Synthesis of Z-scheme Bi/TiO₂/WO₃·0.33H₂O heterojunction material for the enhanced photocatalytic degradation of pollutants

In this work, Bi spheres were deposited on bulk WO₃·0.33H₂O and TiO₂ (P25) nanoparticles to form Z-scheme Bi/TiO₂/WO₃·0.33H₂O heterojunction material for the first time by a simple hydrothermal method. The as-prepared materials were comprehensively characterized by XRD, XPS, SEM, TEM, UV–Vis DRS, BET surface area, EIS, and Mott-Schottky analysis. The ternary Bi/TiO₂/WO₃·0.33H₂O composites exhibited superior degradation efficiency for RhB than pure WO₃·0.33H₂O, TiO₂ (P25), and their binary composites. The degradation rate reached 99.84% after 30 min under simulated sunlight. The enhancement of photocatalytic activity could be attributed to the Z-scheme heterojunction system with metal Bi as an electronic medium, which greatly enhanced the efficiency of charge separation. This report demonstrated that Z-scheme Bi/TiO₂/WO₃·0.33H₂O heterojunction photocatalytic material has potential application value in dye wastewater treatment.