Construction of surface pit-structured g-C3N4 by induced SiO2 hard template for boosted piezoelectric-assisted photocatalytic H2O2 production

Abstract

Solar-driven synthesis of hydrogen peroxide (H₂O₂) represents a promising pathway for sustainable energy production, characterized by environmental friendliness and industrial feasibility. The coupling of multi-field co-assisted systems, integrating piezoelectric field modulation, represents a pioneering modification strategy that significantly enhances the photocatalytic H₂O₂ production efficiency through synergistic interfacial charge separation and optimized redox kinetics. Herein, the surface pit-structured g-C₃N₄ (SP-CN) was successfully synthesized via a straightforward hard-template-assisted thermal polymerization method for boosted piezoelectric-assisted photocatalytic H₂O₂ production under full-spectrum irradiation. Systematic investigations demonstrate that these surface pits of SP-CN endow the material with dual functional enhancements, including broadened light absorption and amplified dipole moment, promotes charge carrier separation/migration under piezoelectric polarization while creating abundant exposed active sites for oxygen adsorption. The testing results indicated that under piezoelectric-assisted photocatalysis, the H₂O₂ generation rate of SP-CN reached 189.8 μM·h⁻¹ (227.76 μmol·g⁻¹·h⁻¹), which is 14.4 times that of g-C₃N₄ under sole photocatalysis, and the saturation phenomenon observed in the later stages of performance testing highlighted its exceptional capability. In addition, cyclic testing confirms that SP-CN can still maintain its activity after multiple reactions. This unique structural configuration establishes a synergistic piezoelectric-photocatalytic system that effectively addresses the intrinsic limitations of conventional g-C₃N₄ through simultaneous improvements in photon utilization, charge dynamics, and surface reactivity.