ChemElectroChem最新文献

Hydrogen produced by seawater splitting coupled with offshore wind power and offshore photovoltaics will not require the use of pure water; furthermore, on-site preparation of related chemicals, along with direct energy supply, can be realized without transportation loss. In this review, we summarize and compare the recent advances in each component of seawater splitting anode and propose the outlook of efficient anodes fabrication for green hydrogen production via electrochemical seawater splitting. Finally, we outline future research directions toward durable, high-performance anodes for scalable and cost-effective green hydrogen production from seawater.

Although Ti₃C₂T_x is an exceptional energy storage material due to its high capacitance, tunable surface functional groups, and excellent electrical conductivity, a disordered interfacial environment caused by the inherent surface terminal groups on the Ti₃C₂T_x nanosheets causes the slowing of the ion transport kinetics and decrease of the specific capacitance. A simple boron modified Ti₃C₂T_x surface strategy is developed to covalently anchor boron species onto the Ti₃C₂T_x surface via B–O–Ti bonds in the present work, B modified Ti₃C₂T_x electrode material (B-Ti₃C₂T_x−400) is obtained and its structure, surface chemistry, and the electrochemical performance are systematically investigated. The modified boron species reorganize the local interfacial environment of Ti₃C₂T_x nanosheets, reduce ion diffusion resistance, and enhance accessibility of active sites, thus significantly improve the specific capacitance and rate performance, and the as-prepared B-Ti₃C₂T_x−400 material electrode exhibits a high specific capacitance of 491 F g⁻¹. Moreover, the assembled B-Ti₃C₂T_x-400-based symmetric supercapacitor achieves an energy density of 7.94 Wh kg⁻¹ (at 400 W kg⁻¹) and retains 88.5% of its initial capacitance over 10,000 charge–discharge cycles at 50 mV s⁻¹. This work offers a facile and practical strategy for optimizing the energy storage performance of Ti₃C₂T_x-based energy storage materials through surface chemical modification approach.

Electrochemical pathways that convert CO₂ into multi-carbon (C₂₊) products could mitigate greenhouse gas emissions while supplying chemical building blocks. Realizing this potential requires scalable process designs and optimized operating strategies, including dynamic modes such as pulsed current. Here, we systematically investigate the effects of current density, electrolyte temperature, CO₂ excess rate, and pulsed operation on C₂₊ production in a commercially available flow cell equipped with gas diffusion electrodes (GDEs) and industrially relevant materials. High current densities up to 400 mA cm⁻² significantly increased the Faradaic efficiency toward C₂₊ products. Lower electrolyte temperature (20 °C) enhanced C₂₊ production compared to 40 °C, likely due to greater CO₂ solubility and CO adsorption, which promote CO dimerization. A reduced CO₂ excess rate (λ = 2) further favored C₂₊ formation, potentially by decreasing CO₂ adsorption in favor of CO surface coverage. Contrary to prior reports in H-type cells, pulsed current operation did not improve C₂₊ production in the GDE-equipped flow cell, suggesting that enhanced mass transport minimizes pulsing benefits observed in diffusion-limited systems. This study identifies low temperature, reduced CO₂ excess, and statically applied high current densities as key parameters for enhancing C₂₊ formation under scalable conditions.

The use of Kevlar separators with high mechanical strength and thermal stability enhances the safety of lithium-ion batteries. However, the dense structure formed by entangled aramid nanofibers (ANFs) networks via extensive hydrogen bonds limits porosity, resulting in low ionic conductivity. Here, we present a simple fabrication method, using a porogen-containing ANF dispersion and vacuum-assisted filtration, to prepare a porous Kevlar separator. The removal of the porogen embedded within the membrane creates a porous structure. This Kevlar separator demonstrates high ionic conductivity, outstanding thermal stability, flame retardance, and excellent electrolyte wettability. The assembled lithium-ion batteries not only demonstrate excellent electrochemical performance but also offer good impact resistance to mitigate mechanical abuse.

Enhancing conductivity is important for supercapacitor electrochemical behavior, and this is especially evident when using nonmetallic 3D printed cell components. Here, we study two different 3D-printed cell types and examine the influence of the conductivity enhancement of the printed current collector and the slurry composition on the response of supercapacitor cells. Current collectors printed using vat polymerization and subsequently metallized, and similar collectors made using conductive polylactic acid by fused deposition modeling, are compared in a similarly designed printed coin cells. Various slurry mixtures of porous Mn₃O₄ with carbon electrode materials and additives (single-walled carbon nanotubes, graphene nanoplatelets (GNPs), and Super-P) bound with PVDF are compared in both types of cell. Electrochemical analysis using cyclic voltammetry and galvanostatic charge–discharge measurements reveals that composite conductivity strongly influences charge storage behavior in 3D-printed supercapacitors, while the conductivity of the current collector interface influences rate capability, ohmic losses, and long-term cycling stability. Metallized Vat-P printed current collectors, with smoother and entirely conductive interface with the composite material, offer improved voltammetric and galvanostatic stability and response for all slurries. Whereas FDM printed, rough PLA current collectors with sparsely distributed graphitic surface contacts to the electrode material, show poorer stability during long-term cycling and rate tests.

We report an electrochemical method for the highly sensitive detection of the widely used chlorinated aromatic herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) using a bare screen-printed carbon electrode. Experimental conditions were optimized, yielding a pulse amplitude of 150 mV, a sample of pH of 2.0, and an electrolyte concentration of 0.5 M. Under these conditions, the method exhibited a linear response from 2 to 100 µM (R² = 0.9963), with an LOQ of 2.1 µM and an LOD of 0.7 µM. The sensitivity of the sensor is 0.8055 µA µM⁻¹, and the sensitivity normalized for the active surface area of the electrode is 6.2 µA µM⁻¹ cm⁻². The overall performance of the proposed method is better or similar, compared to some of the modified electrodes used in recent studies reported in the literature for 2,4-D sensing. The method showed good electrode-to-electrode reproducibility of the signal and reusability of the sensor for the detection of 2,4-D in different solutions using the same electrode. The developed method also showed acceptable percentage recoveries (ranging from 80.1% to 112.0 %) when used for the detection of 2,4-D spiked in real water samples from different sources.

