Search Results (1,310)

Azo dyes are a major cause of environmental pollution, but under lab-based conditions can be removed using a coupled adsorption and electrochemical oxidation process; the Nyex Rosalox™ (NR) process. However, wastewater effluents are more complex than tap water, indicating that there is a need to assess how altered effluent conditions affect the adsorption of azo dyes onto the adsorbent used (Nyex™ 2000) and overall removal efficiency of the NR process. Analysis indicates that higher temperatures, the addition of minor amounts of sodium chloride, or acidification increased adsorption, while the presence of dissolved organic carbon (DOC) only showed a minor impact if compared to baseline tap water conditions and appears to be dye-specific. Analyses further indicated that effluent conditions could have a major impact on the overall dye removal efficiency using the NR process, with up to 48% more being removed during acidic or saline conditions and, to a lesser extent, when DOC was present. Increased temperature or alkalinity had minimal impact, with inconsistent results across the dyes assessed. Combined, this highlights that effluent-specific conditions can have a major impact on the removal efficiency and should be considered during the planning stage of the azo dye treatment process. Full article

Layered Li-rich manganese-based Li_1.2Ni_0.13Co_0.13Mn_0.54O₂ (LNCMO) is regarded as a promising high-capacity cathode material. However, its commercial application is severely hindered by rapid capacity fading, serious voltage decay and poor cycling stability. Herein, a facile non-sintering electrostatic adsorption strategy employing PDDA is proposed to fabricate a uniform and dense graphene oxide (GO) coating on LNCMO particles. Structural and morphological characterizations confirm the successful decoration of GO on the surface of LNCMO. The optimized 0.5@LNCMO sample delivers a discharge capacity of 330 mAh g⁻¹ at 0.1C, and maintains a capacity retention of 86.5% after 200 cycles at 1C and 83.3% after 400 cycles at 5C, showing much better electrochemical performance than pristine LNCMO. This study proves that the proposed strategy is an effective modification method for constructing high-performance Li-rich cathode materials. Full article

Inorganic mercury ions (Hg²⁺) are highly toxic, posing a threat to aquatic ecosystems and human health. In this study, iron phthalocyanine (FePc) was anchored onto the surface of MXene via a self-assembly strategy to construct an FePc/MXene-x (F/M-x) heterostructure. Characterization by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption–desorption (BET) confirmed that the high specific surface area and good conductivity of MXene effectively inhibited FePc aggregation and increased the exposure of active sites. The F/M-x composite was then modified onto a glassy carbon electrode (GCE) to fabricate an electrochemical sensor, and the detection performance for Hg²⁺ was evaluated using square-wave anodic stripping voltammetry (SWASV). Under optimized conditions (pH = 5.0, accumulation at −1.2 V for 180 s), the F/M-100/GCE exhibited a linear range of 0.1–1.0 μM, a sensitivity of 19.02 μA/μM, and a detection limit of 5.9 nM. The sensor showed good anti-interference ability against coexisting metal ions such as Cd²⁺, Cu²⁺, and Pb²⁺, with a batch-to-batch RSD of 2.03% and a long-term stability RSD of 2.49%. Spike recovery experiments in real water samples (lake water and groundwater) verified the accuracy of the method. This study provides a new electrochemical platform for the rapid detection of trace Hg²⁺ in water environments. Full article

In nitrate electrochemical reduction reaction (NO₃RR), competing side reactions like hydrogen evolution often lead to poor selectivity and subpar kinetics, limiting practical use. Herein, using iron oxyhydroxide nanoarrays grown on a titanium mesh as the substrate, silver nanoparticles were introduced onto the tips of the iron oxyhydroxide nanowires via electrochemical deposition, thereby forming an Ag/FeOOH heterojunction electrocatalyst. At −0.85 V, Ag/FeOOH demonstrates excellent performance, with 97.56% ammonium selectivity, 92.45% nitrate conversion rate, and an ammonium yield of 3.21 mg h⁻¹ cm⁻². Furthermore, the Zn-NO₃⁻ battery exhibited a power density of 1.28 mW cm⁻². Ag/FeOOH’s structure enhances interfacial nitrate adsorption and reduces NO₃RR energy barriers, accelerating reaction kinetics. It promotes NO₃⁻-to-NO₂⁻ conversion via dual-site synergy, boosting NH₄⁺ yield and advancing electrocatalyst design. Full article

