Sunlight-Induced Photocatalytic Degradation of Organic Pollutants by Carbon-Modified Nanotitania with Vegetable Oil as Precursor

Abstract

An attempt has been made in this study to prepare a nanosized titanium dioxide catalyst by an ultrasonication assisted sol−gel process at low temperature. The as-synthesized titania was modified with carbon from coconut oil as a carbon precursor in two different proportions and then subjected to thermal and microwave treatment. The characterization of the pure and carbon modified titania catalysts was accomplished by XRD, SEM, HR-SEM/EDX, UV−vis absorption spectroscopy, and BET surface area analysis. The average size of the carbon modified TiO2 catalysts was found to be in the range of 90 nm. The solar photocatalytic activity of the catalysts was monitored by the degradation of a cationic dye, methylene blue, and an anionic dye, methyl orange. The effect of pH on the degradation of the dyes was also investigated. The study revealed that the degradation of the cationic dye was highly pronounced in the alkaline pH, whereas, the degradation of the anionic dye was effective in acidic pH. A solar photochemical study was also conducted with 2,4-dichlorophenol to ensure the degradation of visible light nonabsorbing organic compounds. The study revealed that carbon-modified catalysts with about 8.0 wt % of carbon was found to have the highest solar phoactivity, when compared to the pure titania and the carbon modified titania with 42% of carbon.