Christian Gómez-Solís

Photodegradation of indigo carmine and methylene blue dyes in aqueous solution by SiC–TiO2 catalysts prepared by sol–gel

Indigo carmine and methylene blue dyes in aqueous solution were photodegraded using SiC-TiO(2) catalysts prepared by sol-gel method. After thermal treatment at 450°C, SiC-TiO(2) catalysts prepared in this work showed the presence of SiC and TiO(2) anatase phase. Those compounds showed specific surface area values around 22-25 m(2)g(-1), and energy band gap values close to 3.05 eV. In comparison with TiO(2) (P25), SiC-TiO(2) catalysts showed the highest activity for indigo carmine and methylene blue degradation, but this activity cannot be attributed to the properties above mentioned. Therefore, photocatalytic performance is due to the synergy effect between SiC and TiO(2) particles caused by the sol-gel method used to prepare the SiC-TiO(2) catalysts. TiO(2) nanoparticles are well dispersed onto SiC surface allowing the transfer of electronic charges between SiC and TiO(2) semiconductors, which avoid the fast recombination of the electron-hole pair during the photocatalytic process.

Sonochemical synthesis of Fe–TiO2–SiC composite for degradation of rhodamine B under solar simulator

Fe–TiO2–SiC composite with photocatalytic activity has been synthesized by a low cost sonochemical process in the presence of citric acid. The addition of citric acid during the sonochemical process allows the formation of a photocatalytic coating of Fe–TiO2 onto silicon carbide. Experimental characterization results indicate that the composite was formed over all the surface of the silicon carbide (SiC) with an anatase crystalline TiO2 phase with iron incorporation. The incorporation of iron narrows the band gap of TiO2 which allow the absorbtion of light with a large wavelength. The obtained Fe–TiO2–SiC composite exhibits good enhanced photocatalytic activity for the degradation of rhodamine B under solar simulator irradiation in comparison with the commercial TiO2–P25.