Visible light-responsive g-C3N4/SiO2-HNb3O8 composite photocatalysts were prepared by a solid state-reaction method with melamine as a g-C3N4 precursor. The photocatalytic activities of the samples were evaluated for rhodamine B (RhB) degradation under visible light irradiation and the results were compared with those obtained over pure SiO2-HNb3O8 and g-C3N4. Techniques such as XRD, FT-IR, SEM, TEM, and UV-vis diffuse reflectance spectroscopy were adopted to explore the characteristics of samples. The g-C3N4/SiO2-HNb3O8 composite materials exhibited superior activities than pure SiO2-HNb3O8 and g-C3N4; the sample prepared with SiO2-HNb3O8 to melamine ratio being 1:2 and the heating duration being 4h performed the best. The improved activity of g-C3N4/SiO2-HNb3O8 is attributed to the unique synergetic effect between SiO2-HNb3O8 and g-C3N4. (C) 2011 Elsevier B.V. All rights reserved.