催化学报 ›› 2025, Vol. 74: 294-307.DOI: 10.1016/S1872-2067(25)64690-0

• 论文 • 上一篇    下一篇

自定义暴露晶面: 最佳晶面各向异性和欧姆异质结的协同效应促进光催化析氢

周正宇, 靳治良*()   

  1. 北方民族大学化学与化学工程学院, 宁夏太阳能化学转化技术重点实验室, 国家民委化工技术基础重点实验室, 宁夏银川 750021
  • 收稿日期:2025-02-08 接受日期:2025-03-10 出版日期:2025-07-18 发布日期:2025-07-20
  • 通讯作者: *电子信箱: zl-jin@nun.edu.cn (靳治良).
  • 基金资助:
    宁夏自然科学基金重点项目(2023AAC02046)

Custom exposed crystal facets: Synergistic effect of optimum crystal facet anisotropy and Ohmic heterojunction boosting photocatalytic hydrogen evolution

Zhengyu Zhou, Zhiliang Jin*()   

  1. School of Chemistry and Chemical Engineering, Ningxia Key Laboratory of Solar Chemical Conversion Technology, Key Laboratory for Chemical Engineering and Technology, State Ethnic Affairs Commission, North Minzu University, Yinchuan 750021, Ningxia, China
  • Received:2025-02-08 Accepted:2025-03-10 Online:2025-07-18 Published:2025-07-20
  • Contact: *E-mail: zl-jin@nun.edu.cn (Z. L. Jin).
  • Supported by:
    Ningxia Hui Autonomous Region Natural Science Foundation Project(2023AAC02046)

摘要:

过渡金属硫化物如Cd0.5Zn0.5S (CZS)固溶体, 由于能带可调和光生载流子的高效分离而备受关注. 近年来, 利用掺杂、空位工程和异质结构设计等策略来提高光催化性能的研究得到了广泛的关注. 通过调控暴露晶面来获得最佳的晶面各向异性, 是提高异质结的光催化活性的有效的手段之一. 虽然传统的异质结构可以在一定程度上提高光生载流子的分离效率, 但在异质结形成过程中, 两种材料的暴露晶体面不能很好协同, 导致异质结界面表现出不理想的晶面各向异性. 如果在异质结构建时预先调节光催化剂的暴露晶面(即构建自定义晶面异质结)可以使不同材料之间最佳的晶面相互作用, 从而提升光催化效率.

本文采用溶剂热法和煅烧法分别合成了暴露(111)晶面的六边形Co3O4、暴露(110)晶面的棒状Co3O4和暴露(100)晶面的立方体形Co3O4 (分别命名为HCO, NCO和CCO), 并成功与Cd0.5Zn0.5S (CZS)偶联. 在这些复合材料中, HCOCZS20表现出最佳的析氢活性. 在5 h内, HCOCZS20的析氢总量分别是CZS和HCO的209.12倍和6.20倍, 明显高于NCOCZS20和CCOCZS20. 结合密度泛函理论计算和飞秒瞬态吸收光谱分析发现, HCO与CZS之间的晶面相互作用使该复合催化剂在晶面载流子输运、晶面反应活性位点和晶面电子结构等方面表现出较好的各向异性. 这种相互作用诱导电子在CZS和HCO接触界面处重新排布, 从而建立了由HCO指向CZS的内建电场(IEF), 促进了HCO和CZS之间欧姆异质结的形成. 当CZS和HCO接触时, 由于费米能级的差异, 界面处的电子将从HCO向CZS转移, 直至达到费米能级平衡. 在光照条件下, IEF的存在有利于光生电子从CZS的CB向HCO迁移, 而保留在VB上的空穴则被牺牲试剂有效消除. HCO上的光生电子向催化剂表面迁移参与水的还原反应. 欧姆异质结和异质结晶面各向异性的协同作用不仅显著的降低了氢吸附的吉布斯自由能, 而且促进了电子-空穴对的高效空间分离和快速转移.

综上, 调控光催化剂暴露的晶面并构建特定的晶面异质结能有效提升光催化剂的光催化活性. 本研究为定制晶面异质结提供了一种思路, 即异质结晶面之间的各向异性相互作用可以有效增强光催化析氢.

关键词: 晶面异质结, 晶面相互作用, 欧姆异质结, 各向异性, 光催化制氢

Abstract:

The design of customized crystal plane heterojunction can effectively leverage the optimal anisotropic interaction of crystal plane, thereby enhancing photocatalytic activity. In this study, Co3O4 exposed (111), (110), and (100) crystal planes (designated as HCO, NCO, and CCO, respectively) were synthesized and successfully coupled with Cd0.5Zn0.5S (CZS). Among these composites, the HCO/CZS exhibited best hydrogen evolution activity. In conjunction with DFT calculations and femtosecond transient absorption spectroscopy, it has been found that: the crystal plane interaction between HCO and CZS enabled the composite catalyst to exhibit optimal anisotropy in crystal plane carrier transport, crystal plane active sites, and crystal plane electronic structure. This interaction induces a redistribution of electrons at their contact interface, thereby establishing a built-in electric field that facilitates the formation of ohmic heterojunction between HCO and CZS. The synergistic effect of the ohmic heterojunction and crystal plane anisotropy not only decreases the Gibbs free energy of hydrogen adsorption but also facilitates the efficient spatial separation and rapid transfer of electron-hole pairs. This study offers valuable insights into the customization of crystal plane heterojunctions, aiming to maximize anisotropic interactions between crystal planes in order to enhance photocatalytic hydrogen evolution.

Key words: Crystal plane heterojunction, Crystal plane interaction, Ohmic heterojunction, Crystal plane anisotropy, Photocatalytic hydrogen evolution