Three-dimensional bismuth oxide/red phosphorus heterojunction composite with enhanced photoreduction activity

In order to solve the problems of easy recombination of carriers and low efficiency of photocatalysis in red phosphorus photocatalyst, Bi2O3/HRP heterostructure composite photocatalyst was prepared by hydrothermal method. Cr(VI) was selected as the model contaminant to investigate the photoreduction activity of the photocatalysts. The experimental results revealed that the composite photocatalyst obtained at 3% Bi2O3 mass fraction (3%Bi2O3/HRP) exhibited the strongest photoreduction ability, and its rate constant was 14.9 and 50 times that of pure HRP and Bi2O3. The photoelectric conversion efficiency of the photocatalyst improved, which was illuminated by the high current density (16.7 and 42 times higher than that of HRP and Bi2O3) and the heterogeneous interface that facilitated charge transfer and separation. On the basis of the matched band structure of Bi2O3 and HRP, Bi2O3 with wide band gap (E-g) is introduced into HRP with narrow E-g to form a heterojunction structure, which provides an effective strategy to promote space charge separation and transfer.