Hydrothermal synthesis of TiO2/carbon composites and their application for removal of organic pollutants

Abstract

TiO2/carbon composites were synthesized by hydrothermal carbonization, using titanium isopropoxide and glucose precursor solution to obtain composites with Ti/C molar ratios ranging from 0.05 to 0.30. Characterization of obtained composites was performed by thermogravimetric analysis, scanning electron microscopy, nitrogen adsorption–desorption isotherms, X-ray diffraction, UV–Vis diffuse reflectance spectroscopy and Fourier transform infrared spectroscopy. The possibility of using TiO2/carbon composites as photocatalysts for UV assisted degradation of methylene blue in aqueous solution and selected pharmaceuticals from multicomponent solution was examined. It was found that increase in the glucose concentration, i.e. increased carbon content, leads to the higher porosity and increase in the share of photocatalytically active anatase phase in obtained TiO2/carbon composites. Sample obtained from the most concentrated glucose solution (TiO2/HTC4), showed the superior photocatalytic activity under UV irradiation toward both methylene blue and selected pharmaceuticals. In addition, TiO2/HTC4 show high recycling ability with degradation ratio of methylene blue higher than 81% after five cycles. Also, TiO2/HTC4 is expected to be a promising candidate for photocatalytic processes using visible light.