Rational modulation of the electronic structure of catalysts is pivotal for enhancing their catalytic activity. In this work, a bimetallic Co-modified Cu@C catalyst (Co-Cu@C) was synthesized via a one-pot MOF-derived strategy, combining hydrothermal MOF assembly with controlled calcination and employed for highly efficient peracetic acid (PAA) activation. The introduction of Co induced the formation of a new phase, resulting in electron redistribution and an upshift of the d-band center (epsilon d) from -1.829 to -1.624 eV. This electronic modulation significantly strengthened the PAA adsorption energy (-4.39 eV) and increased the Bader charge transfer (0.198 e). The Co-Cu@C/PAA system exhibited superior catalytic performance, achieving a 1.38-fold higher PAA utilization efficiency and a 2.72-fold increase in the degradation rate constant (kobs) for sulfamethoxazole (SMX) compared to the Cu@C/PAA system. Electron paramagnetic resonance and quenching tests identified singlet oxygen (1O2) and organic radicals (CH3C(O)OO center dot and CH3C(O)O center dot) as the dominant reactive species. The synergistic combination of radical and non-radical pathways conferred strong anti-interference capability in complex water matrices and enabled effective broad-spectrum pollutant removal. Furthermore, Co incorporation enhanced ferromagnetic properties of the catalyst, facilitating magnetic recovery and thus promoting practical application. This study provides fundamental insight into enhancement of PAA activation via d-band center regulation and offers a promising strategy for designing efficient Fenton-like catalysts for advanced water treatment.

The environmentally friendly degradation of organic pollutants in aqueous systems has attracted increasing attention, particularly regarding the formation mechanisms and roles of environmentally persistent free radicals (EPFRs) in metal-free carbon catalysts. In this study, N-and P-doped biochar (N-DC and P-DC) were synthesized from cotton seed hull via co-precipitation and pyrolysis. In the N-DC/PMS and P-DC/PMS systems, 91.3% and 87.0% of doxycycline (DOX) were removed, respectively. After ruling out contributions from the adsorption and the effect of oxygen-containing functional groups, quenching experiments and quantitative analysis further demonstrated that EPFRs served as the dominant contributors to activate PMS for DOX degradation. Spearman correlation (r = 0.998 for pyrrolic N and 0.995 for-PO3) together with DFT results indicated that pyrrolic N and-PO3 groups, regulated by heteroatom doping and calcination temperature, acted as key active sites improving EPFRs intensity and promoting DOX degradation. Simultaneously, both the N-DC/PMS and P-DC/PMS systems exhibited strong resistance to interference from common environmental anions and natural organic matter, and effectively degraded various organic pollutants, thus demonstrating promising application potential. This study systematically elucidated the mechanisms of how heteroatom doping enhanced EPFRs intensity, established the dominant role of EPFRs as active sites in the removal of refractory pollutants via PMS activation, and provided a theoretical foundation for the rational design of advanced biochar-based catalysts.

The release of recalcitrant micropollutants into aquatic environments poses severe ecological and health risks, necessitating efficient and sustainable treatment strategies. Here, a high performance heterogeneous electro-Fenton (HEF) cathode was constructed by in situ incorporation of phosphomolybdic acid (PMo12) into MIL-101(Fe) on carbon felt. Combined characterization and theoretical analyses identified Fe sites in the MOF structure as the principal active centers, while PMo12 introduction promoted electron delocalization and improved electrical conductivity, thereby synergistically enhancing catalytic efficiency. Quenching and EPR experiments confirmed that the 1O2 served as the predominant reactive oxygen species governing doxycycline (DOX) degradation. The optimized PMo12/MIL-101(Fe) cathode, with a H2O2 production of 32 mg L-1, achieved nearly 90 % DOX removal and 82.4 % TOC reduction, while still maintaining high stability under salinity stress (81.88 %) and continuous-flow conditions over a sustained operation exceeding 25 h. Furthermore, liquid chromatography coupled with ecotoxicity assessments verified the stepwise decomposition of DOX into less toxic intermediates. Overall, this work established a sustainable 1O2-dominated EF paradigm and offered a generalizable strategy for designing advanced POM/MOF-based cathodes for practical wastewater remediation.

