Cysteine-assisted synthesis of CuS-TiO2 composites with enhanced photocatalytic activity

CuS-TiO2 composites are in situ synthesized via an environmentally friendly route using biomolecule L-cysteine as a sulfur source and chelating agent. The prepared samples are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV vis diffuse reflectance spectra (DRS), X-ray photoelectron spectroscopy (XPS). Results indicate that CuS nanoparticles are successfully loaded on TiO2 nanobelts. The photocatalytic activity of CuS-TiO2 composites is more than twice of that of pure TiO2 nanobelts under visible-light irradiation. The enhanced photocatalytic activity can be ascribed to energy band match and the formed heterostructures between CuS and TiO2, which lead to the efficient separation of photogenerated electrons and holes. The synthesized CuS-TiO2 composites by methods of cysteine-assist exhibit superior stability.