OPTICAL AND STRUCTURAL STUDIES OF ANODIC COPPER PIGMENTED TITANIUM PHOTOCATALYST

Abstract

Thousands of lives have been lost worldwide due to the shortage of clean water resources caused by waste water disposal challenges from manufacturing and processing industries, population growth and long-term droughts. In Kenya, the disposal of organic pollutants and colored water from industries has become a major challenge both to the humans and the environment. This has led to the study of titanium dioxide (TiO2) photocatalysis as an advanced oxidation process with a potential for practical application in water treatment over other treatment technologies. In this study, commercial pure grade 1 titanium foils measuring 6 cm × 3 cm were used to fabricate anodic TiO2 films at different time intervals by anodization at 200 V in a mixture of 0.5 M sulphuric acid, hydrofluoric acid and distilled water at inter-plate distances of 1 cm. An electrodeposition cell was prepared using a 0.1 M CuSO4.5H2O electrolyte solution, and thereafter pigmentation of the anodized plate was done at 12 V for a period of 5 s and annealed in muffle furnace for a period of 4 hours at a temperature of 450 0C. The determination of both the surface and optical characteristics of the anodic TiO2 films were done using Lambda 9 UV/VIS/NIR Spectrophotometer, Fourier Transform Infrared Spectroscopy, Atomic Force Microscopy, X-ray diffraction (XRD) and Scanning Electron Microscopy. The XRD measurements confirmed the presence of both rutile and anatase phases in TiO2 films. The photocatalytic performances of the films were assessed by the photo-degradation of 10 ppm methylene-blue solution under UV irradiation. Methylene-blue was used in place of the industrial waste water effluent containing dye because of its ability to lend easily to spectroscopic analysis. The optimum anodization time for the films with a high photocatalytic activity in the degradation of methylene blue for this study was found to be 2 minutes.