Coupling photocatalytic water oxidation on decahedron BiVO4 crystals with catalytic wet peroxide oxidation for removing organic pollutions in wastewater

Catalytic wet peroxide oxidation (CWPO) is widely used to remove organic pollutants in industrial wastewater, however, the remained challenges in circulating Fe 3+ /Fe 2+ ions, inevitably forming iron sludge and massively consuming H 2 O 2 limit its applications. Herein, the coupling of CWPO and photocatalytic water oxidation on decahedron BiVO 4 crystals was reported to solve the above challenges. Using spatial photogenerated charge separation between different facets of BiVO 4 , efficiently circulating Fe 3+ to Fe 2+ was realized with a selectivity of ~100%, which greatly inhibits the formation of iron sludge. Moreover, in-situ formation of H 2 O 2 through two-hole-involved photocatalytic water oxidation on BiVO 4 replenishes the H 2 O 2 consuming in the CWPO process. The coupling system exhibits a much higher total organic carbon (TOC) removal than the CWPO process in various pollutants, giving an improvement of rate constant to more than 10 times. This work provides a potential coupling route for advanced degradation of organic pollutants in wastewater treatment. • The coupling of CWPO and photocatalytic water oxidation was proposed for degradation. • Irreversible reduction from Fe 3+ to Fe 2+ ions was achieved on decahedron BiVO 4 . • H 2 O 2 was produced during photocatalytic water oxidation process on decahedron BiVO 4 . • The coupling system shows much higher TOC removal for organic pollutants. • Charge separation between different facets efficiently affects the degradation.