Engineering a non-noble plasmonic center in MOF-derived Z-scheme heterojunctions for enhanced photoelectrochemical water splitting

Abstract

Photoelectrochemical (PEC) water splitting is a promising strategy to convert solar power into clean hydrogen energy. However, the poor bulk charge-separation ability and sluggish oxygen evolution dynamics of the photoanodes severely limit the PEC catalytic performance. Herein, a plasmonic perovskite oxide (reduced SrTiO₃, R-STO) is synthesized via the in situ derivation of Ti-metal–organic frameworks (NH₂-MIL-125) and further oxygen-vacancy engineering. Finite-difference time-domain (FDTD) and density functional theory (DFT) calculations forcefully evidence the metallic properties and plasmonic characteristics of the MOF-derived R-STO. Then, a plasmon-promoted direct Z-scheme photoanode (TiO₂@NH₂-MIL-125@R-STO) is designed, which exhibits high PEC water oxidation performance due to the synergistic effect of the MOF-based Z-scheme arrangement and the surface plasmon resonance (SPR) of the non-noble R-STO. This work proposes a new method for the design of high-efficiency PEC nanomaterials.