Fine-tuning piezoelectric potential enhances self-powered quartz/ZnO microsystem for photocatalytic H2O2 production

Abstract

With the growing global demand for hydrogen peroxide (H₂O₂), the traditional anthraquinone process faces challenges of high energy consumption and environmental pollution, making photocatalytic technology a promising green and sustainable alternative. However, the efficiency of photocatalysis is often limited by the recombination of photogenerated electron–hole pairs. In this study, a piezoelectric effect was introduced to enhance photocatalytic H₂O₂ synthesis by designing ZnO-based nanocomposite catalysts supported on quartz. The piezoelectric effect, triggered by ultrasonic excitation, promoted electron–hole separation, thereby improving photocatalytic efficiency. The structural characteristics of the materials were analyzed using XRD, SEM, and PFM techniques, while their photoelectrochemical performance and H₂O₂ production were evaluated through electrochemical tests. Results showed that the ZQ-P25 catalyst, with a particle size of 25 μm, achieved an H₂O₂ generation rate of 1.72 mmol g⁻¹ h⁻¹ under combined light and ultrasonic conditions, significantly outperforming smaller particle-sized catalysts. This study elucidates the enhancement mechanism of the piezoelectric effect in photocatalysis, providing new insights into the design of the photocatalyst materials and advancing the green production of H₂O₂.