This study presents a novel nonradical catalytic oxidation system for targeted p-hydroxybenzene sulfonate (PHS) production from sulfonamides (SAs). A positive external electric field was applied to induce the in-situ activation of O2 on Mn-doped Co3O4 surface, with Mn-doping used to manipulate the reactivity of surface complexes. Theoretical simulations predicted CoMn-peroxides as thermodynamically favorable candidates for the targeted PHS production. Experimental validation achieved PHS yields of 18.4-32.6 % from five typical SA compounds. While 1O2 also actively participated in the oxidation of SAs, disruption of the 1O2 oxidation pathway significantly enhanced the PHS yields to 47.6-50.3 %. The intensity of electric field regulated the O2 activation pathways by influencing the stability of CoMn-peroxides. This nonradical catalytic oxidation system demonstrated excellent catalyst reusability and environmental robustness for energy-efficient SAs removal and PHS recovery. These findings provide new insights into leveraging nonradical = pathways to advance catalytic oxidation technology for sustainable water management.

Large-scale deployment of alkaline fuel cells is hampered by sluggish cathodic oxygen reduction reaction (ORR) and costly Pt-based catalysts. To address this issue, we fabricated interconnected Pd/carbon dot nanowires via oxalic acid coordination and temperature control for efficient alkaline ORR. Nitrogen-doped carbon dots and oxalic acid jointly confine Pd growth, suppress agglomeration and modulate its electronic structure. The catalyst prepared at 40 ℃ forms well-dispersed nanowires with abundant active sites. X-ray absorption fine structure (XAFS) and density functional theory (DFT) verify strong Pd-N interaction optimizes intermediate adsorption and lowers reaction barriers. It delivers an onset potential of 0.996 V and half-wave potential of 0.878 V, exhibiting far better activity than commercial Pt/C. This reliable strategy guides the synthesis of high-performance fuel cell catalysts.

The practical application of aqueous zinc-ion batteries (AZIBs) is severely hindered by uncontrolled zinc dendrite growth and parasitic reactions arising from intrinsic inhomogeneous ion flux and electric field concentration at the anode interface. Herein, we propose a rational interfacial engineering strategy by integrating a sustainable, hierarchical porous carbon interlayer (RC-5) derived from reed catkins onto a commercial glass fiber (GF) separator. The RC-5, activated by KOH, possesses a high specific surface area (3259.52 m² g⁻¹) and abundant oxygen functional groups. This functional layer acts as a multifunctional regulator that optimizes the separator's pore structure, enhances electrolyte wettability, and, more importantly, homogenizes the interfacial electric field and Zn²⁺ flux. Consequently, the Zn||Zn symmetric cell with the RC-5-GF separator achieves an ultralong lifespan of 880 hours at 0.5 mA cm⁻², exhibiting a 13-fold improvement over the pristine GF separator. Combined experimental characterizations and COMSOL simulations reveal that the RC-5 layer effectively mitigates the "tip effect" and guides uniform zinc deposition. This work provides a low-cost, eco-friendly route to stabilize zinc anodes by manipulating interfacial electrochemistry through biomass resources.

The oxygen reduction reaction (ORR) serves as the core cathodic reaction for fuel cells. However, the sluggish ORR kinetics and high cost of Pt-based catalysts severely restrict the commercialization of fuel cell devices. Herein, a facile in-situ synthetic strategy is developed to fabricate carbon dot-supported cobalt (CD@Co) electrocatalysts, in which carbon dots (CDs) act as both reducing agent and structural modulator. With the aim of optimizing catalytic activity and stability, the effects of CDs dosage on Co dispersion, nitrogen configuration and ORR performance are systematically investigated. The optimized CD@Co-0.12 exhibits a half-wave potential of 0.89 V (vs. RHE) and a limiting current density of 4.47 mA·cm− 2, outperforming commercial 20

