Constructing low-cost Ni3C/twin-crystal Zn0.5Cd0.5S heterojunction/homojunction nanohybrids for efficient photocatalytic H2 evolution  

构建低成本的Ni3C/孪晶Zn0.5Cd0.5S异质结/同质结纳米杂化体系来实现高效的光催化分解水产氢

作　　者：Rongchen Shen Yingna Ding Shibang Li Peng Zhang Quanjun Xiang Yun Hau Ng Xin Li 沈荣晨;丁英娜;李世邦;张鹏;向全军;吴永豪;李鑫(华南农业大学林学与风景园林学院,农业部能源植物资源与利用重点实验室,广东广州510642;华南农业大学材料与能源学院,广东广州510642;郑州大学材料与工程学院,低碳环保材料智能设计国际联合研究中心,河南郑州450001;电子科技大学电子薄膜与集成器件国家重点实验室,四川成都610054;香港城市大学能源与环境学院,中国香港)

机构地区：[1]College of Forestry and Landscape Architecture,Key Laboratory of Energy Plants Resource and Utilization,Ministry of Agriculture,South China Agricultural University,Guangzhou 510642,Guangdong,China [2]College of Materials and Energy,South China Agricultural University,Guangzhou 510642,Guangdong,China [3]State Center for International Cooperation on Designer Low-Carbon&Environmental Materials(CDLCEM),School of Materials Science and Engineering,Zhengzhou University,Zhengzhou 450001,Henan,China [4]State Key Laboratory of Electronic Thin Film and Integrated Devices,University of Electronic Science and Technology of China,Chengdu 610054,Sichuan,China [5]School of Energy and Environment,City University of Hong Kong,Hong Kong SAR

出　　处：《Chinese Journal of Catalysis》2021年第1期25-36,共12页催化学报（英文）

基　　金：国家自然科学基金(21975084,51672089);广东省重大科技研发计划(2017B020238005);武汉理工大学材料复合新技术国家重点实验室(2015-KF-7);香港研究资助局-优配研究金(GRF13054).

摘　　要：The development of low-cost semiconductor photocatalysts for highly efficient and durable photocatalytic H2 evolution under visible light is very challenging.In this study,we combine low-cost metallic Ni3C cocatalysts with twin nanocrystal Zn0.5Cd0.5S(ZCS)solid solution homojunctions for an efficient visible-light-driven H2 production by a simple approach.As-synthesized Zn0.5Cd0.5S-1%Ni3C(ZCS-1)heterojunction/homojunction nanohybrid exhibited the highest photocatalytic H2-evolution rate of 783μmol h‒1 under visible light,which is 2.88 times higher than that of pristine twin nanocrystal ZCS solid solution.The apparent quantum efficiencies of ZCS and ZCS-1 are measured to be 6.13%and 19.25%at 420 nm,respectively.Specifically,the homojunctions between the zinc blende and wurtzite segments in twin nanocrystal ZCS solid solution can significantly improve the light absorption and separation of photogenerated electron-hole pairs.Furthermore,the heterojunction between ZCS and metallic Ni3C NP cocatalysts can efficiently trap excited electrons from ZCS solid solution and enhance the H2-evolution kinetics at the surface for improving catalytic activity.This study demonstrates a unique one-step strategy for constructing heterojunction/homojunction hybrid nanostructures for a more efficient photocatalytic H2 evolution compared to other noble metal photocatalytic systems.开发低成本的半导体光催化剂以实现可见光下高效、持久的光催化分解水产氢化是一个非常具有挑战性的课题.近年来,具有孪晶结构的ZnxCd1-xS(ZCS)固溶体引起了人们的研究兴趣,这主要是由于孪晶相之间形成了同质结,同质结可以通过提高体相光生电子-空穴对的分离效率,从而提高原始硫化物光催化剂的光催化分解水产氢活性.但由于孪晶ZCS固溶体表面超快载流子复合以及活性位点不足,进一步提高其光催化析氢活性还需解决这些不足.负载助催化剂被认为是加速产氢动力学和促进表面光生电子空穴分离最有效策略之一.因此,我们将低成本的类金属Ni3C助催化剂与孪晶ZCS固溶体通过简单的研磨方法结合来实现高效的可见光催化分解水产氢.合成的Zn0.5Cd0.5S-1%Ni3C(ZCS-1)异质结/同质结最高的可见光光催化分解水产氢速率可达783μmol h–1,是纯ZCS的2.88倍.在420 nm时,ZCS和ZCS-1的表观量子效率分别为6.13%和19.25%.这是由于孪晶ZCS固溶体中闪锌矿段和纤锌矿段的同质结连接可以显著提高光生电子空穴对的体相转移和分离.同时,ZCS与金属Ni3C助催化剂间的异质结可以有效地增加孪晶ZCS固溶体的光捕获及表面载流子分离,增强产氢活性位,从而提高催化活性.本文以乙酸镉、乙酸锌和氢氧化钠为原料合成了CdZn(OH),后者与硫代乙酰胺水热合成了孪晶CZS,并用超声研磨方法合成CZS-Ni3C.在可见光下进行了产氢测试,实验结果证实了优化的ZCS-1在Na2S·9H2O和Na2SO3的水溶液中光催化析氢活性最高.经过4次连续的循环反应,ZCS-1二元复合体系展现出良好的稳定性.为深入探讨高效产氢机制,对纳米级ZCS复合材料的光催化物化性能及载流子分离机制进行了表征.通过X射线衍射确定了ZCS和ZCS-1的晶体结构.用高分辨电子显微镜和X射线光电子能谱证实合成了ZCS和Ni3C助催化剂的成功复合.用紫外-可见漫�

关 键 词：Photocatalytic H2 evolution Zn0.5Cd0.5S solid solution Twin nanocrystal Heterojunction/homojunction Earth-abundant Ni3C cocatalysts 

分 类 号：TQ116.2[化学工程—无机化工] O643.36[理学—物理化学] O644.1[理学—化学]