High-Throughput Screening of Inorganic Photocatalysts for Hydrogen Peroxide Photoproduction

Artificial photosynthesis offers a sustainable route to H2O2 production, but it is hindered by low experimental throughput, inconsistent quantification, and limited durability evaluation. Here, we report a semi-automated high-throughput photocatalyst screening workflow, comprising sample preparation, light irradiation, filtration, and computer vision-guided colorimetric titration, to enable reproducible benchmarking. Using this workflow, 72 inorganic semiconductors were tested candidates, selected from a literature-derived pool of ~400 materials, and unmodified gallium selenide (GaSe) was identified as an efficient visible-light photocatalyst for hydrogen peroxide production. GaSe achieved an H2O2 production rate of 1300 μmol L⁻¹ h⁻¹ in pure water saturated by O2 without using any sacrificial agents or additives. The photocatalyst also exhibited good durability and reusability, consistently generating solutions with H2O2 concentrations above 1 mM over 48 h across multiple reaction cycles.