Carbon modification facilitates piezocatalytic H2O2 production over BiOCl nanosheets: Correlation between piezoresponse and surface reaction

Piezocatalysis offers a facile approach for the production of H2O2, which is a green fuel and oxidant with broad application scenarios. Clarifying the role of various factors is critical to the rational design of the piezocatalytic system. Herein, carbon species are modified over BiOCl nanosheets, achieving a piezocatalytic H2O2 production rate of 2110 µmol g−1 h−1 in pure water. Mechanistic studies reveal that although the modification weakens the piezoelectricity of BiOCl, the contribution of carbon species in raising the carrier density and serving as the O2 activation sites promotes H2O2 generation. As a result, the decline of piezoresponse is surmounted by the improvement in surface reaction, and the piezocatalytic activity of C-BiOCl outperforms the pristine BiOCl nanosheets. This work emphasizes that the surface active site is the bridge connecting piezoelectricity and catalytic efficiency, which puts forward an insightful strategy for the modularization of the piezocatalytic system. [Display omitted] •Piezocatalytic H2O2 production over BiOCl is promoted after carbon modification.•C-BiOCl exhibits enhanced O2 activation capability but weakened piezoelectricity.•Surface reaction refinement compensates for the impact on piezoelectricity decay.•Surface active sites mediate the injection of induced charges into the reactants.