Green and controllable synthesis of one-dimensional Bi2O3/BiOI heterojunction for highly efficient visible-light-driven photocatalytic reduction of Cr(VI).

BiOI nanosheets have been successfully deposited on the porous Bi2O3 nanorobs via a one-pot precipitation method. The physicochemical features of the as-prepared materials were characterized in detail by a series of techniques, and the results revealed that BiOI nanosheets were evenly distributed on the porous Bi2O3 nanorobs. Because of higher photogenerated electron-hole pairs separation efficiency and the larger specific surface area compared to the pristine Bi2O3 and BiOI, the 50%Bi2O3/BiOI composite exhibited significantly enhanced photocatalytic activity for Cr(VI) reduction under visible light irradiation, and the reduction rate constant was 0.02002 min-1, which was about 27.4 and 2.6 times higher than that of pure Bi2O3 (0.00073 min-1) and BiOI (0.00769 min-1), respectively. Moreover, the 50%Bi2O3/BiOI composite also possessed the excellent photochemical stability and recyclability, thereby facilitating its wastewater treatment application.