The visible light photocatalytic activity of graphitic carbon nitride, g-C3N4, can be enhanced by coupling with other semiconductors. In this work, mesoporous TiO2 nanoparticles were grown over g-C3N4 sheets resulting in the coupled nanocomposite photocatalyst. The morphological analyses using FE-SEM, TEM and AFM revealed the uniform deposition of TiO2 on g-C3N4 sheet. The visible light photocatalytic activity of g-C3N4 and g-C3N4/TiO2 composites were tested by methyl orange (MO) dye degradation and Cr(VI) reduction. The results revealed an enhancement in the visible light photocatalytic activity of g-C3N4 when it was coupled with TiO2 in the nanocomposite. Mesoporous TiO2 nanoparticles deposited over g-C3N4 provides the necessary large surface for the adsorption of the pollutant molecules. The enhanced visible light photocatalytic activity of g-C3N4 in the nanocomposite is due to the high surface area and efficient photogenerated charge carrier separation in the nanocomposite as evidenced in photoluminescence (PL) results. (C) 2015 Elsevier Ltd. All rights reserved.