Fabricating 3D porous PANI/TiO2–graphene hydrogel for the enhanced UV-light photocatalytic degradation of BPA

Abstract Polyaniline (PANI)/TiO 2 composite graphene hydrogel was successfully prepared by chemical reduction method. TiO 2 and PANI were uniformly dispersed in the three-dimensional network of graphene hydrogels. This rich network of macroscopic structures not only provides desirable conditions for synergistic adsorption and photocatalytic degradation of pollutants, but also improves the chemical stability of composites. Specifically, 80% PANI/TiO 2 -reduced graphene oxide hydrogel (rGH) can completely degrade BPA in 40 min, and BPA was almost completely mineralized into small molecules in 65 min. After five cycles of experiments, the degradation rate of PANI/TiO 2 -rGH for BPA was more than 90%. XPS analysis indicated that there is a strong interaction between PANI and TiO 2 . Hydrogen bonding between TiO 2 and rGH was also demonstrated. Quenching experiments indicated •O 2 − and h + are the main active species in the degradation of BPA by PANI/TiO 2 -rGH and •OH and h + are the main active species by PANI/TiO 2 , suggesting that rGH and PANI acts as a transmitter for e − and h + , respectively.