In-depth study on adsorption and photocatalytic performance of novel reduced graphene oxide-ZnFe2O4-polyaniline composites

Ternary photocatalyst, reduced graphene oxide-ZnFe2O4-polyaniline (RZP), has been successfully developed by the in-situ polymerization of aniline on the reduced graphene oxide-ZnFe2O4 (RG/ZF) surface for sewage purification. The SEM, TEM and STEM images suggest that PANI has coated the RG/ZF composite well. The XRD, TG-DTG and FT-IR analysis confirm that there are some interactions between RG/ZF composite and PANI. Importantly, the decontamination performance of RZP composites has been investigated using RhB as a model organic in view of adsorption and photocatalysis. On one hand, thermodynamic researches indicate that the adsorption behaviors of RZP composites conform to the Langmuir model, and their adsorption mechanism can be well described by the second-order kinetic model. On the other hand, RZP composites with different mass ratios of PANI to RG/ZF (m(P/RZ)) present a better photocatalytic activity than that of RG/ZF composites, and their photocatalytic behaviors under different pH could be described by the first-order kinetic model. Furthermore, it can be observed that the RZP composite with m(P/RZ) = 0.4 has the excellent photocatalytic activity and photocatalytic stability under pH = 1. Finally, the possible photocatalytic degradation mechanisms of the RZP composite on RhB have been discussed. These results can unveil that the prepared RZP photocatalyst is very promising for application in water purification. (C) 2016 Elsevier B.V. All rights reserved.