Multilayer ultrathin Ag-δ-Bi2O3 with ultrafast charge transformation for enhanced photocatalytic nitrogen fixation

Abstract

Photocatalytic nitrogen fixation provides an attractive approach to produce reactive nitrogen compounds at benign conditions. Herein, Ag decorated δ-Bi2O3 photocatalyst, which has the features of multilayer ultrathin structure, suitable absorption edge and many exposed surface sites, is prepared by a hydrothermal and photoreduction process. Under visible light illustration, the obtained Ag-δ-Bi2O3 photocatalyst exhibits efficient photocatalytic activity for NH4+ generation at room temperature and atmospheric pressure in aqueous solution. The multilayer ultrathin sheets in the structure of Ag-δ-Bi2O3 favors the effective separation of photogenerated electron-hole pairs and fast interfacial charge transfer. Due to the Ag surface plasmonic resonance, obvious trap is formed in the ultrathin Ag-δ-Bi2O3 sheets, which not only inhibites the recombination of electron hole pairs but also produces light-induced oxygen vacancies under irradiation. Those factors significantly improve the photocatalytic ability of as-prepared Ag-δ-Bi2O3. The results provide insights into rational design of enhanced active photocatlysts with Ag surface plasmonic resonance and ultrafast charge carrier transfer for photocatalytic nitrogen fixation.