Achieving scalable fabrication of robust and uniform single-atom catalyst-based gas-diffusion electrodes (SAC-GDEs) remains challenging. Here, a universal one-step soot-deposition route was developed to convert various metal-containing paraffins into conformal single-atom catalyst (SAC) coatings on diverse electrodes (1D fibers, 2D plates, and 3D foams). The process provides multiscale control, from precursor-defined molecular coordination to micropore wettability and macroscopic geometry, to collectively engineer hierarchical coating films that couple intensified mass transfer and high intrinsic catalytic activity for efficient H2O2 electrosynthesis. As a device-level demonstration, Pd-SAC-GDE delivers pH-universal H2O2 production under an industrial-level current (500 mA cm-2) for 100 h, achieving a record-high H2O2 yield of 16.9 mol g-1 h-1. A tip-enhanced mechanism was proposed based on constant-potential calculations. The results reveal that the curvature-enhanced localized electric field promotes O2 polarization and activation at the Pd-O3 sites, thereby facilitating both *OOH generation and adsorption and ultimately leading to highly selective H2O2 production. This facile, broadly applicable fabrication strategy significantly advances the scalable manufacture of SAC-coated GDEs for environmental and sustainable catalysis.

Modified divacancies in the 4H polytype of silicon carbide (SiC) exhibit enhanced charge stability and spin addressability at room temperature, making them attractive for quantum applications. However, their low formation yield and lack of direct structural identification have hindered progress. Here, we demonstrate a controllable method for high-yield engineering and identification of oxygen-related modified divacancy color centers in 4H-SiC via oxygen-ion implantation. Based on their distinct optical and spin-resonance characteristics, we experimentally resolve four types of modified divacancies. Furthermore, by measuring isotope-resolved 17 O $^{17}{\rm O}$ hyperfine interactions, we identify them as the four crystallographic configurations of oxygen-vacancy (OV) complexes. Remarkably, single OV centers account for over 90% of the total defect population and exhibit superior optical properties and spin coherence compared with defects created by conventional carbon or nitrogen implantation. We characterize the zero-phonon lines of these OV centers and reveal distinct temperature-dependent behavior in spin-readout contrast. By optimizing implantation dose and annealing temperature, we achieve high-density ensembles and observe Rabi-oscillation beating patterns associated with different orientations of basal-type defects. These results establish a high-yield route for scalable engineering of these four oxygen-related modified divacancies in 4H-SiC and clarify their atomic structure, opening new opportunities for solid-state quantum technologies.

Although single-atom catalysts (SACs) are emerging as advanced heterogeneous catalysts for Fenton-like reactions, enhancing their performance by precisely tailoring d-p orbital hybridization remains challenging. Herein, single Cu atoms with a unique Cu-N2S asymmetric coordination structure are designed and fabricated to catalyze photo-Fenton reactions. Density functional theory (DFT) calculation reveals that strong d-p orbital hybridization elevates the HOMO energy level and promotes splitting of d-orbital energy levels, thereby regulating the adsorption affinity of single-atom Cu sites toward H2O2 via a unique anti-d-band-center principle. Consequently, the Cu-N2S single sites exhibit unique photo-switching behavior, transforming the inactive sites into Fenton-active ones under light irradiation, thereby enabling sustained and enhanced generation of hydroxyl radicals for efficient degradation of various organic micropollutants. The developed photo-Fenton system achieves 98.9% removal of sulfamethoxazole, along with broad pH applicability (pH 3-11), high tolerance for complex water matrices, and exceptional durability for long-term operation. This work highlights the critical role of single-atom coordination symmetry in modulating electronic orbital structures, providing an avenue for the rational design of advanced Fenton-like catalysts.

