Photocatalytic nitrogen fixation provides an attractive approach to produce reactive nitrogen compounds at benign conditions. Herein, Ag decorated delta-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-delta-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-delta-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-delta-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-delta-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. (C) 2018 Elsevier Inc. All rights reserved.