Environmental green chemistry applications of nanoporous carbons

Influence of surface properties of nanoporous carbons on activity and selectivity during the photooxidation of 4-chlorophenol on UV-irradiated TiO2 was performed. Characterization by infrared spectroscopy, X-ray photoelectronic spectroscopy and X-ray absorption near edge structure spectroscopy confirm the presence of a contact interface between both solids and suggest the coordination of some functional organic groups of the carbon surface, mainly ethers and carboxylic acids, to metallic centre Ti+4 in TiO2. Changes in surface pH of carbons from basic to neutral or acid remarkably increase the production of 4-chlorocathecol by a factor of 22 on TiO2–Carbon in comparison of TiO2 alone. A scheme of interaction between TiO2 and carbon is proposed to the increased photoactivity of TiO2 and a reaction mechanism for the different intermediate products detected is also proposed. Results showed that TiO2–Carbon can be used as an alternative photocatalyst for environmental green chemistry and selective organic synthesis applications.