Amid escalating global water quality decline and the urgent energy crisis, photoelectrocatalysis (PEC) technology emerges as a promising remedy for removing emerging micropollutants (EMs) from water while aiding in energy/resource recovery. This review systematically summarizes the fundamental principles of PEC processes and provides an in-depth analysis of the key mechanistic factors governing PEC-mediated EM removal. Moreover, the size-dependent surface chemistry and electronic structure of carbon quantum dots (CQDs) offer extensive opportunities for tailoring nanohybrid architectures with multifunctional capabilities. Consequently, this paper also focuses on the latest advances in CQDs engineering techniques (including heteroatom doping, heterostructure construction and surface functionalization) for regulating charge separation, transport pathways, and interfacial redox activity. Furthermore, emerging CQDs-based dual-functional PEC systems are highlighted, in which oxidative pollutant degradation is coupled with value-added reduction processes including metal ion reduction, nitrate reduction, carbon conversion, hydrogen (H2) evolution and hydrogen peroxide (H2O2) production. Finally, current challenges and future perspectives for advancing CQDs-based dual-functional PEC systems are outlined, providing guidance for sustainable water treatment and solar-driven resource recovery.

In this study, a novel single-atom catalyst featuring atomically dispersed Co and Mn bimetallic active sites (CoMn-SAC) supported on biomass-derived carbon was successfully synthesized through a hydrothermal and pyrolysis strategy. The catalyst exhibited exceptional activity in activating peracetic acid (PAA) for oxidative degradation. Mechanistic investigations revealed that Co sites acted as the primary active site, while Mn significantly promoted the metals redox cycle and enhanced PAA activation. Quenching experiments identified acetylperoxy radicals (CH3C(O)OO & sdot;) and singlet oxygen (1O2) as the dominant reactive oxygen species (ROS) involved in the degradation process. Under optimized PAA dosing conditions, the CoMn-SAC/PAA system achieved 97.25 % contaminant removal within 20 min at a low catalyst dosage over a wide pH range. Furthermore, the system demonstrated strong resistance to common environmental interferents and maintained high operational stability in a continuous-flow reactor. This work provided new mechanistic insights into PAA activation by bimetallic single-atom catalysts and offered a practical strategy for designing efficient, sustainable, and scalable advanced oxidation processes for water treatment.

The escalating global crises of water contamination and energy depletion underscore the urgent need for innovative technologies to simultaneously achieve water purification and sustainable energy production. Herein, we report the synthesis of a melamine (MEL)-mediated Cu-MOF-encapsulated phosphomolybdic acid-derived nanocluster catalyst (p-POM@MOF-MEL). The fluorine-doped tin oxide (FTO) electrode coated with this composite enables rapid disappearance of dissolved pollutants in the photoelectrocatalytic (PEC) system within 5 min, accompanied by ultrafast degradation kinetics (kobs = 0.5535 min- 1) and hydrogen (H2) evolution (26.77 mmoL & sdot;g- 1 & sdot;h- 1), while maintaining stable performance over a broad pH range (3-13) and in diverse water matrices. Mechanistic studies infer that the system operates via a hole (h+)-dominated direct oxidative transfer pathway (h+-DOTP), facilitating the transformation of phenolic pollutants into recoverable polymeric products rather than complete mineralization, while achieving approximately 90% remove of total organic carbon (TOC) and chemical oxygen demand (COD). Theoretical calculations suggest that Cu and Mo sites may contribute to the catalytic process, while N atoms may facilitate charge transfer. These findings underscore the prospect of removing persistent pollutants from wastewater via polymerization, paving the way for sustainable wastewater treatment.