This study developed a CoCu@Cu2O heterojunction via a calcination-electrodeposition procedure for high-efficiency electrocatalytic nitrate reduction into ammonia. Characterizations revealed that CoCu@Cu2O formed a stable heterostructure consisting of CoCu alloy nanoparticles uniformly loaded onto Cu2O nanowires. At -0.25 V vs. reversible hydrogen electrode, CoCu@Cu2O achieved a NH3-synthesis Faradaic efficiency of 99.87% at an NH3 yield rate of 0.89 mmol h(-1) cm(-2) while showing structural stability for 100 h, markedly outperforming that of Cu2O@Cu and CoCu@Cu. In situ infrared spectroscopy and theoretical calculations revealed that the CoCu-Cu2O interface exerted a synergistic effect: it promoted electron transfer via d-band coupling and Cu+/Cu2+-Co-0/Co2+ redox cycling, enhancing nitrate adsorption, optimizing the eight-electron transfer process, and suppressing the hydrogen evolution reaction. A lifecycle assessment indicated that this system reduces global warming and resource use by similar to 30%-40% compared with the benchmark electrocatalysts. This study provides a cost-effective, stable, and ecofriendly non-noble metal-based electrocatalyst for sustainable ammonia synthesis via nitrate reduction.

Research on single-atom photocatalysts (SAPCs) has been rapidly expanding, driven by their nearly 100% atom utilization efficiency, tunable electronic structures, and unique metal–support interactions. Significant advances have been made in...

Radioactive iodine (I-2, CH3I) and pertechnetate (TcO4-), both byproducts of uranium and plutonium fission processes, make up the majority of long half-life radionuclide waste from nuclear power plants. Imidazolium-based cationic polymeric networks (CPN-tib-x) were rationally designed by modulating benzyl bromide substituents to optimize electrostatic potential distribution and steric hindrance. Representatively, CPN-tib-1 exhibited high efficiency in simultaneous removal of volatile and aqueous I-2 via charge-transfer complexes, affording both adsorption capacities of 5.11 and 1.71 g g(-1), respectively. CPN-tib-3 demonstrated superior CH3I uptake (1.54 g g(-1)) through N-methylation at nonionic N sites, surpassing most imidazolium-based materials. More significantly, CPN-tib-2 achieved the highest ReO4- (TcO4- surrogate) adsorption capacity (921.9 mg g(-1)) as well as fast kinetics through strong anion exchange and electrostatic attraction, maintaining >60 % efficiency even in simulated Hanford low-activity waste (LAW). The impressive ReO4- adsorption performance of CPN-tib-2 was attributed to the synergistic effects arising between steric hindrance and densely imidazolium-N+ sites. The structure-adsorption performance relationships highlighted the synergy of charge density, steric accessibility, and binding site geometry in governing selective adsorption. This work provides a versatile platform for designing multifunctional polymers tailored for nuclear waste remediation, offering insights into balancing electrostatic and steric effects for efficient radionuclide sequestration.

Recent studies show that MG catalysts largely improve the catalyst design strategy for the wastewater treatment. However, common types of catalysts such as Fe-based and Co-based MGs already cannot satisfy the increasing challenge under complex water environment. Herein, we newly design a series of MnSiBFe MGs for the degradation of Rhodamine B (RhB) dye. The reaction rate of Mn69Si12B11Fe8 MG increases 10 times than that of Mn73Si16B11 MG, achieving a complete degradation of RhB dye within 15 min. In addition, the activation energy is only 23.5 kJ/mol, and they can be reused up to11 times. The highly improved catalytic ability of MnSiBFe MG originates from the synergistic effect of active Mn0 combined with Fe0 on the ribbon surfaces, which react with H2O2 to rapidly produce hydroxyl radicals for effective dye degradation. Additionally, surface analysis demonstrates that the microalloying of Fe leads to a surface cracking with an easy layer detachment of the ribbons, thus significantly enhancing their service life of dye degradation. This study highlights the significant role of microalloying in MG for surface modification and provides new insights into designing novel alloy catalysts.

