Zinc-triggered photocatalytic selective synthesis of benzyl acetate on inverse spinel CuFe2O4 3D networks: a case of coupled redox photocatalytic reaction

Coupled redox photocatalytic (CRP) reaction is a concept which corresponding reduction and oxidation products are further reacted and serve as each other's redox partners. Herein, we developed a Zn doped CuFe2O4 3D network for the CRP reaction to generate benzyl acetate with high selectivity. The ammonia assisted sol-gel method helps to improve the specific surface area of inverse spinel CuFe2O4 and therefore the concentration of oxygen vacancies. With optimized doping content of 0.5%, Zn doped CuFe2O4 presents a photocurrent as high as 34.72 A/cm2, which indicates that Zn-doping largely boosts the charge separation efficiency in accordance with the surface photovoltage measurement. Most importantly, in the CRP reaction, zinc-trigger the selectivity of benzaldehyde to benzyl acetate from 2.97% to 74.80%. Density functional theory (DFT) calculations further reveal that zinc doping enhances the adsorption energy of the intermediate product of acetone in CuFe2O4-based CRP reaction leading to enhanced activity and selectivity.