In this study, a calcination and boron-doping strategy was developed to construct a metal defect-rich B@Co1-xS catalyst for Fenton-like reaction. Density functional theory (DFT) calculation and mechanistic investigation confirmed that the enhanced Co vacancies could increase the adsorption of the terminal oxygen in the peroxymonosulfate (PMS) molecules to the surrounding Co atoms, resulting in the activation mechanism by highvalent cobalt-oxygen species (Co(IV)=O), boosting the reaction rate constant by 7.14 times. The B@Co1-xS/ PMS system possessed excellent interference resistance and renewability for efficient degradation of a wide range of contaminants. Moreover, a continuous flow reactor loaded with B@Co1-xS was developed, which could operate continuously and stably with ciprofloxacin (CIP) removal efficiency above 97 %, proving that the system was promising for applications. Taken all together, this study delved into how to rationally develop cation-deficient transition metal catalysts in Fenton-like systems at the molecular level, which was of critical meaning for wastewater treatment.

Herein, an electron-optimized core-shell CoFe alloy-carbon composite (CoFeC) was developed from prepared CoFe Prussian blue analogues (CoFe PBAs) through pyrolysis and applied for peracetic acid (PAA) activation. Characterization analysis and theoretical calculations indicated that the Co sites as the primary active centers, with the presence of C and Fe in CoFeC significantly narrowed the difference between the d-band center (epsilon d) and the Fermi level (EF), thereby reducing PAA adsorption energy on Co sites and enhancing electron transfer. The identification of reactive species confirmed that acetylperoxy radicals (CH3C(O)OO.) and singlet oxygen (1O2) were the dominant species driving the reaction. The CoFeC/PAA system demonstrated exceptional pollutant degradation efficiency, achieving nearly 100 % removal within 30 min, along with strong interference resistance and high durability in continuous-flow reactors. This work provided novel insights into the activation of PAA by bimetallic carbon catalysts and offered guidance for the development of efficient and sustainable water treatment technologies.

The development of two-dimensional (2D) transition metal dichalcogenides (TMDs) based transistors has been constrained by high contact resistance and inadequate current delivery, primarily stemming from metal-induced gap states and Fermi level pinning. Research into addressing these challenges is essential for the advancing 2D transistors from laboratory experiments to industrial-grade production. In this work, we present amorphous Ga_2O_3 as a novel tunneling contact layer for multilayer WS2-based field-effect transistors (FETs) to enhance electrical performance. The addition of this innovative tunneling layer avoid Schottky barrier forming while finally change into a tunneling barrier with the barrier height to just 3.7 meV, near-ideal ohmic contacts. This approach effectively reduces contact resistance to only 2.38 kΩ μm and specific contact resistivity as low as 3 × 10^-5 Ωcm^2. A record-high electron mobility of 296 cm^2 V^-1 s^-1 and ON-OFF ratio over 106 are realized for WS_2 transistor at room temperature. Compared to other tunneling materials, ultrathin Ga_2O_3 layer offers scalability, cost-efficient production and broad substrate compatibility, making it well-suited for seamless integration with industrial wafer-scale electronics. A robust device performance remains highly consistent in a large-scale transistor array fabricated on 1.5× 1.5 cm^2 chips, with the average mobility closing to 200 cm^2 V^-1 s^-1. These findings establish a new benchmark for contact performance in 2D transistors and prove the potential of tunneling contact engineering in advancing high-performance, scalable 29 pelectronics with promising applications in quantum computing and communication.

A novel bimetallic heterojunction catalyst (Co2Mo3O8/Co9S8) with hydrangea-like structure was prepared by a straightforward one-pot hydrothermal and pyrolysis method, which was then applied for the efficient activation of peroxymonosulfate (PMS) in wastewater purification. Density functional theory (DFT) simulations revealed that the formation of the Co2Mo3O8/Co9S8 heterojunction increased the adsorption energy of PMS and elongated the O-O bond within PMS. Moreover, an internal electric field generated within the heterojunction further activated PMS through electron-deficient centers, establishing a degradation mechanism primarily dominated by non-radical pathways. Meanwhile, the exist Co(II) and Mo(IV) involved as active sites for enhanced catalytic performance through the redox cycling of metal valence states. In the optimized Co2Mo3O8/Co9S8-PMS system, the target pollutant doxycycline (DOX) was rapidly and efficiently degraded, with a relatively low activation energy (3.93 kJ & sdot;mol- 1). Furthermore, the system demonstrated strong adaptability to interference from inorganic anions, humic acid, and pH variations, while effectively removing various pollutants. It consistently maintained a relatively high DOX removal efficiency in cyclic experiments and continuous flow reaction experiments. The present study provided new insights for improving the rational design of bimetallic heterojunction catalysts, and contributed to a more effective and sustainable solution for environmental remediation.