This study presents a novel approach to water contamination remediation by developing cobalt-doped carbon nanofiber films using electrospun ZIF-67 precursors, aiming to degrade tetracycline hydrochloride (TCH) and other antibiotics. This method uniquely combines the advantages of metal-organic frameworks (MOFs) and electrospinning to enhance catalytic performance, demonstrating significant innovation in environmental catalysis. The research systematically evaluated the impact of various factors on the catalytic activity of carbonized PAN@ZIF-67 films (CPZF), including carbonization temperature, ZIF-67 content, and PMS dosage. Notably, the CPZF catalyst with 11% ZIF-67 content (named as CPZF-11%) achieved an impressive 99.7% degradation of TCH within just 10 min under visible light and PMS activation, highlighting its superior catalytic efficiency. The study revealed that CPZF-11% exhibited excellent stability and recyclability, maintaining near 100% degradation rates even after six cycles. This catalytic performance is attributed to the synergistic effect of photogenerated electrons and PMS activation, leading to the formation of reactive oxygen species (ROS) such as sulfate radicals and singlet oxygen. The research further elucidated the degradation pathways and intermediate products through quenching experiments and electron paramagnetic resonance (EPR) analysis. The findings demonstrate the broad applicability of CPZF/Vis/PMS in various water matrices, including tap water and wastewater, underscoring its potential for real-world applications in wastewater treatment. This innovative integration of MOFs and electrospinning offers a promising strategy for developing efficient, recyclable, and high-performance catalysts for environmental remediation.

This study investigates the strategic incorporation of highly electronegative fluorine (F) atoms into Co3O4 to steer peroxymonosulfate (PMS) activation toward a nonradical pathway. Integrated in situ spectroscopic characterization and theoretical simulations elucidate that F-doping induces electron delocalization at Co sites and elevates the spin states of adjacent Co centers. This electronic modulation enhances the adsorption affinity of active sites toward PMS, culminating in the efficient and selective generation of the reactive species PMS*. The nonradical electron-transfer process mediated by PMS* endows the F-Co3O4/PMS system with exceptional catalytic activity, broad substrate applicability, and remarkable environmental robustness. Furthermore, scalable synthesis and successful continuous-flow reactor operation demonstrate its practical potential. This work proposes a novel electronic structure-tuning strategy on metal oxides for efficient nonradical Fenton-like reactions, providing fundamental insights into the correlation between the electronic configuration of active centers and the underlying reaction mechanism.

Nanoplastics (NPs), ubiquitous environmental pollutants, are increasingly documented to accumulate in plants and induce phytotoxicity. However, the mechanisms governing their cellular-level interactions with plants, particularly root cell wall adaptations to limit translocation, remain unresolved. Here, we elucidate how rice (Oryza sativa L.) root cell walls employ pectin-mediated remodeling to immobilize europium-doped polystyrene NPs (PS-Eu NPs) under hydroponic conditions. Exposure to 50 mg/L PS-Eu NPs for 14 days resulted in 96.94 % retention in roots and only 3.06 % translocation to shoots. Remarkably, root pectin content surged by 64.7 %, directly enhancing NP entrapment (43.9 % of total PS-Eu NPs bound to pectin). This pectin-driven response induced structural reorganization of the cell wall, characterized by increased thickness, stiffness, and adhesiveness, which collectively immobilized 51.47 % of NPs within root cell walls and suppressed upward transport. Multi-omics analyses further uncovered coordinated upregulation of pectin biosynthesis genes (e.g., galacturonosyltransferases, 26-80 %) and modification enzymes (e.g., pectin methylesterases, 12-63 %), accompanied by elevated polysaccharide metabolic intermediates. These findings establish that pectin-dominated cell wall fortification is a critical plant defense strategy to mitigate NP stress, providing mechanistic insights into cellular barriers against nanoparticle translocation in agroecosystems.

