Synthesis and characterization of CdS/TiO2 nanocomposite: Methylene blue adsorption and enhanced photocatalytic activities

In this report, CdS/TiO2 nanocomposite was synthesized by hydrothermal method using KOH as an alkaline medium. The prepared sample was calcined at 200 degrees C for 2 h. The sample was characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) analysis, UV-Vis-NIR absorption spectroscopy, Raman spectroscopy and nitrogen adsorption-desorption tests. X-ray analysis confirmed the hexagonal wurtzite/titanate phase formation of nanocomposite. TEM images revealed the titanate nanotube and CdS particle formation of CdS/TiO2 nanocomposite. The presence of functional groups in the sample was analyzed by IR spectroscopy. Band-gap energy of the sample was determined by UV-vis-NIR diffuse reflectance spectrum. Raman intensities confirm the presence of CdS and TiO2 in the synthesized nanocomposite. From BET analysis, surface area of the sample is determined as 31.7 m(2)/g and an average pore diameter is 10.41 nm. The as-prepared sample was used in the photodegradation reaction of methylene blue (MB) dye under sunlight and analyzed by UV-visible absorption spectroscopy. The results recommend that the nanocomposite exhibited much higher visible light photocatalytic activity for the degradation of methylene blue and the photodegradation efficiency can reach 77% after 180 min.