Rational design of ternary NiS/CQDs/ZnIn_2S_4 nanocomposites as efficient noble-metal-free photocatalyst for hydrogen evolution under visible light  

三元NiS/CQDs/ZnIn_2S_4 光催化体系的合理设计及其产氢性能（英文）

作　　者：Bingqing Wang Yao Ding Zirong Deng Zhaohui Li 王冰清;丁瑶;邓子榕;李朝晖(福州大学化学学院能源与环境光催化国家重点实验室催化研究所,福建福州350116)

机构地区：[1]Research Institute of Photocatalysis, State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou350116, Fujian, China

出　　处：《Chinese Journal of Catalysis》2019年第3期335-342,共8页催化学报（英文）

基　　金：supported by the National Key Basic Research Program of China(973 Program,2014CB239303);the National Natural Science Foundation of China(21872031,U1705251);the Award Program for Minjiang Scholar Professorship~~

摘　　要：The NiS/CQDs nanocomposite (CQDs represents carbon quantum dots), with a mass ratio of NiS/CQDs to be 1.19:1 based on the ICP result, was obtained via a facile hydrothermal method from a mixture of CQDs, Ni(OAc)2 and Na2S. The self-assembly of ZnIn2S4 microspheres on the surface of NiS/CQDs was realized under microwave conditions to obtain a ternary NiS/CQDs/ZnIn2S4 nanocomposite. The as-obtained NiS/CQDs/ZnIn2S4 nanocomposite was fully characterized, and its photocatalytic hydrogen evolution under visible light irradiation was investigated. The ternary NiS/CQDs/ZnIn2S4 nanocomposite showed superior photocatalytic activity for hydrogen evolution than ternary CQDs/NiS/ZnIn2S4, which was obtained by deposition of NiS in the preformed CQDs/ZnIn2S4. The superior photocatalytic performance of ternary NiS/CQDs/ZnIn2S4 is ascribed to the introduction of CQDs, which act as a bridge to promote the vectorial transfer of photo-generated electrons from ZnIn2S4 to NiS. This result suggests that the rational design and fabrication of ternary CQDs-based systems are important for the efficient photocatalytic hydrogen evolution. This study provides a strategy for developing highly efficient noble-metal-free photocatalysts for hydrogen evolution using CQDs as a bridge to promote the charge transfer in the nanocomposite.氢气是一种清洁能源,利用半导体光催化技术将水转化成氢气是解决全球能源危机和环境污染问题的有效途径之一.开发高效的光催化体系以实现水分解产氢是目前能源领域中的一个研究热点.六方相的ZnIn_2S_4 是一种三元金属硫化物,因其具有能够吸收可见光的窄带隙(约2.4 eV)和良好的化学稳定性,在光催化产氢方面得到了较好应用.在半导体光催化产氢体系中,往往需要加入助催化剂来提供产氢活性位并降低产氢反应的过电位,这种半导体/助催化剂体系中光催化产氢效率不仅取决于助催化剂的组成和结构,还受二者界面之间光生电子传输效率的影响.我们课题组前期研究发现,NiS作为一种廉价的非贵金属助催化剂能够提高ZnIn_2S_4 在可见光下的光催化产氢活性.考虑到碳量子点(CQDs)是一种具有良好导电能力的纳米材料,并已被负载于半导体光催化剂上来促进半导体表面光生电子的传输,本文将CQDs作为光生电子传输的"桥梁"引入到NiS/ZnIn_2S_4 体系中,用来促进光生电子从ZnIn_2S_4 到NiS的定向传输,从而提高其光催化产氢效率.实验首先合成Ni S/CQDs复合材料,然后在其存在下进行ZnIn_2S_4 的自组装制得Ni S/CQDs/ZnIn_2S_4 .利用X射线粉末衍射、扫描电镜、透射电镜、傅立叶红外光谱、X射线光电子能谱和紫外-可见漫反射光谱对催化剂的组成、结构及光学性质进行了详细表征,考察了其在可见光下以三乙醇胺(TEOA)为牺牲剂时的光催化分解水产氢性能.结果表明,含有CQDs的NiS/CQDs/ZnIn_2S_4 光催化剂在光照5 h后的产氢总量达到142μmol,分别为相同条件下ZnIn_2S_4 和NiS/ZnIn_2S_4 产氢总量的5.5和1.6倍.相比于通过将Ni S沉积在预先合成的CQDs/ZnIn_2S_4 上所获得的CQDs/NiS/ZnIn_2S_4 光催化剂, NiS/CQDs/ZnIn_2S_4 显示出更优越的光催化产氢活性.TEM观测发现,在NiS/CQDs/ZnIn_2S_4 中CQDs与ZnIn_2S_4 和NiS均有明显�

关 键 词：Photocatalysis Hydrogen evolution NIS Carbon quantum dots ZnIn2S4 

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]