BiOI/Bi₂MoO₆ p-n Junction to Enhance Visible Light Photocatalytic Activity toward Environmental Remediation

Photocatalytic degradation of organic pollutants via semiconductors with high visible light response and effective carrier separation is an economical and green route to greatly achieve environmental remediation. Herein, an efficient BiOI/Bi₂MoO₆ p-n heterojunction was in situ fabricated through hydrothermal method by substituting Mo₇O₂₄^6- species for I ions. The characteristic p-n heterojunction exhibited a strongly enhanced visible light responsive absorption from 500 to 700 nm owing to the narrow band gap of BiOI and a greatly effective separation of photoexcited carriers because of the built-in electric field on the interface between BiOI and Bi₂MoO₆. Moreover, the flower-like microstructure also promoted the adsorption of organic pollutants owing to the large surface area (about 10.36 m²/g), good for further photocatalytic degradation. As a result, BiOI/Bi₂MoO₆ p-n heterojunction showed an excellent photocatalytic activity of RhB of almost 95% in a short time of 90 min under wavelength longer than 420 nm, 2.3 and 2.7 times higher compared with single BiOI and Bi₂MoO₆, respectively. This work offers a promising approach to purify the environment through the utilization of solar energy by constructing efficient p-n junction photocatalysts.