Strain-Enriched Active Sites on Anatase TiO2(001) Boost Photocatalytic H2O2 Production

Artificial photosynthesis of H2O2 by TiO2-based semiconductors is a promising route for H2O2 production, but pristine TiO2 suffers from rapid charge recombination and weak O2 adsorption. Herein, we demonstrate that strain-induced active-site enrichment on the anatase TiO2(001)-(1 × 4) surface can overcome this critical bottleneck. Through facet engineering, a highly strained anatase TiO2(001)-(1 × 4) surface reconstruction is formed on {001}-dominated TiO2; this structure lowers the reduction barrier, thereby creating a high density of active sites composed of fine Ag nanoparticles and photoreduced Ti3+ species. These abundant sites facilitate efficient spatial charge separation and markedly enhance O2 activation, thereby accelerating H2O2 formation. As a result, the {001}-facet-dominated Ag/TiO2 delivers an excellent H2O2 production rate of 5360 μmol g–1 h–1, outperforming reported photocatalysts under comparable conditions and with comparable crystal facets. This work highlights strain-engineered surface reconstruction as a powerful strategy for enriching active sites in artificial H2O2 photosynthesis.