Tantalates-based solid acid modified Bi°-BiVO4 for synergistic reduction of aromatic nitrobenzene with a significant enhancement effect

In view of the environmental pollution and human health risks posed by nitrobenzene compounds in pesticide and pharmaceutical industry waste, a novel tantalate-based solid acid modified Bi°-BiVO₄ was successfully prepared via in-situ reduction method, with the goal of enhancing multi-active site synergy and clarifying the catalytic reduction mechanism. Crystal phase and morphology analysis revealed that nano-octahedral H₂Ta₂O₆ was uniformly dispersed on the BiVO₄ surface, creating multiple active sites. This facilitated efficient reactant interactions and enabled rapid interfacial electron transfer to p-nitrophenol (PNP). The H₂Ta₂O₆/Bi°-BiVO₄ catalyst was able to reduce PNP completely in 3 min with kinetic constant of 686.88 min⁻¹g⁻¹, which significantly exceeds the values from the pure BiVO₄ catalyst, Bi and H₂Ta₂O₆. Furthermore, the catalyst demonstrated excellent cycling stability. Density functional theory (DFT) calculations were employed to investigate the reaction mechanism of PNP reduction. The results indicate that the structural H species in tantalate-based solid acids facilitate the catalytic reduction process and each unit active sites exhibiting synergistic effects. This study provides a viable basis for understanding semiconductor-catalyzed PNP reduction mechanisms.