Porous carbon layer has been formed by treating the carbon-coated titania (C@TiO2) with KOH solution. Carbon-coated titania (C@TiO2) was obtained by pyrolysis of polystyrene-coated titania (PS@TiO2), which was produced by in situ polymerization of styrene by using aqueous hydrogen peroxide. The presence of polystyrene and carbon on the surface of titania were confirmed by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopy techniques. Carbon content was about 2.2 wt.% with thickness of carbon layer ca. 5 nm. After treating with KOH solution, PC@TiO2 with the pore size of ca. 5 nm, total pore volume of 0.05 cm(2) g(-1) and Brunauer-Emmett-Teller (BET) specific surface area of 46 m(2) g(-1) has been obtained. Catalytic activity results showed that PC@TiO2 gave a higher activity in styrene oxidation compared to bare TiO2, and C@TiO2. The highest catalytic activity was obtained by using PC@TiO2 that obtained after treating C@TiO2 with 1.0 M KOH solution with benzaldehyde and phenylacetaldehyde as the main reaction products. At the higher concentration of KOH solution, the catalytic activity decreased when crystallinity of TiO2 decreased. (C) 2012 Elsevier By. All rights reserved.