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In this study, BiPO4 was prepared by precipitation method, which exhibited high peroxymonosulfate (PMS) activation performance for DS degradation under UV irradiation. The PMS/BiPO4/UV system achieved the superior removal and mineralisation performance for DS (99%). The pH was an important factor, so that at pH 7 and 9 the degradation performance were 99.22% and 98.98%. The removal efficiency increased from 60.64 to 99.12% with increasing doses of BiPO4 0.01 to 0.04 g, while with the increase in the dose up to 0.05 g the removal efficiency decreased to 98.86%. The best values for PMS were 0.05 and 0.06 mgL−1, where the removal efficiency of DS were 98 and 99%, while in 0.04 and 0.07 mgL−1 those were lower than 0.05 and 0.06 mgL−1. Simultaneous existence of PMS and BiPO4 under UV light could improve removal of DS. During reaction, $$SO_4^{^\circ -}$$ S O 4 ∘ − played a major role, and $$H{O^\circ}$$ H O ∘ played a secondary role in the present photo-catalytic degradation process. Correspondingly, a possible pathway of DS degradation were proposed. After five times uses of the BiPO4 the removal efficiency of DS reduced from 99.2% to 97% that was indicating stability and sustainability of PMS/BiPO4/UV process. In general, PMS/BiPO4/UV process could be presented as an applicable method with high performance on removal of DS. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ru monoatoms are stabilized on LDH, which is proved by HAADF-STEM and XANES. • Ru@NiFe-LDH/ PMS system showed excellent degradation efficiency to SMX. • Ru@NiFe-LDH maintains its excellent catalytic activity over a wide pH range. • High-valent species (Ru(V) = O) as the main active species in PMS-based AOPs. • DFT calculations indicate the formation of Ru-PMS* complexes intermediate product. The application of single-atom catalysts (SACs) to advanced oxidation processes (AOPs) based on peroxymonosulfate (PMS) has attracted considerable attention. However, the catalytic pathways and mechanisms underlying these processes remain unclear. In this study, NiFe-LDH was synthesized and single Ru atoms were stably loaded onto it by forming Ru–O–M (M=Ni or Fe) bonds (Ru@NiFe-LDH). This was demonstrated using high-angle annular dark-field scanning TEM (HAADF-STEM) and X-ray absorption fine structure spectra (XANES). The Ru@NiFe-LDH/PMS system showed a high catalytic reactivity (100 % sulfamethoxazole degradation in only 30 min), high stability (97 % reactivity was maintained after continuous operation for 400 min), and wide pH suitability (working pH range 3–11) for AOPs. The crucial roles of the high-valent species (Ru(V) = O) and 1O 2 in this reaction were verified. Density functional theory (DFT) calculations revealed that electron transfer produced a positively charged Ru. This enhances the adsorption of negatively charged PMS anions onto the Ru monoatomic sites, thereby, causing the formation of Ru-PMS* complexes. This study implies that the structure–function relationship between organic compounds and SACs plays a significant role in PMS-based AOPs, and provides a comprehensive mechanism for the role of high-valent species in heterogeneous Fenton-like systems. [ABSTRACT FROM AUTHOR]

MgCoFe layered double oxides (MgCoFe-LDO) were fabricated to activate peroxymonosulfate (PMS) for degradation of sulfamethoxazole (SMX), and the highly efficient degradation of SMX revealed an excellent catalytic activity of Mg2Co1Fe1-LDO for PMS under different pH values and water matrix. Scanning electron microscope analysis indicated the catalyst has a typical "flower-like" structure, and the X-ray powder diffraction analyses proved that the main crystal phase of Mg2Co1Fe1-LDO is CoFe2O4 and Mg1−xFexO, which is responsible for the good catalytic activity of Mg2Co1Fe1-LDO. The radical scavenging experiments confirmed that 1O2, SO 4 · - , OH and O 2 · - were involved in the degradation of SMX, but 1O2 and SO 4 · - played the dominant roles. According to the X-ray photoelectron spectroscopy (XPS) of Mg2Co1Fe1-LDO catalyst, it was referred that the species including CoOH+, CoO+, Fe3+, FeOH2+, Fe2+, etc. involve in the activation process of PMS. Moreover, the possible degradation pathways of SMX were proposed according to the detected intermediates including N-hydroxy sulfamethoxazole, 3-amino-5-methylisoxazole from LC–MS analysis, and the toxicity analysis via Toxicity Estimation Software Tool software shows that most of the degradation products of SMX have lower toxicity than SMX. [ABSTRACT FROM AUTHOR]

Different manganese salt precursor-doped g-C3N4 catalysts prepared by the mixed calcination method were applied in the heat-assisted visible light catalytic peroxymonosulfate (PMS) activation (Heat/Vis/PMS) system for the degradation of diclofenac (DCF). Under this Heat/Vis/PMS system, the CN-Mn-S catalyst using MnSO4 as the manganese salt precursor showed the optimal DCF degradation efficiency (96.9%) with the fastest reaction rate (0.1607 min−1). Besides, with the advantages of large specific surface area, high Mn3O4 generation, and good visible light absorption performance, CN-Mn-S catalyst also maintained excellent catalytic activity after five cycles. Electron paramagnetic resonance (EPR) analysis revealed that the generation of active species with relatively high contribution to DCF degradation, including generation of superoxide anion (O2·−) and singlet oxygen (1O2), were significantly increased in the CN-Mn-S/Heat/Vis/PMS system. Meanwhile, combined with the analysis of influence factor experiments and the DCF degradation characteristics, the CN-Mn-S/Heat/Vis/PMS system was able to maintain excellent DCF degradation ability in complex environments. This work provides a new idea for the application of PMS in real environment. [ABSTRACT FROM AUTHOR]

[Display omitted] The defects formed by N doping always coexist with pyrrole nitrogen (Po) and pyridine nitrogen (Pd), and the synergistic mechanisms of H 2 O 2 production and PMS activation between the different Po: Pd are unknown. This paper synthesized MOF-derived carbon materials with different nitrogen-type ratios as cathode materials in an electro-Fenton system using precursors with different nitrogen-containing functional groups. Several catalysts with different Po: Pd ratios (0:4, 1:3, 2:2, 3:1, 4:0) were prepared, and the best catalyst for LEV degradation was FC-CN (Po: Pd=3:1). X-ray Photoelectron Spectroscopy (XPS) and density-functional theory (DFT) calculations show that the introduction of nitrogen creates an interfacial micro-electric field (IMEF) in the carbon layer and the metal, accelerates the electron transfer from the carbon layer to the Co atoms, and promotes cycling between the Fe3+/Co2+ redox pairs, with the electron transfer reaching a maximum at Po: Pd = 3:1. FC-CN (Po: Pd=3:1) achieved more than 95 % LEV degradation in 90 min at pH = 3–9, with a lower energy consumption of 0.11 kWh m−3 order−1. and the energy consumption of the catalyst for LEV degradation is lower than that of those catalysts reported. In addition, the degradation pathway of LEV was proposed based on UPLC-MS and Fukui function. This study offers some valuable information for the application of MOF derivatives. [ABSTRACT FROM AUTHOR]

[Display omitted] Azo compounds, particularly azo dyes, are widely used but pose significant environmental risks due to their persistence and potential to form carcinogenic by-products. Advanced oxidation processes (AOPs) are effective in degrading these stubborn compounds, with Oxone activation being a particularly promising method. In this study, a unique nanohybrid material, raspberry-like CuCo alloy embedded carbon (RCCC), is facilely fabricated using CuCo-glycerate (Gly) as a template. With the incorporation of Cu into Co, RCCC is essentially different from its analogue derived from Co-Gly in the absence of Cu, affording a popcorn-like Co embedded on carbon (PCoC). RCCC exhibits a unique morphology, featuring a hollow spherical layer covered by nanoscale beads composed of CuCo alloy distributed over carbon. Therefore, RCCC significantly outperforms PCoC and Co 3 O 4 for activating Oxone to degrade the toxic azo contaminant, Azorubin S (AS), in terms of efficiency and kinetics. Furthermore, RCCC remains highly effective in environments with high NaCl concentrations and can be efficiently reused across multiple cycles. Besides, RCCC also leads to the considerably lower E a of AS degradation than the reported E a values by other catalysts. More importantly, the contribution of incorporating Cu with Co as CuCo alloy in RCCC is also elucidated using the Density-Function-Theory (DFT) calculation and synergetic effect of Cu and Co in CuCo contributes to enhance Oxone activation, and boosts generation of SO 4 •−and •OH. The decomposition pathway of AS by RCCC + Oxone is also comprehensively investigated by studying the Fukui indices of AS and a series of its degradation by-products using the DFT calculation. In accordance to the toxicity assessment, RCCC + Oxone also considerably reduces acute and chronic toxicities to lower potential environmental impact. These results ensure that RCCC would be an advantageous catalyst for Oxone activation to degrade AS in water. [ABSTRACT FROM AUTHOR]

