Overlayer‐Engineered BiVO ₄ Suppresses H ₂ O ₂ Decomposition to Enable Sustained Photocatalytic Production

Abstract

ABSTRACT Inorganic semiconductor photocatalysts are highly promising for hydrogen peroxide (H 2 O 2 ) production due to their inherent robustness against radical oxidation. However, the rapid surface‐mediated decomposition of H 2 O 2 in pure water remains a critical bottleneck for sustained production. This study demonstrates that an amorphous metal oxide overlayer strategy can effectively suppress H 2 O 2 decomposition on Mo‐doped BiVO 4 (BiVO 4 :Mo) photocatalyst, enabling enhanced and sustained H 2 O 2 production. It is revealed that an amorphous TiO 2 thin layer on BiVO 4 :Mo not only weakens H 2 O 2 adsorption but also inhibits the activation of adsorbed H 2 O 2 molecules, leading to a decrease in the decomposition rate constant to only ∼13% of its pristine counterpart. Meanwhile, the amorphous TiO 2 overlayer maintains the photocatalytic activities for two‐electron oxygen reduction and four‐hole water oxidation by enabling effective charge transfer while remaining permeable to water and oxygen. Consequently, the Au/TiO 2 /BiVO 4 :Mo photocatalyst achieves a threefold increase in the yield compared to the unmodified Au/BiVO 4 :Mo. Furthermore, the effectiveness of other amorphous metal oxides, such as SiO 2 and Nb 2 O 5 , underscores the universality of this amorphous overlayer strategy. This work provides a general method for sustained H 2 O 2 production over BiVO 4 photocatalysts, offering broad potential for efficient solar energy conversion.