这一想法构思巧妙新颖,相关的研究目前鲜有报道。
2、p-PxCN/CQDsy(以x=1,y=25时为例)在可见光下,不添加牺牲剂和通氧的条件下,呈现出高度提升的H2O2生成活性,反应5 h后H2O2的生成量高达494μM/L(分别是p-CN和p-P1CN的21倍和14倍),生成速率常数Kf为238μM h-1(分别是p-CN和p-P1CN的34倍和22倍)。
附图说明
图1样品的XRD图。
图2 样品的TEM图(a)p-CN,(b)p-P1CN,(c)p-P1CN/CQDs25,(d),p-CN/CQDs25在(c)中圈出部分的放大图。
图3样品的紫外可见吸收和能带结构结果图(a)紫外可见吸收,(b)莫特-肖特基曲线,(c)XPS价带谱,(d)和(e)p-P1CN和p-P1CN/CQDs25的理论计算DOS图,(f)推测的样品的能带结构图。
图4样品的电化学测试结果图(a)荧光测试PL图,(b)电化学阻抗测试EIS结果图,(c)没有添加快速电子清除剂(MVCl2)的瞬态光电流结果,(d)添加快速电子清除剂(MVCl2)的瞬态光电流结果。
图5样品的光催化产H2O2的结果图(不加牺牲剂,且不曝氧气)(a)样品在可见光下产H2O2的结果(b)样品在近红外光下产H2O2的结果(c)样品分解H2O2的结果(初始H2O2浓度为1.25 mmol L−1),(d)样品可见光下产H2O2的生成速率常数和分解速率常数。
图6:负载不同CQDs的p-CN/CQDs25复合物产过氧化氢的结果,(A)在碱液超声法中使用氨水(1mol/L)制备得到的CQDs;(B)在碱液超声法中使用氢氧化钠(1mol/L)制备得到的CQDs。
具体实施方式
为了与不掺杂磷的情形进行对比,以下分别合成了不掺磷多孔g-C3N4(p-CN)与掺磷的多孔g-C3N4(p-PxCN)。
1.多孔g-C3N4(p-CN)的合成
多孔g-C3N4是通过热聚合方法制备的。具体来说,将15 g的三聚氰胺加入到150 mL的蒸馏水中加热。待冷却后向溶液中缓慢加入15mL的盐酸(HCl,37%)并搅拌30分钟,随后将混合溶液放入80℃的烘箱中干燥。干燥后的样品被称为盐酸三聚氰胺。随后,将10g盐酸三聚氰胺置于带盖的坩埚中,在马弗炉中以5℃/min的加热速率在550℃下煅烧3小时,得到的样品是多孔的g-C3N4(简称p-CN)。
2.掺磷的多孔g-C3N4(p-PxCN)的合成
掺磷的多孔g-C3N4是通过一种热聚合方法合成的。具体的步骤是,10g盐酸三聚氰胺与一定量(0.5g、1g和1.5g)的六氯三聚磷氰均匀混合。将混合物放在一个带盖的坩埚中,利用马弗炉在550℃下以5℃/min的加热速度煅烧3小时。得到的黄色粉末是磷掺杂的多孔g-C3N4(简称为p-PxCN,x代表六氯三聚磷氰的添加量,上述样品分别记为p-P0.5CN、p-P1CN和p-P1.5CN)。
3.碳量子点(CQDs)的合成
碳量子点(CQDs)是使用改良的碱辅助超声法制备的。具体来说,将9.0g葡萄糖均匀地溶解在50ml的去离子水中,然后加入50ml的氨水(1mol/L)并持续搅拌8小时。加入盐酸将原液调节到pH=7,并通过半透膜(MWCO 3000)进行透析。最后,得到透明的棕色溶液,称为CQDs水溶液。它被储存在4℃的冰箱中备用。
4.复合光催化剂p-P1CN/CQDsy的合成
通过水热法将CQDs负载于p-P1CN上。具体来说,在50mL去离子水中加入1.0g的p-P1CN和一定量(20mL、25mL、30mL)的CQDs溶液,在室温下搅拌6小时。之后,将混合溶液转移到一个80mL的聚四氟乙烯内衬不锈钢高压釜中,在180℃下反应8小时。得到的样品被简称为p-P1CN/CQDsy(y是CQDs溶液的添加量,它们分别被记为p-P1CN/CQDs20、p-P1CN/CQDs25和p-P1CN/CQDs30)。
为了比较,也合成了CQDs负载的多孔g-C3N4。合成过程与p-P1CN/CODsy相似,只是在合成过程中加入了p-CN而不是p-P1CN,结果样品被记为p-CN/CQDsy。
5.光催化实验
光催化H2O2的生成是在环境温度(25℃)下进行的,由300W Xe灯提供可见光,加有420nm截止滤光片。在反应***中没有添加牺牲剂,也没有曝氧气。通常情况下,将0.8 g样品加入200 mL蒸馏水中,在黑暗中搅拌30分钟,以达到吸附-解吸平衡,然后用可见光照射反应体系。在照射过程中,每隔一段时间从反应体系中取出5mL的悬浮液,并进行过滤以去除光催化剂。用草酸钛钾法分析H2O2的含量。产生的H2O2可以在酸性介质中与草酸钛钾反应,形成稳定的橙色复合物。橙色复合物的数量由波长为400nm的紫外可见光谱测定,由此估计产生的H2O2的浓度[50]。此外,在可见光下,在初始浓度为1.25mM的情况下,研究了H2O2在所制备的样品上的分解行为60分钟。
