Single-phased and (111)-oriented Ag2O film deposited using direct-current reactive magnetron sputtering is annealed using different annealing temperatures (T-a) for 1 h in Ar and H-2 mixture. After hydrogen annealing, a very weak but clear Ag(200) diffraction peak begins to appear, and the Ag2O diffraction peak weakens at T-a = 175 degrees C. However, the Ag diffraction peak becomes discernable at T-a = 190 degrees C. No Ag2O diffraction peaks but rather Ag diffraction peaks are discerned at T-a = 200 degrees C. The hydrogen reduction effect can reduce the film's critical thermal decomposition temperature to 175 degrees C. After hydrogen annealing, the surface of the film evolutes from compact and uniform to osteoporosis, and then to a porous structure. Moreover, the optical properties of the film obviously change at T-a over 190 degrees C, indicating that the hydrogen reduction can significantly enhance the decomposition of Ag2O due to H-2 dissociation on the surface followed by gaseous H2O molecule formation and desorption. (C) 2011 Elsevier B.V. All rights reserved.