This study engineers diatomic Mo-Fe (DA-MoFe) sites anchored on carbon nitride (CN) to precisely regulate the spin state of Fe centers via adjacent high-valent Mo atoms, inducing a transition from low spin (t(2g) (5) e(g)(0)) to medium spin (t(2g) (4 )e(g)(1)) configuration. This electronic modulation and synergistic Mo-Fe bridging significantly optimized peroxymonosulfate (PMS) adsorption/activation and stabilized surface-complexed PMS (PMS*), thereby triggering a non-radical pathway, effectuating a substantial transformation in Fenton-like reaction activity from inactive to highly active. The DA-MoFe/CN/PMS system achieves >95 % removal of diverse organic micro-pollutants with high mineralization efficiency, negligible Fe leaching (<0.3 ppm), broad pH applicability (3-11), and robust resilience to competing anions and complex real water matrices. Beyond establishing an efficient, durable platform for advanced wastewater remediation, this work advances spin-state engineering in single-atom catalysts and presents a universal design principle for amplifying catalytic activity across diverse reactions.

Single-atom nanozymes possess high catalytic activity and selectivity, and are emerging as advanced heterogeneous catalysts for environmental applications. Herein, we present the innovative synthesis and characterization of a single-atom manganese-doped carbon nitride (SA-Mn-CN) nanozyme, integrated into a polyvinylidene fluoride (PVDF) membrane for advanced water treatment applications. The SA-Mn-CN nanozyme demonstrates high peroxidase-like activity, efficiently catalyzing the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) and generating reactive oxygen species (ROS) for effective antibacterial action. Notably, the SA-Mn-CN/PVDF membrane showcases enhanced water permeability, superior antifouling properties, and ultra-fast degradation kinetics of organic pollutants. Mechanistic studies reveal that the nanozyme selectively generates Mn(IV)-oxo species via peroxymonosulfate (PMS) activation, crucial for the efficient oxidation processes. Our integrated membrane system effectively removes (within 1 min, > 92 % removal) a variety of organic micropollutants in continuous-flow operations, demonstrating excellent stability and minimal manganese leaching. Compared to conventional advanced oxidation process (AOPs)/membrane system, the SA-Mn-CN/PVDF/PMS system holds the advantages of high catalytic activity and selectivity for generation of reactive species, wide working pH range (pH3-11) and excellent stability and reusability under the backwashing conditions. The developed device-scale AOPs/membrane system was proven to be effective in bacterial inactivation and pollutants degradation, verifying the vast application potential of the SA-Mn-CN/PVDF membrane for practical water decontamination. This work pioneers the development of enzyme-mimicking nanozyme membranes, offering a sustainable and high-performance solution for wastewater treatment, and sets a new benchmark for the design of nanozyme-based catalytic membranes in environmental applications.

The application of metal-based catalysts derived from metal-organic frameworks (MOFs) to activate peroxymonosulfate (PMS) in wastewater decontamination has attracted enormous attention, but its common radical pathway extremely restricted its practical application due to the unavoidable quenching effect from water matrices. Herein, a biomass-derived carbon loading strategy was adopted to transform the reaction pathway from radical to non-radical. First, CuOx-C@CCDC (CCDC denotes the carboxylated cotton-derived carbon) was fabricated with Cu-MOFs/cotton as precursors. Serving as a PMS activator, CuOx-C@CCDC performs well for Fenton-like degradation of sulfoxazole (SIZ), attributing to the synergism between CuOx-C and CCDC, and its apparent rate constant (Kobs) for CuOx-C@CCDC was found to be 6.47 and 10.44 times higher than that of CuOxC and CCDC, respectively. Mechanistic analysis by a series of characterization technologies including in-situ Raman spectroscopy, in-situ Fourier infrared spectroscopy, electron paramagnetic resonance spectroscopy, and electrochemical analysis unveiled that the radical pathway dominated by center dot OH made the main contribution in the CuOx-C/PMS system. In contrast, the electron-transfer-mediated nonradical pathway was responsible for SIZ degradation in the CuOx-C@CCDC/PMS system, wherein CuOx-C@CCDC functioned as the conductive mediator to transfer electron from SIZ to the surface-confined PMS*. Benefited from this, other electron-rich refractory organic pollutants including sulfamethoxazole, ciprofloxacin and tetracycline hydrochloride could also be efficiently eliminated. In addition, its superiorities including good recyclability, robustness, wide pH range, strong anti-interference against various inorganic anions and adaptability for actual wastewater display a promising prospect. Overall, this work provides a facile and feasible strategy to regulate the reaction pathways in PMSbased advanced oxidation processes.

