Defect-induced charge redistribution of MoO3-x nanometric wires for photocatalytic ammonia synthesis

Abstract

Photocatalytic ammonia synthesis technology has become one of the effective methods to replace the Haber method for nitrogen fixation in the future for its low energy consumption and green environment. However, limited by the weak adsorption/activation ability of N2 molecules at the photocatalyst interface, the efficient nitrogen fixation still remains a daunting job. Defect-induced charge redistribution as a catalytic site for N2 molecules is the most prominent strategy to enhance the adsorption/activation of N2 molecules at the interface of catalysts. In this study, MoO3-x nanowires containing asymmetric defects were prepared by a one-step hydrothermal method via using glycine as a defect inducer. It is shown that at the atomic scale, the defect-induced charge reconfiguration can significantly improve the nitrogen adsorption and activation capacity and enhance the nitrogen fixation capacity; at the nanoscale, the charge redistribution induced by asymmetric defects effectively improved the photogenerated charge separation. Given the charge redistribution on the atomic and nanoscale of MoO3-x nanowires, the optimal nitrogen fixation rate of MoO3-x reached 200.35 µmol g−1h−1.