Band gap engineering for improved photocatalytic performance of CuS/TiO2 composites under solar light irradiation

M H Farooq,A Shuaib,I Aslam,M Rizwan,Q Kanwal,H S Anam

doi:10.4314/bcse.v33i3.16

Abstract

ABSTRACT . Nanoparticles of CuS, TiO 2 and CuS/TiO 2 composites were prepared by template free hydrothermal method. Prepared nanoparticles were characterized by X-ray diffraction (XRD) and electron dispersive X-ray spectroscopy to confirm the formation of nanoparticles. Field emission scanning electron microscopy (FESEM) was applied to investigate the morphology and particle size of the nanoparticles which were measured in the range of 30–40 nm. Photocatalytic performance of CuS, TiO 2 and Cus/TiO 2 were measured by degradation of methyl orange (MO) under solar light irradiation. Coupling of n-type TiO 2 (3.2 eV) with p-type CuS (1.9 eV) showed efficient degradation of the contaminants under the solar light irradiation. Photocatalytic performance of CuS/TiO 2 composite improves 1.4 times than CuS for the degradation of methyl orange (MO) under solar light irradiation. KEY WORDS : CuS/TiO 2 composites, Photocatalytic performance, Hydrothermal growth, Solar light, Irradiation Bull. Chem. Soc. Ethiop. 2019 , 33(3), 561-571. DOI: https://dx.doi.org/10.4314/bcse.v33i3.16

Highlights

TiO2 is widely used as a photocatalyst due low toxic, highly stable and of being low cost material
Crystalline size of the particles was calculated by using the data of X-ray diffraction (XRD) peaks with the help of Debye-Scherrer formula: Dc = K / Cos, where K is constant and called shape factor with value of 0.9 for tetragonal structure, λ stands for the wavelength of X-rays which is 1.5406 Å for CuKα, β stands for the full wave half maximum (FWHM) of the peak and indicates the Bragg’s angle
Synthesized nano particles were characterized by X-ray diffraction (XRD) by using CuKα radiations to confirm the crystal structure and formation of required material

Summary

Introduction

TiO2 is widely used as a photocatalyst due low toxic, highly stable and of being low cost material. Deposition of metal ions V, Cr, Co and Fe [25,26,27,28] on the surface of TiO2 increase the spectral response of material to visible light region and improve the photocatalytic performance. Band gap engineering for improved photocatalytic performance of CuS/TiO2 composites 563 induce oxygen vacancies and reduced Ti+4 to Ti+3 providing new energy levels inside the band gap of TiO2 to make it active under visible light region.

Results

Conclusion