Facile one-pot synthesis of novel hierarchical Bi2O3/Bi2S3 nanoflower photocatalyst with intrinsic p-n junction for efficient photocatalytic removals of RhB and Cr(VI)

The construction of heterojunction system can promote the separation and transfer of photogenerated electron-hole pairs, which is conducive to the degradation of sewage. In this paper, heterostructured Bi 2 O 3 /Bi 2 S 3 nanoflowers are fabricated by a one-step hydrothermal method. The microstructure and optical absorption properties are studied through the detailed characterization of this heterojunction. The visible light photocatalytic ability of as-prepared Bi 2 O 3 /Bi 2 S 3 heterojunctions are investigated by photocatalytic removals of RhB and Cr(VI). The results of photocatalysis indicate that removal efficiencies of RhB and Cr(VI) over Bi 2 O 3 /Bi 2 S 3 heterojunction are higher than those of pure Bi 2 O 3 and Bi 2 S 3 . The improved photocatalytic performance of the Bi 2 O 3 /Bi 2 S 3 heterojunctions could be attributed to a combination of the p-n junction between the p-type Bi 2 S 3 and n-type Bi 2 O 3 , and large specific surface areas (46.31 m 2  g −1 ). Moreover, the probable photocatalytic mechanism of composite photocatalysts is explored in detail by active species trapping experiments, N 2 adsorption–desorption, the transient photovoltage electrochemical impedance spectroscopy and photoluminescence measurements. This work provides new insights into building of the efficient and novel heterogeneous photocatalysts and other energy-related devices.