Functional CdS/TiO2 Nps thin films obtained by soft chemistry applied in degradation of methyl orange by sunlight

Abstract

This research reports the degradation of methyl orange (MO) by heterogeneous solar photocatalysis with CdS/TiO2 Nps thin films as an alternative to wastewater treatment. CdS thin films were deposited by chemical bath deposition in one and two layers, while the TiO2 nanoparticles (Nps) were obtained by sol-gel process -assisted by microwave method and deposited by spin coater technique on CdS. All applied techniques for the synthesis of these materials are considered of soft chemistry. The optical characterization of the CdS/TiO2 Nps thin films was evaluated by Ultraviolet-Visible spectroscopy, and the calculated band gap for the films was 3.0-2.8 eV. Agglomerated TiO2 nanoparticles were observed on homogeneous CdS thin films with polycrystalline structure. The degradation of MO was done with three replicates of CdS/TiO2 Nps thin films exposed to sunlight for 60 minutes, resulting in a degradation of 22%.