A novel charge-driven self-assembly method to prepare visible-light sensitive TiO₂/activated carbon composites for dissolved organic compound removal

An experimental study was devised to explore the possible improvements to the conventional wet chemical impregnation technique of TiO₂/activated carbon composites preparation. The surface characteristics of activated carbon adsorbents were chemically modified with poly (sodium styrene sulfonate), which enabled the charge-driven self-assembly with visible-light sensitive colloidal TiO₂ nanoparticles. Characterization and humic acid removal test results discovered a significant increase of TiO₂ loading to the activated carbon structure via the charge-driven self-assembly method. Photocatalytic kinetics studies also revealed that TiO₂/activated carbon composites prepared via the charge-driven self-assembly method fitted the pseudo-first-order equation well, which is similar to the unsupported TiO₂ photocatalysts. These findings confirmed the better distribution of TiO₂ coating over the AC surface with poly (sodium styrene sulfonate) modification rather deep into their pores. As a result, fast and effective photocatalytic regeneration of spent activated carbon adsorbents within composites is expected.