Metallic Ni is widely used for oxygen evolution reaction (OER) catalysis. It acts as a precatalyst and undergoes surface reconstruction into NiOOH, which is the active species used in OER. Consequently, OER performance is highly related to the NiOOH structure, which is determined by the precatalyst. Thus, the modulation of metallic Ni to obtain superior NiOOH is critical. Herein, an interfacial redox modulation strategy is proposed to oxidize a Ni foam (NF) surface into the desired Ni2+ species using electrochemically exfoliated graphene (EG). OER-favorable c-NiOOH on EG-oxidized NF was investigated under anodic potentials by in situ characterization techniques, whereby the formation of inferior b-NiOOH was found to be inhibited. Single Ni atoms and clusters were anchored onto the EG layers after reduction. The altered c-NiOOH and Ni single atoms and clusters improved the OER performance of the EG-oxidized NF with low overpotential and enhanced stability. Subsequently, controllable EG and Ni-based metals were used to verify the versatility of the proposed interfacial redox modulation strategy. The optimized EG-oxidized NiFe system achieved an overpotential of 243 mV at 10 mA cm-2 and long-term stability at 500 mA cm-2 for 100 h. (c) 2025 THE AUTHORS. Published by Elsevier LTD on behalf of Chinese Academy of Engineering and Higher Education Press Limited Company. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Acidic CO2 electroreduction (CO2ER) enhances carbon utilization but faces significant challenges: intense hydrogen evolution reaction competition and poor multicarbon (C2+) product selectivity. We identify that this stems primarily from acid-induced destabilization of the critical *CO intermediate, exacerbated by adsorbed hydrogen. Here, we propose a dual-modification "molecular-fence" strategy to reconfigure the catalyst-electrolyte interface. We first engineer atomically dispersed Lewis acid Zr sites on Cu to electronically accelerate *CO formation. Subsequently, we anchor π-conjugated benzo-2,1,3-thiadiazole (BTD) molecules, which form a physical fence that spatially confines *CO intermediates and electrogenerated OH-. This synergy creates and sustains a localized, highly alkaline microenvironment in bulk acidic media, which concentrates *CO coverage and strengthens *CO binding to accelerate C-C coupling kinetics for acidic CO2ER. As a result, we achieve Faradaic efficiencies of 57.0% for ethylene (C2H4) and 74.9% for total C2+ products at 600 mA cm-2. Single-pass carbon efficiencies reach 64.2% for C2H4 and 79.9% for C2+. Remarkably, a high C2H4 selectivity (>52.0%) is sustained across a wide current density range of 400 to 700 mA cm-2. This work establishes the molecular-fence strategy as a broadly applicable paradigm for regulating interfacial microenvironments to enable efficient and selective CO2ER in challenging acidic media.

Nitrate reduction to ammonia represents a promising route for wastewater treatment and valorizing ammonia recovery, yet faces persistent challenges such as dependence on external power supplies, low production rates, and difficult separation of dilute aqueous ammonia. Herein, we develop a self-powered closed-loop system that couples efficient nitrate reduction with simultaneous NH3 recovery as crystalline MgNH4PO4 (MAP). A Mg anode functions as both sacrificial source and Mg2+ supplier, paired with a CuS-decorated nickel foam (CuS@NF) cathode for nitrate-to-NH3 conversion. The generated NH3 is efficiently separated in situ through a PTFE gasdiffusion membrane and precipitates as solid MAP in external crystallizer. This system achieves a MAP production rate of 4.38 mg center dot cm- 2 center dot h- 1 and an OCV exceeding 8 V. The CuS@NF exhibits 97.13 % Faradaic efficiency and 98.8 % NH3 selectivity. DFT calculations reveal that high electronic density near the Fermi level in the Cu d and S p orbitals facilitates electron transfer, weakens the N-O bonds, and suppresses competing H2O dissociation, thereby enhancing nitrate adsorption, promoting deoxygenation pathway. Spatial decoupling of electrolysis and crystallization mitigates catalyst fouling and improves reduction efficiency by 11.37-fold compared to the coupled baseline. Economic analysis shows a 372.7-fold enhancement in potential revenue, highlighting the techno-economic feasibility of this integrated strategy for simultaneous wastewater purification and resource recovery.