样品的晶体结构由Aeris X射线衍射仪(XRD)在铜靶Kα辐射(0.154178nm)下进行分析。通过扫描电子显微镜(SEM)(JSM-6701 F仪器,JEOL,日本)和透射电子显微镜(TEM)(JEM2100 FS,JEOL,日本)对形态和微结构进行了研究。使用Nicolet Avatar-70 FTIR光谱仪(FT-IR)在400-4000cm-1的扫描范围内研究分子结构。化学成分和状态是由ThermoScientific K-Alpha X射线光电子能谱仪(XPS)测量的。使用Shimadzu紫外-可见漫反射光谱(DRS)(Shimadzu UV-2450分光光度计),以BaSO4粉末作为反射标准来研究光学特性。光致发光(PL)光谱是用日立F-4500分光光度计以150W氙灯作为激发源获得的。使用ContaCHEMBET TPR/TPD对样品的O2吸附能力进行了程序化温升化学吸附(TPD-O2)测试。在可见光照射下,使用5,5-二甲基-L-吡咯啉N-氧化物(DMPO)作为探针,在布鲁克EMXPLUS光谱仪上通过电子自旋共振(EPR)检测自由基中间产物。
6.表征分析
样品的晶体结构由X射线衍射仪(XRD)进行分析。样品的形态和微结构通过扫描电子显微镜(SEM)和透射电子显微镜(TEM)进行研究。样品的分子结构使用FTIR光谱仪(FT-IR)研究。化学成分和组态是由X射线光电子能谱仪(XPS)测量。光学吸收通过紫外-可见漫反射光谱(DRS)进行分析。光生电子空穴的分离和迁移通过光致发光(PL)光谱和电化学测试进行分析。样品对O2的吸附能力使用程序升温化学吸附(TPD-O2)测试。在可见光照射下,自由基中间产物使用电子自旋共振(EPR)检测。
如图1所示,XRD结果表明上述方案已经成功合成了p-CN,p-P1CN,p-P1CN/CQDs25和p-CN/CQDs25四种光催化剂,而且四种光催化剂均在2θ为13.1°和27.5°处有两个明显特征峰,分别对应g-C3N4的(100)和(002)晶面,表明掺杂的磷和负载的碳点没有明显破坏g-C3N4的结构。由图2的TEM图结果表明,p-CN呈现出表面不均匀的多孔层状结构,而掺杂磷之后其微观结构基本没有改变。对于p-P1CN/CQDs25,可以明显的看到碳量子点均匀的分布在p-P1CN表面,而且碳点表现出明显的晶格条纹,晶格间距为0.34 nm,其对应于碳量子点的(002)晶面。图3(a)中的紫外可见吸收结果表明,掺杂的磷可以将p-CN的可见光响应范围由470nm拓宽至475nm波长处,而负载碳点之后,p-P1CN/CQDs25在光吸收强度和光吸收范围两个方面都得到极大的提升。此外,图3(b)莫特-肖特基测试表明p-CN,p-P1CN,p-P1CN/CQDs25的导带分别为-1.29, -1.26 and -1.16 V (vs. RHE),而图3(c)XPS价带谱表明p-CN,p-P1CN,p-P1CN/CQDs25的价带分别为2.67, 2.66 and 2.61 eV。图3(d)、(e)p-P1CN和p-P1CN/CQDs25的理论计算DOS图表明,对于p-P1CN,P的s和p轨道都对复合物的价带有贡献,而对于p-P1CN/CQDs25,除了P的轨道对复合物价带有贡献外,CQDs中C的p轨道也对复合物的价带有贡献,表明掺杂的磷和负载的碳量子点之间存在强的耦合作用。根据的莫特-肖特基测试和XPS价带谱结果给出了p-CN,p-P1CN,p-P1CN/CQDs25能带结构图,他们的带隙分别为2.67,2.66和2.61 eV,如图3(f)。图4(a)中PL结果表明掺杂掺杂磷之后,p-P1CN表现出比p-CN更好的光生电子-空穴分离效率。而负载碳量子点之后,p-P1CN/CQDs25表现出进一步提高的光生电子-空穴分离效率。而p-CN/CQDs25表现出与p-P1CN/CQDs25相似的光生电子-空穴分离效率。但是从图4(b)EIS结果可以看出,p-P1CN表现出比p-CN更小的光生载流子迁移阻抗,而p-P1CN/CQDs25的光生载流子迁移阻抗进一步减小,而且比p-CN/CQDs25的光生载流子迁移阻抗更小。