The influence of carbonization temperature on the modification of TiO2in the removal of methyl orange from aqueous solution by adsorption

This work investigated the adsorption ability of unmodified and carbon-modified TiO2 nanoparticles for the removal of methyl orange (MO) from aqueous solution. Carbon–TiO2 was obtained by carbonization of ethanol vapors at three different temperatures (200, 300, and 400°C), and their adsorption was compared with unmodified TiO2 nanoparticles. The Freundlich adsorption model was found to fit for TiO2 and C–TiO2-200, while carbon modification of TiO2 at a high temperature fitted the Langmuir–Freundlich model (C–TiO2-300 and C–TiO2-400). Generally, the carbonization of C–TiO2 increased the adsorption capacity of TiO2 nanoparticles, however the BET surface of modified and pristine TiO2 was almost the same. The zeta potential of modified TiO2 is higher than unmodified TiO2, which leads to efficient adsorption of MO onto modified TiO2.