The development of efficient and poison-resistant catalysts for volatile organic compounds (VOCs) oxidation remains a critical challenge in industrial applications. Herein, a series of CuMn bimetallic in mesoporous silica catalysts with varying Cu/Mn ratios were synthesized and evaluated for toluene oxidation. The optimal Cu0.87Mn/meso-SiO2 catalyst exhibits promising catalytic performance with a T90 of 271 degrees C and an apparent activation energy of 48.31 kJ & sdot;mol- 1, significantly outperforming its monometallic samples. Comprehensive characterization reveals that the confined mesoporous structure ensures high dispersion of active phases, while the strong electronic interaction between Cu and Mn significantly promotes redox agility and oxygen vacancy proliferation. This synergy enables more efficient C-H bond activation and promotes complete mineralization at lower temperatures by facilitating both oxygen supply and surface reactivity. Notably, the abundant surface oxygen vacancies generated by the Cu-Mn interplay contribute to improved lattice oxygen mobility and sustained catalytic activity. Mechanistic investigation into sulfur poisoning reveals that SO2 preferentially attacks Mn3+ sites, forming stable surface sulfates that irreversibly consume reactive oxygen species and decouple the Cu-Mn redox synergy, leading to progressive deactivation. This work establishes a comprehensive relationship between structure, activity, and deactivation for Cu-Mn bimetallic catalysts and provides rational guidance for designing poison-resistant, high-performance oxidation catalysts.

Interaction between dissolved organic matter (DOM) and iron oxides would significantly affect the environmental behaviors of nanoparticles. In this study, the transport of titanium dioxide nanoparticles (TiO2 NPs) in goethite-coated quartz in the presence of DOM extracted from corn straw (CSDOM) and fulvic acid (FA) was investigated, and special emphasis was placed on evaluating how goethite’s fractionation effect on DOM influenced its impact on nanoparticle mobility. The results demonstrated that the presence of patchy goethite significantly hindered TiO2 NPs mobility under acidic and neutral conditions (pH 4.0 and 6.5) due to electrostatic attraction between negatively charged nanoparticles and positively charged goethite sites. The inhibition was pH-dependent and diminished under alkaline conditions (pH 10.0) where all surfaces were negatively charged. DOM (CSDOM and FA) generally enhanced TiO2 NPs mobility at pH 4.0 and 6.5 by increasing nanoparticle stability and blocking attachment sites on collector surfaces. FA exhibited a stronger enhancing effect than CSDOM at low concentrations, attributed to its higher aromaticity and stronger steric repulsion. A key finding was that goethite’s fractionation effect on DOM decreased its total amount and altered its properties, reducing its ability to stabilize nanoparticles and consequently compressing its mobility-enhancing effect under both acidic and neutral conditions. However, this effect of fractionation was negligible at pH 10.0. The study highlights that interactions between environmental components (e.g., DOM and iron oxides) critically determine nanoparticle fate, and overlooking these interactions may lead to overestimating nanoparticle mobility in realistic environmental scenarios, particularly under acidic and neutral pH conditions.

Electrocatalytic dechlorination (EDC) offers an efficient and environmentally friendly approach to removing chlorinated pollutants, but its selectivity is frequently undermined by the competing hydrogen evolution reaction (HER). To overcome this limitation, this study fabricated an innovative Ag-NiOx-NC/CF cathode, integrating a NiOx and nitrogen-doped carbon co-modified Ag composite onto a carbon felt substrate. The composite cathode demonstrates good EDC activity for 2,4-dichlorophenol (2,4-DCP), achieving a 95.8 % removal efficiency on the Ag-NiOx-NC/CF electrode within 180 min under neutral conditions, with an apparent rate constant (kobs) of 0.0168 min-1, comparable to commercial Pd electrodes. This enhanced performance is attributed to its abundant oxygen vacancies and the synergistic interactions among NiOx, nitrogen-doped carbon, and Ag. The EDC of 2,4DCP involves both H*-mediated electrocatalytic hydrogenation (ECH) and direct electron transfer (DET). This work provides a cost-effective strategy for developing noble metal-free EDC systems, advancing practical remediation of chlorinated pollutants.

