The band engineering of visible-light-driven photocatalysts is a promising route for harnessing of effective solar energy to perform high chemical reactions and to treat environmental pollution. In this study, two narrow band gap semiconductor nanomaterials, graphitic carbon nitride (g-C3N4) and Bi2MoO6, were selected and coupled to form series of g-C3N4/Bi2MoO6 photocatalysts. Their structure, light absorption wavelength range, charge transport properties and energy level were investigated. Through perfect manipulation of their composition, enhanced photocatalytic activity of the Z-scheme g-C3N4/Bi2MoO6 photocatalysts with efficient reduction of recombination of photogenerated electrons and holes was achieved. The optimized Z-scheme g-C3N4/Bi2MoO6 photocatalysts with 25 wt% g-C3N4 showed apparent pseudo-first-order rate constant k(app) as high as 0.0688 min(-1), which was 4.8 times and 8.2 times higher than that of g-C3N4 and Bi2MoO6 photocatalyst, respectively. (C) 2015 Elsevier B.V. All rights reserved.