Photocatalytic Degradation of Orange II by Active Layers of Ag-Doped CuO Deposited by Spin-Coating Method

Abstract

In this work we studied the effect of doping on heterogeneous photocatalysis application we used the samples CuO, 5% Ag:CuO, 15% Ag:CuO, 25% Ag:CuO and 50% Ag:CuO catalysts thin layers which were prepared by the sol gel method on a glass substrate. The structural, morphological, optical and electrical characteristics of these layers were studied by XRD, IR, SEM, UV-Vis spectrophotometry and four-point analysis. The results of the XRD, it is observed that the structure of the monoclinic phase develops, with preferential orientations following the plane (-111). This indicated that the thin films are polycrystalline, these results and confirmed by the IR spectra. In the case of Ag doping the SEM revealed the creation of pores on the surface of the samples, which enhanced the degradation of orange II under UV light. The gap energy decreases from 2.17 eV to 1.25 eV with increasing doping. These results show that thin films doped with Ag exhibit a higher degradation than that obtained by pure CuO. After 5 hours in the case of doping with 50% Ag the percentage of degradation is 43%, on the other hand in the pure case the percentage of degradation is 27%.With this, it can be said that 50% Ag:CuO is a good catalyst because the sample has pores, and therefore a larger catalytic area. Creating pores on the surface of the samples, obtaining a less energy gap enables the creation of a greater number of •Oand OH• that works to disintegrate the dye and give the white color to the solution.