Accelerating Fe2+ regeneration emerges as a promising approach to boost Fenton reaction. However, most cocatalysts to accelerate Fe2+ regeneration embrace drawbacks including cumbersome synthesis, expensive precursors and metal leaching. Herein, we report an approach to remarkably accelerate Fe2+ regeneration by metalfree biochar. Quantitatively, the overall reaction rate constant for Fe2+ regeneration by biochar was 9.68 x 10(-4), and correspondingly the concentration of OH center dot generated in biochar/Fe2+/H2O2 system was 2.08 times higher than that in Fe2+/H2O2. Favored by this, satisfying performance on both mineralization and detoxification on sulfamethoxazole was achieved. Moreover, 99.6 % of Chemical Oxygen Demand (COD) was removed from medical wastewater in a biochar-packed fixed-bed column, while comparably the traditional Fenton process achieved only 14.6 %. Distinguished with traditional knowledge, surface carboxyl groups on the surface of biochar were identified as reactive sites to capture Fe3+, while, carbon defects played multifunctional roles as electron donors and shuttle to reduce Fe3+. Besides, advantages including negligible metal leaching, low interferences from water matrixes and suppression of toxic BrO3- generation suggested the strategy promising. The achievements shed light on the acceleration of Fe2+ regeneration in Fenton processes in an economic and environmentally-friendly way, and also the modulation of the reactivity of biochar.

In this study, a series of Px-Co3O4 catalysts were prepared by regulating the doping level of P in Co3O4. The results showed that the addition of P significantly affected the activation efficiency of permonosulfate (PMS). 100 % of p-nitrobenzaldehyde (4-NBA) was degraded within 40 min at 0.4 g/L PMS and 0.05 g/L P3-Co3O4. The influence mechanism of P doping on oxidation process of Px-Co3O4/PMS system was revealed through physicochemical characterization, experimental analysis, and theoretical calculation. Specifically, P doping first increased the contact frequency between Px-Co3O4 and PMS by inducing OV production. In addition, P doping promoted the formation of Co-O-P bond on the catalyst. Co-O-P could weaken the strength of Co-O bond and promoted the conversion of available Co Species-Co2+. Meanwhile, Co-O-P induced local electron enrichment enhanced the electron transfer ability of Px-Co3O4 to PMS, and thus weakened the energy barrier of PMS conversion to free radicals. Our research provides a new strategy and theoretical guidance for the preparation of novel and efficient heterogeneous catalysts.

The sulfate radical (SO4•-) generated in the heterogeneous persulfate catalyzed oxidation system can be released into the bulk solution or adsorbed on the catalyst surface. The oxidation capacity of the surface adsorbed SO4•- is relatively mild, but this also gives it a longer life cycle and a stronger ability to resist the environmental interference, giving it more potential for practical sewage treatment. However, to date, there is still a lack of effective strategies to regulate its existence state. Herein, a series of MOx-CaO (M = Cu, Co, Ni, etc.) catalysts were prepared by combining CaO with typical transition metal oxides for the purpose of activating peroxymonosulfate. Mechanistic investigations revealed that the strong electron coupling effect between CaO and Cu/Co significantly altered the electronic structure of the composite catalysts, causing a shift in the d-band center relative to the Fermi level. Specifically, compared to Co3O4-CaO (-2.401 eV), the d-band center of CuO-CaO (-1.870 eV) showed a more pronounced downward shift, significantly enhancing the chemisorption capacity for SO4•-. Additionally, the SO4•-adsorbed on the catalyst surface effectively avoids its accumulation in the reaction system and thus improves its utilization efficiency. This study affirms the viability of manipulating the adsorption characteristics of SO4•-onto the catalyst surface. Furthermore, it offers a pivotal strategy for modulating the adsorption dynamics of pertinent reactive oxygen species on the catalyst surface within heterogeneous persulfate reaction systems.

Enhancing the selectivity of 2e- oxygen reduction reaction (ORR) to produce H2O2 has been a longstanding focus in the field of heterogeneous electro-Fenton (EF). This study presents the development of composite electrodes prepared by different iron sources, which feature graphene oxide (GO) enhanced single-atom iron-carbon aerogel (SA-FeNGA/CF) electrodes and nanometer iron-carbon aerogel (NP-FeNGA/CF) electrodes. The microstructure and composition of the cathodes were explored using SEM, TEM, XPS, FTIR, XRD and AC-HAADF-STEM. The COD of the reaction solution on SA-FeNG1A/CF electrode can be almost completely removed within 4 h in neutral conditions with the current densities of 3 mA/cm2, and the mineralization current efficiency (MCE) could reach up to 98.5 % within 1 h. The incorporation of GO significantly enhanced the graphite N content in the SAFeNG1A/CF composite to 51.5 %, which is instrumental in facilitating the formation of H2O2, but the graphite N content in the NP-FeNG1A/CF experiences a decline. A higher concentration of 2.46 mg/L hydroxyl radicals (center dot OH) can be produced on the SA-FeNG1A/CF electrode, which is capable of to the phenol degradation. This work proposes a new insight into the rational design of efficient iron-carbon aerogel electrode for the EF system.

