Interfacial regulation of Bi2MoO6@B-TiO2 three-dimensional extended heterojunction photoelectrode and its photoelectrocatalytic water purification performance

A 3D Bi 2 MoO 6 @Black-TiO 2 heterojunction photoelectrode was successfully fabricated. • Interfacial regulation induces Type-II band alignment and a built-in electric field. • Enhanced charge separation promotes generation of •OH and 1 O 2 reactive species. • The optimized electrode achieves 92.3% PEC degradation of KN-R dye. A Bi 2 MoO 6 @B-TiO 2 composite photoelectrode was successfully fabricated via a sequential hydrothermal-hydrogenation-solvothermal process. The three-dimensional network architecture constructed from ultrathin Bi 2 MoO 6 nanosheets and black-TiO 2 (B-TiO 2 ) nanowire arrays achieves uniform interfacial chemical distribution, integrating the merits of each component and endowing the electrode with low charge‑transfer resistance, favorable charge‑transport kinetics, and more accessible electroactive sites for PEC reactions. Band structure analysis suggests the possible formation of a Type-II heterojunction between B-TiO 2 and Bi 2 MoO 6 . Upon photoexcitation, this heterojunction can drive the migration of photogenerated electrons from Bi 2 MoO 6 to B-TiO 2 and holes in the opposite direction, effectively suppressing charge carrier recombination while promoting the generation of dominant reactive species such as •OH and ¹O₂. In photoelectrocatalytic degradation experiments of reactive brilliant blue KN-R, the optimized electrode achieves a removal rate of 92.3%, significantly higher than the sum of its photocatalytic and electrocatalytic performances, and maintains 78.9% activity after five cycles. This work provides a feasible interfacial regulation strategy for constructing high-performance photoelectrodes. Download: Download high-res image (324KB) Download: Download full-size image