A circular two-stage process is proposed to upcycling silicon-rich hazardous liquid waste into high-value three-dimensional graphene foams (3DGFs). Owing to the silicon contained in the waste, conventional pyrolysis often leads to incomplete detoxification, while directly using it as a carbon feedstock may introduce Si-containing impurities into graphene products. Herein, the process begins with steam-assisted gasification of dimethyldiethoxysilane (DOMS) at 900 degrees C (liquid:steam = 1:2), generating syngas at 68.6 mmol/h with high concentration of H-2, CH4 and C2H4. By increasing the N-2 carrier-gas flow rate, the H-2/CH4/C2H4 ratio can be precisely tuned with higher ethylene fraction for downstream low-defect graphene synthesis. In the second stage, the purified syngas directly serves as the carbon precursor for atmospheric-pressure chemical vapor deposition (APCVD) on nickel-foam templates, facilitating the growth of multilayer 3DGFs with minimal structural defects. Under optimized conditions (900 degrees C, 500 sccm, 30 min), the resulting 3DGFs exhibit a well-defined multilayer architecture (similar to 20 layers), high electrical conductivity (1.18 x 10(3) S/m), and exceptional electromagnetic interference (EMI) shielding effectiveness of nearly 50 dB in the X-band (similar to 99.999 % attenuation). Life-cycle assessment shows that relative to conventional methane-based CVD, this waste-derived route reduces CO2-equivalent emissions and cumulative energy demand by 45 % and 40 %, respectively, and lowers the monetized environmental cost to 8.50 x 10(3) $ per kg 3DGF. This work demonstrates a sustainable pathway for valorizing hazardous siloxane waste into functional graphene materials, supporting circular carbon utilization and carbon mitigation.

A hybrid system combining water electrolysis and H2 autotrophic microorganism enables sustainable CO2 valorization, but is hindered by low H2 bioavailability and sluggish hydrogenase kinetics. Here, we report an interface-engineered inorganic–biological biohybrid, constructed by covalently anchoring iron single-atom catalysts (ISA) onto Cupriavidus necator (C.N@ISA) via click chemistry. The ISA anchored interface generates a localized H2-rich microenvironment, accelerates H2 dissociation, while the synergy between ISA and polyethylene glycol-phenylboronate linker stabilizes the inorganic-biological hybrid interface and promotes electron/proton transfer across microbial membrane. These coupled effects boost reduced form of nicotinamide adenine dinucleotide (NADH) regeneration and adenosine triphosphate (ATP) synthesis. In addition, ISA exhibits nanozyme-like activity, scavenging reactive oxygen species to protect cell viability. As a result, C.N@ISA achieves CO2-to-bioplastic poly-β-hydroxybutyrate production of 1058.8 mg L−1 with a Faradaic efficiency of 42.0%. Integrating theoretical calculations, electrochemical analysis, and transcriptomics confirms that ISA simultaneously enriches and activates H2 while reinforcing intracellular metabolism, offering a generalizable strategy for carbon-negative biomanufacturing. The integration of inorganic–microbial systems offers promise for CO2-to-chemical conversion but faces efficiency bottlenecks. Here, the authors report an engineering strategy of anchoring iron single-atom catalysts onto bacterial membranes to achieve enhanced bioplastic production.

ABSTRACT Producing hydrogen from formaldehyde oxidation reaction (FOR) offers a promising low‐energy approach for generating clean fuel. However, the FOR involves continuous C─H bond cleavage of adsorbed intermediates to generate abundant surface H*. This necessitates rapid transfer and consumption of H* to sustain fast oxidation kinetics. Herein, we developed a hydrogen‐spillover strategy to redistribute these surface H* to accelerate FOR kinetics by constructing RhCu single‐atom alloy supported on a Cu single‐atom‐rich carbon matrix (RhCu@Cu SA NC). In this design, Cu incorporation creates a favorable landscape for H* migration toward the Cu SA NC support, which acts as efficient H* acceptors and H─H coupling centers. Verified through multiple analyses, this hydrogen‐spillover mechanism is demonstrated to enhance FOR activity by accelerating H* redistribution. Consequently, RhCu@Cu SA NC shows outstanding FOR performance, achieving a current density of 800 mA cm − 2 at 0.39 V with nearly 100% H 2 selectivity and excellent durability. When integrated into a hybrid alkali‐acid cell, it provides an open circuit voltage of 1.72 V and peak power density of 152.6 mW cm − 2 with stable H 2 production for over 1200 h at 10 mA cm − 2 . These results demonstrate that hydrogen spillover boosts oxidative electrocatalysis, providing a general design principle for multicomponent catalysts with coordinated hydrogen dynamics.

