One-Pot Hydrothermal Synthesis of SnO2/BiOBr Heterojunction Photocatalysts for the Efficient Degradation of Organic Pollutants Under Visible Light.

The establishment of p-n heterojunction between semiconductors is an effective means to improve the performance of semiconductor photocatalysts. For the first time, we synthesize SnO2/BiOBr heterojunction photocatalysts using a one-step hydrothermal method. Systematic material characterizations suggest that the photocatalysts consist of irregular BiOBr nanosheets with the length about 200 nm and width about 150 nm, and SnO2 nanoparticles are anchored uniformly onto the nanosheets. Most importantly, electrochemical characterizations including transient photocurrent profiles and electrochemical impedance spectra suggest that SnO2/BiOBr heterojunctions are created, which facilitates the charge separation and transfer efficiency of photogenerated charge carriers. As such, SnO2/BiOBr photocatalysts exhibit remarkable photocatalytic activities in terms of degrading a series of organic pollutants. Radical trapping experiments and electron spin resonance spectra suggest that superoxide radicals (•O2-) and hydroxyl radicals (•OH) are primary medium species running through the photocatalytic degradation process and enhanced photocatalytic performance.