posted on 2022-06-24, 16:03authored byShuang Zhong, Zhong-Shuai Zhu, Peng Zhou, Lei Shi, Xiaoguang Duan, Bo Lai, Shaobin Wang
Electrochemical
advanced oxidation processes (EAOPs) are a class
of promising technologies for wastewater remediation. The challenge
of EAOPs is the in situ generation and activation of hydrogen peroxide
(H2O2) to evolve reactive oxygen species (ROS)
simultaneously with low energy consumption and high performances.
In this work, we designed an EAOP system, coupling FeOCl nanoparticles
on oxygen-enriched carbon nanotubes (O-CNTs) and a nickel foam (FeOCl/O-CNTs/NF)
cathode for electro-Fenton (EF) reactions and an IrO2/Ti
anode for anodic oxidation (AO) simultaneously. Specifically, the
defects and oxygen functional groups on O-CNTs introduced by a modified
Hummers’ method could induce the charge redistribution of O-CNTs
for outstanding two-electron oxygen-reduction-reaction performances
(H2O2 selectivity of 73%) and provide more anchoring
sites for the loading of active cocatalyst nanoparticles. Thus, abundant
FeOCl nanoparticles were successfully loaded onto O-CNTs. Such a FeOCl/O-CNTs/NF
cathode exhibited a high H2O2 production rate
of 95 mmol gcat–1 h–1 because of the improved exposure of catalytic active sites supported
on nickel foam to attain a large specific surface area. •OH was generated from H2O2 via both heterogeneous
and homogeneous EF processes induced by the FeOCl/O-CNTs/NF cathode
and leached ferrous ions accordingly. Sulfamethoxazole (SMX) was completely
removed within 30 min at a low specific energy consumption of 0.024
kWh g–1 SMX–1. Thus, the simultaneous
FeOCl/O-CNTs/NF-based EF system and AO provide an efficient and cost-effective
technology for organic contaminant remediation.