Bioelectrochemical sensors often exhibit non-additive responses in mixed-toxicity matrices and, more importantly, lack a quantitative linkage between fast electrode-level signals and downstream process performance. Here, we develop a cascaded prediction framework that uses a S. oneidensis MR-1 electroactive biofilm sensor to translate rapid bioelectrochemical perturbations into activated-sludge inhibition indicators. A multimodal response feature space was constructed from cyclic voltammetry (CV), differential pulse voltammetry (DPV), and chronoamperometry (I-t) to characterize mixture-dependent inhibition behaviors induced by Hg²⁺, tetrahydrofuran (THF), and formaldehyde (HCHO). Using mechanism-inspired but phenomenological feature transformations and full-spectrum descriptors, feature-enhanced XGBoost and LightGBM models enabled mixture-aware quantification of the three toxicants (average R² = 0.82 on a held-out test split). In particular, HCHO prediction improved from R² = 0.653 to 0.840 after incorporating kinetic-focused descriptors. The estimated toxicant concentrations were then used as intermediate variables in a second-stage mapping to predict activated-sludge inhibition quantified by the specific oxygen uptake rate (SOUR) index, achieving R² ≈ 0.898. Robustness of the cascaded framework to upstream prediction uncertainty was evaluated via Monte Carlo error propagation using a nearest‑neighbor wild bootstrap with the Mammen distribution (k = 5). The sensor response remained stable against common matrix variations (pH 5-7 and salinity up to 30 g·L⁻¹) under anoxic operation. Overall, the framework provides a proof-of-concept route for linking rapid bioelectrochemical responses to process-relevant inhibition indicators within the calibrated operating domain.

Electrochemical CO2 reduction (eCO2R) powered by renewable electricity offers a sustainable route for carbon cycling and value-added chemical synthesis. Among possible products, methane (CH4) is particularly attractive due to its high energy density and direct compatibility with existing natural gas infrastructure. However, it remains challenging to selectively produce CH4 with conventional copper catalysts. Herein, we developed a copper-phenolic network catalyst featuring atomically dispersed Cu─O4 sites, where adjacent uncoordinated hydroxyl groups from tannic acid (TA) act as intrinsic hydrogen-bond donors to stabilize the oxygen-bound formate intermediate (*OCHO). This hydrogen-bond-enabled microenvironment redirects eCO2R from the conventional *CO-mediated pathway toward a formate-derived route, while simultaneously suppressing the competing hydrogen evolution reaction. As a result, the optimized Cu-PTA catalyst delivers a high CH4 Faradaic efficiency of 75.5% with a partial current density of 302.0 mA cm-2 in aqueous electrolyte. Notably, this pathway-steering strategy is readily applicable to deuterated electrolytes, enabling efficient production of deuterated methane (CD4) with a record-high Faradaic efficiency of 83.1% and a partial current density of 415.6 mA cm-2. This work establishes hydrogen-bond engineering as a general approach for manipulating reaction pathways through local stabilization of oxygen-bound intermediates toward sustainable synthesis of high-value chemicals.