Advanced processes for peroxymonosulfate (PMS)-based oxidation are efficient in eliminating toxic and refractory organic pollutants from sewage. The activation of electron-withdrawing HSO5− releases reactive species, including sulfate radical (·SO4−), hydroxyl radical (·OH), superoxide radical (·O2−), and singlet oxygen (1O2), which can induce the degradation of organic contaminants. In this work, we synthesized a variety of M-OMS-2 nanorods (M = Co, Ni, Cu, Fe) by doping Co2+, Ni2+, Cu2+, or Fe3+ into manganese oxide octahedral molecular sieve (OMS-2) to efficiently remove sulfamethoxazole (SMX) via PMS activation. The catalytic performance of M-OMS-2 in SMX elimination via PMS activation was assessed. The nanorods obtained in decreasing order of SMX removal rate were Cu-OMS-2 (96.40%), Co-OMS-2 (88.00%), Ni-OMS-2 (87.20%), Fe-OMS-2 (35.00%), and OMS-2 (33.50%). Then, the kinetics and structure–activity relationship of the M-OMS-2 nanorods during the elimination of SMX were investigated. The feasible mechanism underlying SMX degradation by the Cu-OMS-2/PMS system was further investigated with a quenching experiment, high-resolution mass spectroscopy, and electron paramagnetic resonance. Results showed that SMX degradation efficiency was enhanced in seawater and tap water, demonstrating the potential application of Cu-OMS-2/PMS system in sewage treatment. [ABSTRACT FROM AUTHOR]

BACKGROUND: The increasing presence of antibiotics in aquatic environments poses significant ecological risks, with sulfamethoxazole (SMX) being a prominent example due to its persistence and widespread use in medical and veterinary practices. Advanced oxidation processes, particularly those based on peroxymonosulfate (PMS), have shown promise in degrading such contaminants. This work explored the efficacy of a bimetallic selenide catalyst, FeSe2/MoSe2 (FM), synthesized via a hydrothermal method, for the rapid activation of PMS and subsequent degradation of SMX. RESULTS: Over 95% SMX degradation was achieved with a 0.25 g/L catalyst dosage and 1.5 g/L PMS dosage, demonstrating that FM was an effective PMS activator capable of efficiently oxidizing SMX. The EPR tests and quenching experiments confirmed the presence of 1O2, SO4•– and •OH in the degradation system, with SO4•‐ predominating. The redox cycling of Mo with Fe was involved in the activation of PMS. Moreover, the DFT calculations of the SMX molecule revealed that the vulnerable sites were mainly in the vicinity of the sulfonamide group and the oxygen‐containing group. The toxicity assessment disclosed that most of the primary degradation intermediates of SMX were toxic, while the further small molecule products were non‐toxic. CONCLUSION: This work underscores the potential of the FM/PMS system as an efficient and sustainable solution for degrading antibiotic contaminants like SMX in water. The low toxicity of the final degradation products further supports the environmental safety of this approach, making it a promising candidate for real‐world water treatment applications. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Despite the promising potential of piezo‐catalysis in environmental remediation applications, the performance of various piezoelectric materials still suffer from low carrier concentrations, limited carrier mobility, and rapid recombination of electron‐hole pairs, and the reported modification strategies are quite intricate and challenging to implement. Herein, MoS2 with varying degrees of crystallinity is synthesized through drying and thermal treatment processes, and the effect of crystal engineering on the performance of the piezo‐activated peroxomonosulfate (PAP) system is investigated. The MoS2 annealed at 700 °C (M‐700) with a crystallization of 60.4% exhibited superior performance in the PAP system, which can degrade 99.6% of bisphenol A within 30 min with a mineralization rate of 57.0%. The positive correlation among the crystallinity of piezoelectric catalysts, the parameters of piezoelectric performance (d33) and piezo‐catalytic performance within a certain range is proposed. From the density functional perturbation theory (DFPT), the crystalline‐amorphous hybrid of M‐700 provided an appropriate charge transfer rate, electron concentration, and mechanical strength, which is more conducive to stimulate the active species chain reaction of PMS. This study provides a novel method for improving the piezo‐catalytic activities and holds great promise for water pollution treatment. [ABSTRACT FROM AUTHOR]

Coordination engineering of high-valent Fe(IV)-oxo (FeIV=O) is expected to break the activity-selectivity trade-off of traditional reactive oxygen species, while attempts to regulate the oxidation behaviors of heterogeneous FeIV=O remain unexplored. Here, by coordination engineering of Fe-Nx single-atom catalysts (Fe-Nx SACs), we propose a feasible approach to regulate the oxidation behaviors of heterogeneous FeIV=O. The developed Fe-N2 SACs/peroxymonosulfate (PMS) system delivers boosted performance for FeIV=O generation, and thereby can selectively remove a range of pollutants within tens of seconds. In-situ spectra and theoretical simulations suggest that low-coordination Fe-Nx SACs favor the generation of FeIV=O via PMS activation as providing more electrons to facilitate the desorption of the key *SO4H intermediate. Due to their disparate attacking sites to sulfamethoxazole (SMX) molecules, Fe-N2 SACs mediated FeIV=O (FeIVN2=O) oxidize SMX to small molecules with less toxicity, while FeIVN4=O produces series of more toxic azo compounds through N-N coupling with more complex oxidation pathways. Coordination engineering of high-valent Fe(IV)-oxo may break the activity-selectivity trade-off of traditional reactive oxygen species but the controllable generation of heterogeneous FeIV=O remains unexplored. Here, the authors alter the coordination number of Fe-Nx single-atom catalysts to regulate oxidation behaviors of heterogeneous FeIV=O. [ABSTRACT FROM AUTHOR]

In this study, the sodium perborate (SP)-activated peroxymonosulfate (PMS) process was used to enhance the coagulation efficiency of cyanobacteria with polymeric aluminum chloride (PAC), aiming to efficiently mitigate the impact of algal blooms on the safety of drinking water production. The optimal concentrations of SP, PMS, and PAC were determined by evaluating the removal rate of OD680 and zeta potential of the algae. Experimental results demonstrated that the proposed ternary PMS/SP/PAC process achieved a remarkable OD680 removal efficiency of 95.2%, significantly surpassing those obtained from individual treatments with PMS (19.5%), SP (5.2%), and PAC (42.1%), as well as combined treatments with PMS/PAC (55.7%) and PMS/SP (28%). The synergistic effect of PMS/SP/PAC led to the enhanced aggregation of cyanobacteria cells due to a substantial reduction in their zeta potential. Flow cytometry was performed to investigate cell integrity before and after treatment with PMS/SP/PAC. Disinfection by-products (DBPs) (sodium hypochlorite disinfection) of the algae-laden water subsequent to PMS/SP/PAC treatment declined by 57.1%. Moreover, microcystin-LR was completely degraded by PMS/SP/PAC. Electron paramagnetic resonance (EPR) analysis evidenced the continuous production of S O 4 • − , •OH, 1O2, and O 2 • − , contributing to both cell destruction and organic matter degradation. This study highlighted the significant potential offered by the PMS/SP/PAC process for treating algae-laden water. [ABSTRACT FROM AUTHOR]

[Display omitted] A heterojunction of trace Co 3 O 4 bonded on oxygen vacancies (OVs)-rich ZnO (OVs-ZnO/Co 3 O 4) was synthesized via defect-assisted method to promote peroxymonosulfate (PMS) activation and pollutants degradation. Experiments and theoretical calculations demonstrated that electrons could efficiently transfer from OVs-ZnO to Co 3 O 4. OVs-ZnO and Co 3 O 4 played different roles in activating PMS. PMS was easily adsorbed on the OVs-ZnO to form PMS* complex and mediated electron transfer to oxide ciprofloxacin (CIP), whereas, Co 3 O 4 facilitated breakup of peroxide bond to produce radicals. The optimal OVs-ZnO/Co 3 O 4 with Co content of 1.34% exhibited good PMS decomposition ability (94.2% in 30 min) compared to unmodified ZnO (24.2%), stability and anti-interference feature in removing CIP, 96.9% CIP (10 ppm) and 79.6% of total organic carbon were removed in 30 min. Moreover, the OVs-ZnO/Co 3 O 4 achieved 91.2% CIP removal ratio with 1.0 mM PMS via a flow-through device in 180 min. This study proposes a new strategy to enhance PMS activation of ZnO and provides new viewpoint in PMS activation way. [ABSTRACT FROM AUTHOR]

