▎ 摘　　要

A modified Stober process using vinyltriethoxysilane as the precursor and in the presence of graphene oxide unprecedentedly leads to the exclusive growth of monodispersed silica nanocrystals (SiO2 NCs) (ca. 3-4 nm) at room-temperature on single-layer graphene sheet with a high deposition density (ca. 10(16)/m(2)), where graphene oxide is simultaneously reduced by ammonia. Well-resolved lattice fringes with the spacing of 0.19 nm demonstrate the excellent crystallinity of SiO2 NC, which has an absorption band in the range of 200-400 nm. The anchoring of vinyl-silanols on graphene oxide through Si-O-C oxo-bridging and the pi-pi interaction between double bonds of vinyl-silanols and graphene oxide co-direct the orderly growth of SiO2 NC nuclei on graphene. Compared with isolate and physically mixed SiO2 and graphene, the composite has decreased impedance and 4.5 times improved photocurrent, which also shows extraordinarily high photocatalytic activity toward the degradation of organic pollutant. (C) 2015 Elsevier B.V. All rights reserved.