Tin chloride metal salt modified carbon nitride for efficient hydrogen and hydrogen peroxide production from pure water via piezocatalysis

Abstract

Piezocatalysis presents a sustainable and energy-efficient method for producing hydrogen (H₂) and hydrogen peroxide (H₂O₂), utilizing mechanical energy to drive chemical reactions without the need for external power sources or harmful chemicals. In this study, we used a one-pot synthetic method to modify graphitic carbon nitride (g-C₃N₄). The obtained catalysts showed enhanced H₂ and H₂O₂ production from pure water without any co-catalysts or sacrificial agents via piezocatalysis. In the cost-effective synthetic method, a metal oxide/g-C₃N₄ composite structure was constructed through the molten salt method. During thermal pyrolysis, non-noble metal-based SnCl₂ provided a molten medium to facilitate the exfoliation of the g-C₃N₄ layer. The oxidation of SnCl₂ and its interaction with g-C₃N₄ promoted the formation of g-C₃N₄/Sn-based composites. The synergistic interaction between exfoliated, defect-rich g-C₃N₄ and non-piezoelectrically active Sn species leads to a significant enhancement of the piezoelectric effect compared to pristine g-C₃N₄. Notably, the g-C₃N₄/Sn-based composites achieved superior H₂ (3846.46 µmol g⁻¹ h⁻¹) and H₂O₂ (999.11 µmol g⁻¹ h⁻¹) production rates from pure water. This work provides new insights into the structural and compositional modulation of g-C₃N₄ without the use of any noble metals and paves the way for further piezocatalytic research using two-dimensional carbon nitride materials.