Formation of TiO2 composites on activated carbon modified by nitric acid and their photocatalytic activity

摘要

We have studied a method for the preparation of carbon/TiO2 composites involving the penetration of titanium n-butoxide (TNB) solution into activated carbon. The study has focused on the characterization of the TiO2 obtained in the porous carbon and how increased surface functional groups were created by the acid treatment The conversion of TNB to TiO2 during the heat treatment must be important for the preparation of carbon/TiO2 composites. From the surface textural properties, both the BET surface area and the total pore volume decreased with the distribution of TiO2 on the activated carbon surfaces after the acid treatment According to the results of SEM micrographs, titanium complex particles were regularly distributed on the carbon. Also some large clusters were found when the amount of acid treatment was increased. The changes in XRD patterns show typical anatase type on carbon/TiO2 composites prepared with activated carbon modified by nitric acid. The EDX results of carbon/TiO2 composites show the presence of C, O and S with strong Ti peaks. Observation of the absorption bands for the FT-IR spectra shows that the changes for the carbon/TiO2 composite prepared with activated carbon modified by nitric acid are mainly due to the formation of functional groups. Finally, the excellent photocatalytic activity of carbon/TiO2 composites between relative concentration (c/c_o) of MB and UV irradiation time could be attributed to both effects between photocatalysis of the formation of titania complexes and the adsorptivity of the activated carbon.