Recent advances of mechanical stress-assisted photocatalysis: mechanisms and optimization strategies

Photocatalysis, which directly converts solar energy into chemical fuels, faces a fundamental efficiency limitation due to the rapid recombination of photogenerated carriers. The integration of mechanical stress fields has recently emerged as a powerful means to overcome this bottleneck. By coupling piezoelectric polarization with photoexcitation, this approach provides an intrinsic driving force to spatially separate electrons and holes, thereby markedly enhancing photocatalytic performance. However, the overall efficiency is critically dependent on the material's responsiveness to mechanical stimuli, which remains a central challenge. This review systematically elucidates the mechanisms behind mechanical stress-assisted photocatalysis and, more importantly, outlines targeted optimization strategies from the viewpoints of macroscopic deformation, intrinsic polarization, and piezo-photocatalytic composites. We also discuss future research directions and key challenges toward the rational design of high-performance piezo-photocatalytic systems for sustainable energy applications.