Support work-function dependent Fenton-like catalytic activity of Co single atoms for selective cobalt(IV)=O generation.

In Fenton-like reactions, high-valent cobalt-oxo (Co=O) has attracted increasing interests due to high redox potential, long lifetime, and anti-interference properties, but its generation is hindered by the electron repulsion between the electron rich oxo- and cobalt centers. Here, we demonstrate Co=O generation from peroxymonosulfate (PMS) activation over cobalt single-atom catalysts (Co-SACs) using in-situ Co K-edge X-ray absorption spectra, and discern that Co=O generation is dependent on the support work-function (W) due to the strong electronic metal-support interaction (EMSI). Supports with a high W value like anatase-TiO facilitate the binding of PMS-terminal oxo-ligand to Co sites by extracting Co-d electrons, thus decreasing the generation barrier for the critical intermediate (Co-OOSO).

Correlating active sites and oxidative species in single-atom catalyzed Fenton-like reactions.

Single-atom catalysts (SACs) have gained widespread popularity in heterogeneous catalysis-based advanced oxidation processes (AOPs), owing to their optimal metal atom utilization efficiency and excellent recyclability by triggering reactive oxidative species (ROS) for target pollutant oxidation in water. Systematic summaries regarding the correlation between the active sites, catalytic activity, and reactive species of SACs have rarely been reported. This review provides an overview of the catalytic performance of carbon- and metal oxide-supported SACs in Fenton-like reactions, as well as the different oxidation pathways induced by the metal and non-metal active sites, including radical-based pathways (, ·OH and SO˙) and nonradical-based pathways ( O, high-valent metal-oxo species, and direct electron transfer).

Polyvinyl alcohol as solid proton donor to modify g-CN hydrogen bonding enabling efficient photocatalytic HO production from HO and O.

Polyvinyl alcohol (PVA) was used as a solid proton donor to improve the photocatalytic performance of graphitic carbon nitride (CN) for hydrogen peroxide (HO) production. The modified CN (CN/PVA) was prepared by mixing CN and PVA at room temperature. The HO production efficiency of CN/PVA was 5.

Synergistic catalysis of TiO/WO photoanode and Sb-SnO electrode with highly efficient ClO• generation for urine treatment.

Urine is the major source of nitrogen pollutants in domestic sewage and is a neglected source of H. Although ClO• is used to overcome the poor selectivity and slow kinetics of urea decomposition, the generation of ClO• suffers from the inefficient formation reaction of HO• and reactive chlorine species (RCS). In this study, a synergistic catalytic method based on TiO/WO photoanode and Sb-SnO electrode efficiently producing ClO• is proposed for urine treatment.

Understanding the role of transition metal single-atom electronic structure in oxysulfur radical-mediated oxidative degradation.

The ubiquity of refractory organic matter in aquatic environments necessitates innovative removal strategies. Sulfate radical-based advanced oxidation has emerged as an attractive solution, offering high selectivity, enduring efficacy, and anti-interference ability. Among many technologies, sulfite activation, leveraging its cost-effectiveness and lower toxicity compared to conventional persulfates, stands out.

Keto-anthraquinone covalent organic framework for HO photosynthesis with oxygen and alkaline water.

Hydrogen peroxide photosynthesis suffers from insufficient catalytic activity due to the high energy barrier of hydrogen extraction from HO. Herein, we report that mechanochemically synthesized keto-form anthraquinone covalent organic framework which is able to directly synthesize HO (4784 μmol h g at λ > 400 nm) from oxygen and alkaline water (pH = 13) in the absence of any sacrificial reagents. The strong alkalinity resulted in the formation of OH(HO) clusters in water, which were adsorbed on keto moieties within the framework and then dissociated into O and active hydrogen, because the energy barrier of hydrogen extraction was largely lowered.

Heteroatom substitution enhances generation and reactivity of surface-activated peroxydisulfate complexes for catalytic fenton-like reactions.

Peroxydisulfate (PDS)-based Fenton-like reactions are promising advanced oxidation processes (AOPs) to degrade recalcitrant organic water pollutants. Current research predominantly focuses on augmenting the generation of reactive species (e.g.

Plastic wastes-derived N-doped carbon nanotubes for efficient removal of sulfamethoxazole in high salinity wastewater via nonradical peroxymonosulfate activation.

