Ultrafine Bi3TaO7 Nanodot-Decorated V, N Codoped TiO2 Nanoblocks for Visible-Light Photocatalytic Activity: Interfacial Effect and Mechanism Insight

Bi3TaO7 is a potential photocatalyst because of its high chemical stability, defective fluorite-type structure, and superior mobility of photoinduced holes. However, few studies have focused on the interfacial effects of Bi3TaO7-based photocatalysts. In this work, 0D Bi3TaO7 nanodot-hybridized 3D V and N codoped TiO2 nanoblock (B/VNT) composites were first synthesized for the photocatalytic removal of oxytetracycline hydrochloride, 2,4,6-trichlorophenol, and tetrabromobisphenol A. The fabricated B/VNT had a photocatalytic performance superior to that of pristine components, and probable degradation pathways were proposed according to the primary intermediates identified by a gas chromatography–mass spectrometer. Interestingly, on B/VNT, the transfer of interfacial electrons was observed from V/N–TiO2 to Bi3TaO7, and the formed built-in electronic field led to a direct Z-scheme structure, rather than type II, as confirmed by the generated •OH and •O2– radicals and band structures from the density functional theory calculation. Therefore, the strong interfacial electronic interaction on the B/VNT was significant, which drove faster photogenerated charge transfer, more visible-light adsorption, and active •OH and •O2– generation, thus improving the photocatalytic activity.