The advanced oxidation technology based on persulfate has excellent performance in the efficient removal of refractory organic pollutants in water bodies, among which the heterogeneous catalytic activation system has been studied extensively due to its characteristics of convenient operation, low energy consumption, and no secondary pollution. Many studies have been focused on improving the overall oxidation efficiency of target substrates in heterogeneous catalytic oxidation systems. Herein, a series of bimetallic composite oxides (CaOMOx) x ) (M = Cu, Fe, Ni, etc.) were prepared by combining inert metal oxides-CaO with various transition metal oxides, and were used for permonosulfate (PMS) activation. Among them, the introduction of CaO has the most obvious effect on the catalytic efficiency of CaOCuO/PMS system. Almost 100 % of benzothiazole (BTH) was degraded within 40 min at 0.3 g/L PMS and 0.15 g/L CaOCuO. The mechanism study showed that the introduction of CaO significantly increased the content of oxygen vacancies (OVs) on CaOCuO, and thus promoted the formation of surface hydroxyl groups to strengthen the adsorption capacity for PMS. In addition, the introduction of CaO enhanced the reducibility of Cu species and thus promoted the transformation of Cu2+ 2 + to Cu+, + , ensured the continuous and rapid generation of SO4 center dot-, 4 center dot- , thereby promoting the improvement of oxidation efficiency. Our study provides a novel strategy for improving the conversion efficiency of free radical in heterogeneous persulfate catalytic oxidation systems.

The interaction between microplastics (MPs) and heavy metals would significantly determine their environmental impacts. The aim of this study was to investigate the influences of weathering on the affinity of MPs derived from polyethylene mulching film towards Cd(II). Weathered (w-PEMP) and pristine MPs (p-PEMP) were prepared from mulching film sampled from a garlic planting field and the pristine one, respectively. MPs were characterized by spectrum, surface charge and hydrophobicity analysis to determine the variations in physicochemical properties during the weathering process. Batch adsorption and desorption experiments were conducted to compare the affinity of MPs towards Cd(II) before and after the weathering process. Results showed that the Pseudo-second-order dynamics model satisfactorily described the adsorption of Cd(II) onto w-PEMP, indicating the different binding sites on the surface and the main role of chemical adsorption in the interaction. According to Langmuir model, maximum adsorption capacity of w-PEMP was more than 4 times higher than that of p-PEMP, corresponding to the coarse microscopic surface and the exogenous elements and more oxygen containing groups introduced in weathering process. A higher Kf value of w-PEMP in Freundlich model suggested that the weathered microplastics surfaces had a higher adsorption affinity for the Cd(II) than p-PEMP. The weathering process also significantly increased desorption capacity of the MPs for Cd(II), and mitigated the influence of pH on the adsorption of Cd(II) onto the MPs. The weathering process markedly altered the surface morphology and physicochemical properties of MPs, and significantly enhanced the adsorption and desorption capacity of Cd(II).

To obtain a high-efficiency and low-cost electrocatalytic anode for environmental pollutant degradation, a nitrogen doped graphene aerogel supported tin oxide (SnO2-NGA) composite catalyst was prepared and SnO2-NGA/Ti anode was fabricated. The influence of nitrogen doping content on electrocatalytic activity of the catalysts was investigated. The effects of current density and initial solution pH on degradation efficiency were studied. The SnO2-N3.0GA/Ti anode shows good catalytic activity for phenol degradation. The conversion of phenol and COD removal by SnO2-N3.0GA/Ti reached 83.6% and 61.2% within 4h when applied current density was 5.00mA/cm2 and initial pH was 3.0. The SnO2-N3.0GA/Ti electrode has higher specific surface area, and lower charge transfer resistance. The nitrogen atoms doping increased the content of pyridinic N species, which is beneficial for providing more in-situ catalytic active sites and enhancing the production of reactive oxygen species, especially hydroxyl radical (•OH). This work provides a novel strategy for synthesis of electrocatalytic anode with enhanced activity for degradation of refractory organic pollutants in water.

