Boosting Reactive Oxygen Species Generation Using Inter-Facet Edge Rich WO3 Arrays for Photoelectrochemical Conversion

Water oxidation reaction leaves room to be improved in the development of various solar fuel productions, because of the kinetically sluggish 4-electron transfer process of oxygen evolution reaction. In this work, we realize reactive oxygen species (ROS), H2O2 and OH., formations by water oxidation with total Faraday efficiencies of more than 90% by using inter-facet edge (IFE) rich WO3 arrays in an electrolyte containing CO32-. Our results demonstrate that the IFE favors the adsorption of CO32- while reducing the adsorption energy of OH., as well as suppresses surface hole accumulation by direct 1-electron and indirect 2-electron transfer pathways. Finally, we present selective oxidation of benzyl alcohol by in situ using the formed OH., which delivers a benzaldehyde production rate of approximate to 768 mu molh(-1) with near 100% selectivity. This work offers a promising approach to tune or control the oxidation reaction in an aqueous solar fuel system towards high efficiency and value-added product.

Automated summary

By using inter-facet edge (IFE) rich WO3 arrays in an electrolyte containing CO32-, reactive oxygen species (ROS), H2O2, and OH. are efficiently generated by water oxidation with total Faraday efficiencies of more than 90%. The IFE favors the adsorption of CO32- and reduces the adsorption energy of OH., while suppressing surface hole accumulation. In situ selective oxidation of benzyl alcohol using the formed OH. achieves a benzaldehyde production rate of approximately 768 μmolh(-1) with near 100% selectivity. This work provides a promising approach to enhance the efficiency and value-added product of oxidation reactions in aqueous solar fuel systems.