Cobalt Doping Bismuth Oxybromide Piezocatalysts for Boosting Hydrogen and Hydrogen Peroxide Synthesis

Efficient piezocatalysts are crucial for energy conversion processes. In this work, we synthesized cobalt-doped bismuth oxybromide (Co-BiOBr) piezocatalysts to enhance the piezocatalytic performance. Our findings reveal a correlation between piezocatalytic activity and cobalt doping levels (1, 10, and 20%) in the synthesis of hydrogen (H₂) and hydrogen peroxide (H₂O₂). Notably, 10% Co-BiOBr exhibits remarkable piezocatalytic activity, producing H₂ and H₂O₂ at rates of 1647.8 and 251.3 μmol g^-1 h^-1, surpassing the performance of undoped BiOBr. This catalyst also demonstrates strong stability and recoverability. Furthermore, characterization studies indicate that cobalt incorporation alters morphology and electronic states, enhances charge carrier transfer and separation, and facilitates the hydrogen evolution reaction and dual-channel reaction for H₂O₂ production, leading to enhanced piezocatalytic performances. Finally, a novel piezocatalytic mechanism has been elucidated. This doping engineering strategy offers a straightforward approach for the development of highly efficient piezocatalysts in clean energy applications.