Micro–supercapacitors (MSCs) based on graphene have gained substantial attraction in flexible energy storage devices. Nevertheless, owing to the van der Waals interactions between graphene, the stacking issues can significantly block the ion and electron transport, resulting in poor electrochemical performances. Herein, inkjet–printing heterostructures of reduced graphene oxide/molybdenum disulfide (RGO/MoS2) binary nanosheets was demonstrated for high–performance flexible MSCs. The pre–printed PEDOT: PSS organic film can greatly improve the conductivity of the interdigital electrodes. The RGO/MoS2 heterostructure thin film electrodes with different layers were simultaneously printed on the conductive film, respectively. Accordingly, the internal resistance and performance of MSCs has been significantly improved due to their synergistic effect. The assembled MSCs delivered a maximum areal capacity value (557 μF·cm–2) at 4 μA·cm–2. Notably, the maximum areal energy density and power density of MSCs are 0.04 μWh·cm–2 and 0.003 mW·cm–2, respectively. Moreover, the MSCs manifested a good cycle stability with a capacity retention rate of 88.7% after 10,000 cycles. The six MSCs connected in series can power a blue light–emitting diode light for 1 min. Therefore, the approach combining layered RGO with MoS2 by inkjet printing can offer distinctive insights into the flexible energy storage systems with high power density.

Abstract Dissolved organic matter (DOM), ubiquitously present in aquatic systems, exerts a significant impact on advanced oxidation processes (AOPs), typically acting as an inhibitor. However, our investigation in this work reveals that DOM can function as an activator of molecular oxygen (O2) for selective singlet oxygen (1O2) production through an innovative electrochemical regulation strategy. A positive electric field was utilized to trigger the electrochemical oxidation of MnII in MnO, generating high-spin MnIII that targets the transformation of ortho-hydroquinone moieties in DOM to ortho-semiquinone radical (ortho-SQ•–). The metal–ligand cooperation stabilized ortho-SQ•– on the MnO surface as MnII-ortho-SQ•– complexes, which effectively activated dissolved O2 into 1O2 with •O2– as an intermediate. Elementary electron-transfer steps among high-spin MnIII, ortho-hydroquinone, and O2 were systematically elucidated, based on which a quantitative relationship between the structural characteristics of ortho-hydroquinone and 1O2 production was established. Electron-donating groups on ortho-hydroquinone showed an enhancing effect on 1O2 production by promoting the formation of surface MnII-ortho-SQ•– complexes as well as their reactions with O2. By integrating the DOM-mediated O2 activation pathway into an electrochemical oxidation system, we achieved a remarkable improvement in phenol degradation efficiency, with a twofold acceleration of the degradation rate and over 50% reduction in energy consumption. This work establishes a mechanistic framework describing how DOM synergizes with electrochemical oxidation reactions to in situ activate dissolved O2 under an electric field drive, paving a new avenue for developing innovative water remediation processes by exploiting DOM-O2 interactions in aquatic systems.

The large-scale deployment of alkaline fuel cells is still hindered by the sluggish cathodic oxygen reduction reaction (ORR) and the high cost of Pt-based catalysts. Herein, interconnected Pd/carbon-dot (Pd/CD) nanowires were fabricated through an oxalic-acid-assisted coordination strategy coupled with temperature-controlled reduction for efficient alkaline ORR. Nitrogen-doped carbon dots provide abundant anchoring sites for Pd species, while oxalic acid provides a mild reducing environment and coordinates with Pd2+ through carboxylate groups. This process regulates Pd nucleation and growth, suppresses aggregation, and promotes interfacial electronic coupling. The catalyst prepared at 40 °C exhibits a well-dispersed, interconnected nanowire architecture with abundant accessible active sites. It delivers an onset potential of 0.996V and a half-wave potential of 0.878V, outperforming commercial Pt/C under identical testing conditions. X-ray absorption fine structure analysis and density functional theory calculations suggest that strong Pd–CD interfacial coupling optimizes the adsorption energetics of key oxygenated intermediates and reduces the ORR energy barrier. This work provides a coordination-regulated strategy for designing efficient Pd-based electrocatalysts for alkaline fuel-cell applications.

