Peroxymonosulfate enhanced photoelectrocatalytic degradation of phenol activated by Co 3 O 4 loaded carbon fiber cathode

Abstract

In this paper, a photoelectrocatalytic (PEC) system consisting of c-Bi 2 MoO 6 anode and Co 3 O 4 loaded carbon fiber paper (Co 3 O 4 /CFP) cathode prepared by a hydrothermal method was established and used to degrade phenol. In order to enhance the PEC degradation efficiency of phenol, peroxymonosulfate (PMS) was introduced into this system. At an applied bias of 1.5 V, the removal efficiency of 10 mg/L phenol was increased from 6% to 100% with 2 mM PMS addition into the PEC process. The degradation rate constant of phenol was also increased to be 0.0496 min À1 . Effects of PMS concentration, applied bias and initial pH were investigated. Based on the ESR analysis, sulfate radicals (SO 4 ÅÀ) and hydroxyl radicals (HO Å ) were proved to be the dominant oxidizing species for phenol degradation in the combined system. The PMS was activated to generate SO 4 ÅÀ by loaded Co 3 O 4 , in which photogenerated-electrons accelerated the cobalt cycle process on the cathode. As a result, Co leaching was largely inhibited. The stability of the PEC system for organics degradation was exhibited.

Strongly Coupled g‐C3N4 Nanosheets‐Co3O4 Quantum Dots as 2D/0D Heterostructure Composite for Peroxymonosulfate Activation

“…As one of the most popular AOPs, the∙OH generated from H 2 O 2 through the homogeneous/heterogeneous Fenton reaction is highly recognized to degrade various organic compounds; however, disadvantages such as acidic pH condition, relatively low efficiency, and instability of H 2 O 2 remains a problem . Compared to ∙OH, SO 4 ∙− based AOPs is being increasingly adopted by the following reasons: i) SO 4 ∙− has a higher redox potential (SO 4 ∙− : ≈2.5–3.1 V vs OH: ≈1.9–2.7 V) for pollutants decompose; ii) SO 4 ∙− can be generated from peroxymonosulfate (PMS), which can be easily activated in comparison with H 2 O 2 due to the asymmetric molecular structure . Transition metal oxides (Co, Cu, and Mn, etc.)…”

“…are generally used as activators for PMS activation . Among them, Co 3 O 4 nanoparticles (NPs) as the promising candidate have attracted increasing attention due to its high activity, while the bulk Co 3 O 4 NPs have poor dispersion and tendency to form large particle size to minimize surface active sites inevitably . Thus, there remains a big challenge to explore new approaches of constructing advanced catalysts with increased available active sites to meet the practical requirement through tailoring the morphology of Co 3 O 4 NPs …”

Rapid Removal of Azophloxine via Catalytic Degradation by a Novel Heterogeneous Catalyst under Visible Light

“…The absorbance of azophloxine was determined using a UV-visible spectrophotometer (Shimadzu, Kyoto, Japan, UV-2550) at a maximum wavelength of 531 nm. According to the change in the absorption value of the sample before and after the reaction, the removal ratio (v) was calculated according to the absorbance of the solution before and after the treatment, using the following equation: v = C t /C 0 × 100% = A t /A 0 × 100% (16) where C 0 is the initial concentration of azophloxine, C t is the azophloxine concentration after reaction time t, A 0 is used to show the initial absorbance of azophloxine, and A t is the absorbance of azophloxine after the reaction time [51][52][53].…”

“…•− by transition metal ions with advantages of simple reaction conditions, rapid reaction rate, and low cost [16][17][18].…”

Rapid Removal of Azophloxine via Catalytic Degradation by A Novel Heterogeneous Catalyst under Visible Light

“…Peroxymonosulfate (PMS) is a widely used material to provide ROS to remove a variety of refractory organic pollutants in environmental remediation [14,15]. PMS could be activated to produce •OH and SO4 •− by transition metal ions with advantages of simple reaction conditions, rapid reaction rate, and low cost [16][17][18].…”