Precipitation synthesis and characterization of SnO2@g-C3N4 heterojunctions for enhanced photocatalytic H2 production

Abstract

This study reports the development of SnO₂@g-C₃N₄ heterojunctions, a hybrid semiconductor photocatalyst with varying mass percent ratios using a facile precipitation method for hydrogen (H₂) production. The synergistic effect between the SnO₂ nanoparticles and g-C₃N₄ sheets suppresses the charge recombination and enhances carrier separation, leading to improved photocatalytic activity. The nanocomposites demonstrate increased hydrogen production across all composites, with SC-20 sample (i.e., 80% SnO₂ and 20% g-C₃N₄) achieving the highest H₂ production rate of 287.7 μmol g⁻¹ h⁻¹, that is, 1.87-fold and 1.63-fold higher than that of SnO₂ and of g-C₃N₄ counterparts, respectively. Furthermore, the nanocomposites maintain excellent photostability. Specifically, SC-20 achieves approximately 1500 μmol H₂ evolution per 5 hour-cycle. The facile precipitation-based synthesis and enhanced photocatalytic activity of the SnO₂@g-C₃N₄ nanocomposite position it as a reliable, cost-effective, and sustainable candidate for solar-driven hydrogen production and other clean energy applications.