Given that Li-ion batteries are rapidly increasing in their spread, effective recycling approaches and thus contamination management of the recycled material have become essential. We investigated oxalate-based recycling options using metal oxalates (focusing on Al and Cu) as model impurities in graphite || LiNi_0.8Mn_0.1Co_0.1O₂ (NMC811) full cells. Fresh 1 M LiPF₆ in 50/50 v/v ethylene carbonate/dimethyl carbonate (LP30) electrolytes without and with contaminants at their maximum solubility were compared with aged electrolytes. Electrochemical testing revealed that aged LP30-based contaminated electrolytes matched cells with freshly contaminated electrolytes: they retain the same capacity and have matching impedance spectra. In the absence of vinylene carbonate (VC), neither is time-dependent degradation detectable nor does metal oxalate contamination impair cell performance. Chemical analyses confirmed that no detectable chemical reactions occurred between any metal oxalate and the VC-free electrolyte during the 30-day aging period. In contrast, when VC was present, adding Al or Cu oxalate to the electrolyte increased internal cell resistance and accelerated capacity fade during cell cycling. Post-mortem analyses revealed Al-containing surface layers on graphite electrodes, indicating that performance decreases because Al oxalate-derived films are formed. These results highlight the complex interplay between electrolyte additives and impurity specification in battery aging.

Organic electrosynthesis has emerged as a powerful strategy for leveraging electricity in organic synthesis. Despite its growing popularity, the fundamental molecular interactions governing electrochemical systems remain poorly understood. Many electrosynthetic reactions show strong dependence on the identity of the allegedly inert supporting electrolyte, which can significantly impact yields and selectivity, yet the physical origins of these effects are largely unexplored. A mechanistic understanding of electrolyte effects would enable more rational reaction design for applications. Here, we use cyclic voltammetry to investigate cobalt-based metal–carbon bond homolysis and elucidate how common supporting electrolytes influence reaction rates. Bulk electrolysis experiments further reveal how electrolyte choice affects overall selectivity. Peak-ratio analysis indicates that Co(Salen)–benzyl bond cleavage proceeds via a reversible homolysis mechanism that becomes rate-limited by bond dissociation at high substrate concentrations. The reaction rate varies systematically with electrolyte identity, and changes in oxidative addition rates are quantified using simulations. These experimental findings are supported by ab initio and classical molecular dynamics simulations, as well as density functional theory calculations, which provide insights into reaction pathways, energetics, and dynamics. Together, these results demonstrate that electrolyte selection enables rational tuning of reaction rates and downstream selectivity, highlighting the critical role of electrolytes in metal-catalyzed organic electrosynthesis.

With the rapid increase in demand for smart, wearable and flexible electronics, sustainable and high-performing energy storage devices have received enormous attention. In general, electrode materials are supported over metal-based scaffolds such as nickel/copper foam or stainless steel. However, their insufficient mechanical flexibility, higher mass density and high susceptibility towards corrosion limit their applications in electrochemical energy storage devices. In contrast, carbon cloth (CC) emerged as a potential scaffold material owing to its light weight, high flexibility, mechanical robustness and chemical inertness. Flexible CC-based supercapacitors are highly demanding when compared with secondary batteries. Moreover, due to the rigid nature of current commercial batteries, it is difficult to integrate them into flexible and wearable applications, whereas CC-based supercapacitors can be easily integrated into flexible and wearable devices. The inherently hydrophobic CC surface can be activated or modified further with nanomaterials using several methods, with each approach having some advantages and disadvantages, playing a significant role in impacting energy storage performance. Here, we discuss some methods used to activate/hydrophilize the CC and the impact of synthesis parameters on morphology, crystallinity, mass loading and overall electrochemical performance. Key applications and critical aspects that still require attention to achieve optimal performance are discussed with the cost metrics necessary for widespread adoption are highlighted.

Microbial electrochemical technologies (MET), among others, facilitate sustainable CO₂ conversion into chemicals at ambient temperature and neutral pH. Reactors used in MET, called bioelectrochemical systems (BES), come in different types; bed electrodes are prominent; however, they lack reproducible, geometrically defined granular electrodes. Typical carbon granules are irregular, have wide size distributions, and poorly defined electrochemical properties, which limit their engineering applications. This study introduces sphere-like granular biochar (GB) cathodes, produced by pyrolyzing beechwood spheres at 850°C (GB850). GB850 electrodes were modified and characterized on a single-granule basis. The hydrogen evolution reaction (HER) at neutral pH models abiotic cathodic reactions, reflecting its important role as an intermediate in CO₂-reducing BES. To improve electrocatalytic activity, GB850 was modified with nickel-molybdenum (GB850-NiMo), and the uniform electrodeposition was verified through structural and compositional analysis. GB850-NiMo exhibited an HER overpotential of only 106 ± 9 mV at −1 mA/cm², 85% lower than that of GB850. Its electrochemical double-layer capacitance (C_dl) increased fourfold after NiMo deposition, indicating a larger electrochemically active surface area. The apparent stability of GB850-NiMo highlights its potential to optimize bed electrodes in CO₂-reducing BES through controlled modifications. The highly defined geometry of sphere-like GB offers a valuable tool for future engineering.