Singlet oxygen (1O2) has attracted great attention owing to its superior comprehensive oxidizing performance and extensive application in dealing with ever‐growing environmental pollution. However, the efficient catalytic generation of 1O2 is very challenging due to the low catalytic activity of most catalysts and the generation of oxygen‐containing radicals in the catalytic reaction. Herein, C‐doped Co nanoparticles (CoNPs) supported on porous carbon (C─Co/C) as highly reactive and selective 1O2‐producing catalysts are demonstrated for efficient catalytic oxidation of recalcitrant organics via activation of peroxymonosulfate (PMS). The doped C 2p orbitals can accept Co 3d electrons, thereby weakening the Co─O bonding between Co and PMS or other oxygen‐containing intermediates such as *SO4, *OH, *OOH, and *O. The adsorption and cleavage energy of PMS on Co nanoparticle is reduced from 8.09 to 4.64 eV by C doping. The energy barrier of the *OOH to 1O2 step is also lowered significantly, thereby kinetically improving the activity for the generation of 1O2. The C─Co/C catalysts promotes the efficient and 100% selective generation of 1O2 with high modified kinetic model (K) values of 457.0 and 94.5 µmol s−1 g−1 for rhodamine (RhB) and 2,4‐dichlorophenol (2,4‐DCP), respectively. [ABSTRACT FROM AUTHOR]

Peroxymonosulfate (PMS) is widely used in advanced oxidation processes. Fe(II) is an excellent catalyst for PMS, and organic pollutants in water can be effectively degraded in the Fe(II)/PMS system. However, the pollutant degradation efficiency is limited by the low conversion efficiency of Fe(II). Natural antioxidants exist in the water environment and have strong electron-donating ability. At present, the research on the introduction of natural antioxidants into the advanced oxidation processes to degrade pollutants focuses on a few polyphenols, and the effects of other natural antioxidants on the removal of pollutants are worth studying. In this study, natural antioxidants, proanthocyanidins (PCs), saponins (SPs), and Lycium barbarum polysaccharides (LBPs), were introduced into the Fe(III)/PMS system. The reduction ability of natural antioxidants was used to improve the conversion efficiency of Fe(III) to Fe(II), and PMS was more effectively activated to produce ROS, which promoted the degradation of ofloxacin (OFL). After the introduction of PC in the Fe(III)/PMS system, 80% of OFL was degraded at 20 min, and 90% of OFL was degraded at 120 min after the introduction of SP. The experimental results showed that the degradation of OFL was affected by the amount of antioxidants, PMS and Fe(III), pH value, and coexisting anions. Free radical quenching experiments showed that 1O2, SO4−·, and ·OH play an important role in the degradation of OFL in the Fe(III)/antioxidant/PMS system. This paper proves that the introduction of proanthocyanidins and saponins into the advanced oxidation processes can remove organic pollutants more efficiently. [ABSTRACT FROM AUTHOR]

Improving the utilization of active sites in carbon catalysts is significant for various catalytic reactions, but still challenging, mainly due to the lack of strategies for controllable introduction of active dopants. Herein, a novel "Ar plasma etching‐NH3 annealing" strategy is developed to regulate the position of active N sites, while maintaining the same nitrogen species and contents. Theoretical and experimental results reveal that the edge‐hosted‐N doped carbon nanotubes (E‐N‐CNT), with only 0.29 at.% N content, show great affinity to peroxymonosulfate (PMS), and exhibit excellent Fenton‐like activity by generating singlet oxygen (1O2), which can reach as high as 410 times higher than the pristine CNT. The remarkable utilization of edge‐hosted nitrogen atom is further verified by the edge‐hosted‐N enriched carbocatalyst, which shows superior capability for 4‐chlorophenol degradation with a turnover frequency (TOF) value as high as 3.82 min−1, and the impressive TOF value can even surpass those of single‐atom catalysts. This work proposes a controllable position regulation of active sites to improve atom utilization, which provides a new insight into the design of excellent Fenton‐like catalysts with remarkable atom utilization efficiency. [ABSTRACT FROM AUTHOR]

The composite Fenton catalyst was prepared by attaching MgCo2O4 to the surface of g‐C3N4 using a one‐pot method after preparing MgCo2O4 through co‐precipitation. The microstructure of the composites was analyzed using X‐ray diffraction (XRD) and other characterization methods. The catalytic activity of the composites towards tetracycline (TC) was studied, and a possible catalytic mechanism was proposed. The experimental results indicate that the degradation of TC by MgCo2O4@g‐C3N4 reached almost 99.0 % within 30 min in the presence of PMS and visible light. The combination of MgCo2O4 and g‐C3N4 improved the absorption of visible light, and the energy level‐matched heterojunction facilitated the separation of photogenerated electrons and holes, accelerating the redox cycle of ≡Co3+/≡Co2+. The free radical quenching experiment confirmed that the main active substances were free radical ⋅O2− and 1O2. The one‐step synthesis of composite catalysts exhibits high catalytic performance and good stability, offering a potential solution for the efficient treatment of tetracycline wastewater. [ABSTRACT FROM AUTHOR]

Advanced oxidation process based on heterogeneous activation of peroxymonosulfate (PMS) has received significant attention in wastewater remediation. Herein, a facile and effective electrochemical method was introduced in a tungsten sulfide (WS2)-activated PMS process for the removal of a typical azo dye Acid Orange 7 (AO7) in aqueous solution. It was found that the electrochemical activation could remarkably promote the removal of organic pollutants by coupling with WS2/PMS system. The elimination of AO7 in the electro-assisted WS2-activated PMS (E/WS2/PMS) system achieved 95.8% of AO7 removal in 30 min, with the optimal conditions of 1.0 g/L WS2, 1.0 mM PMS, current density of 1.0 mA/cm2 and initial pH of 6.5. Based on quenching experiments and EPR techniques, mechanistic studies confirmed that hydroxyl radical (•OH) and singlet oxygen (1O2) are the primary reactive oxygen species for the oxidation of pollutants. In addition, the influences of pH, WS2 dosage, PMS concentration, current density, common anions and humic acid on the AO7 removal are also investigated in detail. Furthermore, the system exhibited resistance to aqueous matrices, verifying the accepted applicability in real water (i.e., Yangtze River water and Shahu Lake water). In summary, this study demonstrates a green system for the effective removal of contaminants in water, holding significant implications for practical application. [ABSTRACT FROM AUTHOR]

The application of antibiotics has advanced modern medicine significantly. However, the abuse and discharge of antibiotics have led to substantial antibiotic residues in water, posing great harm to natural organisms and humans. To address the problem of antibiotic degradation, this study developed a novel catalytic membrane by depositing Co catalysts onto MXene nanosheets and fabricating the polyethersulfone composite (Co@MXene/PES) using vacuum-assisted self-assembly. The dual role of MXene as both a carrier for Co atoms and an enhancer of interlayer spacing led to improved flux and catalytic degradation capabilities of the membrane. Experimental results confirmed that the Co@MXene/PES membrane effectively degraded antibiotics through peroxymonosulfate activation, achieving up to 95.51% degradation at a cobalt concentration of 0.01 mg/mL. The membrane demonstrated excellent antibacterial properties, minimal flux loss after repeated use, and robust anti-fouling performance, making it a promising solution for efficient antibiotic removal and stable water treatment. [ABSTRACT FROM AUTHOR]