Herein, a single-atom catalyst (SAC) featuring Fe-N-5 sites (FeNC) with optimized electronic structures was constructed and applied to activate peroxymonosulfate (PMS) for wastewater purification. The high-coordinated Fe-N-5 sites was obtained by creating a high-nitrogen gas environment around fully exposed Fe atomic sites on chitosan surface during pyrolysis. The FeNC/PMS system demonstrated excellent decontamination capability, superior anti-pH interference ability, while also exceptional durability in a continuous-flow catalytic filtration reactor. Experiments and density functional theory calculations unveiled that Fe-N-5 site was the active center. Meaningfully, neighboring carbonyl groups narrowed the gap between d-band center of Fe 3d and Fermi level, which increased the adsorption energy of PMS on Fe-N-5 sites, thus lowering the energy barrier for singlet oxygen generation. This study brings a vivid electronic structure optimization strategy for enhancing the catalytic activity of Fe SAC as well as guiding the selection of desirable catalysts for wastewater purification by Fenton-like chemistry.

The pervasive presence of antibiotics in the environment poses ecological risks and jeopardizes human health. Herein, a simple one-step hydrothermal method was used to prepare a boron-doped (B-doped) bimetallic carbon felt as a cathode for the heterogeneous electro-Fenton (HEF) system. In the HEF process, the modified electrode (B-Co/Fe@CF) demonstrated exceptional efficiency in degrading the target pollutant doxycycline (DOX), owing to its maximal degree of defect and minimal electrochemical impedance. In addition, XPS and structure-activity relationship analysis results revealed that the superior performance of the modified electrode stemmed from the predominant influence of sp(3)/sp(2), C=O and metal-boron (M-B) groups in initiating the production of H2O2 and the consequent formation of reactive oxygen species (ROS). Meanwhile, the introduction of non-metallic boron species significantly accelerated the sustainable cycling of Co(II)/Co(III) and Fe(II)/Fe(III). The quenching and probe experiments suggested that the radicals center dot O-2(-) and center dot OH significantly contributed to the elimination of DOX. Moreover, the advanced B-Co/Fe@CF-HEF system exhibited remarkable versatility, stability and effectiveness throughout the degradation process. Three pathways for the degradation of the pollutants were identified using density functional theory (DFT) calculations and LC-MS detection. Additionally, the treated DOX solution significantly reduced the toxicity to the growth of E. coli and mung bean in actual toxicity experiments. This research presented a novel outlook on developing the B-doped metal catalysts for efficient degradation of pollutants and showcased promising applications in organic wastewater treatment.

Electro-Fenton (EF) process stands out as an energy-efficient and highly promising advanced oxidation technology for organic contaminants degradation. However, achieving optimal heterogeneous catalytic conditions for simultaneous H2O2 generation and spontaneous Fe2+ regeneration poses difficulties in conventional EF. This is due to the electric potential difference between H2O2 generation and Fe2+ regeneration at a single cathode. Therefore, the boron doped biochar modified dual-cathode EF (DCEF) system was designed in this work to overcome the defect of conventional EF system, which not only demonstrated outstanding accumulation of H2O2 (>300 mg L-1) but also exhibited a remarkable capability of degradation (> 90%). Furthermore, the system could also adapt to a broad pH range of 3-11. The superior doxycycline (DOX) degradation efficiency of DCEF system could be attributed to the dominant role played by C=O and BCO2 groups in the activation of H2O2 and subsequently generating reactive oxygen species (ROSs), as revealed by XPS analysis and DFT calculation. In addition, the DCEF system achieved an impressive TOC removal efficiency of 70.5% and a minimal energy consumption (EC) of 0.32 kWh (g TOC)-1. Therefore, this work introduced a DCEF system to address the challenges of conventional EF system, which shed light on the design of wastewater treatment technology and lied the groundwork for a strategy of resource utilization.

