Promoting Formation and Suppressing Decomposition of H ₂ O ₂ via Photocarrier Flow at Au@TiO ₂ Interfaces

Abstract

High Resolution Image Download MS PowerPoint Slide Hydrogen peroxide (H 2 O 2 ) is an attractive green oxidant and energy carrier, but its industrial production remains energy- and resource-intensive. Photocatalytic synthesis from O 2 and H 2 O offers a safer and more sustainable alternative, yet its efficiency is hampered by sluggish formation and rapid decomposition pathways. Here, we demonstrate a plasmon-engineered strategy to overcome both challenges using Au@TiO 2 core–shell nanostructures. The nanocubic Au@TiO 2 (NC@TiO 2 ) achieves a remarkable H 2 O 2 production rate of 350.5 mM h –1 g –1 under full-spectrum irradiation −1.6 times higher formation and 47% lower decomposition compared to bare TiO 2 . Spectroscopic analysis and simulations reveal that localized surface plasmon resonance (LSPR) in the Au core orchestrates photocarrier dynamics: electrons generated in TiO 2 are funneled to Au sites to drive O 2 reduction, while plasmonic hot electrons neutralize TiO 2 holes that would otherwise decompose H 2 O 2 . The morphology dependence of this effect is evident: NC@TiO 2 with stronger LSPR outperforms rhombic dodecahedral Au@TiO 2 . These results establish plasmon-mediated charge steering as a powerful tool to enhance both efficiency and selectivity in solar-to-chemical conversion, providing a design principle for next-generation photocatalysts.