Heterogeneous Mg-Fe oxide/biochar (MgFeO@BC) nanocomposites were synthesized by a co-precipitation method and used as biochar-based catalysts to activate peroxymonosulfate (PMS) for sulfamethoxazole (SMX) removal. The optimal conditions for SMX degradation were examined as follows: pH 7.0, MgFeO@BC of 0.4 g/L, PMS concentration of 0.6 mM and SMX concentration of 10.0 mg/L at 25 ℃. In the MgFeO@BC/PMS system, the removal efficiency of SMX was 99.0% in water within 40 min under optimal conditions. In the MgFeO@BC/PMS system, the removal efficiencies of tetracycline (TC), cephalexin (CEX), ciprofloxacin (CIP), 4-chloro-3-methyl phenol (CMP) and SMX within 40 min are 95.3%, 98.4%, 98.2%, 97.5% and 99.0%, respectively. The radical quenching experiments and electron spin resonance (ESR) analysis suggested that both non-radical pathway and radical pathway advanced SMX degradation. SMX was oxidized by sulfate radicals (SO4•−), hydroxyl radicals (•OH) and singlet oxygen (1O2), and SO4•− acted as the main active species. MgFeO@BC exhibits a higher current density, and therefore, a higher electron migration rate and redox capacity. Due to the large number of available binding sites on the surface of MgFeO@BC and the low amount of ion leaching during the catalytic reaction, the system has good anti-interference ability and stability. Finally, the intermediates of SMX were detected. [ABSTRACT FROM AUTHOR]

In this work, rice-husk-derived biochar (RBC) was synthesized by using simple one-step pyrolysis strategies and served as catalysts to activate peroxymonosulfate (PMS) for degrading sulfamethoxazole (SMX). When the annealing temperature (T) = 800 °C, RBC800 exhibits the typical hardwood structure with several micropores and mesoporous. Furthermore, RBC800 obtains more defect sites than RBC600, RBC700, and RBC900. In the RBC800/PMS system, the removal rate of the SMX reached 92.0% under optimal conditions. The kinetic reaction rate constant (kobs) of the RBC800/PMS system was 0.009 min−1, which was about 1.50, 1.28, and 4.50 times that of the RBC600/PMS (kobs = 0.006 min−1), RBC700/PMS (kobs = 0.007 min−1), and RBC900/PMS (kobs = 0.002 min−1) systems, respectively. In the RBC800/PMS system, sulfate radical (SO4•−) is the main active species. Compared with other active sites, the hydroxyl group (C-OH) on the surface of RBC800 interacts more strongly with PMS, which is more likely to promote the stretching of the O-O bond of the PMS, thus breaking into the activated state and significantly reducing the activation energy required for reaction. The degradation intermediates of SMX were speculated, and the toxicity analysis was conducted. Generally, this work reveals in depth the interaction between reactive sites of biochar-based catalysts and PMS at the molecular level. [ABSTRACT FROM AUTHOR]

Azoxy coupling of 5‐amino‐1‐methyl‐tetrazole, 5‐amino‐2‐methyl‐tetrazole, and 5‐amino‐1‐methoxy‐tetrazole was performed by reacting each with various oxidants. These reactions revealed aqueous Oxone to be the most facile system for yielding the azoxy couple for the previously mentioned tetrazoles. Chemical and structural characterization of each novel azoxy‐coupled tetrazole was conducted with 1H NMR, 13C NMR, HRMS, and single‐crystal x‐ray diffraction. Energetic characterization was evaluated by analysis of each compounds' single crystal x‐ray diffraction density, impact sensitivity, friction sensitivity, and decomposition temperature. All compounds were found to be very sensitive to impact and friction stimuli. [ABSTRACT FROM AUTHOR]

[Display omitted] Single-atom catalysts (SACs) have been widely studied in Fenton-like reactions, wherein their catalytic performance could be further enhanced by adjusting electronic structure and regulating coordination environment, although relevant research is rarely reported. This text elucidates fabrication of dual atom catalyst systems aimed at augmenting their catalytic efficiency. Herein, atomically dispersed copper-zinc (Cu-Zn) dual sites anchored on nitrogen (N)-doped porous carbon (NC), referred to as CuZn-NC, were synthesized using cage-encapsulated pyrolysis and host–guest strategies. The CuZn-NC catalyst exhibited high activity in activation of peroxymonosulfate (PMS) for degradation of organic pollutants. Based on synergistic effects of adjacent Cu and Zn atom pairs, CuZn-NC (PMS) system achieved 94.44 % bisphenol A (BPA) degradation in 24 min. The radical pathway predominated, and coexistence of non-radical species was demonstrated for BPA degradation in CuZn-NC/PMS system. More importantly, CuZn-NC/PMS system showed generality for degradation of various refractory contaminants. Our experiments indicate that CuZn-N sites on CuZn-NC act as active sites for bonding PMS molecules with optimal binding energy, while pyrrolic N sites are considered as adsorption sites for organic molecules. Overall, this research designs diatomic site catalysts (DACs), with promising implications for wastewater treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] The activation of peroxymonosulfate (PMS) by carbon-based catalysts is deemed to be a promising method for the degradation of refractory organic contaminants in wastewater. Herein, a Cu-doping strategy in B and N co-doped carbon nanotubes with highly dispersed B O Cu sites and graphite nitrogen were successfully synthesized for activating PMS to degradate tetracycline. The best removal rate of tetracycline within 60 min (97.63 %) was obtained by the 1.5 % Cu-BNC and the degradation rate was increased by 17.9 times. The enhanced catalyst activity was attributed to the promoting the cycle of the Cu(I)/Cu(II) redox pair by the formed B O Cu sites, and the accelerating the electron transfer process by the adsorption of graphitic N for PMS. The non-free radical pathway including 1O 2 and electron transfer played a dominant role in the 1.5 % Cu-BNC/PMS system. The degradation intermediates of TC were identified and three possible degradation pathways were proposed. Further toxicity analysis of the intermediates showed that the 1.5 % Cu-BNC/PMS system had a significant effect on weakening and reducing the biological toxicity and mutagenicity of TC. Moreover, it presented an excellent degradation performance in raw natural water. In general, the proposed regulation of carbon-based catalysts via the coordination-driven effect provides ideas for efficient wastewater treatment. [ABSTRACT FROM AUTHOR]

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Anaerobic granular sludge (AnGS) is a potential resource for biochar production due to its unique microstructure and high organic contents. In this study, Fe3O4-loaded biochar derived from AnGS as a catalyst for peroxymonosulfate (PMS) activation was synthesized through iron modification and pyrolysis at different temperatures. The biochar characterization indicated that surface area (249.145 m2 g−1) and microporosity (131.819 m2 g−1) were significantly enhanced at 800 °C. Furthermore, the excellent magnetic properties of the iron-modified biochar at 800 °C (S@Fe-800) (45.28 emu g−1) were confirmed, in which Fe3O4 was identified as the dominant reactive species. S@Fe-800 exhibited remarkable PMS activation ability for organic pollutants, which displayed superior Rhodamine B (RhB) removal efficiency. Results from the quenching experiments and electron paramagnetic resonance (EPR) detections demonstrated that the reactive oxidizing species (ROS), including sulfate radical (SO4•−), were generated in the S@Fe-800/PMS system. Meanwhile, the significant intermediates and possible degradation path of PMS decomposition over RhB were proposed. It is believed that this work provides an effective method for organic contaminants removal and a green utilization route for AnGS. [ABSTRACT FROM AUTHOR]

The large amount of refractory organic wastewater produced from industry and agriculture sectors poses a significant threat to both water ecosystems and human health, necessitating the exploration of cost-efficient and efficacious removal techniques. Persulfate, when activated by various catalysts, can produce oxidative species, demonstrating promising potential in remediating organic wastewater. In recent years, numerous studies have unveiled that persulfate can be readily decomposed into nonradicals, which exhibits high selectivity toward pollutants and robust performance in complex wastewater environments. However, the challenges in identifying non-radicals and the unclear catalytic mechanism hinder its further application. This paper critically reviews the research progress on non-radical oxidation in persulfate-based heterogeneous catalytic system. The main advancements and existing challenges in three non-radical oxidation pathways, i.e., singlet oxygen, electron transfer, and high-valent metal oxides, are summarized, and the key factors influencing the production of nonradicals are elaborated. The engineering aspects of non-radical oxidation system are further discussed, and the future prospects of this technology in wastewater treatment are envisaged. This review aims to bridge the knowledge gaps between current research and future requirements. [ABSTRACT FROM AUTHOR]

