A novel graphene oxide-carbon nanotubes anchored α-FeOOH hybrid activated persulfate system for enhanced degradation of Orange II
Shanshan Su , Yuyang Liu , Wei He , Xianchun Tang , Wei Jin , Yaping Zhao
DOI:10.1016/j.jes.2019.02.015
Received November 04, 2018,Revised , Accepted February 18, 2019, Available online February 27, 2019
Volume 31,2019,Pages 73-84
Persulfate activation has been applied as one of the efficient advanced oxidation processes (AOPs) to remediate polluted environments. In this study, a novel α-FeOOH anchored by graphene oxide (GO)-carbon nanotubes (CNTs) aerogel (α[email protected]) nanocomposite activated persulfate system (α[email protected] + K2S2O8) was applied for decolorization of Orange II (OII). The decolorization of OII was remarkably enhanced to a level of ~ 99% in this system compared with that of pristine α-FeOOH (~ 44%) or GO-CNTs (~ 18%). The enhanced catalytic activity of α[email protected] was due to the formation of a heterojunction by α-FeOOH and GO-CNTs as confirmed by the presence of Fe–O–C chemical bonds. The degradation intermediates of OII were comprehensively identified. The proposed degradation pathway of OII begins with the destruction of the conjugated structures of OII by the dominant reactive oxygen species, surface-bound SO4•−. The decolorization efficiency of OII by the α[email protected] activated persulfate system decreased from the first to third cycle of recycling. Ultraviolet (UV) irradiation or introduction of a small amount of Fe2+ could restore the activation of this system. The results show that the α[email protected] persulfate activation system promises to be a highly efficient environmental remediation method for organic pollutants.