Whether copper fundamentally alters Mo-centered redox thermodynamics or mainly tunes hydrogen adsorption in Ni–Mo electrocatalysts under alkaline hydrogen evolution reaction (HER) conditions remains unresolved. Density functional theory calculations combined with a field-corrected computational hydrogen electrode framework are used to evaluate the thermodynamic stability of H₃Mo, H₃MoOH, H₂Mo(OH)₂, and MoO(OH)₃ on Cu(111) and Ni(111) and to construct surface Pourbaix diagrams under electrochemical conditions. The results show that substrate identity reorganizes the redox stabilization hierarchy of these Mo intermediates. Across the examined conditions, at least one of H₃Mo, H₃MoOH, or MoO(OH)₃ is thermodynamically favored over H₂Mo(OH)₂ on both surfaces. However, only Cu(111) exhibits measurable pH-dependent free-energy shifts, reaching 0.25 eV on the reversible hydrogen electrode scale. The magnitude of this electrostatic modulation is comparable to the intrinsic substrate-dependent relative Gibbs free-energy differences, suggesting that Cu reshapes Mo redox thermodynamics rather than merely weakening hydrogen binding strength. Electronic structure and vibrational analyses further show that Cu(111) preferentially weakens Mo–O interactions, whereas Ni(111) more strongly perturbs Mo–H bonding in hydrogen-rich complexes. Overall, these results establish that substrate identity governs the electrostatic modulation of Mo redox thermodynamics under alkaline HER conditions and provide mechanistic insight into substrate effects relevant to Cu-containing Ni–Mo systems. Full article

Sensors and biosensors designed for biomarker detection in biological samples often suffer from performance loss caused by surface fouling, interface blocking, and matrix interference. Although these effects are frequently discussed separately, in real sensing systems they are strongly interconnected and they determine analytical reliability, especially in body fluids like serum, plasma, whole blood, sweat, and other complex media. This review provides a practical and mechanism-oriented overview of how these processes originate, how they differ, and how they ultimately lead to signal drift, reduced sensitivity, false-positive responses, and shortened sensor lifetime. We first discuss the molecular origins of interface failure, including protein adsorption, conditioning film formation, nonspecific binding, ionic strength effects, pH fluctuations, viscosity-related diffusion changes, and electroactive interferents. The impact of these phenomena is then compared across major sensing platforms, including electrochemical, potentiometric, optical, capacitive sensors, field-effect transistors and wearable biosensors. A central part of this review focuses on practical prevention strategies already employed in real biomarker sensing platforms. These include hydration-driven antifouling coatings, zwitterionic and hydrogel interfaces, post-immobilization blocking with bovine serum albumin, mercaptohexanol and ethanolamine, ionophore and membrane engineering in ion-selective electrodes, hydrophobic solid-contact layers for water-layer suppression, regeneration workflows, membrane and microfluidic pre-treatment, and AI-assisted drift correction. By combining advances in materials engineering, surface chemistry, sample handling, and algorithmic correction, this review highlights strategies to improve sensor stability in complex biological fluids. Overall, it offers a practical guide for developing next-generation low-fouling, drift-resistant, and self-correcting sensing systems for reliable biomarker analysis at the point of care. Full article

The hydrogen evolution reaction (HER) plays a pivotal role in electrochemical water splitting for sustainable hydrogen production. However, its practical implementation is hindered by sluggish kinetics and the reliance on costly noble-metal catalysts. In this work, a conductive polymer-inorganic hybrid electrode based on vanadium pentoxide (V₂O₅) and polyaniline (PANI) is rationally designed and fabricated on carbon cloth via a combined hydrothermal synthesis and electropolymerization strategy. Initially, hierarchical V₂O₅ nanoflowers were synthesized, followed by controlled PANI deposition through cyclic voltammetry at varying cycle numbers to tailor the interfacial architecture and electronic properties. Morphological and structural analyses reveal the formation of well-defined V₂O₅ nanoflowers uniformly decorated with PANI nanorods, establishing an interconnected conductive network. Among the prepared samples, the optimized V₂O₅-PANI-2 electrode exhibits superior interfacial integration and structural homogeneity. Electrochemical evaluation in 1.0 M KOH demonstrates that V₂O₅-PANI-2 achieves a low overpotential of 79.9 mV at −10 mA cm⁻², accompanied by a small Tafel slope of 46.6 mV dec⁻¹, indicating accelerated HER kinetics. Furthermore, the electrode shows reduced charge-transfer resistance and an enhanced electrochemically active surface area (ECSA), facilitating efficient charge transport and abundant active site exposure. The catalyst also delivers excellent durability, maintaining stable performance over 5000 CV cycles and prolonged 24 h operation. The enhanced HER performance is attributed to the synergistic interaction between V₂O₅ and the conductive PANI matrix, which promotes charge redistribution, improves electrical conductivity, and optimizes the adsorption/desorption energetics of hydrogen intermediates. Full article