In this study, the KOH-modified Fe-ZIF-derived carbon materials (Fe@NC-KOH-x) were designed for Fenton-like systems to enhance bisphenol A (BPA) removal from wastewater. Compared with the Fe@NC without KOH activation, the pore structure, BET (Brunner-Emmet-Teller) surface area, and oxygen-containing functional group of KOH-activated Fe@NC-KOH-x are dramatically improved, which increases the adsorption and catalytic performance. The Fe@NC-KOH-900/PMS system showed significant BPA removal reactivity across wide pH ranges and low doses of Fe@NC-KOH-900. Interestingly, our findings indicated that the removal effectiveness of BPA improved when PMS was introduced following the saturation adsorption of Fe@NC-KOH-x, as compared to the simultaneous introduction of Fe@NC-KOH-x and PMS. More particularly, through regression analysis, we found that the proportion of reactive species in the Fe@NC-KOH-x/PMS system changes with the increase of pyrolysis temperature, and there was a certain relationship between structure–function and active species in the Fe@NC-KOH-x/PMS system. O-C = O, Fe-N4, C-O, and pyrrolic N in Fe@NC-KOH-x lead to the generation of •OH, and SO4−•, C = O, Fe-N4, and defect are closely related to FeIV = O, and the formation of 1O2 is affected by Fe-N4, graphite N, C = O, and defect. Also, the density functional theory (DFT) calculation and the potential correlation between catalyst active centers and reactive oxygen species indicate that Fe-N4 is the main active site of Fe@NC-KOH-x. These outcomes of the study offer an innovation for enhanced elimination of BPA in wastewater treatment and provide a dynamic understanding of the mechanism of BPA degradation. [ABSTRACT FROM AUTHOR]

A novel colorimetric approach specifically designed to effectively identify the presence of 3-aminophenol (3-AP) in environmental water is introduced. Briefly, a nitrogen-doped carbon-supported cobalt nanozyme (Co@CN-1) was synthesized and utilized to improve the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of peroxymonosulfate (PMS). Comparative catalytic reactions confirmed that the performance of PMS as an activator exceeds that of hydrogen peroxide catalytically by a factor of 3.5. The catalytic reaction parameters underwent optimization, further resulting in the derivation of a linear detection equation for 3-AP, expressed as inhibition rate (IR%) = 3.35[3-AP]—4.36 (0–20 μM, R2 = 0.994) and IR% = 1.43[3-AP] + 31.87 (20–36 μM, R2 = 0.992), with the limit of detection (LOD) of 2.84 μM. The linear relationship between 3-AP concentration and the conversion of color to grayscale value (GSV) was established by smartphones, expressed as GSV = 1.28[3-AP] + 147.10 (R2 = 0.972). Density functional theory calculations revealed that Co acts as the preferred active site for donating electrons in PMS activation. This work provides a rapid and accurate approach for monitoring 3-AP concentration, enabling real-time analysis and potentially contributing to environmental and ecological studies. [ABSTRACT FROM AUTHOR]

In this study, Fe, N co-doped biochar (Fe@N co-doped BC) was synthesized by the carbonization–pyrolysis method and used as a carbocatalyst to activate peroxymonosulfate (PMS) for sulfamethoxazole (SMX) removal. In the Fe@N co-doped BC/PMS system, the degradation efficiency of SMX (10.0 mg·L−1) was 90.2% within 40 min under optimal conditions. Radical quenching experiments and electron spin resonance (ESR) analysis suggested that sulfate radicals (SO4•−), hydroxyl radicals (•OH), and singlet oxygen (1O2) participated in the degradation process. After the reaction, the proportion of pyrrolic N decreased from 57.9% to 27.1%. Pyrrolic N served as an active site to break the inert carbon network structure and promote the generation of reactive oxygen species (ROS). In addition, pyrrolic N showed a stronger interaction with PMS and significantly reduced the activation energy required for the reaction (∆G = 23.54 kcal/mol). The utilization potentiality of Fe@N co-doped BC was systematically evaluated in terms of its reusability and selectivity to organics. Finally, the intermediates of SMX were also detected. [ABSTRACT FROM AUTHOR]

Many existing research focuses on the differences or performance comparisons between single‐atom or small‐sized nanocluster catalysts, but there is a lack of comprehensive research on the coupling relationship between the structure and activity and the mechanism of synergy. This study investigates the combined catalytic potential of cobalt single atoms (SAs) and nanoclusters (NCs) for enhanced peroxymonosulfate (PMS) activation to degrade norfloxacin (NFX). A novel CoSAs‐NCs/CN/TiO2 catalyst is synthesized, featuring cobalt SAs and NCs uniformly dispersed on the carbon film wrapping TiO2, and the degradation efficiency of the NFX solution is almost completely degraded, with a mineralization rate of 76.35%. Density functional theory (DFT) calculations indicate that the synergistic interaction between cobalt SAs and NCs promotes more efficient PMS adsorption and activation and significantly reduces the activation energy barrier, which enhances electron transfer and increases reactive oxygen species (ROS) generation. This research highlights the robust and versatile nature of this novel catalyst system in addressing various contaminants. This study elucidates the activation mechanism of catalysts, providing new ideas for advanced oxidation processes (AOPs) in environmental remediation, linking the structure and performance of catalysts, and emphasizes the practicality and importance of the CoSAs‐NCs/CN/TiO2 catalyst in effectively and long‐term remediation of water pollutants. [ABSTRACT FROM AUTHOR]

[Display omitted] • Prepared ZIF-67/CoFe-LDH has excellent catalytic performance. • DFT demonstrated that oxygen vacancies mediated free radical and non-free radical pathways. • The role of reactive oxygen species in ZIF-67/CoFe-LDH/PMS system was studied. • The SMX degradation pathway was analyzed and the biotoxicity of the degradation intermediates was estimated. Herein, a novel rich oxygen vacancy (Ov) cobalt-iron hydrotalcite composite cobalt metal–organic framework material (ZIF-67/CoFe-LDH) was prepared by simple urea water and heat reduction approach and utilized for the peroxymonosulfate (PMS) system to remove sulfamethoxazole (SMX). 95 ± 1.32 % SMX (20 mg/L) was able to degraded in 20 min with TOC removal of 53 ± 1.56 % in ZIF-67/CoFe-LDH/PMS system. The system maintained a fantastic catalytic capability with wide pH range (3–9) and common interfering substances (Cl−, NO 3 −, CO 3 2−, PO 4 2− and humic acid (HA)), and the degradation efficiency could even remain 80.2 ± 1.48 % at the fifth cycle. Meanwhile, the applicability and feasibility of the catalysts for practical water treatment was verified by the degradation effects of SMX in different water environments and several other typical pollutants. Co and Fe bimetallic active centers synergistically activate PMS, and density functional theory (DFT) predicted adsorption energy about Ov in ZIF-67/CoFe-LDH for PMS was 1.335 eV, and O O bond length of PMS was stretched to 1.826 Å. As a result, PMS was more easily activated and broken, which accelerated the singlet oxygen (1O 2), sulfate radical (SO 4 •−), high-valent metals and other reactive oxygen species (ROS). Radical and non-radical jointly degrading the pollutants improved the catalytic effect. Finally, SMX degradation intermediates were analyzed to explain the degradation pathway and their biotoxicity was also evaluated. This paper provides a new research perspective of oxygen vacancy activating PMS to degrade pollutants. [ABSTRACT FROM AUTHOR]

Aspergillus flavus and its mycotoxin aflatoxin (AF) are widely present in the environment and cause various acute and chronic diseases in humans and animals. UV irradiation has been a versatile method for disinfecting A. flavus and detoxifying AFs. Combined effects of UV and other agents were scarcely tested yet. Here, we investigated the combinatorial effects of UVC and peroxymonosulfate (PMS) on the disinfection of A. flavus and accumulation of AFB1 under aqueous conditions. UVC efficiently disinfected A. flavus in a dose-dependent manner. PMS (~4 mM) exhibited no disinfection but enhanced the inactivation activity of UVC. Notably, PMS or UVC (72 J/cm²) increased the accumulation of AFB1 in the mycelia. Higher (144 J/cm²) doses of UVC suppressed AFB1 accumulation. At the genetic level, PMS and UVC upregulated the expression of the AF biosynthetic genes aflS and aflR. In contrast, UVC degraded AFB1 in vitro, which was enhanced by PMS treatment. The in-vivo and in-vitro studies indicated that AFB1 accumulation may be compromised by the dual effects of UVC and PMS on the upregulation of AF biosynthesis and degradation activities. In conclusion, PMS and UVC are efficient disinfecting agents against A. flavus but also stimulate AF biosynthesis under moderate treatment conditions. [ABSTRACT FROM AUTHOR]

