A novel and simple synthetic approach toward core-shell Ag@C3N4 nanocomposites is developed. Ag@C3N4 core-shell nanostructures were formed via reflux treatment of Ag nanoparticles with graphitic C3N4 nanosheets in methanol. The core-shell hybrid photocatalysts showed dramatic photoinduced electron-hole separation efficiency and photocatalytic activity under visible light irradiation. The photocurrent intensity, photocatalytic activity for the photodegradation of methylene blue (MB) and hydrogen evolution reaction of Ag@C3N4 were about 4, 1.8 and 30 times as that of pure C3N4 sample, respectively. The enhanced photocatalytic activity for core-shell Ag@C3N4 originated from a combined result of the localized surface plasmon resonance (LSPR) effect for Ag and hybrid effect from C3N4, resulting in the coupling interaction of the enhanced light absorption intensity, high separation efficiency of photogenerated electrons-holes, longer lifetime of charge carriers and its favorable adsorptivity. (C) 2013 Elsevier B.V. All rights reserved.