Nicotinamide-adenine dinucleotide (NAD+/NADH) is a coenzyme that acts as a donor and acceptor of electrons in redox reactions within all eukaryotic cells. The reduction of NAD+ produces NADH that subsequently acts as the key electron carrier. However, limited stability of enzymes under operational conditions, unwanted by-products and limited external electron donors result in low efficiency of NADH regeneration to drive the downstream enzymatic reactions. Herein, we modularly designed a peptide hydrogel, which provided an appropriate physiological microenvironment for maintaining the bioactivity of alcohol dehydrogenase. Meanwhile, Bi nanoparticles were in situ synthesized and doped into nanofibers during the peptide self-assembly to afford a conductive hydrogel with enhanced bioelectrocatalytic efficiency. Both linear sweep voltammetry and chronoamperometry data unveiled excellent electrochemical performance of this hydrogel for sustained NADH regeneration at low potential (-0.37 V vs. RHE). Even at a relatively high potential of -0.79 V vs. RHE, the yield of NADH for 10 h was as high as 81%. The regenerated NADH could further drive propionaldehyde alcoholization to produce 1-propanol sustainably with a rate of 1.34 mM h-1 at -0.62 V (vs. RHE). Overall, this peptide-based conductive hydrogel could achieve sustained 1-propanol production by leveraging in situ bioelectrocatalytic NADH regeneration, demonstrating a promising approach for electroenzymatic biofuel and pharmaceutical production.

Arranging the active ingredients on the support surface at the molecular or atomic scale to create high-selectivity sites for the electrocatalytic CO2 reduction reaction (CO2RR) holds great promise, which is highly challenging. In this study, we report a strategy for constructing a bimetallic Ag-Ni electrocatalyst with Ni nanoparticles for H2O dissociation, as well as Ni atoms in the carbon skeleton and Ag nanoparticles on the surface for the CO2RR. These sites synergistically enable high selectivity for improving the conversion of CO2 to CO. Specifically, the FECO reaches 99.3% on Ag-Ni/CB at -0.8 V vs. RHE, and its FECO can be maintained over 95.8% in the potential range from -0.8 to -1.1 V vs. RHE. Our research presents an approach for alignment of bifunctional two-component active sites on the surface of a carbon support.

Electrochemical oxidation is effective for water decontamination, but its large-scale application is constrained by high energy demands. This work addresses this challenge by developing an ultramicroporous carbon (UMC) electrocatalyst to effectively activate molecular oxygen (O2) for assisting the electrochemical oxidation of contaminants. Participation of O2 switches the electrochemical oxidation pathway of 2,4-dichlorophenol from polymerization to degradation, allowing its deep mineralization at low potentials. Experimental findings and density functional theory (DFT) calculations attribute the UMC's catalytic activity to the synergistic sp2-carbon conjugation and ultramicroporous structure. In the confined space of ultramicropores, O2 convert into •OH by capturing electrons from the sp2-conjugated carbon wall. The ultramicropores supplies an inner surface exclusively available for O2 activation, and the confinement effect enhances O2 adsorption to the sp2-conjugated carbon wall and interfacial electron transfer. Taking advantage of the UMC electrocatalyst, the air-enhancing strategy reduces the energy consumption for electrochemical oxidation of phenolic compounds by over 50 %, and demonstrates stability across broad pH and real water conditions. These findings open up new opportunities for designing efficient O2 activators towards more energy-efficient and less wasteful electrochemical oxidation processes.

The widespread applications of fuel cell depend on the reasonable designment of excellent catalysts that are easy to synthesize or abundant in reserves for oxygen reduction reaction (ORR). The application of precious metal catalysts (such as Pt, Pd etc.) is limited due to their scarcity of resources and high cost, while Ag/C catalysts have shown unique advantages in fuel cell and are expected to replace precious metal catalysts. In this paper, the fabrication of core-shell Ag@carbon dot (Ag@CD) with varying Ag loadings was achieved through a one-step method utilising CD as both a reducing agent and stabiliser, with the assistance of ultraviolet (UV) irradiation. Its suitable silver salt concentration and stable core-shell structure are the fundamental reasons for the excellent catalytic performance of ORR. The results show that the limiting current density (5.8 mA cm(-2)) of Ag@CD-0.1 catalyst is much greater than that of Ag@CD-0.05 and Ag@CD-0.2 catalysts. The Tafel slope of Ag@CD-0.1 catalyst is almost equivalent to those for Pt/C catalysts, suggesting the Ag@CD-0.1 exhibits an outstanding catalytic activity. The relative current density of Ag@CD-0.1 catalyst only decreased by 2.5 % after 50,000 s, suggesting that Ag@CD-0.1 exhibits more excellent stability for ORR, which is ascribing to the carbon layer coated outside the Ag nanoparticles (NPs).