The transition bimetallic oxide catalyst demonstrates the ability to activate peroxymonosulfate (PMS), generating oxidative active groups and facilitating room temperature reactions, all at a relatively low cost. The freeze-drying method was successfully utilized to obtain CuFe2O4 to boost peroxymonosulfate activation to degrade rhodamine-B dye. The catalyst underwent characterization through XRD and SEM. The impact of various reaction parameters, such as initial pH value and PMS dosage on the degradation of rhodamine-B, was examined. The results revealed that the CuFe2O4 catalyst obtained via freeze-drying method as the precipitant exhibited uniform and regular particle characteristics, remarkable crystallization degree, high purity, enormous specific surface area, and an absence of impurity functional groups. Additionally, the prepared CuFe2O4 material showcased enhanced catalytic performance. To carry out the catalysis process, the rhodamine-B concentration was set at 20 mg·L−1, with an amount of 200 mg·L−1 of CuFe2O4 material used. The optimal pH was determined to be 9.0, while the ideal PMS concentration was found to be 1.0 mmol·L−1. Under these specific conditions, an impressive 99% degradation rate of rhodamine-B was achieved in just 27 min of catalysis. [ABSTRACT FROM AUTHOR]

The development of heterogeneous electrodes with high conductivity and electrocatalytic activity is a crucial goal. Achieving this using a simple and low‐cost method is essential for wastewater purification by anodic oxidation combined with peroxymonosulfate (PMS). Herein, TiO2–CaTiO3(CTO)‐Cu2O–Cu heterojunction electrodes are prepared by mixing CaCu3Ti4O12 with different amounts of graphene oxide (GO). The different mixtures are pressed into pellets and sintered under inert atmosphere at 1100 °C for 3 h. The obtained pellets are used as anodes for PMS activation in the electrocatalysis. The efficiency of paracetamol (PCM) removal reaches its maximum (93%) after 90 min using the CTO–Cu–5GO electrode in a solution containing 10 ppm PCM, 210 mL sodium sulfate, and 0.5 mM PMS. The higher amount of metallic copper in this anode promotes the generation of radicals to effectively degrade PCM. In optimal conditions (1.2 V versus Ag/AgCl, 1 mM PMS, and 10 ppm PCM), PCM is completely removed in 45 min. According to the quenching test results, •O2− and •OH are the radicals generated during PCM degradation, and •O2− plays the main role. In this work, insights are provided into the rational combination of different metal oxides with TiO2 as a heterostructure electrode to ensure high mineralization of pharmaceuticals by electrocatalysis. [ABSTRACT FROM AUTHOR]

Magnetic CuFe2O4 was prepared with the modified sol–gel method and used for enhanced peroxymonosulfate (PMS) activation and ofloxacin (OFL) degradation. The OFL could almost degrade within 30 min at a catalyst dosage of 0.66 g/L, PMS concentration of 0.38 mM, and initial pH of 6.53 without adjustment, using response surface methodology (RSM) with Box-Behnken design (BBD). In the CuFe2O4/PMS system, the coexisting substances, including CO32−, NO3−, SO42−, Cl− and humic acid, have little effect on the OFL degradation. The system also performs well in actual water, such as tap water and surface water (Mei Lake), indicating the excellent anti-interference ability of the system. The cyclic transformation between Cu(II)/Cu(I) and Fe(III)/Fe(II) triggers the generation of active radicals including SO4•−, •OH, •O2− and 1O2. The OFL degradation pathway, mainly involving the dehydrogenation, deamination, hydroxylation, decarboxylation and carboxylation processes, was proposed using mass spectroscopy. Moreover, the toxicity assessment indicated that the end intermediates are environmentally friendly. This study is about how the CuFe2O4/PMS system performs well in PMS activation for refractory organic matter removal in wastewater. [ABSTRACT FROM AUTHOR]

In order to catalytically degrade organic pollutants, a CoAl-layered double hydroxide catalytic membrane (CoAl-LDH-M) was fabricated for the activation of peroxymonosulfate (PMS). Notably, at the dosage of 50 mg/L PMS and flow rate of 1.0 mL/min, 99.7% removal of Rhodamine B (RhB) was obtained. The corresponding removal efficiency of total organic carbon (TOC) was 59.9%. This demonstrated that CoAl-LDH-M possessed high efficiency for PMS activation. Inductively coupled plasma (ICP) results showed that the leached amount of cobalt and aluminum were 0.13 and 0.04 mg/L, indicating the high stability of CoAl-LDH-M. The CoAl-LDH-M /PMS system could also effectively degrade several other contaminants, obtaining removal efficiencies of 92.7–99.6%. The effects of pH and co-existing ions were investigated as well. Reusability of the catalytic membrane was evaluated in both distilled water and synthetic wastewater. Mechanism studies showed that both reactive oxidative species (ROSs) and non-radical electron transfer were involved. The non-radical electron transfer played the primary role. The degradation pathway of RhB was unraveled by liquid chromatography-mass spectrometry measurements and theoretical calculations. Furthermore, the ecotoxicity of the reaction intermediates was evaluated by utilizing quantitative structure activity relationship (QSAR) calculations. [ABSTRACT FROM AUTHOR]

The correction notice for the article "Oxidized Resveratrol Metabolites as Potent Antioxidants and Xanthine Oxidase Inhibitors" in the journal "Antioxidants" addresses errors in the original publication related to the purification and structure elucidation of compounds. Corrections were made to the purification methods and stereochemistry of the compounds discussed in the article. The scientific conclusions of the study remain unaffected by these corrections. [Extracted from the article]

In this study, a new sludge-based biochar loaded with Fe species (Fe/SSBC) was prepared by a two-step process involving hydrothermal treatment and low-temperature air calcination, and used to degrade tetracycline (TC) by activating peroxymonosulfate (PMS). After 30 min reaction, more than 98 % TC (50 mg/L) could be removed by optimized Fe/SSBC/PMS system (k = 0.166 min−1), which was 2.18 times compared with individual hydrothermal treatment (k = 0.076 min−1). Besides, it also exhibited good stabilization. Detailed characterizations revealed the effect of hydrothermal treatment on the Fe–O coordination of the biochar surface and the change of the Fe valence state by air calcination. The electron paramagnetic resonance (EPR), electrochemical analysis and quenching experiments confirmed that singlet oxygen (1O2) was the main active substance. We further elucidated the influence of grafting Fe–O on the surface electron distribution of biochar by DFT calculations. Moreover, two possible pathways were proposed based on LC-MS analysis. In this study, a method of preparing high catalytic performance sludge-based carbon materials under low energy consumption has been proposed, which provides a new strategy for sludge recycling.

Schematic showing the main electron transfer degradation mechanism, degradation of TC, and structural advantages of the activation of H 2 O 2 and PMS by Fe-MOF. [Display omitted] Fe-based metal–organic frameworks (Fe-MOFs) have been used to catalyze the degradation of organic pollutants; however, the underlying mechanism remains unclear. In this study, we prepared Fe-MOF catalysts featuring a three-dimensional ordered structure and active Fe-N 4 coordination centers using self-designed polypyrazole compounds as ligands. Because the coordination centers are similar to the classical single-atom Fe-N 4 active neutral structure, Fe-MOFs exhibit excellent performance in activating hydrogen peroxide (H 2 O 2) and peroxymonosulfate (PMS) for the degradation of antibiotics. Moreover, the two adjacent nitrogen atoms in pyrazole strengthen the interaction with active neutral Fe, thereby enhancing the efficiency and selectivity of the catalytic sites. In the presence Fe-MOF/H 2 O 2 , a free radical process involving hydroxyl radicals (OH) is activated to achieve a degradation rate of 98.36 % for tetracycline (TC) within 10 min. In a Fe-MOF/PMS system, 97.01 % of TC can be degraded within 10 min through a non-free radical process with singlet oxygen (1O 2) as the primary active species. The high degradation efficiency of Fe-MOF is primarily attributed to its highly catalytically active structure, which exerts a van der Waals force effect on the pollutants, thereby facilitating electron transfer between the pollutants and active centers. This shortens the distance between the pollutants and Fe catalytic center, enhances electron transfer, and promotes the chemical adsorption of H 2 O 2 and PMS to form FeN 4 -H 2 O 2 and FeN 4 -PMS, respectively. Additionally, the strong coordination within the Fe-N 4 pyrazole structure significantly suppresses Fe leaching, facilitating a stable adsorption configuration. [ABSTRACT FROM AUTHOR]

