Exquisitely designed (0 0 1) active face of Bi2O2CO3 based on Bi3O4Br/g-C3N5 layers with multi-channel charge transfer for efficient purification of organic water pollutants under visible light

The design of heterojunction and active crystal face is an effective way to promote the separation and migration of photogenerated charge in the process of photocatalytic reaction. In this work, the band gap intercalation Bi 3 O 4 Br/Bi 2 O 2 CO 3 /g-C 3 N 5 (BBC) ternary photocatalyst was successfully designed by one step hydrothermal method. It is found that under alkaline conditions, the addition of g-C 3 N 5 to Bi 3 O 4 Br leads to the preferential growth of the (0 0 1) crystal face of the third phase Bi 2 O 2 CO 3 , and the (0 0 1) crystal face is the active crystal face of the photocatalytic reaction. In addition, the constructed double Z-scheme heterojunction has two different electron transport pathways and bidirectional interface electric fields, which reduces the electron-hole pair recombination rate, maintains a strong redox ability, and enables the photogenerated carrier to effectively separate and transfer, thus improving the catalytic activity of the material. Under visible light irradiation, 15 %BBC presented excellent catalytic activity, the degradation rates of ARB ( k  = 0.0238 min −1 ), HCl-TC ( k  = 0.0183 min −1 ) and RHB ( k  = 0.0200 min −1 ) exceeded 90 % within 120 min. This work is not only of great significance for the purification of water pollution, but also provides a new way for further exploration of novel composite photocatalytic systems.