Performance and mechanism on the photocatalytic-adsorption removal of Cr(VI) from water by Platanusacerifolia fibers loaded rGO-TiO₂

Inorder to remove Cr(Ⅵ) from water efficiently, reduced graphene oxide-TiO₂@ae-PAF(rGO-TiO₂@ae-PAF) composite material was prepared via one-step hydrothermal method using pretreated Platanusacerifolia fibers(ae-PAF) as carriers. The morphology, crystal structure and physicochemical properties of as-obtained materials were characterized with SEM, TEM, XRD, FT-IR and UV-vis. The performance and mechanism underlying the photocatalytic-adsorption removal of Cr(Ⅵ) from water were investigated as well. It was shown that rGO-TiO₂@ae-PAF possessed micron-sized hollow tubular structure. Under ultraviolet light irradiation, the Cr(Ⅵ) removal rate from the 50 mL solution with a concentration of 30 mg·L⁻¹ was beyond 98% by the photocatalyst with TiO₂ loading amount of 10% at 0.2 g·L⁻¹ catalyst dosage, pH=2 and 25℃. The mechanism analysis confirmed that the rapid conduction of photogenerated electrons by rGO and remarkable adsorption of ae-PAF for Cr(Ⅲ) achieved the synergy between the photocatalytic reduction of Cr(Ⅵ) and the adsorption of Cr(Ⅲ) in rGO-TiO₂@ae-PAF, which significantly improved the performance of photocatalytic-adsorption removal of Cr(Ⅵ) from water.