The biochar carrier was constructed based on pomelo peel biomass, and the surface crystallization, organic polymer protection and pyrolysis cascade strategies were used to effectively embed Co and CoO species in biochar to achieve efficient degradation of tetracycline organic. [Display omitted] The development of highly catalytic activity, low-cost and environmentally friendly catalysts is crucial for the use of advanced oxidation processes (AOPs) to treat organic pollutants. In this study, to reduce costs, enhance catalytic activity and avoid secondary pollution form metal ions, pomelo peel was used as raw material, combined with surface crystallization, carbon layer protection and heat treatment technology to effectively construct AOPs catalyst that can efficiently activate peroxymonosulfate (PMS) to degrade harmful organic pollutants. Under the optimal conditions, the Co/BC-PMS system can degrade about 100 % of tetracycline (TC, a spectral antibiotic) within 5 min, and the degradation rate of TC can still reach 100 % even if Co/BC (cobalt anchored on biochar) was reused for 6 times. The Co/BC-PMS system can resist complex environmental conditions, including acidic solution, alkaline solution, coexisting ions, different water quality, and is universal for the degradation of most organic pollutants. The integrated purification column with Co/BC as the core realizes the continuous and complete degradation of organic pollutants and has the ability of practical application. Radical capture and monitoring combined with density-functional-theory calculations confirmed that the Co(111) and amorphous CoO sites in Co/BC are the key to driving PMS to degrade organic pollutants, Co/BC can efficiently adsorb PMS and promote the dissociation of PMS into highly active OH, SO 4 − and 1O 2 , and these reactive oxygen species jointly promote the degradation of organic pollutants. This study provides experimental support and theoretical insights for the design of efficient AOPs catalysts, and plays an important role in promoting the development of AOPs. [ABSTRACT FROM AUTHOR]

[Display omitted] • LaCo 0.95 Mo 0.05 O 3 -CeO 2 can efficiently activate PMS for rapid HCQ degradation. • 1O 2 , O 2 − and SO 4 − make an important contribution to HCQ degradation. • Mo and Ce promote the redox cycle of Co3+/Co2+ and facilitate the ROS generation. • DFT calculation is used to describe the susceptible reaction sites of HCQ. • To evaluate the ecotoxicity of degradation intermediates of HCQ. Hydroxychloroquine sulfate (HCQ) is extensively utilized due to its numerous therapeutic effects. Because of its properties of high solubility, persistence, bioaccumulation, and biotoxicity, HCQ can potentially affect water bodies and human health. In this study, the LaCo 0.95 Mo 0.05 O 3 -CeO 2 material was successfully prepared by the sol–gel process, and it was applied to the experiment of degrading HCQ by activating peroxymonosulfate (PMS). The results of characterization analysis showed that LaCo 0.95 Mo 0.05 O 3 -CeO 2 material had good stability, and the problem of particle agglomeration had been solved to some extent. Compared with LaCo 0.95 Mo 0.05 O 3 material, it had a larger specific surface area and more oxygen vacancies, which was helpful to improve the catalytic activity for PMS. Under optimal conditions, the LaCo 0.95 Mo 0.05 O 3 -CeO 2 /PMS system degraded 95.5 % of HCQ in 10 min. The singlet oxygen, superoxide radicals, and sulfate radicals were the main radicals for HCQ degradation. The addition of Mo6+/Mo4+ and Ce4+/Ce3+ promoted the redox cycle of Co3+/Co2+ and enhanced the degradation rate of HCQ. Based on density functional theory and experimental analysis, three HCQ degradation pathways were proposed. The analysis of T.E.S.T software showed that the toxicity of HCQ was obviously reduced after degradation. The LaCo 0.95 Mo 0.05 O 3 -CeO 2 /PMS system displayed excellent reusability and the ability to remove pollutants in a wide range of real-world aqueous environments, with the ability to treat a wide range of pharmaceutical wastewater. In summary, this study provides some ideas for developing heterogeneous catalysts for advanced oxidation systems and provide an efficient, simple, and low-cost method for treating pharmaceutical wastewater that has good practical application potential. [ABSTRACT FROM AUTHOR]

[Display omitted] • Nickel foam supported CuCo 2 O 4 catalysts enhanced utilization of active sites. • CuCo 2 O 4 @NF catalysts exhibits good stability, low cobalt metal leaching and easy recovery. • DFT calculation reveal that 1O 2 is produced synergistically activate PMS by Cu/Co dual-sites. • SO 4 •− and 1O 2 are the main radicals for tetracycline degradation. The modulation of bimetallic oxide structures and development of efficient, easily recoverable catalysts are expected to effectively overcome the limitations associated with powdered catalysts in activating peroxymonosulfate (PMS). In this study, CuCo 2 O 4 was successfully immobilized on the surface of nickel foam (NF) via an electrodeposition-calcination procedure, with highly efficient activation of PMS for tetracycline (TC) degradation (0.55 min−1). Besides acting as a support carrier and providing ample active sites, NF mediated electron transport, prevented the leaching of metal ions and enhanced the efficiency of recycling. Density functional theory (DFT) calculations and experimental tests illustrated that Cu/Co dual-sites can efficiently adsorb PMS, enabling simultaneous reduction and oxidation reactions. The dual-site synergy substantially decreased the adsorption barrier and increased the electron transfer rate. Especially, the Cu+/Cu2+ redox couple acted as an electron donor and facilitated rapid charge transfer, leading to the conversion of Co3+ to Co2+. Moreover, the CuCo 2 O 4 @NF + PMS system effectively eliminated TC by employing radical pathways (SO 4 •−, •OH) and nonradical processes (1O 2 , e−). Therefore, this study introduces a new approach to overcome the limitations of powdered bimetallic oxides, providing a promising solution for practical applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • The N C defects regulate interfacial electric field characteristics, which significantly promotes electron transfer process. • The interfacial electric field mediated hyperexchange interaction realizes directional electron transfer. • QSAR analysis confirms the critical role of defects in regulating the interfacial electric field. • The pollutant removal efficiency was improved through the electric field strategy of the defect control interface. • A possible degradation pathway for TTCH is proposed. Peroxymonosulfate (PMS) activation technology has important application value in treating emerging contaminant (ECs), but it still faces challenges in achieving efficient electron transfer and metal valence cycling. In this study, the interfacial electric field characteristics of FeNC catalysts were adjusted by introducing N C defects to affect the electron transfer process, thereby enhancing the catalytic performance of PMS. It is found that in the Fe N C structure, the shift of the charge generates an interfacial electric field, which can promote the directional transfer of electrons. Through quantitative structure–activity relationship (QSAR) analysis, it was confirmed that the defect played a decisive role in regulating the interfacial electric field and improving the catalytic reaction efficiency. The interfacial electric field-mediated superexchange interaction realizes the electron donor effect of organic pollutants and the effective electron transfer between the Fe site, accelerates the electron cycling of the Fe site, and realizes the rapid and stable catalysis of PMS. The increase of the occupancy state distribution of d orbitals near the Fermi level provides favorable conditions for electron transitions and catalytic activation of PMS. ECs can be converted into environmentally friendly, non-toxic and harmless substances through. This defect-controlled interface electric field strategy realizes rapid electron directional transfer, which provides a new solution for improving the catalytic efficiency of PMS and the safe treatment of ECs in water. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ni 2 Fe 0.25 Al 0.75 -LDH with abundant hydroxyl groups was fabricated. • Ni 2 Fe 0.25 Al 0.75 -LDH/PMS system showed higher purification performance. • The presence of complexes and metal synergy was conducive to ROS formation. • The mechanism and the degradation pathway of SMX were proposed. Layered double hydroxide (LDH) material with abundant OH was successfully prepared by co-precipitation method, and a water purification system of Ni 2 Fe 0.25 Al 0.75 -LDH activated peroxymonosulfate (PMS) was constructed to rapidly degrade sulfamethoxazole (SMX) pollutants. The optimal conditions for the degradation of SMX in the system were as follows: 0.30 g/L Ni 2 Fe 0.25 Al 0.75 -LDH, 0.30 mM PMS, pH = 7 and 90 % SMX was removed in 10 min and almost completely in 40 min, which was consistent with the predicted results of response surface methodology (RSM) analysis. The abundant OH in Ni 2 Fe 0.25 Al 0.75 -LDH could form M (O)OSO 3 complexes with PMS, accelerating the generation of reactive oxygen species (ROS) and promoting the removal of SMX. Quenching experiments and electron paramagnetic resonance (EPR) spectra showed that SO 4 −, OH, O 2 − and 1O 2 also existed in the system. The surface-bound SO 4 − and O 2 − contributed greatly to the removal of SMX and the electron transfer between metals was also conducive to the production of active substances. The possible degradation pathways and intermediates of SMX were proposed. The toxicity assessment software tool (T.E.S.T) and total organic carbon (TOC) results indicated that the Ni 2 Fe 0.25 Al 0.75 -LDH/PMS system could reduce the overall environmental risk of SMX to some extent. This study provided a new strategy for the practical application of heterogeneous catalysts in sewage treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • Co doping facilitated the formation of more oxygen vacancies (Ov) in Co 0.5 Mn 0.5 Fe 2 O 4. • Co 0.5 Mn 0.5 Fe 2 O 4 exhibited better catalytic performance than MnFe 2 O 4. • Ov promoted the adsorption of PMS to obtain the optimal adsorption energy. • The removal of bisphenol A (BPA) by the Co 0.5 Mn 0.5 Fe 2 O 4 /PMS system was 100 % at 30 min. • Both free and non-free radicals played a role in BPA degradation. Peroxymonosulfate (PMS) based on heterogeneous catalytic reaction was a promising advanced oxidation process (AOP) to remove refractory contaminants. However, the contaminant degradation efficiency was challenged by the limited number of catalytic active site and low capacity for durable electron transfer. In this study, cobalt-doped manganese-iron oxides (Co x Mn 1-x Fe 2 O 4) rich in oxygen vacancy (Ov) were synthesized using a microwaved hydrothermal method and applied to activate PMS for bisphenol A (BPA) degradation, which achieved the complete removal of BPA within 30 min. In all samples, Co 0.5 Mn 0.5 Fe 2 O 4 exhibited good catalytic activity for PMS, which was approximately 21.10 times higher than that of MnFe 2 O 4. The results of density functional theory calculations and in-situ characterization demonstrated that the enhanced performance was ascribed to the generation of Ov and the enrichment of active site, which significantly accelerated the cycling of redox pairs and improved the PMS adsorption, which was more favorable to the formation of active specie in the electron transport process. The oxidation process involved both free radical and non-radical mechanisms, with main reactive species of O 2 −, and 1O 2 being responsible for BPA degradation. In addition, the effects of different aqueous matrices, the results of reusability experiments, and ecotoxicity assessment experiments demonstrated the viability of the Co 0.5 Mn 0.5 Fe 2 O 4 /PMS system for real sewage purification. This research revealed a structural regulation method to enhance the catalytic activity of the material and offered new perspectives on the engineering of rich Ov. [ABSTRACT FROM AUTHOR]