Here, we demonstrate that the iron (Fe) single-atom nanozyme (SAzyme) exhibits excellent peroxidase (POD)-like activity, triggering a unique electron-transfer oxidation mechanism in Fenton-like reactions. The Fe-SAzyme was fabricated by embedding an enzyme-mimicking single-atom iron (EMSA-Fe) site supported on nitrogen-rich graphene (NG). The EMSA-Fe-NG SAzyme showed exceptional POD-like activity (9.70 s(-)(1)) and high catalytic efficiency (6.47 x 10(5) M--(1) s(-)(1)), surpassing those of natural horseradish peroxidase, and the state-of-the-art SAzymes and nanozymes. Mechanism studies revealed that the medium-spin Fe(II) species in EMSA-Fe-NG possesses moderate adsorption affinity toward H2O2, facilitating H2O2 activation via an electron-transfer pathway. The EMSA-Fe-NG+H2O2 system exhibited outstanding performance in the oxidation of organic micropollutants and the inactivation of multidrug-resistant bacteria, achieving high pollutants' removal efficiency (> 95 %) and sterilization rate (>96 %). This study highlights the spin-dependent POD-like activity of artificial Fe-SAzymes and the potential application of advanced SAzymes for environmental remediation.

Monitoring the assembly process of coordination polymers (CPs) is crucial for elucidating the assembly mechanism and developing new CPs with well-defined structures and functions. In this paper, a one-dimensional coordination polymer of {Mn2-1D} have been constructed from discrete {Mn4} clusters, along with thermal dehydration. The thermotropic dimension augmentation process was monitored via single crystal/powder X-ray diffraction (SC/P-XRD), infrared spectroscopy and Raman spectroscopy. Additionally the enhanced magneto-thermal properties of CPs were investigated. During the dimension augmentation, the magnetic entropy change values increased from 26.92 J K-1kg-1 in {Mn4} to 36.78 J K-1kg-1 in {Mn2-1D} (T = 2 K, Delta H = 7 T).

Selective generation and effective utilization of sulfate radicals (SO4-) in water treatment has been restrained by the multiple reaction pathways of Fenton-like catalysis and the short radical lifetime. Here, we designed a nanocomposite composed of hydroxyapatite (HAP) 'core' and single-atom Co (CoSA) catalyst 'shell' that creates a nanoconfined environment for selective generation of the surface-bound SO4- via peroxymonosulfate (PMS) activation. This surface-confinement strategy markedly prolongs the half-lifetime of sulfate radicals from 40.0 μs (free SO4-) to 72.7 μs (surface-bound SO4-), thus improving the utilization efficiency of SO4- radical. In situ spectroscopy and computations revealed that the CoSA 'shell' activated PMS and the HAP 'core' with abundant oxygen vacancy stabilized PMS and SO4-, resulting in oriented generation of the surface-confined SO4-. Mechanisms studies demonstrated that the HAP@CoSA/PMS system effectively degraded diverse emerging organic contaminants (EOCs) by the inner-surface-bound SO4-. Moreover, the HAP@CoSA catalyst flocculated natural organic matter (NOM) through outer-surface complexation by the released Ca2+ ions, excluding coexisting NOM from the nanoconfined inner-surface. The cooperative coupling of nanoclay-mediated flocculation and confined Fenton-like oxidation provides an efficient and robust platform for selective oxidation of EOCs in complex real waters.

