Efficient and stable H2O2 production from H2O and O2 on BiPO4 photocatalyst

Photocatalytic H2O2 production from H2O and O2 is a sustainable alternative to the present anthraquinone process, but most available systems need sacrificial reagents to maintain continuous activity. In this work, BiPO4 photocatalyst is reported to produce H2O2 efficiently from non-sacrificial systems. The photocatalyst exhibits H2O2 production activity as high as 12.0 mM/h/g and negligible decay for 40 cycles (ca. 200 h) with only H2O and O2. The photocatalyst is demonstrated to show a core-shell structure. The monoclinic BiPO4 core exhibits a wide bandgap of 3.85 eV, supplying sufficient driven force for photogenerated e- and h+ to produce H2O2. More importantly, instinct hydrate voids in coated hexagonal BiPO4 cause strong adsorption with H2O and O2 rather than H2O2 via the steric hindrance effect, which facilitates the diffusion of H2O2 away from the active photocatalyst surface, avoiding its overreaction. The findings may help to design more efficient and stable photocatalysts for H2O2 production in the future.