Peroxymonosulfate (PMS) catalytic activation is effective to eliminate organic pollutants from water, thus the development of low-cost and efficient catalysts is significant in applications. The resource conversion of plastic wastes (PWs) into carbon nanotubes (CNTs) is a promising candidate for PMS-based advanced oxidation processes (AOPs), and also a sustainable strategy to realize plastic management and reutilization. Herein, cost-effective PWs-derived N-doped CNTs (N-pCNTs) were synthesized, which displayed efficient activity for PMS activation through an electron transfer pathway (ETP) for sulfamethoxazole (SMX) degradation in high salinity water.

Cooperation of ferrous ions and hydrated ferric oxide for advanced phosphate removal over a wide pH range: Mechanism and kinetics.

Excessive phosphate loading leads to eutrophication problems in rivers or lakes and causes serious environmental and economic damages, urging new technologies to reduce effluent phosphate at ultra-low levels. As a promising candidate, adsorption over metal oxides is restricted by the released hydroxide anions (OH) through ligand exchange, which elevates pH and suppresses further adsorption. In this contribution, we found ferrous ions (Fe) significantly enhance phosphate removal over hydrated ferric oxide (HFO) in a wide pH range via a cooperation of adsorption and precipitation, and clarified the synergistic mechanism by a series of characterizations and the modified models of adsorption isotherms and pseudo second-order kinetics.

Merits and Limitations of Radical vs. Nonradical Pathways in Persulfate-Based Advanced Oxidation Processes.

Urbanization and industrialization have exerted significant adverse effects on water quality, resulting in a growing need for reliable and eco-friendly treatment technologies. Persulfate (PS)-based advanced oxidation processes (AOPs) are emerging as viable technologies to treat challenging industrial wastewaters or remediate groundwater impacted by hazardous wastes. While the generated reactive species can degrade a variety of priority organic contaminants through radical and nonradical pathways, there is a lack of systematic and in-depth comparison of these pathways for practical implementation in different treatment scenarios.

Carbon nanotubes production from real-world waste plastics and the pyrolysis behaviour.

The investigation of the pyrolysis behaviour of real-world waste plastics (RWWP) and using them as the feedstock to produce carbon nanotubes (CNTs) could serve as an effective solution to address the global waste plastics catastrophe. This research aimed to characterize the pyrolysis behaviour of RWWP via thermogravimetric analysis (TG) and fast pyrolysis-TG/mass spectrometry (Py-TG/MS) analyses. Activation energies (131.

CoN O Single-Atom Catalyst for Efficient Peroxymonosulfate Activation and Selective Cobalt(IV)=O Generation.

High-valent metal-oxo (HVMO) species are powerful non-radical reactive species that enhance advanced oxidation processes (AOPs) due to their long half-lives and high selectivity towards recalcitrant water pollutants with electron-donating groups. However, high-valent cobalt-oxo (Co =O) generation is challenging in peroxymonosulfate (PMS)-based AOPs because the high 3d-orbital occupancy of cobalt would disfavor its binding with a terminal oxygen ligand. Herein, we propose a strategy to construct isolated Co sites with unique N O coordination on the Mn O surface.

Single-Atom MnN Catalytic Sites Enable Efficient Peroxymonosulfate Activation by Forming Highly Reactive Mn(IV)-Oxo Species.

Four-nitrogen-coordinated transitional metal (MN) configurations in single-atom catalysts (SACs) are broadly recognized as the most efficient active sites in peroxymonosulfate (PMS)-based advanced oxidation processes. However, SACs with a coordination number higher than four are rarely explored, which represents a fundamental missed opportunity for coordination chemistry to boost PMS activation and degradation of recalcitrant organic pollutants. We experimentally and theoretically demonstrate here that five-nitrogen-coordinated Mn (MnN) sites more effectively activate PMS than MnN sites, by facilitating the cleavage of the O-O bond into high-valent Mn(IV)-oxo species with nearly 100% selectivity.

Rapid Simulation of Decade-Scale Charcoal Aging in Soil: Changes in Physicochemical Properties and Their Environmental Implications.

aging can change biochar properties, influencing their ecosystem benefits or risks over time. However, there is a lack of field verification of laboratory methods that attempt simulation of long-term natural aging of biochar. We exploited a decade-scale natural charcoal (a proxy for biochar) aging event to determine which lab-aging methods best mimicked field aging.

Treasuring industrial sulfur by-products: A review on add-value to reductive sulfide and sulfite for contaminant removal and hydrogen production.

