Engineering Piezoelectricity and Strain Sensitivity on Nanostructured Bi₂WO₆ for Piezocatalytic Hydrogen Peroxide Production

Piezocatalytic production of hydrogen peroxide (H2O2) has emerged as an innovative method for capturing and utilizing mechanical energy. Bismuth tungstate (Bi2WO6 and BWO), a well-established material in photocatalytic pollutant degradation, has been less explored for its piezocatalytic performance, and the link between its structural properties and piezocatalytic performance remains unclear. In this study, Bi2WO6 nanoparticles (BWO-NPs) and nanosheets (BWO-NSs) were synthesized to address these questions. Under ultrasonic vibration, BWO-NSs exhibited a remarkable piezocatalytic H2O2 production rate of 376 μmol g–1 h–1, approximately four times greater than that of BWO-NPs. Piezoelectric force microscopy, finite element simulations, and electrochemical tests revealed that BWO-NSs possess a higher piezoelectric coefficient, greater mechanical energy harvesting capability, and enhanced strain sensitivity. These characteristics contribute to higher piezopotentials and more effective separation of carriers. This research offers perspectives on the design of efficient piezocatalysts capable of converting mechanical energy to sustainable energy through nanostructure optimization.