One-Pot Synthesis of C@BiOBr for Efficient Photocatalytic Degradation of Phenol.

Abstract

This work describes the synthesis of C@BiOBr using glucose as the carbon precursor by a repeatable one-step hydrothermal method. Characterization studies indicate that the structure of BiOBr did not change after the carbon layer was encapsulated on the surface. The highest activity is achieved at 1.2-C@BiOBr, with 97% of phenol (50 mg·L^-1) degrading within 90 min, and the degradation amount of phenol is determined to be 48.5 mg·g^-1 with a speed of 0.54 mg·g^-1·min^-1. The useful species of phenol degradation are studied and assigned to •O₂^-, ¹O₂, and h⁺. The effect of coated carbon layer for photocatalytic degradation of phenol over BiOBr is studied by photoelectrochemical experiments, fluorescence spectra, and density functional theory (DFT) calculations. It is attributed to the good conductivity of carbon, enhanced separation of the photocarriers by carbon coating, and thermodynamically favorable reactive oxygen species (ROS) production on the surface of carbon. This work demonstrates that carbon coating is an effective strategy to improve the photocatalytic activity of BiOBr and reveals the detailed mechanism.