Enhancing Photocatalytic H2o2 Production Through the Improvement of Water Oxidation Via a Novel Lattice-Oxygen-Involved Pathway

Bi-vacancy-rich BiPO4 nanocrystals (VBi-BIP) have achieved high H2O2 production, providing an in-situ source for UV/H2O2 degradation. These nanocrystals produce H2O2 at 26.7 mM·g-1·h-1, surpassing most inorganic and organic photocatalysts, and have an AQY of 43.4% and ECE of 10.7% at 254 ± 10 nm. The Bi vacancies enhance activity by enabling a new lattice-oxygen-involved pathway for H2O2 formation, with a potential 0.34 V lower than conventional water oxidation reactions. Using in-situ generated H2O2 on VBi-BIP, organic pollutants can be efficiently degraded, achieving a 92% removal rate for ciprofloxacin in a flow reactor operated at 2.4 L/h for 400 hours. The energy cost per unit of treated water (EE/O) in this in-situ degradation device is 0.58 kWh/m3, half of that in traditional UV/H2O2 treatment. The creation of cation vacancies and their function elucidation for H2O2 generation paves the way for designing more efficient photocatalysts for in-situ H2O2 use in the future.