2D g-C3N4/BiOBr heterojunctions with enhanced visible light photocatalytic activity

The two-dimensional (2D) layered photocatalysts are promising to improve the separation efficiency of photogenerated electron-hole pairs. Herein, 2D graphitic carbon nitride (g-C3N4)/BiOBr heterojunctions were successfully prepared via a facile solvothermal method. The micromorphology, structure, and chemical composition/states were characterized. The visible light–induced photocatalytic properties were estimated by the degradation of rhodamine B (RhB), photocurrent responses, Nyquist spectra, and Mott-Schottky measurement. Comparing with pure g-C3N4 and BiOBr, 2D g-C3N4/BiOBr heterojunctions exhibit the enhanced visible light photodegradation. After coupling between (001) crystal planes of BiOBr with (002) planes of g-C3N4, 2D g-C3N4/BiOBr heterojunctions have the large and intimate contact surface allowing fast interfacial charge transfer rate. It is explored that photoinduced superoxide radicals (·O2−) and holes (h+) actively participate in the photodegradation, while the contribution of hydroxyl (·OH) radicals is negligible.