Physicochemical characterization and catalytic performance of Fe doped CuS thin films deposited by the chemical spray pyrolysis technique

摘要

The thin films Fe doped copper sulphide Cu_(1-x)Fe_xS (CFS) (x=0.01, 0.03, 0.05, and 0.07) were elaborated by spray pyrolysis deposition technique. The characterization by XRD and SEM of the thin films shows a Covellite CuS single phase without formation of other phases. The structure is a simple hexagonal with unit cell dimension, a - b = 3.79 A and c = 16.34 A. The Analysis of the UV-Vis spectra reveals that the energy band gap has been decreased from 2.47 to 1.98 eV with the increase of Fe concentration. The absorption coefficients of CFS films have increased from 1.155 × 10~5 to 1.712 × 10~5 cm~(-1). It has demonstrated that a right band gap with a right band edge alignment at a pH value for Fe-doped CFS can boost the material application as a photocatalyst for the visible light. According to this study, CFS (0.07) thin films for a pH = 3 solutions is a promising material for photocatalysis application for water splitting to hydrogen-oxygen production. Nevertheless, we demonstrate that the formation of straddling gap heterostructure for CuS and CFS for a pH solution between 7 and 8 induces the production of oxygen and hydrogen.