Enhancing Photocatalytic Activity of Nb₂O5-x for Aerobic Oxidation Through Synergy of Oxygen Vacancy and Porosity.

Abstract

A major reduction in energy consumption and the costs of catalysts will be required in future chemical manufacturing processes. To reach this goal, the transitional metal oxides (TMOs) as photocatalysts under solar energy have been widely studied. Nb₂O5, as a promising photocatalyst, has attracted increasing attention owing to their unique properties. However, the intrinsic large bandgap of Nb₂O5 hinder its potential applications in a variety of fields. Herein, we report an effective and simple strategy to synthesize black mesoporous Nb₂O5-x nanorods (BMNb) with abundant oxygen vacancies. The formation of oxygen vacancy reduces the bandgap of Nb₂O5 which extend the photoresponse from the ultraviolet to the visible and infrared light regions. In addition, The mesoporous structure of BMNb lead to a higher surface area than the as-prepared Nb₂O5 precursor (36.24 m²/g cf 8.69 m²/g). Benefitting from coordinated regulation of structure and composition, the BMNb exhibits better photocatalytic performance than Nb₂O5 in aerobic oxidative coupling of amines to imines under visible light irradiation at room temperature. The yield of BMNb for benzylamine oxidation increases by 63% over the Nb₂O5. This work could open new perspectives to design TMOs with enhanced photocatalytic properties.