Nanoplastics (NPs) pose severe environmental threats, while sewage sludge management remains a major hurdle for municipal wastewater treatment plants (WWTPs). This study addresses these critical concerns by developing a ZnAl-layered double oxides@biochar (ZnAl-LDO@biochar) composite from sewage sludge for effective NPs remediation. Such material demonstrated remarkable adsorption capacities for five representative NPs, achieving 716.3 mg g-1 for polyethylene terephthalate (PET), 615.8 mg g-1 for polystyrene (PS), 406.0 mg g-1 for polymethyl methacrylate (PMMA), 271.6 mg g-1 for polyvinyl chloride (PVC), and 178.6 mg g-1 for poly-lactic acid (PLA) at 25 degrees C. During the adsorption process, LDO in ZnAl-LDO@biochar regenerated a layered double hydroxide (LDH) structure via the "memory effect", enabling NPs adsorption via electrostatic attraction, hydrogen bonding and it-it interactions. Biochar contributed to hydrogen bonding and it-it interactions, meanwhile its dispersive effect promoting the exposure of LDH's adsorption sites. A quantitative structure-activity relationship (QSAR) model was established by correlating the adsorption behavior with molecular descriptors of NPs. Guided by the QSAR model, ZnAl-LDO@biochar achieved a treatment capacity of 5 m3 g-1 for removing high-concentration PET NPs from a WWTP effluent. These findings highlighted the exceptional potential of the ZnAl-LDO@biochar composite for real-world NPs remediation in water treatment.

Coal gasification fine slag (GFS) is a solid waste produced in the coal gasification process, and its landfill disposal poses a great threat to environmental protection. Herein, the Zn supported on porous carbon derived from coal gasification fine slag was synthesized through the carbon extraction combined with facile wetness chemical impregnation, which can realize electroreduction CO2 to CO with a FECO of 92.5 % at -1.1 V vs. RHE in the context of electrocatalytic CO2 reduction. Experimental and theoretical analyses rationalize that the strong cooperativity between Zn and PC improves the formation of *COOH and *CO on the Zn sites, substantially accelerating the conversion of CO2RR towards CO. Our results provide an effective approach to utilize residual carbon in GFS and realize internal circulation of CO2 in chemical plants.

Electrochemical oxidation offers a clean approach for wastewater treatment, yet challenges such as high energy demand and electrode deactivation impede its practical application. Here, we address these critical issues by integrating air into an electrochemical oxidation process, achieving deep mineralization of refractory aromatic pollutants at low potentials to avoid significant impact of water discharge. To enable active participation of atmospheric oxygen (O2) in pollutant oxidation, oxygen-functionalized carbon nanotubes (OCNTs) were exploited to serve dual roles as the electrocatalyst and O2 activator. The introduction of O2 significantly enhanced the electrochemical oxidation of the probe pollutant, sulfamethoxazole (SMX), with its mineralization efficiency improved from 13.3 % to 80.1 %. The carbonyl (C=O) groups on OCNTs were identified to be the key sites for binding O2, with formation of surface complexes that oxidized SMX via direct electron transfer. Density functional theory (DFT) simulations revealed the pivotal contribution of C=O in promoting the adsorption of O2, fostering the formation of surface-O2 complexes, and facilitating the oxidation of SMX by surface-O2 complexes. The positive electric field applied during the electrochemical oxidation process promoted O2 activation by reinforcing its interaction with the OCNTs surface. The air-enhancing strategy mitigated electrode fouling and proved effective across diverse water matrices, including high-salinity and natural organic matter-rich environments. These findings highlight the potential of oxygen-functionalized carbonaceous materials in advancing energy-efficient electrochemical oxidation systems for sustainable wastewater remediation.