In recent years, photothermal-assisted Fenton-like degradation of organic pollutants has become a prominent green method in environmental pollution control. Nevertheless, the design of suitable catalysts remains a significant challenge for this approach. Herein, zeolite-imidazolate framework-derived CoMn bimetallic nanoparticles embedded in hollow carbon nanofibers (CoMnHCF) have been developed as a photothermal nano-confinement reactor with multiple active sites to enhance reaction performance and promote peroxymonosulfate (PMS) activation. Under light irradiation, the local temperature within the porous spaces of CoMnHCF was significantly higher than the liquid temperature. The confined space concentrated heat, minimized thermal loss, and effectively utilizes this feature to activate PMS for antibiotic degradation. The results demonstrated that this system efficiently degraded various antibiotics, including tetracycline hydrochloride, levofloxacin, sulfamethoxazole, norfloxacin and chlorotetracycline. Photothermal contribution analysis revealed that thermal effects predominate in this system. Further DFT simulations explored the coordination environment of metal elements and the properties of related pollutants, predicting potential structures and reaction sites. A series of water quality experiments and cyclic tests demonstrated the system's significant application potential. This study offered new insights into advancing the integrated use of photothermal conversion and nano-confinement reactor activation of PMS in sewage purification.

This study developed an innovative reduction-oxidation coupling process for treatment of refractory organic wastewater. We constructed a series of N5-coordinated transition metals (TMs) (TMs = Mn, Fe, Co, Ni, Cu) singleatom sites supported on nitrogen-rich carbon nitride (SA-TM-C3N5) for electrochemical generation of the surfaceadsorbed hydrogen atom (H*) and hydroxyl radical (center dot OH). The SA-Co-C3N5 exhibited the highest activity for production of the H*-center dot OH redox pair, which effectively degraded refractory nitro-organic micropollutants via the parallel reduction-oxidation pathways. The SA-Co-C3N5-mediated electro-Fenton-like system showed high removal efficiency (99 %) and mineralization capacity (78 %) toward metronidazole (MNZ) with low energy consumption (0.019 kWh (g TOC)-1). The trifunctional properties of the H* have contributed to the reduction of nitro compounds, the 2e- ORR for H2O2 production and the Fenton-like catalysis for center dot OH generation. This work sheds lights on the development of advanced reduction-oxidation coupling process for green and sustainable water purification.

Single-atom nanozymes (SAzymes), designed to mimic the active centers of natural enzymes, are emerging as a versatile catalytic platform for heterogeneous catalysis. Herein, enzyme-mimicking single-atom manganese (EMSA-Mn) sites supported on graphitic carbon nitride (g-C3N4) were constructed, marking a pioneering application of EMSA-Mn-C3N4 for periodate (PI; IO4-)-based advanced oxidation processes (AOPs). The EMSA-Mn-C3N4/PI system demonstrated remarkable efficiency in eliminating organic micropollutants across a broad pH range (pH 3-11). The positively charged EMSA-Mn sites facilitated the adsorption of the negatively charged IO4-, forming the EMSA-Mn-PI* complex, subsequently triggering a direct electron-transfer process (ETP) for oxidation of the organic pollutants. Experimental and theoretical results revealed that the EMSA-Mn site possesses higher intrinsic activity than conventional SA-Mn sites anchored on g-C3N4, thereby achieving higher efficiency for PI activation via the ETP. This work provides an advanced design strategy to construct Mn SAzymes for environmental catalysis and deeper insights into the nonradical PI-AOP systems.

Selective production of specific radical species with prolonged lifetime is challenging in advanced oxidation process. Herein, we constructed single-atom Co (SA-Co) catalytic sites confined in layered double hydroxide (LDH) for selectively and sustainably generate radical species via peroxymonosulfate (PMS) activation. The negatively charged PMS was stabilized by the positively charged LDH and simultaneously activated by the nanoconfined Co single-atom sites, resulting in oriented-production of surface-bonded & BULL;OH and SO4 & BULL; radicals with long-term efficiency (up to 48 h), suppressed PMS decomposition and radical self-quenching. Ion competition experiments and in-situ spectroscopic studies were applied to monitor the PMS activation processes. The SA-Co-LDH/PMS system outperforms the benchmark homogeneous (Co2+/PMS) and heterogeneous (Co3O4/ PMS) catalytic systems for the degradation of emerging organic contaminants (EOCs) with the lowest Co consumption and highest catalytic efficiency.