Reductive sulfur-containing by-products (S-BPs) released from industrial process mainly exist in the simple form of sulfide and sulfite. In this study, recent advances to remove and make full use of reductive S-BPs to achieve efficient contaminant removal and hydrogen production are critically reviewed. Sulfide, serves as both reductant and nucleophile, can form intermediates with the catalyst surface functional group through chemical interaction, efficiently promoting the catalytic reduction process to remove contaminants.

Rapid Conversion of Co to Co by Introducing Oxygen Vacancies in CoO Nanowire Anodes for Nitrogen Removal with Highly Efficient H Recovery in Urine Treatment.

Urine is a nitrogenous waste biomass but can be used as an appealing alternative substrate for H recovery. However, urine electrolysis suffers from sluggish kinetics and requires alkaline condition. Herein, we report a novel system to decompose urine to H and N under neutral conditions mediated by Cl using oxygen-vacancy-rich CoO nanowire (O-CoO) anodes and CuO nanowire cathodes.

Ultrahigh Peroxymonosulfate Utilization Efficiency over CuO Nanosheets via Heterogeneous Cu(III) Formation and Preferential Electron Transfer during Degradation of Phenols.

In persulfate activation by copper-based catalysts, high-valent copper (Cu(III)) is an overlooked reactive intermediate that contributes to efficient persulfate utilization and organic pollutant removal. However, the mechanisms underlying heterogeneous activation and enhanced persulfate utilization are not fully understood. Here, copper oxide (CuO) nanosheets (synthesized with a facile precipitation method) exhibited high catalytic activity for peroxymonosulfate (PMS) activation with 100% 4-chlorophenol (4-CP) degradation within 3 min.

A non-invasive smart scaffold for bone repair and monitoring.

Existing strategies for bone defect repair are difficult to monitor. Smart scaffold materials that can quantify the efficiency of new bone formation are important for bone regeneration and monitoring. Carbon nanotubes (CNT) have promising bioactivity and electrical conductivity.

Hydrogen spillover in complex oxide multifunctional sites improves acidic hydrogen evolution electrocatalysis.

Improving the catalytic efficiency of platinum for the hydrogen evolution reaction is valuable for water splitting technologies. Hydrogen spillover has emerged as a new strategy in designing binary-component Pt/support electrocatalysts. However, such binary catalysts often suffer from a long reaction pathway, undesirable interfacial barrier, and complicated synthetic processes.

Quantitative structure-activity relationship for the oxidation of organic contaminants by peracetic acid using GA-MLR method.

Peracetic acid (PAA) is considered as an effective and powerful oxidant for eliminating organic contaminants in wastewater treatment. The second-order rate constant (k) for the reaction of PAA with organic contaminants is practically important for evaluating their removal efficiency in wastewater treatment, but only limited numbers of k values are available. In this study, 70 organic compounds with various structures were selected, and the k of PAA with each organic compound was used to develop two quantitative structure-activity relationship (QSAR) models based on three kinds of descriptors including constitutional, quantum chemical, and the PaDEL descriptors.

Cyclic coupling of photocatalysis and adsorption for completely safe removal of N-nitrosamines in water.

The incomplete removal of N-nitrosamines in water through current degraded techniques and the carcinogenicity of N-nitrosamines call for alternative complete and safe removal approaches. Here, we describe a cyclic coupling process of photocatalysis and adsorption enabling N-nitrosamines in water thoroughly and safely removed. Among them, the immobilized TiO/Ti photocatalyst degraded N-nitrosamines into primary and secondary amines up to 100% by attacking on nitrosyl nitrogen via •OH originated from its nanowire film morphology.

Catalyzed HO decomposition over iron oxides and oxyhydroxides: Insights from oxygen production and organic degradation.

Iron minerals, such as iron oxides and iron oxyhydroxides, are the main influential soil components in catalyzed hydrogen peroxide propagation (CHP). Due to their dual effects on HO activation to produce reactive oxygen species (ROS) and invalid consumption to produce oxygen, the intrinsic reactivity of iron minerals toward HO decomposition requires comprehensive investigations. Herein, six iron minerals (hematite, magnetite, maghemite, goethite, feroxyhyte, and ferrihydrite) for HO decomposition were investigated by a combination of normalized kinetic rate constants of HO decomposition (Nk), O production (Nk), benzoic acid degradation (Nk), and hexachloroethane degradation (Nk) over the surface area of each mineral.