Black TiO2 and Graphene Oxide (GO) have attracted intensive attention as an effective catalyst on visible light driven for photodegrading of dyes. In this study, nano-black TiO2 was prepared by a simple hydrogenation of the anatase titanium oxide and the graphene oxide was prepared by applying the modified Hummers method. The prepared powders and nanofiber membranes are carefully examined to ensure their single phase and compound structure formation as well as to measure the equivalent crystallite size and particle distributions.
The optimum degradation efficiency of malachite green and methylene blue dyes occurred at pH values of 8 and 10, respectively. Afterwards, at the optimum pH value of 8, for malachite green, the degradation efficiency is peaked at 20 mg of the nano-black TiO2 concentration. Then, a comparison of the degradation efficiency of the two mentioned dyes are performed as the fore-mentioned nanofibers are loaded with 20 mg nano-black TiO2 at the corresponding optimum pH vales.
The diffuse reflectance spectroscopy has been investigated to find out the optical energy gaps of the treated and nano-black samples. Finally, a schematic of the redox reaction mechanism has been proposed.