Synergetic effect between adsorption and photodegradation on rGO/TiO2/ACF composites for dynamic toluene gaseous removal

The toluene poses a serious threat to the atmospheric environment and human health. Herein, the reduced graphene oxide (rGO)/TiO2 immobilized on the activated carbon fiber (ACF) are fabricated by ultrasonic assisted sol-gel impregnation method to photodegrade dynamic toluene. Characterizations of rGO/TiO2/ACF composites reveal that the majority of graphene oxide (GO) is reduced to rGO and rGO/TiO2 is evenly loaded onto the ACF surface in the form of a smooth film. Furthermore, the photoelectrochemical experiments demonstrate both rGO and ACF can enhance significantly the separation efficiency of electron-hole pairs. The maximum removal efficiency of rGO/TiO2/ACF-0.75% can be up to 85% under ultraviolet irradiation. The rGO/TiO2/ACF exhibits more excellent adsorption and photodegradation activity for dynamic toluene than both rGO/TiO2 and ACF due to the synergetic effect rather than a simple linear combination of the rGO/TiO2 and ACF for toluene conversion. The possible photodegradation pathway is proposed according to intermediates measured by GC-MS, and adsorption coupling photocatalytic mechanisms are discussed.