Activating molecular oxygen (O2) into singlet oxygen (1O2) represents a promising way for selective oxidation of the electron-rich pollutants in wastewaters. However, such potential remains largely untapped due to poor knowledge regarding the mechanism governing the O2 activation pathways. Here, we address this challenge by exploiting one-dimensional tunnel structured MnO2 to initiate 1O2-dominated wet air oxidation reaction under ambient condition. Experimental results and theoretical calculations suggest an O2 activation pathway at the oxygen vacancy of MnO2 through the Mn redox cycle. Temperature demonstrates an important role in regulating the products from O2 activation. The wet air oxidation system applies 1O2 oxidation pathway at more than 80 % selectivity below 100 degrees C, but center dot OH is involved to mediate the oxidation reaction as the temperature rises above 100 degrees C. The various MnO2 polymorphs exhibit discrepant catalytic activities dependent upon Mn valence state and facet exposure. alpha-MnO2 possesses higher 1O2-triggering capacity than (3- and gamma-MnO2, due to more abundant oxygen vacancies on its (310) facet that favors the adsorption of O2. In contrast, center dot OH is more easily triggered by (3-MnO2 because of more facile adsorption and dissociation of H2O on its defective (100) surface. The wet air oxidation system with alpha-MnO2 obtains COD removal efficiency approximating 100 % on a landfill leachate under ambient condition. These findings provide insight into the principles regulating the activation of O2 towards 1O2 production, and demonstrate a great potential of MnO2 as an O2 activator for on-site remediation of contaminated surface water bodies.

Lanthanide metals have attracted particular interest in the catalysis of electrochemical CO2 reduction. The synthesis and precise spatial distribution of active sites are fundamental important but still formidably challenging owing to the strong oxygen affinity of lanthanide. Here, heteronuclear Pr1-Ni1 single atoms are supported on the carbon matrix containing surface framework defects from lanthanide contraction. The Pr/Ni-NC catalyst exhibits a CO Faradaic efficiency of 99.1 % with a commercial-scale current density of 237 mA cm−2 and a turnover frequency as high as 18,038 h−1 at −1.1 V due to d-f coupling effect and electronic structure perturbation of Pr. Furthermore, mechanistic investigations unveil that the diatomic active sites effectively reduce the energy barrier of the crucial *COOH formation, in which the Pr site facilitates CO2 activation and the Ni site enables H2O dissociation to accelerate the proton transfer process, thereby ensuring the synergy of catalytic sites to greatly facilitate CO2-to-CO conversion.

Oxygen is a green oxidant for the oxidative removal of environmental pollutants. In this work, we employed Mn-doped Co3O4 for electrocatalytic activation of O-2 and investigated the effects of structure and facet on catalysis. Co3+ substitution by Mn3+/Mn4+ leads to Co3O4 structural distortion and a shift of preferentially exposed (311) to a more catalytically active (220) plane. Meanwhile, more vacancies are created due to the structural defects and charge imbalance between Co3+ and Mn4+. Experimental and theoretical investigations suggest that Mn-doping facilitates adsorption of O-2 on the deficient (220) plane of Co3O4 by triggering a thermodynamically more stable Mn0.65Co2.35O4-[O-2]* intermediate. Mn0.65Co2.35O4 gives a turnover frequency value 9.5 times higher than that for pure Co3O4. The electrocatalytic wet air oxidation process with Mn0.65Co2.35O4 shows a great energy-saving merit with specific energy consumptions as low as 2.2-5.0 kW h kg-TOC-1 in mineralizing phenolic compounds. This work opens up new opportunities for advancing air oxidation technology into more competitive processes.

Lanthanide metals have attracted particular interest in the catalysis of electrochemical CO2 2 reduction. The synthesis and precise spatial distribution of active sites are fundamental important but still formidably challenging owing to the strong oxygen affinity of lanthanide. Here, heteronuclear Pr1-Ni1 1-Ni 1 single atoms are supported on the carbon matrix containing surface framework defects from lanthanide contraction. The Pr/Ni-NC catalyst exhibits a CO Faradaic efficiency of 99.1 % with a commercial-scale current density of 237 mA cm-- 2 and a turnover frequency as high as 18,038 h- 1 at-1.1 V due to d-f coupling effect and electronic structure perturbation of Pr. Furthermore, mechanistic investigations unveil that the diatomic active sites effectively reduce the energy barrier of the crucial *COOH formation, in which the Pr site facilitates CO2 2 activation and the Ni site enables H2O 2 O dissociation to accelerate the proton transfer process, thereby ensuring the synergy of catalytic sites to greatly facilitate CO2-to-CO 2-to-CO conversion.