Eco-friendly TiO2–AC Photocatalyst for the Selective Photooxidation of 4-Chlorophenol

• DOI: 10.1007/s10562-009-9989-8
• Publication Date: 2009-05-22T17:52:02Z
• Authors: Juan Matos; Andreina Garcia; Tulynan Cordero; Jean-Marc Chovelon; Corinne Ferronato
• Keywords: [CHIM.CATA] Chemical Sciences/Catalysis; [CHIM.CATA]Chemical Sciences/Catalysis; 02 engineering and technology; 0210 nano-technology

The influence of surface pH of activated carbon on selectivity of TiO2 during the photooxidation of 4-chlorophenol on UV-irradiation was studied. Chlorine substitution by p-hydroxylation yielding hydroquinone in equilibrium with benzoquinone and o-hydroxylation to 4-chlorocathecol were detected as the main intermediates in the photooxidation of 4CP. Changes in surface pH of carbons from basic to closely neutral induce a remarkably increase in the production of 4-chlorocatechol by a factor of 22 on TiO2-AC in comparison of TiO2 alone. A mechanism of interaction between both solids is proposed to explain changes both in photoactivity and photoselectivity of TiO2. In conclusion, results showed that TiO2-AC can be used as an alternative green photocatalyst in organic synthesis.