物理化学学报 >> 2025, Vol. 41 >> Issue (11): 100137.doi: 10.1016/j.actphy.2025.100137

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功函数工程调控Mo2C MXene的Mo 4d电子结构以提升光催化产氢效率

刘瑞云1, 王苹1,*(), 王雪飞1, 陈峰1, 余火根2,*()   

  1. 1 武汉理工大学化学化工与生命科学学院, 湖北 武汉 430070
    2 中国地质大学(武汉)材料与化学学院太阳能燃料实验室, 湖北 武汉 430074
  • 收稿日期:2025-06-29 修回日期:2025-07-22 录用日期:2025-07-24 发布日期:2025-09-29
  • 通讯作者: Email: wangping0904@whut.edu.cn (王苹)yuhuogen@cug.edu.cn (余火根)
  • 基金资助:
    国家自然科学基金(22472127); 国家自然科学基金(22178275); 国家自然科学基金(U22A20147); 湖北省自然科学基金(2022CFA001)

Work-function-engineered Mo 4d electronic structure modulation in Mo2C MXene cocatalyst for efficient photocatalytic H2 evolution

Ruiyun Liu1, Ping Wang1,*(), Xuefei Wang1, Feng Chen1, Huogen Yu2,*()   

  1. 1 School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, Hubei Province, China
    2 Laboratory of Solar Fuel, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, Hubei Province, China
  • Received:2025-06-29 Revised:2025-07-22 Accepted:2025-07-24 Published:2025-09-29
  • Contact: Email: wangping0904@whut.edu.cn (Ping Wang)yuhuogen@cug.edu.cn (Huogen Yu)
  • Supported by:
    the National Natural Science Foundation of China(22472127); the National Natural Science Foundation of China(22178275); the National Natural Science Foundation of China(U22A20147); the Natural Science Foundation of Hubei Province of China(2022CFA001)

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摘要：

Mo2C MXene(Mo2CTx)由于其表面Mo活性位点具有类Pt的电子结构在光催化中展现出优异的析氢潜力。然而，Mo2CTx中的Mo位点在析氢反应(HER)过程中通常表现出过强的H吸附能力，显著限制了Mo2CTx的本征催化活性。为了削弱Mo活性位点的H吸附能力，本论文通过功函数诱导效应原位构建MoC-Mo2C MXene异质结，实现了d轨道电子的调控。利用Co诱导的熔盐法将Mo2C MXene原位转化为MoC，随后通过简单的超声辅助方法与TiO2耦合，制备了MoC-Mo2CTx/TiO2光催化剂。光催化产氢测试表明，最优的MoC-Mo2CTx/TiO2样品实现了1886 μmol∙h−1∙g−1的产氢速率，分别是TiO2和Mo2CFx/TiO2(Mo2CFx通过常规蚀刻剂NH4F+HCl制备)的117.9倍和3.9倍。实验和理论计算证实，MoC与Mo2C MXene之间的功函数梯度诱导电子从MoC向Mo2C MXene转移，从而削弱了Mo2CTx助催化剂中Mo活性位点的H吸附能力，进而提升了其HER活性。该研究为原位构建基于Mo2C MXene的异质结以调控Mo活性位点的H吸附能力提供了一种新策略。

关键词: 光催化产氢, 助催化剂, Mo2C MXene, 异质结, d轨道调控

Abstract:

Mo2C MXene (Mo2CTx) exhibits exceptional hydrogen-evolution potential in photocatalysis due to the Pt-like electronic structure of surface Mo active sites. However, the Mo sites in Mo2CTx usually show excessively strong H-adsorption during HER, significantly limiting the intrinsic catalytic activity of Mo2CTx. To weaken the H-adsorption capacity of Mo active sites, a strategy of modulating d-orbital electron is implemented via in-situ constructing MoC-Mo2C MXene heterojunction by a work-function-induced effect. The MoC-Mo2CTx heterojunction was synthesized by in situ conversion of Mo2C MXene into MoC via a Co-induced molten salt method, followed by coupling with TiO2 through a simple ultrasonication-assisted method to prepare the MoC-Mo2CTx/TiO2 photocatalyst. Photocatalytic tests showed that the optimal MoC-Mo2CTx/TiO2 sample achieves an excellent hydrogen production rate of 1886 μmol∙h−1∙g−1, representing 117.9 and 3.9 fold enhancements over TiO2 and Mo2CFX/TiO2 (Mo2CF2 prepared by a conventional etchant NH4F+HCl), respectively. Experimental and theoretical calculations substantiate that the work-function gradient between MoC and Mo2C MXene induces electron transfer from MoC to Mo2C MXene to weaken the H-adsorption of Mo active sites in Mo2CTx cocatalyst, thereby enhancing its HER activity. This research provides a new strategy of in situ constructing Mo2C MXene-based heterojunction for adjusting the H-adsorption capacity of Mo active sites.

Key words: Photocatalytic H2 evolution, Cocatalyst, Mo2C MXene, Heterojunction, d-orbital modulation