Synergistic defect engineering and cocatalyst loading in a Bi2MoO6-OVs/MoS2 photoanode for efficient power generation in H2O2 photoelectrochemical cells

Abstract

The integration of solar energy conversion and storage systems offers a promising approach to address the intermittency of sunlight, yet their performance is often limited by insufficient light absorption and rapid charge recombination in photoelectrode materials. Herein, we propose a novel dual-functional modification strategy through the synergistic combination of oxygen vacancy (OV) engineering and MoS₂ cocatalyst loading on Bi₂MoO₆ to construct a highly efficient H₂O₂ photoelectrochemical cell. The Bi₂MoO₆-OVs/MoS₂ photoanode, prepared via a facile solvothermal and photo-deposition method, exhibits significantly enhanced visible-light absorption and charge separation efficiency. OVs serve as electron bridges facilitating electron transfer from Bi₂MoO₆ to anchored MoS₂ clusters, while MoS₂ acts as an effective electron reservoir. Coupled with a cornstalk-derived porous carbon/iron phthalocyanine (CSPC/Fe^IIPc) cathode, the cell achieves an exceptional H₂O₂ yield of 0.051 M and a maximum power density of 4.94 mW cm⁻² under simulated sunlight. Moreover, the system demonstrates remarkable energy storage capability with a specific capacitance of 90.71 F cm⁻² and retains 55% of its initial capacity after 12 h of dark operation. This work highlights the effectiveness of a rational dual-functional modification strategy in advancing photoelectrochemical systems for simultaneous solar energy harvesting, fuel production, and on-demand electricity generation.