催化学报 ›› 2022, Vol. 43 ›› Issue (2): 339-349.DOI: 10.1016/S1872-2067(21)63875-5

• 论文 • 上一篇    下一篇

1D/2D TiO2/ZnIn2S4 S型异质结光催化剂及其高效制氢性能

李金懋a,b, 吴聪聪a, 李矜a,$(), 董兵海a, 赵丽a,*(), 王世敏a,#()   

  1. a湖北大学材料科学与工程学院, 有机化工新材料省部共建协同创新中心, 功能材料绿色制备与应用教育部重点实验室, 湖北武汉 430062
    b湖北师范大学化学化工学院, 污染物分析与资源化技术湖北省重点实验室,湖北黄石 435002
  • 收稿日期:2021-05-02 接受日期:2021-06-10 出版日期:2022-02-18 发布日期:2021-07-02
  • 通讯作者: 李矜,赵丽,王世敏
  • 基金资助:
    国家重点研发计划政府间国际科技创新合作重点专项(2019YFE0107100);国家自然科学基金(52002121);国家自然科学基金(62004064)

1D/2D TiO2/ZnIn2S4 S-scheme heterojunction photocatalyst for efficient hydrogen evolution

Jinmao Lia,b, Congcong Wua, Jin Lia,$(), Binghai Donga, Li Zhaoa,*(), Shimin Wanga,#()   

  1. aCollaborative Innovation Center for Advanced Organic Chemical Materials Co-constructed by the Province and Ministry, Ministry-of-Education Key Laboratory for the Green Preparation and Application of Functional Materials, School of Materials Science and Engineering, Hubei University, Wuhan 430062, Hubei, China
    bHubei Key Laboratory of Pollutant Analysis and Reuse Technology, College of Chemistry and Chemical Engineering, Hubei Normal University, Huangshi 435002, Hubei, China
  • Received:2021-05-02 Accepted:2021-06-10 Online:2022-02-18 Published:2021-07-02
  • Contact: Jin Li, Li Zhao, Shimin Wang
  • Supported by:
    This work was supported by Key Program for Intergovernmental S&T Innovation Cooperation Projects of National Key R&D Program of China(2019YFE0107100);the National Natural Science Foundation of China(52002121);the National Natural Science Foundation of China(62004064)

摘要:

通过半导体催化剂利用太阳能分解水制氢被认为是解决人类面临的环境问题和能源危机的有效途径. 在众多的半导体光催化剂中, TiO2由于其良好的光化学稳定性、无毒性、丰富的形貌以及低廉的价格, 在光催化制氢领域备受关注. 然而TiO2的内在缺陷, 如较宽的带隙、较窄的光响应范围, 光生电子空穴对的快速复合, 极大限制了其太阳能制氢效率. 构建异质结结构被认为是解决以上问题的一个有效方法, 通过将TiO2与另一个半导体复合可以提升催化剂对太阳光的吸收范围, 也可降低光生电子空穴对的复合速率. 但构建一个成功的异质结结构不仅要满足上述的要求, 还需要保留异质结催化剂体系中光生电子和空穴的氧化还原能力.
研究表明, S型异质结是将两个具有合适能带结构的半导体进行耦合, 由于费米能级的差异, 两个半导体间将发生电子转移, 从而引起能带弯曲并形成内建电场. 光照条件下, 具有较弱还原能力的光生电子在内建电场和能带弯曲的作用下与较弱氧化能力的光生空穴复合, 实现异质结催化剂体系中各个半导体内部光生载流子有效分离的目标, 同时保留了异质结催化剂体系中较强氧化能力和较强还原能力的光生电子和空穴, 进而实现光催化活性的提高.
本文采用水热合成方法, 将具有更强还原能力和可见光响应特性的半导体(ZnIn2S4)原位生长在TiO2纳米纤维表面, 构建了1D/2D TiO2/ZnIn2S4 S型异质结光催化剂. 最优比例的TiO2/ZnIn2S4复合材料表现出优越的光催化制氢活性(6.03 mmol/h/g), 分别是纯TiO2和纯ZnIn2S4制氢活性的3.7倍和2倍. TiO2/ZnIn2S4复合材料光催化活性的提高可以归因于紧密的异质结界面、光生载流子的有效分离、丰富的反应活性位点以及增强的光吸收能力. 通过原位XPS和DFT计算研究了异质结内部光生电子的转移机制. 结果表明, 在光照条件下电子由TiO2向ZnIn2S4迁移, 遵循了S型异质结内部电子的转移机制, 实现了TiO2和ZnIn2S4内部光生载流子的有效分离, 同时保留了具有较强还原能力的ZnIn2S4价带电子和较强氧化能力的TiO2导带空穴, 从而显著提升光催化制氢效率. 综上, 本文制备的TiO2/ZnIn2S4 S型异质结光催化剂很好地克服了TiO2在光催化制氢领域所面临的诸多障碍, 为设计和制备高效异质结光催化剂提供了新的思路.

关键词: S型异质结, TiO2, ZnIn2S4, 1D/2D, 光催化产氢

Abstract:

TiO2 is a promising photocatalyst with limited use in practical applications owing to its wide bandgap, narrow light response range, and rapid recombination of photoexcited carriers. To address these limitations, a novel 1D/2D TiO2/ZnIn2S4 heterostructure was designed according to the principles of the S-scheme heterojunction. The TiO2/ZnIn2S4 (TZISx) hybrids prepared via a hydrothermal method afforded significant improvement in photocatalytic hydrogen evolution (PHE) in comparison to pristine TiO2 and ZnIn2S4. In particular, the optimal TZIS2 sample (mass ratio of ZnIn2S4 to TiO2 was 0.4) exhibited the highest PHE activity (6.03 mmol/h/g), which was approximately 3.7 and 2.0 times higher than those of pristine TiO2 and ZnIn2S4, respectively. This improvement in the PHE of the TZIS2 sample could be attributed to the formation of an intimate heterojunction interface, high-efficiency separation of charge carriers, abundant reactive sites, and enhanced light absorption capacity. Notably, theoretical and experimental results demonstrated that the S-scheme mechanism of interfacial electron transfer in the TZISx composites facilitated the transfer and separation of photoexcited charge carriers, resulting in more isolated photoexcited electrons for the PHE reaction.

Key words: S-scheme heterojunction, TiO2, ZnIn2S4, 1D/2D, Photocatalytic hydrogen evolution