Thermodynamic and Kinetic Behaviors of Persulfate-Based Electron-Transfer Regime in Carbocatalysis

Abstract

A carbon-based advanced oxidation process is featured for the nonradical electron-transfer pathway (ETP) from electron-donating organic compounds to activated persulfate complexes, enabling it as a green technology for the selective oxidation of organic pollutants in complex water environments. However, the thermodynamic and kinetic behaviors of the nonradical electron-transfer regime had been ambiguous due to a neglect of the influence of pH on the mechanisms. In this study, three kinds of organic pollutants were divided in the carbon-based ETP regime: (i) physio-adsorption, (ii) adsorption-dominated ETP (oxidation rate slightly surpasses adsorption rate), and (iii) oxidation-dominated ETP (oxidation rate outpaces the adsorption rate). The differential kinetic behaviors were attributed to the physicochemical properties of the organic pollutants. For example, the hydrophobicity, molecular radius, and positive electrostatic potential controlled the mass-transfer process of the adsorption stage of the reactants (peroxydisulfate (PDS) and organics). Meanwhile, other descriptors, including the Fukui index, oxidation potential, and electron cloud density regulated the electrontransfer processes and thus the kinetics of oxidation. Most importantly, the oxidation pathways of these organic pollutants could be altered by adjusting the water chemistry. This study reveals the principles for developing efficient nonradical systems to selectively remove and recycle organic pollutants in wastewater.

Direct Electron Transfer-Driven Nontoxic Oligomeric Deposition of Sulfonamide Antibiotics onto Carbon Materials for In Situ Water Remediation

“…It was evident that as the degree of polymerization of the oligomeric products increased, the number of rings and molecular volume of the oligomers would increase (Table S27), thus enhancing van der Waals forces (including orientation forces and π−π interactions). 46 Consequently, the adsorption of oligomers onto nitrogendoped carbon nanotubes (NCNTs) was strengthened. Moreover, the hydrophobicity of the oligomers also increased with the degree of polymerization in all five kinds of oligomers (Figure 2d and Table S26).…”

“…Yet, the underlying reasons why polymers adhere to the catalyst surface instead of entering into the bulk solution remain unclear, thus introducing ambiguity to the understanding of the pollutant removal process via oligomerization. ,,,, Further discussions on the property change of the oligomers are necessary. It was evident that as the degree of polymerization of the oligomeric products increased, the number of rings and molecular volume of the oligomers would increase (Table S27), thus enhancing van der Waals forces (including orientation forces and π–π interactions) . Consequently, the adsorption of oligomers onto nitrogen-doped carbon nanotubes (NCNTs) was strengthened.…”

Advances in Atomically Dispersed Metal and Nitrogen Co‐Doped Carbon Catalysts for Advanced Oxidation Technologies and Water Remediation: From Microenvironment Modulation to Non‐Radical Mechanisms

“…In the recent studies, different types of pollutants with varies adsorption or oxidation features are divided to uncover the thermodynamics and kinetics of electron transfer process. [ 114 ] Moreover, the wet chemistry features modulation of carbon materials played important roles for tuning of oxidation pathways of pollutants, which revealed a crucial principle for knowledge of charge transfer regime. [ 114,115 ]…”

“…[ 114 ] Moreover, the wet chemistry features modulation of carbon materials played important roles for tuning of oxidation pathways of pollutants, which revealed a crucial principle for knowledge of charge transfer regime. [ 114,115 ]…”

Facet-Dependent Fe2O3/BiVO4(110)/BiVO4(010)/Fe2O3 Dual S-Scheme Photocatalyst as an Efficient Visible-Light-Driven Peroxymonosulfate Activator for Norfloxacin Degradation

“…Second, it can function effectively in pH ranges between 2 and 10, while ·OH is limited to pH values between 2 and 5. Additionally, SO 4 ·– demonstrates higher oxidation selectivity and a longer lifetime 30 to 40 μs, in contrast to the relatively short lifetime of ·OH (10 –3 μs). − Despite the potential benefits of persulfates activation, traditional methods for activating persulfates suffer from various drawbacks. These include higher energy consumption, the generation of secondary pollution, low treatment efficiency, leaching of metal ions, and the inability to recycle the catalyst materials.…”