As a typical non-free radical oxidation mechanism in persulfate-based catalytic oxidation system, 1O2 has received extensive attention and research. 1O2 has been found in alkali activation, reagent activation, and heterogeneous catalyst (metal-based and metal-free catalysts) activation. At present, there is no fixed standard and model for the study of 1O2, coupled with the diversity of reaction systems and the limitation of analysis means, there are widespread controversies in the generation, identification, and derivative mechanism of 1O2. Herein, we first summarized the evolutionary pathways of 1O2 in persulfate catalytic oxidation system. Then arranged and compared the commonly used 1O2 identification techniques at present. Finally, the general controversies and main challenges of 1O2 oxidation were listed. This work could assist researchers to quickly grasp the background knowledge of 1O2 oxidation in persulfate catalytic oxidation system, and is expected to provide a direction for further exploration of 1O2 oxidation.

Investigations on the characteristic of dissolved organic matter released from sludge after agricultural use could help to evaluate and predict the environmental behaviors and ecological effects of the concurrent pollutants in soils. The characteristics change in concentration, molecular weight, composition, structure and other properties of DOM released from aerobic composted municipal sludge sampled from a sludge treatment plant in Luoyang City, Henan Province were characterized with Scanning Electron Microscope (SEM), total organic matter analyzer (TOC), UV-Vis absorbance spectroscopy, gel permeation chromatography (GPC), three-dimensional excitation-emission matrix (3D-EEM), Fourier transformation infrared spectroscopy (FTIR) and H-1 nuclear magnetic resonance (NMR). Results showed a significant change in the microscopic morphology of the released DOM, varying from dense lumps to irregular loose material within 60 d of the release process. Dissolved organic carbon released from sludge was in the range of 4.25 to 6.22 mg center dot g(-1) dry sludge, presenting an early increase and later decrease trend. Significant changes in molecular weight and aromaticity of DOM were seen during the release process. The measured molecular weight of DOM increased from 2 674 g center dot mol(-1) on the 5th day to 129 026 g center dot mol(-1) on the 60th day. The aromatic compounds in DOM gradually accumulate during the release process. 3D-EEM combined with the parallel factor analysis (PARAFAC) model was used to analyze the fluorescent substances in the released DOM, and it was found that the main fluorescent substances in DOM were fulvic-like and humic-like compounds. The humic-like compounds gradually accumulated during the process, resulting in the humification of the released DOM. The reduction of aliphatic alkane compounds and formation of aromatic compounds in DOM were indicated in FTIR. Variations in the quantity and properties of DOM released from sludge after agricultural use might significantly change the environmental behaviors and ecological effects of the coexisting pollutants in soils. These results may provide insights into the evaluation and prediction of sludge for agricultural use and have guiding significance to the utilization of municipal sludge resources.

Petrochemical wastewater contains a high concentration of refractory aliphatic and aromatic hydrocarbons. Bioremediation of these hazardous materials using autochthonous bioaugmentation (ABA) strategy is attracting increasing interest. Herein, an indigenous biosurfactant-producing bacteria Z11 was isolated and identified as Enterobacter sp. The reintroduction of Z11 into petrochemical wastewater led to a substantial reduction (P < 0.01) in TPHs, decreasing from 8099 to 1723 mg/L, as well as a significant decrease in COD, decreasing from 8064.2 to 1689.2mg/L. At a critical micelle concentration of 200mg/L, the biosurfactant synthesized by Z11 exhibited an extraordinary decrease in surface tension from 67.5 to 29 mN/m. The biosurfactant demonstrated favorable surface activity over a wide pH, temperature, and salinity range. Based on a series of chemical analyses, the biosurfactant was classified as phospholipid. The autochthonous bioaugmentation technique developed by Z11 indicated a significant increase (P < 0.05) in the degradation of n-alkanes of varying chain lengths and polycyclic aromatic hydrocarbons. The analysis of the microbial composition demonstrated that the addition of Z11 caused a rise in bacterial populations capable of hydrocarbon decomposition, such as Pseudomonas sp. and Stenotrophomonas sp. The activities of two enzymes involved in degradation, alkane hydroxylase and alcohol dehydrogenase, increased dramatically and showed a significant (P < 0.05) correlation with Enterobacter sp. Z11. The proposed mechanism could be elucidated that functional genes regulate the secretion of biodegradation enzymes and biosurfactants to promote the deep degradation of petroleum hydrocarbons. This study provides technical support for the reintroduction of autochthonous microorganisms capable of producing biosurfactants in implementing in situ ABA strategies.

