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.