Acta Phys. -Chim. Sin. ›› 2025, Vol. 41 ›› Issue (11): 100137.doi: 10.1016/j.actphy.2025.100137

• ARTICLE • Previous Articles     Next Articles

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)

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