KOH-modified Ni/LaTiO2N Schottky junction efficiently reducing CO2 to CH4 under visible light irradiation

Abstract Efficiency of solar-driven CO 2 into fuels is largely limited by the sluggish reaction kinetics resulting from high activation barriers and poor electron-hole separation. Here, a synergistic strategy was proposed to overcome these obstacles. As a prototype, KOH-modified Ni/LaTiO 2 N photocatalyst afforded a high performance in CO 2 reduction with a generation rate of 9.69 μmol g −1 for CH 4 and 0.31 μmol g −1 for CO, about 5 times higher than the catalytic activities of LaTiO 2 N. The prominent enhancement results in the following effects: (1) Schottky barrier at Ni/LaTiO 2 N interface boosts separation of electron-hole pairs. (2) The OH- of KOH as basic sites favors activation of CO 2 into CO 3 2- species, significantly improving the reaction kinetics of CO 2 reduction. (3) The OH- also functions as hole acceptor, boosting the proton release from H 2 O oxidation.