Driven by the “Dual Carbon” goals, supercapacitors have become critical energy storage devices for new energy electric vehicles. In this paper, a ZnFe₂O₄@ZnCo₂O₄ core–shell cathode was prepared by a hydrothermal method followed by high-temperature annealing, and an AC@PANI composite anode was synthesized through in situ polymerization. The materials were characterized by SEM, TEM, XRD, XPS, nitrogen adsorption–desorption and electrochemical tests. The ZnFe₂O₄ rod-like core provides mechanical stability, whereas the ZnCo₂O₄ nanosheet shell increases the specific surface area and exposes more active sites. The cathode delivers 2133 F/g at 1 A/g with 94.4% retention after 10,000 cycles. The anode reaches 398 F/g at 1 A/g. The cathode delivers 2133 F/g at 1 A/g with 94.4% retention after 10,000 cycles. The anode reaches 398 F/g at 1 A/g. The assembled ZnFe₂O₄@ZnCo₂O₄//AC@PANI hybrid supercapacitor works in a wide voltage range of 0–1.6 V. It exhibits a specific capacitance of 157 F/g at 1 A/g and a high energy density of 54.7 Wh/kg at a power density of 1600 W/kg. The device retains 91.4% of its initial capacity after 10,000 charge–discharge cycles. This study offers a promising strategy for high-performance automotive supercapacitors. Full article

Microplastic contamination in soils is an emerging environmental challenge requiring effective and scalable remediation strategies. This review synthesizes advances in physical, chemical, biological, and hybrid approaches, focusing on mechanisms, performance, and practical applicability. Physical methods, particularly adsorption using biochar, achieve removal efficiencies exceeding 86% for 1 μm polystyrene microplastics and maintain > 85% efficiency after multiple reuse cycles, demonstrating strong durability. Filtration and aggregation systems, such as permeable reactive barriers, reach up to 81.55% removal but are less effective in co-contaminated conditions. Chemical strategies exhibit the highest efficiencies. Dielectric barrier discharge plasma achieves 96.5–98.7% degradation within 30–60 min, while electrochemical coagulation reaches ~98% removal via flocculation. Thermal treatments, including pyrolysis, enable near-complete microplastic removal (~100%) at ≥400 °C, although high energy demands limit in situ application. Chemical amendments also improve soil quality, increasing organic matter by ~7.35% and enhancing nutrient availability. Biological approaches offer sustainable but slower remediation. Microbial degradation achieves up to ~60% breakdown within 21 days, while enzyme–microbe systems reach ~21.4% over 60 days. Earthworm activity enhances fragmentation and nutrient cycling (up to 36.1%), whereas phytoremediation alone shows minimal direct degradation (<1% over 12 months). Hybrid strategies, particularly biochar-based systems, provide the most practical solutions by combining adsorption, microbial stimulation, and soil restoration, but their effectiveness in degrading microplastics needs further verification. These systems enhance microbial biomass (up to 57.67%), nutrient availability (up to 66.02%), and crop yield (up to 81.41%). Overall, physicochemical methods ensure rapid removal (>90%), biological approaches support long-term degradation, and hybrid systems offer scalable, sustainable remediation for field applications. Full article

