Enhancement of CdS nanoparticles photocatalytic activity by Pt and In2O3 doping for the degradation of malachite green dye in water

Abstract

A hydrothermal method was used to prepare CdS nanoparticles, and a photoassisted deposition method was used to prepare 0.5wt% In2O3/CdS, 0.5wt% Pt/CdS and 0.5wt% Pt, In2O3/CdS nanoparticles. Different techniques, such as UV–Vis, XPS, TEM, XRD, PL and BET surface area, were used to characterize the prepared materials. The results reveal that the doping of Pt, In2O3 on the surface of CdS nanoparticles plays an important role in the control electron-hole recombination rate. The photocatalytic performance of CdS, 0.5wt% In2O3/CdS, 0.5wt% Pt/CdS, and 0.5wt% Pt, In2O3/CdS nanoparticles was studied by measuring their photocatalytic oxidation of malachite green dye under visible light. Photocatalytic parameters such as the type of doped materials, photocatalyst dosage and photocatalytic stability were also studied. The photocatalytic activity of CdS is lower than that of doped cadmium sulphide nanoparticles. This can be attributed to the fact that the addition of Pt or In2O3 or both In2O3 and Pt to CdS nanoparticles decreases the electron-hole recombination rate or alternatively due to the transfer of electrons between the doped metal and CdS nanoparticles.