One-step solvothermal synthesis of hierarchically porous nanostructured CdS/TiO2 heterojunction with higher visible light photocatalytic activity

One-step solvothermal method was developed for the synthesis of hierarchically porous nanostructured CdS/TiO2 heterojunction materials, which exhibited enhanced visible-light-driven photocatalytic activity in decomposing both methyl orange (MO) and rhodamine B (RhB) in water. The photocatalyst with the highest performance was the one prepared using the Ti:Cd molar ratio of 1:1. Based on the characterization results of XRD, XPS, FT-IR, SEM, HRTEM, UV-vis DRS and N-2 adsorption-desorption, the influence of coupling TiO2 with CdS on the crystal phase, band structure, surface element composition, morphology, optical absorption and surface area of the as-prepared samples are investigated. The results showed that the CdS/TiO2 heterojunction catalysts possessed well-defined hierarchically porous structure composed of anatase TiO2 and hexagonal CdS nanoparticle with average grain size of 4-6 nm. Their enhanced catalytic activity can be attributed to the synergistic effect of crystal compositions, porous architectures, electronic band structure, large specific surface area and strong visible light absorption. (C) 2013 Elsevier B.V. All rights reserved.