The electrochemical carbon dioxide reduction reaction (CO₂RR) offers a promising route to mitigate excessive CO₂ emissions while enabling the production of value-added chemicals. However, achieving high catalytic selectivity and activity toward specific products remains a critical challenge. Here, we engineer a confined interfacial environment formed between adjacent copper nanoparticles and systematically investigate its impact on CO₂RR performance toward CO production. Our theoretical calculations reveal that the confined space effectively stabilizes the *COOH intermediate, a key species governing the CO₂-to-CO conversion pathway. In contrast, this geometric confinement exerts a negligible influence on the adsorption energetics of *H, which is associated with the competing hydrogen evolution reaction (HER). As a consequence, the catalyst exhibits a markedly reduced onset potential for CO₂RR, accompanied by enhanced selectivity and catalytic activity toward CO formation. These findings highlight the critical role of nanoscale confinement in modulating reaction energetics and provide a viable strategy for the rational design of highly efficient and selective catalysts for CO₂RR. Full article

This review presents a mechanistically focused overview of the role of conductive materials in promoting direct interspecies electron transfer (DIET) during anaerobic digestion. A central interpretative issue addressed in this review is whether the improved process performance observed after material addition reflects enhanced DIET or overlapping physicochemical and biological effects. The review systematises the current state of knowledge on the relationships between material properties, the structure of anaerobic consortia, process response, and the strength of evidence supporting DIET involvement. It discusses indirect and direct electron transfer and the criteria used to interpret the process, microbiological, electrochemical, structural, and molecular data. It also addresses functional interactions at the material–microorganism interface and non-DIET pathways of process improvement, including biomass immobilisation, inhibitor adsorption, buffering, micronutrient effects, and biofilm reorganisation. Conductive materials are also systematised into carbon-based, iron-based, composite and engineered, and organic conductive groups, with their roles related to process limitations, practical constraints, and their applicability in reactor-oriented systems. The distinctive contribution of this review lies in moving beyond simple cataloguing of materials and technological effects towards a framework for mechanistic evaluation, evidence grading, and process translation in conductive-material-assisted anaerobic digestion. Full article

Electrochemical water splitting stands as a feasible approach for sustainable hydrogen production, but its industrial implementation is restricted by sluggish oxygen evolution reaction (OER) kinetics and excessive dependence on freshwater resources. As a widely existing alternative, seawater contains a high concentration of chloride ions (Cl⁻), which give rise to serious electrode corrosion and catalyst deactivation, bringing great challenges to actual electrolysis applications. Herein, we report a facile room-temperature two-step soaking strategy to fabricate sulfur-modified NiFe layered double hydroxide (S-NiFe-LDH) catalysts for efficient OER in both alkaline freshwater and seawater electrolytes. The introduction of sulfur not only optimizes the electronic structure of NiFe-LDH to strengthen intrinsic catalytic activity and speed up charge transfer, but also promotes the formation of a Cl⁻-resistant layer, thus significantly improving corrosion resistance. In addition, DFT calculations show sulfur modification in NiFe layered double hydroxide upshifts the O 2p-band center to activate lattice oxygen, switches the oxygen evolution reaction pathway to the lattice oxygen mechanism with reduced thermodynamic barriers, and realizes the selective adsorption of OH⁻ over Cl⁻. As a result, the as-prepared S-NiFe-LDH catalyst exhibits exceptional OER performance, requiring overpotentials (η) of 250, 270, and 290 mV to reach current densities of 50, 100, and 200 mA·cm⁻² in 1 M KOH, respectively, with a Tafel slope of 22.3 mV·dec⁻¹. Moreover, it maintains remarkable stability for more than 200 h in alkaline seawater electrolytes and achieves nearly 100% Faradaic efficiency for water splitting, effectively avoiding the parasitic chlorine evolution reaction (CER). This work provides a scalable and energy-efficient synthetic route for designing advanced non-noble metal catalysts, paving the way for industrial-scale hydrogen production from seawater. Full article

