Simple preparation of copper-doped 2D BiOBr nanosheets for efficiently enhanced chemical adsorption and elimination of tetracycline

Designing and optimizing cost-effective photocatalytic systems for the photocatalytic degradation of antibiotics remains a considerable challenge. Herein, a certain amount of copper was doped into BiOBr with a two-dimensional (2D) structure through a simple hydrothermal method to improve its capability to degrade tetracycline hydrochloride (TC) under visible light. The physicochemical properties of the prepared samples were characterized. By adjusting the CuCl2·2 H2O amounts in the mixture, the 1 wt% Cu/BOB displayed the optimal photocatalytic TC degradation rate of 86.2% under visible light irradiation, which was 1.34 times higher than that of pure BiOBr. The DFT calculation results indicated that the Cu 3d and Cu 4 s orbitals constitute the doped energy level, which modified the band structure of the original BiOBr and effectively improved the visible light response capability. Importantly, the doped copper ions optimized the chemical adsorption capacity of TC by regulating the microenvironment around the active sites on the BiOBr and accelerated the separation of photogenerated charge carriers. This work could provide new insight into enhancing the chemical adsorption performance of 2D BiOBr by ion doping and provide a strategy for photocatalytic antibiotic degradation.