Peracetic acid (PAA) as emerging oxidant in advanced oxidation processes (AOPs) has attracted widespread attention in purifying water pollution. In this research, the removal of target contaminant (sulfamethoxazole, SMX) was investigated through PAA activation by a facile catalyst (Co@C), and the active sites of catalyst were identified as sp3-C, Oads, and Co0 by correlation analysis. Especially, different pH adjustment strategies were designed, including System A (adjusting pH after adding PAA) and System B (adjusting pH before adding PAA), to investigate the impact of oxidant acidity and alkalinity on solution microenvironment as well as effect and mechanism of pollutant removal. The results showed that HO· and CH3C(O)OO· dominated in System A, while Co(IV)O2+ was also observed in System B. Both systems showed optimal SMX degradation (98 %). However, System A exhibited excellent water quality tolerance (efficiency > 78 %), superior sustained catalyst activation (efficiency > 80 % in 40 h), less ion leaching (41 μg L-1), and lower products toxicity. Moreover, the pH of solution after reaction in System B was intensely acidic, requiring costly pH adjustments for discharge. This study unveils the strategy of adjusting pH after adding PAA is preferable for water purification, enriching the emerging research of PAA-based AOPs for the remediation of environments.

Recently, atomically dispersed dual‐metal sites carbocatalysts (DMSCs) make a wave in the field of persulfate‐based advanced oxidation processes (PS‐AOPs) in light of their ≈100% atomic utilization efficiency, high density of active sites, and superior catalytic activity. This review aims to provide a state‐of‐the‐art overview on the development of DMSCs for activating PS. Initially, the types and properties of DMSCs are summarized, as well as the role of doping different heteroatoms is discussed. Subsequently, the properties of different carbon carriers and the methods for the synthesis of DMSCs are outlined. After that, the mechanism and application of DMSCs for the activation of PS toward organic contaminants degradation are revealed. Particularly, the mechanism of nonradical pathway is described, and the necessity of coupling DMSCs‐based PS‐AOPs to other processes for practical water treatment is emphasized. Finally, the formidable challenges and future research directions of DMSCs are proposed. This review is expected to provide insight into the preparation of DMSCs in the field of nanomaterials and to broaden the path for their environmental applications.

构建了两级部分亚硝化(PN)∕厌氧氨氧化(ANAMMOX)耦合脱氮系统,研究了耦合系统处理稀土氨氮废水脱氮性能和微生物群落结构的变化,探讨了稀土元素对系统脱氮功能微生物活性的影响.结果表明,通过控制溶解氧能成功启动两级PN∕ANAMMOX反应器,当进水中稀土元素 Y(Ⅲ)浓度大于10 mg∕L时,两级PN∕ANAMMOX耦合系统脱氮性能将逐步降低,停止添加 Y(Ⅲ)后,其性能也不能恢复.同时短期试验表明,当 Y(Ⅲ)浓度大于 40 mg∕L时对 AOB菌活性有抑制作用,当 Y(Ⅲ)浓度大于20 mg∕L时对 ANAMMOX菌活性有抑制作用,且抑制效果随着浓度的升高而增强.高通量测序技术表明,稀土元素 Y(Ⅲ)冲击会降低系统中 AOB 菌(Nitrosomonas)及 ANAMMOX 菌(Candidatus_Kuenenia)丰度,且对Candidatus_Kuenenia的影响强于Nitrosomonas.

