Carbon Dioxide Anion Radicals Assisted Highly Efficient Photocatalytic H2O2 Production over Bi(C2O4)OH

Carbon dioxide anion radical (CO2•–) can act as a versatile single electron reductant, but its generation pathways are quite limited. Herein, we demonstrate that oxalic acid (OA) could be effectively and continuously utilized to produce CO2•– over Bi(C2O4)OH, a novel photocatalyst, under light irradiation. Bi(C2O4)OH would proceed with self-redox reactions under the light irradiation producing CO2•–, through the oxidation of C2O42–. OA in the solution could recoordinate with Bi3+, thus maintaining the structure of the photocatalysts and the stability of the reactions. Benefiting from the fast reaction between CO2•– and O2 in forming •O2–, hydrogen peroxide (H2O2) would be efficiently produced (219.0 μmol/h). This study proposes a novel approach for harnessing OA containing wastewater and explores its potential application in the efficient production of H2O2.