Ag-Ag2O was prepared by precipitation and thermal decomposition and characterized by X-ray diffraction and high-resolution transmission electron microscopy. A well-matched interfacial contact was formed between the Ag and Ag2O nanoparticles (NPs) by drying Ag2O at 70-100 degrees C. The nanocomposites exhibited a higher photoactivity and stability for the degradation and mineralization of toxic persistent organic pollutants compared to Ag2O, which was demonstrated using 2-chlorophenol, 2,4-dichlorophenol and trichlorophenol under visible or near-infrared light irradiation and simulated solar irradiation. Based on electron storage and transient photocurrent, laser flash photolysis, and electron spin resonance analyses under a variety of experimental conditions, two sequential electron transfer processes were verified from photoexcited Ag2O to Ag NPs to a thionine molecule or surface adsorbed oxygen as well as from water to the Ag2O, resulting in O2(center dot-) and (OH)-O-center dot. The maximum electron storage, the longest lifetime (757 mu s) of photogenerated electrons and the strongest steady state photocurrent were observed for Ag-Ag2O-70 degrees C, which resulted in the highest solar photoactivity. However, electron-hole recombination was dominant in the Ag-Ag2O dried in other temperature ranges, leading to a much lower photoactivity. The results indicated that the interfacial contact with the metal/semiconductor played a key role in charge separation and migration, which improved their photocatalytic efficiency. These results will allow for the application of narrow bandgap semiconductors that can harvest the full spectrum of sunlight to be employed in photocatalysis and photovoltaic fuel cells. (C) 2015 Elsevier B.V. All rights reserved.