To address the severe wear and galvanic corrosion of TC4/Mg three-dimensional interpenetrating composites caused by the potential difference and hardness disparity between the two phases, this work proposes a hybrid surface modification strategy combining plasma electrolytic oxidation (PEO) with a self-assembled monolayer (SAM) doped with multi-walled carbon nanotubes (MWCNTs). A PEO ceramic coating was first grown in situ on the composite surface, followed by sealing modification using MWCNTs-containing SAM. The microstructure, phase composition, tribological behavior and potentiodynamic polarization curves of the coatings were systematically evaluated. The results show that the PEO coating is mainly composed of Mg₂SiO₄, MgO, MgF₂ and TiO₂, exhibiting a typical porous structure. After the MWCNTs-doped SAM composite modification, the nano-fillers and the molecular layer synergistically seal the micropores and cracks, and the surface transforms into a continuous and dense layered morphology. Wear tests reveal that the composite coating reduces the friction coefficient to 0.195 and decreases the wear volume by 93.53% compared with the bare composite. The “micro-roller bearing” effect and debris adsorption of MWCNTs significantly improve the wear resistance, and the dominant wear mechanism changes from abrasive wear to three-body wear. Electrochemical measurements show that the corrosion current density of the composite coating decreases from 2 × 10⁻⁴ A·cm⁻² (bare composite) to 1.401 × 10⁻⁹ A·cm⁻², i.e., a reduction by five orders of magnitude, with a protection efficiency of 99.99%. This is attributed to the physical barrier effect of the PEO coating and the synergistic sealing of defects, as well as the blocking of electron transfer by MWCNTs/SAM. The multi-level protection system of “PEO + MWCNTs + SAM” constructed in this work achieves a synergistic improvement in both wear resistance and corrosion resistance of the TC4/Mg two-phase interpenetrating composite, and holds promise for further investigation as an osseointegration implant material. Full article

The increasing share of renewable energy, such as solar and wind energy, in the energy mix implies a demand for sustainable energy storage systems for the mitigation of the intermittency of these energy sources. One option, therefore, is stationary batteries based on abundant sodium, stored in hard carbon (HC) anodes. In this work, following the sustainable by design principle, HCs were synthesized from cotton-based textile waste using three different thermochemical routes: hydrothermal carbonization (HTC) followed by pyrolysis under nitrogen atmosphere (HC-250-N), HTC followed by pyrolysis under a water vapor stream (HC-250-W), and direct pyrolysis (HC-direct-N). The impact of the synthesis method on the physicochemical properties and electrochemical performance of the HCs was thoroughly investigated. X-ray diffraction, Raman spectroscopy, electron microscopy, and gas adsorption analyses revealed that the HTC pre-treatment significantly enhanced the carbon content, microporosity, and degree of structural graphitic order. HC-250-N exhibited the highest graphitic character and more uniform microstructure, while HC-250-W showed the largest specific surface area and broader micropore distribution. Electrochemical evaluation in sodium-ion half-cells indicated that HC-250-N delivered the most balanced performance, with a reversible capacity of 335 mAh g⁻¹ and good cycling stability. These findings confirm the potential of textile waste-derived HCs as promising and sustainable anode materials for sodium-ion batteries and highlight the importance of tailoring synthesis parameters—such as HTC treatment and pyrolysis conditions—to optimize their structural and electrochemical properties. Full article

Carbon dioxide emissions are a major concern for coal-fired power plants. A capture and utilization method is highly demanded. The wastewater generated by a power plant contains a high concentration of Na⁺. Using wastewater salts to absorb carbon dioxide for sodium carbonate production is a promising strategy, as it can achieve carbon capture and utilization and wastewater resource utilization. However, the salt concentration in raw wastewater from coal-fired power plants is generally insufficient to achieve sustainable carbon capture; thus, concentrating the Na⁺ in the wastewater is key. In this study, desulfurization wastewater was investigated as a source of salts. The reverse osmosis (RO) process was selected for salt concentration. As wastewater is significantly complex and unsuitable for direct RO treatment, pre-treatment was conducted. For chemical oxygen demand (COD) removal, Fenton oxidation (49.7%) and electrochemical oxidation (49.3%) achieved better results than microelectrolysis (25.3%). Precipitation showed a strong ability to remove hardness. The removal efficiencies for Mg²⁺ and Ca²⁺ were 99.9% and 99.8%, respectively. It gave 8.6% COD removal as well. Additionally, 89.8% of ammonia was removed by stripping. To further decrease the pollutant concentrations, activated carbon was used for adsorption. RO then concentrated the pre-treated wastewater after nanofiltration. The final level of NaCl was 40.4 g/L after concentration. This was lower than that required to concentrate the water, which contained only NaCl. This is due to the presence of impurities left in the wastewater after pre-treatment. The study reveals that pre-treatment is essential to achieve the desired NaCl concentration in RO with the ultimate goal of CO₂ capture. Full article