After the outbreak of COVID-19, the severe threat to the entire biological environment caused by the extensive use of chloroquine phosphate (CQ) continues. In this paper, a new sol–gel method was used to inject highly active Co into the PrSmMnO3 matrix structure to prepare a novel perovskite composite catalyst PrSmCo0.8Mn0.2O3 with stable properties, and was used to efficiently activate monopersulfate (PMS) to produce high concentration of 1O2 and degrade CQ. The CQ degradation rate of 40 mg L−1 within 80 min was 97.3%, and excellent performance was maintained after 5 cycles. The fixed variable method found that the PrSmCo0.8Mn0.2O3/PMS system still has high efficiency and adaptability in complex water bodies. Through quenching experiments and electron paramagnetic resonance spectroscopy (EPR), we explored the PrSmCo0.8Mn0.2O3/PMS system. PMS is efficiently adsorbed on highly active Co, forming a high-entropy mixed interface, which promotes the decomposition of PMS and generates a large amount of ⋅O2− radicals. At the same time, Co–Mn synergistically and efficiently utilizes excess electrons and ⋅O2− radicals in the solution to produce high concentrations of 1O2 through disproportionation reactions, promoting the degradation of CQ. It provides new insights into the application of perovskite oxides in medical wastewater treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] Peroxymonosulfate (PMS)-based advanced oxidation processes (AOPs) are attractive approaches for solving the global problem of water pollution, due to the generation of highly-active reactive oxygen species (ROS). Therefore, highly-efficient PMS activation is crucial for promoting the catalytic degradation of environmental pollutants. Here, bimetallic CoGeO 2 (OH) 2 nanosheets with abundant surface hydroxyl groups (CGH) were synthesized via a simple hydrothermal route for PMS activation and degradation of various organic contaminants for the first time. The abundant surface hydroxyl groups (≡Co–OH/≡Ge–OH) could promptly initiate PMS to generate highly-active species: singlet oxygen (1O 2), sulfate radicals (SO 4 ·−) and hydroxyl radicals (HO•), while the asymmetric electron distribution among Co–O–Ge bonds derived from the higher electronegativity of Ge than Co further enhances the quick electron transfer to promote the redox cycle of Co2+/Co3+ and Ge2+/Ge4+, thereby achieving an outstanding catalytic capability. The optimal catalyst exhibits nearly 100 % catalytic degradation performance of dyes (Methylene blue, Rhodamine B, Methyl orange, Orange II, Methyl green) and antibiotics (Norfloxacin, Bisphenol A, Tetracycline) over a wide pH range of 3–11 and under different coexisting anion conditions (Cl−, HCO 3 –, NO 3 –, HA), suggesting the excellent adaptability for practical usage. This study could potentially lead to novel perspectives on the remediation of water areas such as groundwater and deep-water areas. [ABSTRACT FROM AUTHOR]

• Notably enhanced Fe(III)/PMS process by trace Cu(II) was observed in BA buffer. • Cu(III) and Fe(IV) dominated in RhB removal while SO 4 •− and HO• played a minor role. • BA played a dual role of complexant and buffer in this Cu(II)/Fe(III)/PMS/BA system. • This iron-based AOP was applicable in water treatment under alkaline conditions. Dissolved copper and iron ions are regarded as friendly and economic catalysts for peroxymonosulfate (PMS) activation, however, neither Cu(II) nor Fe(III) shows efficient catalytic performance because of the slow rates of Cu(II)/Cu(I) and Fe(III)/Fe(II) cycles. Innovatively, we observed a significant enhancement on the degradation of organic contaminants when Cu(II) and Fe(III) were coupled to activate PMS in borate (BA) buffer. The degradation efficiency of Rhodamine B (RhB, 20 µmol/L) reached up to 96.3% within 10 min, which was higher than the sum of individual Cu(II)- and Fe(III)- activated PMS process. Sulfate radical, hydroxyl radical and high-valent metal ions (i.e., Cu(III) and Fe(IV)) were identified as the working reactive species for RhB removal in Cu(II)/Fe(III)/PMS/BA system, while the last played a predominated role. The presence of BA dramatically facilitated the reduction of Cu(II) to Cu(I) via chelating with Cu(II) followed by Fe(III) reduction by Cu(I), resulting in enhanced PMS activation by Cu(I) and Fe(II) as well as accelerated generation of reactive species. Additionally, the strong buffering capacity of BA to stabilize the solution pH was satisfying for the pollutants degradation since a slightly alkaline environment favored the PMS activation by coupling Cu(II) and Fe(III). In a word, this work provides a brand-new insight into the outstanding PMS activation by homogeneous bimetals and an expanded application of iron-based advanced oxidation processes in alkaline conditions. [ABSTRACT FROM AUTHOR]

In this paper,nano-Ni/Co hydrotalcite catalysts were synthesized by hydrothermal method using zeolite imidazolate framework materials(ZIFs) as templates, and the physico chemical properties of the catalysts were characterized. With sulfamethoxazole solution as simulated wastewater, the catalytic performance of nano-Ni/Co hydrotalcite to degrade sulfamethoxazole in water via persulfate activation was investigated. Characterization results showed that the catalyst had a nano-rhomboid structure with large pore size and a specific surface area of 187.99 m2/g. The degradation experiment results showed that the removal rate of sulfamethoxazole was about 100% in 20 min, under the conditions of 30 ℃, the concentration of sulfamethoxazole as 15 mg/L, the amount of PMS as 2 g/L, and the amount of Ni/Co hydrotalcite catalyst as 100 mg/L. After reuse of 4 times, the degradation rate of sulfamethoxazole was still greater than 90%, showing its good stability and reusability. Quenching experiments and electron paramagnetic resonance analysis showed that SO4•-, ·OH and 1O2 participated in the degradation reaction. During the reaction process, the redox cycle of Co2+/Co3+ and Ni2+/Ni3+ effectively activated PMS and promoted the generation of active oxide species, which improved the performance of the catalyst for the degradation of sulfamethoxazole.