Hydrogen Peroxide Production from Water Oxidation on a CuWO₄ Anode in Oxygen-Deficient Conditions for Water...

Hydrogen peroxide, an environmentally benign oxidant, is an effective chemical agent for water purification. On-site production of H₂O₂ is considered economical because it avoids the cost of storage and transportation. Traditional generation of H₂O₂ from oxygen reduction, as a heterogeneous electrochemical reaction, suffers from mass transfer problems because of the limited solubility and low diffusion rate of oxygen in water. These limitations can be overcome if H₂O₂ is formed by water oxidation. Herein, conversion of water to hydrogen peroxide was achieved efficiently on a CuWO₄ anode. This water oxidation strategy can generate H₂O₂ at a rate of ∼11.8 μmol min^-1 cm^-2 at 3.0 V versus reversible hydrogen electrode. Importantly, this on-site H₂O₂ production shows high efficiency in water purification in O₂-deficient conditions. This water oxidation anode offers a feasible way to provide a green purification agent with only water as the final byproduct, avoiding toxic intermediates and residues during the production and application.