Electrochemical conversion of methane (CH4) is a sustainable route for converting greenhouse gases into valuable liquid fuels and chemicals. However, achieving high-yield products at industrially relevant current densities remains a formidable challenge. Here, we report a machine learning-guided Mo-Cu dual-site cascade catalytic strategy, enabling selective modulation of key *CH3O and achieving ethanol (EtOH) electrosynthesis. This system delivers a current density of 103 mA cm-2 with an EtOH faradaic efficiency of 55.8% +/- 0.2%, establishing new performance benchmarks. Mechanistic and DFT analyses reveal that CH4 is activated by a three-electron *O2--mediated oxidation pathway, while *CH3 spillover from Mo to Mo-Cu active sites facilitates exothermic C-C coupling, leading to high-efficiency EtOH production. Techno-economic analysis suggests that integrating renewable electricity can lower the CH4-to-EtOH production cost from $2.12 per kg to $1.50 per kg within a decade, offering a 53% energy return. This work establishes a cascade-regulated, dual-site framework for efficient CH4-to-EtOH conversion and offers a framework for machine learning-assisted catalyst design, contributing to cleaner energy technologies and substantial reductions in greenhouse gas emissions.

Hybrid electrochemical-biological CO2 conversion systems represent a promising strategy for converting CO2 into value-added chemicals. However, the limited compatibility between electrochemical and microbial processes-primarily due to the generation of reactive oxygen species (ROS)-remains a significant barrier. This study demonstrates that optimizing the iron concentration in the electrolyte can simultaneously enhance biocompatibility and electron transfer efficiency, thereby improving CO2-to-poly-beta-hydroxybutyrate (PHB) conversion by Cupriavidus necator H16. An iron concentration of 1.0 mg L- 1 was found to reduce interfacial electron transfer resistance by 42 %, and decrease ROS levels by 60 %. Transcriptomic analysis further revealed upregulation of key electron transport enzymes, including hydrogenases and iron-sulfur (Fe-S) proteins, indicating enhanced hydrogen utilization. As a result, the system achieved a PHB yield of 718.46 +/- 6.28 mg L- 1 and an energy conversion efficiency of 11.85 +/- 0.42 %, surpassing most prior studies. These findings provide critical insights for advancing hybrid CO2 conversion systems, offering a scalable and efficient approach to sustainable chemical production.

Efficiently reducing nitrate across wide‐range concentrations in wastewater remains a major challenge for electrochemical nitrate reduction (NO 3 RR) to ammonia (NH 3 ), where the dynamic control of active proton is critical. Here we proposed a dynamic proton allocator strategy featuring adaptive control of active proton availability in response to local nitrate levels. Applied to high‐entropy alloy aerogels, this approach achieved >90% Faradaic efficiencies (FE) over a wide nitrate concentration range from 0.01∼1.0 M, nearly an order‐of‐magnitude increase in NH 3 yield rate compared to other catalysts at identical nitrate concentrations. In situ spectroscopic investigations revealed that the high‐entropy element distribution modulated molecular structure of interfacial water, enhancing active proton availability for nitrate hydrogenation. Theoretical calculations demonstrated that the unique high‐entropy electronic configuration optimized intermediate adsorption, shifted the rate‐determining step and lowered the reaction energy, promoting NH 3 formation. These results highlight the pivotal role of proton management across wide‐ranging nitrate concentrations in NO 3 RR, demonstrating the potential for integrating sustainable chemical synthesis with environmental restoration.

Electrochemical conversion of CO2 to methane provides a sustainable pathway for fuel synthesis, yet it inherently struggles to balance carbon utilization efficiency with product selectivity. Conventional surface engineering based on physical hydrophobic coatings often leads to interfacial instability and diminished charge transfer efficiency. To address these issues, we develop a cysteine-coated copper coordination complex catalyst modified with covalently bonded fluoroalkyl silane (FAS), allowing precise control over surface wettability. A breakthrough in highly acidic electrolytes is demonstrated, achieving a methane Faradaic efficiency of up to 66.2% at 400 mA cm-2 (pH 1.8), alongside a single-pass carbon conversion efficiency of 31.1%, surpassing conventional alkaline-system benchmarks. Surface-enhanced Raman spectroscopy reveals a key *COOH intermediate for CO2 activation, while in situ attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy monitors the sequential hydrogenation pathway through *CHO and *CH2O. Molecular dynamics simulations further reveal a distinct water exclusion zone near the catalyst surface, which arises from the hydrophobic covalent interface induced by the FAS coating. This interfacial engineering strategy suppresses the hydrogen evolution reaction by blocking water access, preserves hydrophobicity during operation, and offers a scalable path to improve the kinetics and selectivity of CO2 electroreduction.