Electro-Fenton is one of the promising clean and renewable technologies for refractory pollutants control. Herein, a ternary metal-layered double hydroxide (CoFeCe-LDH) nanoparticle in situ growth on carbon felt (CF) was prepared to fabricate heterogeneous electro-Fenton (HEF) cathode via one-pot hydrothermal strategy. The optimal CoFeCe-LDH@CF cathode demonstrated high oxygen reduction activity, low resistance and efficient degradation of DOX over a wide pH range (pH = 1-9). On one hand, the introduction of Ce resulted in the generation of plenty of oxygen vacancies (O-alpha) on the electrode surface. On the other hand, the coexistence of Co2+/Co3+, Fe2+/Fe3+ and Ce3+/Ce4+ redox pairs significantly enhanced interfacial electron transfer and promoted the generation and decomposition of in situ H2O2, which in turn boosted the production of reactive radicals ((OH)-O-center dot, O-2(center dot-) and O-1(2)). The Estimation Program Interface (EPI) certificated that intermediates resulted from DOX degradation in the system were relatively low in toxicity to typical aquatic organisms. Meanwhile, the effect experiments of various ions, types of wastewater and pollutants were carried out in the CoFeCe-LDH@CFs-HEF system and all showed excellent pollutant degradation, proving that the developed cathode had special applicability and reusability. Thus, this paper gave a global contribution to develop the high-performance cathode by exploring the synergistic effects of trimetals in LDH and proposed a reliable strategy for enhanced degradation of contaminant by HEF system.

污废水的高效节能脱氮技术一直以来都是研究和应用的焦点。短程反硝化-厌氧氨氧化耦合工艺因具有能耗低、产泥少、温室气体减排和脱氮效果好等优点，已成为废水脱氮领域研究和应用的热点。其中，短程反硝化被认为是厌氧氨氧化菌获取底物（NO2--N）的重要途径之一，对其进行研究具有重要的科学和工程意义。基于此，综述了短程反硝化的工艺原理，总结了硫自养短程反硝化和异养短程反硝化微生物的富集方法，并探讨了短程反硝化-厌氧氨氧化耦合工艺处理城市污水、高浓度氨氮废水和硝酸盐废水的工程应用。最后对短程反硝化及其耦合厌氧氨氧化工艺的研究和应用方向进行了展望，以期为短程反硝化-厌氧氨氧化耦合工艺处理实际污水提供参考。

To address the current water pollution issues, one of the most important technologies is the development of efficient and environmental-friendly catalysts for the treatment of organic pollutants in water. In this study, a nitrogen-enriched biochar encapsulated cobalt nanoparticles composite (Co@N-BC) was synthesized using a one- step pyrolysis method based on metal-organic frameworks (MOFs) and leaf biomass as precursors. The obtained Co@N-BC possessed more functional group, large specific surface area and less cobalt ion leaching, which were used for efficient persulfate (PS) activation for approximately 92.72% DOX (50 mg/L) removal in 30 min. The quenching test, electron paramagnetic resonance (EPR), and electrochemical characterization of the Co@N-BC/ PS system revealed that electron transfer was the primary pathway for DOX elimination. Moreover, the Co@N- BC/PS system had satisfactory stability in a wide pH range (2-10) and was not adversely affected by the various anions or water matrix. This research will shed new light on the design and development of MOF derivatives, as well as provide technical support for the eradication of antibiotics.

Emerging micropollutants (MPs) in water present growing environmental concerns, drawing considerable attention in recent years. Of the numerous advanced oxidation processes (AOPs) for MPs removal, the approach based on peracetic acid (PAA) has especially attracted interest from both the academic and industrial realms. This comprehensive review systematically investigates the activation of PAA for MPs degradation using heterogeneous catalysts. The discussion starts with an overview of the fundamental aspects of PAA, along with the research background and prospects of PAA-AOPs. Subsequently, the generation and detection methods of organic radical (R-O center dot) and non-organic radical (non-R-O center dot) pathways in heterogeneous catalyst/PAA systems are discussed. Furthermore, the activation mechanisms of metal- and carbon-based catalysts are extensively revealed. After that, the influencing factors that significantly affect the performance of heterogeneous catalyst/PAA systems are proposed. Additionally, the application of density functional theory (DFT) calculation associated with heterogeneous catalyst/PAA systems is summarized. Finally, the current limitations and future research directions of heterogeneous catalyst/PAA systems are taken over. This review strives to enhance the comprehension of the heterogeneous catalyst-activated PAA systems in removal of MPs, while offering innovative perspectives and outlining future research avenues regarding the applications of these systems.