Nanoscale reduction-site-selective oxygen regulation for promoting hydrogen peroxide production

Solar-driven H2O2 production is a promising sustainable technology, yet its efficiency is hindered by a fundamental conflict. While the oxygen reduction reaction requires a high O2 concentration, this very condition suppresses the water oxidation half-reaction. This trade-off is intrinsic to conventional photocatalysts, where both reaction centers are integrated on a single nanoparticle. Here we present a nano-assembly strategy that addresses this trade-off. We use a faceted photocatalyst to spatially segregate the sites for water oxidation and oxygen reduction. The reduction sites are selectively functionalized with zeolite nanovessels as O2 traps. This design enhances the local O2 concentration where needed, without suppressing the competing oxidation reaction. The optimized system exhibits a 3.1-fold increase in H2O2 production, achieving a solar-to-chemical efficiency of 1.05% and an apparent quantum yield of 15.9% at 420 nm. Successful operation in an outdoor panel reactor demonstrates the approach’s scalability. This study underscores the role of local mass regulation in enhancing H2O2 generation and provides a strategic framework for designing photocatalytic systems. Solar hydrogen peroxide production is hampered by a chemical conflict: the high oxygen levels needed for one reaction inhibit the other. Here, the authors assemble nanoscale oxygen traps selectively on reduction sites, creating ideal local environments to boost H2O2 yield.