表明掺杂的磷在载流子的迁移方面起到了关键作用。为进一步证明,发明人也对样品进行了不同条件的瞬态光电流的测试(加或者不加快速电子清除剂(MVCl2)),计算得到光生电子迁移效率,结果显示p-CN,p-P1CN,p-P1CN/CQDs25和p-CN/CQDs25的光生电子迁移效率分别为66.7 %, 67.6 %, 86.4 %和74.7 %,见图4(c)、(d)。结果表明掺杂的磷和负载的碳量子点都增加了复合物光生电子迁移效率。值得关注的是,p-P1CN/CQDs25和p-CN/CQDs25相比,前者具有更大的光生电子迁移效率,表明掺杂的磷在光生电子传递方面起到了一个桥梁的作用,将光生电子迁移至负载的碳量子点,这将极大地改善复合物光催化产H2O2的性能。因此,发明人利用不同的样品进行了光照条件下产生H2O2的实验,如图5所示,结果表明p-P1CN/CQDs25表现出最优的光催化活性,在反应5 h后H2O2的生成量高达494μM/L,分别是p-CN和p-P1CN的21倍和14倍。而生成速率常数Kf为238μM h-1,分别是p-CN和p-P1CN的34倍和22倍。而对于p-CN/CQDs25,其产生H2O2的量仅为p-P1CN/CQDs25的60%左右。此外,我们也将p-P1CN/CQDs25在波长大于800nm的光照条件下进行光催化产H2O2的实验,结果表明p-P1CN/CQDs25仍具有一定的光催化活性,而p-P1CN却没有体现出光催化活性,这主要基于负载碳量子点的上转换性能。我们对不同的样品进行了H2O2(初始浓度为1.25 mmol L−1)的分解实验,结果表明所有样品均对H2O2表现出较弱的分解速率常数,这非常有利于复合物光催化生成H2O2。另外为了证明碱液超声法中使用氨水制备CQDs的优势,我们将不同条件制备的CQDs与p-CN复合,从图6结果可以看到,由氨水作为碱液制备得到的p-CN/CQDs25表现出明显优越的H2O2生成效率。
Claims (4)
1.一种可见光下不加牺牲剂高效生成过氧化氢的复合光催化剂的制备方法,其特征在于,包括如下步骤:
1)掺磷的多孔g-C3N4的合成
采用热聚合方法合成掺磷的多孔g-C3N4:将盐酸三聚氰胺与六氯三聚磷氰均匀混合,二者质量比为10:x,其中x取0.5~1.5;将混合物放在带盖的坩埚中,利用马弗炉在530~560℃下以3-10℃/min的加热速度煅烧3~5小时,得到的黄色粉末是磷掺杂的多孔g-C3N4,简称为p-PxCN,x代表六氯三聚磷氰的添加量;
2)碳量子点的合成
碱辅助超声法制备碳量子点:将葡萄糖均匀地溶解在去离子水中,然后加入浓度为1mol/L的氨水超声1.5~3小时,然后再持续搅拌6~9小时,葡萄糖溶液的浓度与氨水浓度比为0.5~1.5:1,且葡萄糖溶液和氨水体积比为2:1~1:2;加入盐酸将混合溶液调节到pH=7,并通过MWCO 3000半透膜进行透析,最后得到透明的棕色溶液,称为CQDs水溶液,储存在4℃的冰箱中备用;
3)复合光催化剂p-PxCN/CQDsy的合成
通过水热法将CQDs负载于p-PxCN上:在30~80ml去离子水中加入p-PxCN和CQDs溶液,比例关系为每克p-PxCN中加入20~30ml的CQDs溶液,在室温下搅拌4~10小时,之后将混合溶液转移到聚四氟乙烯内衬不锈钢高压釜中,在170~190℃下反应6~9小时,得到的样品简称为p-PxCN/CQDsy,其中y是CQDs溶液的添加量。
2.如权利要求1所述的可见光下不加牺牲剂高效生成过氧化氢的复合光催化剂的制备方法,其特征在于,步骤(1)中x取0.5、1、1.5;步骤(3)中y取值为20ml、25ml、30ml。
3.如权利要求2所述的可见光下不加牺牲剂高效生成过氧化氢的复合光催化剂的制备方法,其特征在于,x取1。
4.如权利要求3所述的可见光下不加牺牲剂高效生成过氧化氢的复合光催化剂的制备方法,其特征在于,步骤(1)中利用马弗炉在550℃下以5℃/min的加热速度煅烧3小时;步骤(2)中超声2小时,之后持续搅拌8小时;葡萄糖溶液的浓度与氨水浓度比为1:1,且葡萄糖溶液和氨水体积比为1:1;步骤(3)中混合溶液在室温下搅拌6小时,混合溶液转移到一个80mL的聚四氟乙烯内衬不锈钢高压釜中,在180℃下反应8小时,得到p-P1CN/CQDs20、p-P1CN/CQDs25和p-P1CN/CQDs30。
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