Selective resource recovery from waste streams is essential for sustainable nitrogen management. However, conventional ammonia recovery from ammonium (NH4+)-and volatile organic compound (VOC)-containing wastewater is highly energy-intensive, and VOC-NH3 coevaporation further undermines product purity. Here we report an advanced oxidation processes-interfacial solar steam generation (AOPs-ISSG) platform based on a cobalt oxide-loaded nitrogen-doped carbon catalyst (Co-NC) that integrates photothermal conversion and catalytic oxidation. By exploiting the differing adsorption, electron-transfer, and reactive oxygen species (ROS) reactivity of VOCs and NH3, the system achieves selective VOC oxidation while preserving ammonia. Combined with alkaline solar interfacial evaporation, this selectivity supports concurrent VOC removal and efficient NH3 recovery. Under simulated wastewater conditions (pH = 9), the Co-NC/AOPs-ISSG system achieves 90.1% NH3 recovery and 95.3% VOC removal. It also demonstrates broad operational resilience across pH 7-10 and solar intensities up to 1.4 kW m-2, consistently yielding high-purity ammonia suitable for direct reuse, as validated by plant experiments in which recovered-ammonia irrigation promoted ∼40% greater pea seedling growth compared with untreated wastewater. Solar utilization and process integration reduce operating cost and carbon emissions by 23.2% and 27.7% compared with conventional NH3 recovery. These results highlight a low-carbon, economically viable pathway for selective ammonia recovery and sustainable nitrogen management.

ABSTRACT The high cost and limited metal loading of single‐atom catalysts hinder their broader applications in Fenton‐like reaction for water treatment. Herein, we developed an Fe‐Cu diatomic catalyst supported on N‐doped carbon (Fe‐Cu‐CN) that enabled catalyst minimization while maintaining high peroxymonosulfate (PMS) activation efficiency. By tailoring asymmetric Fe‐Cu coordination and inducing a spin‐state transition of Fe from low‐spin to high‐spin, the catalyst enhanced Fe 3d ‐O 2p electron coupling and substantially improved intrinsic activity. The Fe‐Cu‐CN/PMS system enabled a highly efficient electron transfer pathway for pollutant degradation, achieving rapid bisphenol A removal (100% within 5 min; k obs = 1.61 min − 1 ) with only 10%–20% of the catalyst dosage commonly reported in the literature. Density functional theory calculations and electrochemical analyses revealed that heteronuclear coordination modified the spin‐state of the active center, narrowing the gap between the d‐band center of Fe 3d orbitals and the Fermi energy level to strengthen the electronic interaction at the reaction interface, resulting in a lower free energy barrier of PMS adsorption thermodynamically. Furthermore, the life‐cycle analysis demonstrated superior environmental performance. This study provides a generalizable strategy to enhance unit catalytic activity through spin‐state engineering, offering practical potential for PMS‐based water treatment.

Electrocatalytic nitrogen oxidation (NOR) is an environmentally friendly alternative to conventional energydemanding industrial nitrate synthesis. However, two major barriers to achieving high NOR efficiency stem from the chemical inertness of N2 and the competitive nature of the oxygen evolution reaction (OER). Herein, we address the challenges by developing a RuO2 catalyst synergistically doped with Ni and Co, which effectively boosts N2 activation while minimizing OER activity. This dual effect is achieved, on the one hand, by Ni-doping, which enhances surface polarity and introduces electron-deficient Ru sites, thereby facilitating interactions with polar intermediates. On the other hand, Co-doping suppresses parasitic oxygen evolution by raising the energy of the OER rate-determining step. Leveraging this synergistic interplay in Ni0.1Co0.2Ru0.7O2-450 yields an outstanding NOR performance, resulting in a high nitrate yield of 726.46 mu g h-1 mgcat-1 and a Faradaic efficiency of 59.65%. These valuable insights will enable the design of efficient bimetal-doped catalysts for nitrate electrosynthesis, resulting in lower energy consumption and a reduced carbon footprint.

