催化学报

催化学报 ›› 2020, Vol. 41 ›› Issue (1): 82-94.DOI: 10.1016/S1872-2067(19)63454-6

• 光催化产氢 • 上一篇    下一篇

ZIF-9(Co)衍生物磷化钴复合CeVO4协同高效产氢性能

张利君a,b,c, 郝旭强a,b,c, 李俊柯a,b,c, 汪远鹏a,b,c, 靳治良a,b,c   

  1. a 北方民族大学化学与化学工程学院, 宁夏银川 750021;
    b 北方民族大学国家民族事务委员会化学工程与技术重点实验室, 宁夏银川 750021;
    c 北方民族大学宁夏太阳能化学转化技术重点实验室, 宁夏银川 750021
  • 收稿日期:2019-06-16 修回日期:2019-07-12 出版日期:2020-01-18 发布日期:2019-10-22
  • 通讯作者: 靳治良, 郝旭强
  • 基金资助:
    国家自然科学基金（21862002，41663012）；北方民族大学研究生创新项目（YCX19113）；北方民族大学重大科研项目（ZDZX201803）.

Unique synergistic effects of ZIF-9(Co)-derived cobalt phosphide and CeVO4 heterojunction for efficient hydrogen evolution

Lijun Zhanga,b,c, Xuqiang Haoa,b,c, Junke Lia,b,c, Yuanpeng Wanga,b,c, Zhiliang Jina,b,c   

  1. a School of Chemistry and Chemical Engineering, North Minzu University, Yinchuan 750021, Ningxia, China;
    b Key Laboratory for Chemical Engineering and Technology, State Ethnic Affairs Commission, North Minzu University, Yinchuan 750021, Ningxia, China;
    c Ningxia Key Laboratory of Solar Chemical Conversion Technology, North Minzu University, Yinchuan 750021, Ningxia, China
  • Received:2019-06-16 Revised:2019-07-12 Online:2020-01-18 Published:2019-10-22
  • Supported by:
    This work was financially supported by the National Natural Science Foundation of China (21862002, 41663012), the Graduate Innovation Project of the North Minzu University (YCX19113), the new technology and system for clean energy catalytic production, and Major scientific project of North Minzu University (ZDZX201803).

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摘要： 众所周知，太阳能是一种清洁，可持续的能源.如何更有效地利用太阳能来解决人类面临的能源和环境问题已成为近几十年来科研工作者们的研究热点.半导体光催化技术被认为是人工光合作用的主要发现.光催化技术是解决日益严重的能源短缺和环境污染问题的有效途径，越来越受到人们的关注.氢作为理想的清洁能源，具有燃烧价值高，无污染的优点.光催化制氢技术的应用是最具发展性的制氢方法之一.因此，有效光催化剂的设计和开发显得十分重要.
由于光催化析氢反应（HER）主要是半反应，因此必须引入牺牲试剂.同时，光敏剂的存在加速了光催化剂对光的吸收.在这种情况下研究光催化材料的结构和性质之间的关系至关重要，它能指导人们开发低成本，高稳定性，高活性的析氢光催化剂.本文首次成功地合成了以ZIF-9（Co-MOFs）作为前驱体的CoP纳米粒子，并通过简单的化学沉淀法制备了CeVO4光催化剂.深入研究了CoP，CeVO4及其复合催化剂的光催化制氢性能.发现CoP/CeVO4复合催化剂在染料敏化条件下表现出优异的光催化活性.当CoP和CeVO4结合质量比为1：1时，所得样品V1C1的复合光催化活性对于析氢最佳，在5h内氢产生量达到444.6μmol.由于CeVO4和CoP偶联是一步完成.CeVO4牢固地粘附在CoP颗粒的表面上，形成“小点”到“大点”异质结.XRD，XPS，SEM，EDX和TEM的结果显示，CoP和CeVO4纳米颗粒的形成和复合物的结构.基于对Mott-Schottky曲线，UV-vis漫射光谱，光电流-时间曲线，Tafel曲线，奈奎斯特曲线，线性伏安曲线和稳态/瞬态荧光测量结果表明，CoP/CeVO4高效析氢的原因是CoP和CeVO4复合后存在肖特基势垒，导致能带发生弯曲，并且CoP与CeVO4之间异质结所形成的内建电场能加速电荷转移.此外，CoP和CeVO4之间独特的协同效应为彼此提供了新的析氢活性中心.提高了载流子分离效率，降低了光生载流子复合率.因此，CoP/CeVO4复合催化剂具有优异的光催化析氢活性.本文为过渡金属磷化物光催化剂的电子结构和载流子行为的调控提供了新的策略.

关键词: 光催化, CoP, CeVO4, 染料敏化, 产氢

Abstract: The photocatalytic decomposition of water to produce hydrogen is an important process, through which solar energy can be converted to chemical energy. Non-precious metal phosphides have quietly attracted attention as an emerging inexpensive photocatalyst. In this study, we reported that a CoP/CeVO4 hybrid photocatalyst exhibited high hydrogen evolution efficiency owing to EY (eosin Y) sensitization under visible light irradiation for the first time, and the amount of generated hydrogen reached 444.6 μmol in 5 h. The CoP/CeVO4 nanohybrids were synthesized by a simple chemical precipitation method. The coupling of CoP and CeVO4 with ZIF-9 as a precursor could be completed in one step. The CeVO4 particles were firmly attached to the surface of the CoP particles to form a "small point" to "big point" heterojunction. The results of X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, EDX, and transmission electron microscopy showed the formation of CoP and CeVO4 nanoparticles and the structure of the composite. Based on a detailed analysis of the Mott-Schottky plot, the UV-vis diffuse reflectance spectra, photocurrent-time (it) curve, Tafel curve, Nyquist curve (EIS), linear volt-ampere curve (LSV), and steady-state fluorescence spectra were studied. The time-resolved photoluminescence measurements indicated that the reason for the high-efficiency hydrogen evolution of CoP/CeVO4 was that the bands of CoP and CeVO4 were bent due to the existence of the Schottky barrier, and a heterojunction was formed between CoP and CeVO4, which generated an internal electric field and accelerated the charge transfer. In addition, the synergistic effect between CoP and CeVO4 provided a new hydrogen-evolution activity center for each of them. The improved carrier separation efficiency and the decrease in the photo-generated recombination rate led to the excellent photocatalytic hydrogen-evolution activity of the CoP/CeVO4 composite catalyst. This work provides a new strategy for modulating the electronic structure and carrier behavior of transition metal phosphide photocatalysts.

Key words: Photocatalysis, CoP, CeVO4, Dye-sensitized, Hydrogen production