Activation of peroxymonosulfate by a novel EGCE@Fe3O4 nanocomposite: Free radical reactions and implication for the degradation of sulfadiazine

Cobalt sulfide-reduced graphene oxide: An efficient catalyst for the degradation of rhodamine B and pentachlorophenol using peroxymonosulfate

“…In absence of CoS-rGO (Fig. 7A, pink spectrum), a typical four-peak spectrum of DMPO-OH • spin adduct was observed with its characteristic hyperfine coupling constant A N =A H = 14.9 G, resulting from the PMS hydrolysis, as already reported by Tan et al [45]. However, both DMPO-OH • and DMPO-SO •− 4 adducts appeared in PMS and CoS-rGO/PMS systems.…”

Boosting Fenton-Like Reactions via Single Atom Fe Catalysis

“…In comparison to gas phase and electrochemical catalysis, much less attention has been paid to single atom catalysis in aqueous phases, for instance, catalytic oxidation of organic pollutants in water. Over the past decades, remediation technologies for refractory organic contaminants have been receiving considerable attention in both scientific and industrial fields, in view of the increasingly restrictive environmental regulations worldwide and the strong desire of the society for a healthy environment. − It is generally accepted that Fenton reaction, producing highly reactive hydroxyl radicals ( • OH) from H 2 O 2 , is one of the most efficient advanced oxidation processes (AOPs) for degradation of organic contaminants. − Homogeneous catalysts of Fe 2+ or Fe 3+ ions are usually employed for the Fenton or Fenton-like reactions, yet they suffer from iron leaching, sludge formation, recovery, and narrow pH working range issues. − Heterogeneous Fenton-like oxidation was subsequently suggested to be an alternative to alleviate these problems, in which supported iron catalysts are widely used, yet the high activities in homogeneous catalysis are sacrificed. − In the iron based Fenton-like catalysis, the reactions undergo three steps: (i) iron sites contact with H 2 O 2 , (ii) Fe 3+ /Fe 2+ /H 2 O 2 system generates • OH radicals, and (iii) • OH radicals degrade organics. In these steps, the interaction between iron sites and H 2 O 2 is the imperative step to determine the activity of • OH generation .…”

The Confined Interlayer Growth of Ultrathin Two-Dimensional Fe3O4 Nanosheets with Enriched Oxygen Vacancies for Peroxymonosulfate Activation

“…Among the step reactions, the regeneration of Fe 2+ was generally recognized as the rate-determining step in the activation of PMS on iron-based catalysts. , Various kinds of complementary methods had been used to improve the Fe 3+ /Fe 2+ cycle. For example, Fe 3 O 4 modified with epigallocatechin-3-gallate, magnetic ferrospinel MFe 2 O 4 (M = Co, Cu, Mn, and Zn), Mn 1.8 Fe 1.2 O 4 nanospheres with the doping of transition metals, etc. were all designed to enhance the reduction process from Fe 3+ to Fe 2+ by making the thermodynamics viable.…”

“…5,8 Iron, the fourth most abundant element in the Earth's crust, was regarded as an important promising transition metal AOP catalyst. 9,10 The variable chemical states and unoccupied orbits of Fe enabled the electron transfer in a redox cycle, thus activating PMS molecules into reactive species. 11 Unfortunately, the regeneration of Fe 2+ caused by the lower reduction potential of Fe 3+ /Fe 2+ (+0.77 V) in pure iron-based catalysts was thermodynamically unfavorable during PMS activation, thus restricting its activity.…”