Plasma-catalytic ammonia synthesis (PCAS) offers a sustainable pathway to decarbonize the energy-intensive Haber-Bosch process; however, its optimization remains hindered by the complex synergy between plasma physics and catalytic chemistry. Herein, we present a machine learning (ML)-driven framework integrating highdimensional parameter optimization with experimental validation to advance Ru-based catalyst design for PCAS. A comprehensive dataset of 457 data points, specifically focused on cylindrical dielectric barrier discharge (DBD) systems spanning 16 key parameters including catalyst properties, reactor configuration, and operational variable was constructed from published literatures. Among five ML models evaluated, the Random Forest (RF) algorithm achieved superior predictive accuracy for ammonia synthesis rate (R2=0.987) and energy yield (R2=0.887). SHAP (SHapley Additive exPlanations) analysis identified the total gas flow rate as the dominant parameter, revealing its dual regulatory role in modulating radical density and residence time. Systematic optimization determined the optimal ranges for reaction temperature (250-350 degrees C), total gas flow rate (200-300 mL/min), Ru loading (1-3 wt%), and calcination time (4-5 h). Notably, Co doping enhanced catalytic performance by improving Ru dispersion and increasing specific surface area, achieving the metrics of 3455.63 mu mol center dot g-1 center dot h-1 and 1.73 g/kWh. Experimental validation confirmed model robustness, with deviations between predicted and measured NH3 yields predominantly below 10 %. This study establishes a paradigm shift in catalyst development, combining interpretable ML with plasma-catalysis fundamentals to unlock scalable green ammonia production.

A novel sulfur-based autotrophic denitrification coupled with an autotrophic sulfate reduction biocathode (SAD-ASRB) system was developed for nitrogen removal. Compared with the conventional SAD system, the SAD-ASRB system achieved higher nitrogen removal efficiency, reduced sulfate generation, and improved pH stability under external current assistance. With influent nitrate concentrations of 50-80 mg N/L, total nitrogen removal efficiencies of the SAD-ASRB system reached 88.9-96.1%, markedly outperforming the SAD system (72.3-86.1%). Moreover, the denitrification rate has also increased by 16.9-22.2 times. Sulfate production was reduced from 5.7 to 6.4 mg SO4 & sup2;(-)/mg NO3--N in the SAD system to 4.3-4.4 mg SO4 & sup2;(-)/mg NO3--N in the SAD-ASRB system. Meanwhile, Delta pH remained consistently similar to 0.53 across all nitrate loads, unlike the SAD system where Delta pH rose from similar to 0.71-1.24. Mechanistic investigations confirmed that the formation of polysulfide (Sn2-) from sulfide (S2-) and elemental sulfur (S-0) was critical to improving sulfur cycle and accelerating denitrification rates. Furthermore, microbial analysis revealed that the enhanced denitrification performance was underpinned by shifts in the microbial community structure, particularly the enrichment of Ignavibacterium, and the upregulated expression of key denitrification-related genes, including narG , napA, napB, nirS, and norC. These results demonstrate that the SAD-ASRB system is an environmentally friendly, and technically feasible approach for autotrophic denitrification in carbon-deficient wastewater.

Biological treatment offers a sustainable route for remediating toxic cyclohexylamine (CHA) wastewater, yet the ecological mechanisms driving bacterial-fungal community assembly and metabolic partitioning under dissolved oxygen (DO) regulation remain unclear. To address this, we investigated CHA degradation dynamics across DO gradients using high-throughput sequencing coupled with integrated ecological models. Results indicated that high DO conditions (>= 3 mg/L) facilitated deterministic community assembly, selectively enriching aerobic degraders like Pseudomonas to achieve over 90% total organic carbon (TOC) removal. Conversely, hypoxic conditions (0.5 mg/L) shifted the system toward stochastic assembly and simultaneous nitrification-denitrification, enhancing total nitrogen (TN) removal by 10% despite compromised carbon mineralization. Uniquely, structural equation modeling unveiled a dual regulatory pathway where DO directly drives bacterial degradation functions while fungi contribute to community stability and metabolic buffering. These findings clarify a pivotal trade-off between "aerobic mineralization" and "hypoxic denitrification," providing a theoretical basis for optimizing DOregulated strategies in amine-laden wastewater treatment.