One-step synthesis and visible-light-driven H2 production from water splitting of Ag quantum dots/g-C3N4 photocatalysts

Ag quantum dots/g-C3N4 (Ag QDs/g-C3N4) photocatalysts were directly obtained via a novel one-step method. The photocatalysts were composed of Ag quantum dots with an average diameter of ca. 5 nm, which were dispersed uniformly on the surface of g-C3N4 nanosheets. By using methanol as sacrificial reagent, the Ag QDs/g-C3N4 photocatalysts exhibited higher photoactivity for hydrogen production than the AX = 0 photocatalyst under visible-light irradiation (lambda > 420 nm). Among various photocatalysts prepared, the AX = 0.5% photocatalyst showed maximum hydrogen production efficiency, which was enhanced by 4.6 times compared to AX = 0 photocatalyst. Our findings demonstrated that the coupled Ag QDs could enhance the visible light absorption and serve as g-C3N4 electron acceptor for effective charge separation, and further increased it's photocatalytic activity. (C) 2016 Elsevier B.V. All rights reserved.