In heterogeneous persulfate-catalyzed oxidation systems, the mechanism underlying the crystal plane effects of the catalyst on the selective conversion of reactive oxygen species (ROS) remains ambiguous. In this study, nano-Co3O4 catalysts with varying crystallinity and exposure levels of (111) crystal planes are prepared via a hydrothermal method. Compared to low crystalline catalysts, high crystallinity catalysts predominantly expose (111) planes containing higher concentrations of Co2+ and oxygen vacancies (Ov), resulting in an increase degradation efficiency of p-nitrobenzaldehyde (4-NBA) from 74.5% to 100%. Radical quenching experiments and EPR characterization reveal that the degradation of 4-NBA occurs through a radical pathway, and quantification of radicals demonstrates that increasing exposure levels of (111) planes effectively promote radical yield (CSO4 center dot- increase from 18.2 to 172.8 mu m and C center dot OH increase from 1 to 58.9 mu m). Furthermore, XPS and DFT calculations indicate that high crystallinity catalyst possesses more Ov active sites on (111) planes. The presence of Ov not only facilitates the adsorption of PMS molecules but also enhances electron transfer from Co2+ to PMS, leading to directed formation and efficient transformation of radicals. This study presents a novel strategy for promoting efficient radical formation in persulfate-activated systems. A series of nano-Co3O4 catalysts with varying degrees of crystallinity and exposure levels of (111) crystal planes are prepared as a PMS activator. The catalyst with higher crystallinity predominantly exposes (111) planes, which increase the concentration of Co2+ and oxygen vacancies (Ov) and further promote the directed transformation of radicals by enhancing the adsorption of PMS and electron directed transfer. image

The application of organic materials into agricultural soil introduces dissolved organic matter (DOM) into environment. The DOM derived from organic materials would significantly affect the environmental behaviors of nanoparticles. In this study, DOM extracted from corn straw (CSDOM) was characterized and its effects on the transport of titanium dioxides nanoparticles (TiO2 NPs) in porous media were evaluated and compared with those of fulvic acid (FA). The characterization of DOMs indicated marked differences in molecular properties between CSDOM and FA. Weight-average molecular weight (Mw) of CSDOM was 3139g/mol, higher than 1185g/mol of FA, whereas CSDOM had a lower aromaticity than FA. Three distinct scenarios of nanoparticle mobility affected by CSDOM and FA were found. Under unfavorable conditions for nanoparticles mobility (pH 4.0 with/without electrolytes, pH 7.0 with electrolytes, and pH 10.0 with CaCl2), both DOMs facilitated TiO2 NPs mobility, and FA with higher aromaticity exerted stronger enhancing effects than CSDOM. However, the promoting effects of DOM on TiO2 NPs mobility were negligible under favorable conditions (pH 10.0 without electrolytes). Under the remaining conditions (pH 7.0 without electrolytes, and pH 10.0 with NaCl), DOM could facilitate the mobility of TiO2 NPs, while there was no difference in the facilitating effects between CSDOM and FA. It could be concluded that distinction of enhancing effects between CSDOM and FA on TiO2 NPs mobility was environmental chemistry-dependent. Furthermore, aromaticity rather than Mw would be a reasonable property determining the enhancing effects of DOM derived from distinct sources on nanoparticle mobility under unfavorable conditions.

To obtain an electrocatalytic hydrodechlorination (ECH) cathode with low noble metal content, low energy consumption and high catalytic activity, a novel electrode that arming Pd with NiCo-layered double hydroxide (Pd/NiCo-LDH/NF) was prepared. The Pd/NiCo-LDH/NF electrode shows excellent ECH activity, having a mass activity of 32.80 min(-1) gPd(- 1) for dechlorination of 2,4-dichlorophenol (2,4-DCP), which is 5 similar to 10 times higher than other reports on ECH cathodes. The higher ECH activity is due to the synergistic effect between NiCo-LDH interlayer and Pd2+. The influence of preparation parameters on morphology, composition, conductivity and hydrogen evolution performance of the NiCo-LDH was investigated by means of scanning electron microscope, high-resolution transmission electron microscope, X-ray diffraction, X-ray photoelectron spectroscopy, induc-tively coupled plasma emission spectrometer, cyclic voltammetry, electrochemical impedance spectroscopy, and linear scanning voltammetry. Density functional theory (DFT) analysis results showed that the NiCo-LDH con-taining OH- vacancies enhanced the generation of Hads*, weakened the toxicity of phenol to the electrode, and improved the ECH activity of the electrode. This work designed a robust electrocatalytic cathode with low energy consumption, low cost and high efficiency for the ECH of chlorinated phenols.

