Removal of benzene and toluene by carbonized bamboo materials modified with TiO2

Carbonized moso bamboo (Phyllostachys pubescens) was coated with TiO2 nanoparticles to enhance its removal efficiency of harmful gases. Carbonized bamboo–TiO2 composite (CBC) was prepared by heating mixtures of carbonized bamboo powder (CB) and TiO2 nanoparticles, denoted as CBM, under nitrogen condition. TiO2 nanoparticle and carbonized bamboo powder were mixed with the mass ratios of 1/1 and 2/1, respectively. At the same mass ratio of TiO2 to CB, the benzene and toluene removal efficiencies follow the trend: CBC > CBM > CB, which is consistent with the amount of TiO2 validated by elemental analysis. Sorption mechanism of benzene and toluene by CB, CBM and CBC might belong to hydrophobic–hydrophobic interaction, observed by depletion of untreated bamboo (UB) carbohydrates during carbonization. Sorption kinetics was further analyzed, and optimal correlation was found by fitting with the Elovich kinetic equation.