At present, more and more scholars have questioned the reliability of NaN3 as a quench agent of 1O2 in heterogeneous persulfate catalytic oxidation system. In this study, we first compared the decomposition kinetics of PMS in the presence of CuO (CuOMgO), different concentrations of NaN3, and CuO (CuOMgO) with different concentrations of NaN3, respectively. Subsequently, the catalytic performance of common catalysts was compared. These results confirmed that the addition of NaN3 will significantly affect the decomposition process of PMS in heterogeneous persulfate catalytic oxidation system, so it is not suitable to be used as quench agent of 1O2.

Heterogeneous catalytic oxidation is one of the most effective methods to degrade various and complex organic pollutants in aqueous solution. Increasing reactive oxygen species (ROS) yield has always been the main objective to improve the oxidation efficiency. However, the mass production of ROS in a short time is inevitably faced with self-quenching and ineffective consumption. Herein, Cu-based composite oxides (CuOMOx) (M = Ca, Mg, Zn, Mn) were synthesized and used for catalytic activation of permonosulfate (PMS). Although the introduction of unreducible metal oxides significantly improved the activation efficiency of PMS, the abnormal phenomenon of lower substrate degradation efficiency and PMS stoichiometry appeared. The underlying mechanism is that the rapid production of ROS results in a mismatch of the production/effective consumption ratio, which causes massive ROS disappeared naturally before attacking the substrate. In this scenario, reasonable regulation of ROS generation rate by phosphate addition improved the utilization efficiency of ROS without affecting its yield. Our finding is beneficial to achieve a win-win situation of ROS yield and utilization efficiency in heterogeneous catalytic oxidation systems.

A nitrogen-doped carbon-anchored single atom Pd (SA-Pd/NC) electrocatalyst was prepared by pyrolysis of Pd doped zeolite imidazolite framework (ZIF) precursors. The SA-Pd/NC catalyst was characterized by high resolution transmission electron microscopy, aberration-corrected high-angle annular dark field scanning transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and Raman spectrometry and applied in the degradation of 2,4-dichlorophenol (2,4-DCP). We demonstrate that the SA-Pd/NC catalyst has dual functions, with both electrocatalytic hydrodechlorination (ECH) activity and in situ heterogeneous electroFenton (hetero-EF) activity even at low current density. The ECH process was the main pathway of 2,4-DCP degradation without oxygen aeration. Under aerobic conditions, hetero-EF coupling with ECH occurred simultaneously on the SA-Pd/NC cathode, i.e., the dechlorination product phenol was oxidatively degraded with the reactive oxygen species produced on the electrode. The degradation rate of 2,4-DCP and TOC removal rate reached 95.1% and 37.6%, respectively, with a current density of 2.5 mA cm-2 and an initial pH of 3.0. This work provides the design of bifunctional single-atom catalysts for 2,4-DCP degradation, including dechlorination and mineralization.

Heterogeneous electro-Fenton (hetero-EF) system has attracted much attention for the removal of refractory organic pollutants. In this study, hetero-EF for phenol degradation was constructed to use cobalt and nitrogen co -doped graphene (Co/N-GO) modified cathode. The microstructure and composition of the modified cathode material were explored using SEM, TEM, XPS, and XRD. Systematic investigation of the effects of various factors on phenol removal showed that the phenol removal rate could reach 97.00 % in the hetero-EF system by Co/N-GO within 4 h, and the substrate could be removed well in a wide pH range (3-9). The phenol removal rate was still up to 90.71 % after eight consecutive reaction cycles. Combined with the quenching test and EPR analysis, singlet oxygen (1O2) played a major role in the degradation of phenol. Further research revealed that & BULL;OH and & BULL;O2  were not only involved in oxidative degradation of pollutants, but also contributed to the production of 1O2. Meanwhile, dissolved oxygen (DO) also participated in the formation of 1O2. The study is beneficial to further develop the potential of hetero-EF system for environmental organic pollution remediation.