Chemistry and Materials Science

Sort by

Review
Chemistry and Materials Science
Electrochemistry

Tengshi Liu

,

Xuening Zhao

,

Mengxiao Li

,

Sa Liu

,

Yuzhang Zhao

,

Xinsheng Zhao

,

Jianming Lai

,

Han Dong

Abstract: Iron–air batteries (IABs) represent a novel energy storage system based on the iron redox reaction. They offer several advantages such as high energy density (≈ 200 Wh kg−1), environmental friendliness, and low cost, with broad application prospects in large-scale long-duration energy storage, peak-valley power regulation, and emergency power supply. However, hydrogen evolution side reactions easily occur during IAB charging, reducing Coulombic efficiency. Additionally, passivation of the iron anode limits reaction kinetics and cycle life. Thermal imbalance in air batteries also reduces stability. Existing research has addressed these issues by focusing on optimizing electrolyte compositions, additives, structural stability of the iron anode, and material design. We systematically review the progress and application of IABs as energy storage devices in the steel industry, with a systematic outlook on future research directions and applications.

Review
Chemistry and Materials Science
Electrochemistry

Branimir N. Grgur

,

Aleksandra S. Popović

Abstract:

Green hydrogen production via water electrolysis is a cornerstone of the sustainable energy transition. However, the oxygen evolution reaction (OER) remains the kinetic bottleneck, limiting overall efficiency. Nickel-iron (NiFe) based catalysts are among the most promising non precious materials for the OER in alkaline media, offering high activity and low cost. Nevertheless, their practical application at industrially relevant current densities (>100 mA cm–2) is hindered by several challenges: structural degradation, uncontrolled surface reconstruction, metal dissolution (corrosion), particularly Fe leaching, and the ambiguous role of the fundamental mechanisms. This review critically discusses the current understanding of these degradation pathways, the influence of preparation methods, the interplay between Ni and Fe redox chemistry, and strategies for enhancing long-term stability. Future directions for designing durable NiFe OER electrocatalysts are also outlined. The paper also considered a strategy for investigating new catalysts using electrochemical and non-electrochemical techniques, devoted to young scientists interested in this field. In the Outlook and Perspective, the key drawback is present and the possible strategy for improvement is discussed.

Article
Chemistry and Materials Science
Electrochemistry

Ioannis Poimenidis

,

Bochenek Kamil

,

Martsinchyk Aliaksandr

,

Majewska Karolina

,

Shuhayeu Pavel

,

Jaroslaw Milewski

,

Michalis Konsolakis

Abstract: Bifunctional electrocatalysts that offer low overpotentials, robustness, and potential compatibility with scalable fabrication routes are essential for effective alkaline water splitting. In this study, a porous nickel microparticle/polymer interlayer was applied to commercial nickel foam via screen printing, serving as a framework for the solvothermal growth of cobalt-based oxide/hydroxide nanostructures. The optimized electrode demonstrated strong bifunctional performance in 1 M KOH, requiring only 61 mV for the hydrogen evolution reaction and 241 mV for the oxygen evolution reaction at a current density of 10 mA cm-2. In comparison, the control electrodes, such as those with cobalt directly deposited on unmodified nickel foam and altered nickel foam substrates without cobalt, exhibited poorer overall performance. Although the cobalt-modified unaltered nickel foam exhibited a higher Cdl-derived apparent electrochemical surface area, the cobalt-modified screen-printed electrode achieved the best ECSA-normalized HER and OER responses, indicating that the enhancement in activity was not solely due to the capacitive surface area. The increased integrated redox charge suggests a greater contribution from electrochemically accessible Co/Ni redox-active species, while impedance analysis supports a more favorable apparent interfacial response under the tested HER- and OER-relevant conditions. Long-term chronopotentiometry and post-stability SEM supported stable bifunctional operation.

Article
Chemistry and Materials Science
Electrochemistry

Haolong Li

,

Zixian Li

,

Boyan Chen

,

Wei Wang

,

Xuerui Zhang

,

Haijun Zhong

Abstract: Interconnector geometry strongly affects gas transport, polarization loss, and pressure drop in planar solid oxide fuel cells (SOFCs). In this study, four interconnector configurations were investigated for an anode-supported planar SOFC, including one conventional straight-rib interconnector and three connected-rib interconnectors, namely circular-rib(CI), rectangular-rib(RI), and triangular-rib(TI) designs. A three-dimensional multi-physics model coupling electric field, flow field, species transport, and temperature field was established and validated against experimental polarization data of the conventional straight-rib cell. To ensure a fair comparison, all interconnectors were designed with the same interconnector-electrode contact area. The effects of rib configuration on electrical performance, overpotential components, reactant distribution, velocity distribution, and pressure drop were systematically analyzed. At 800 °C, the peak power densities of CI-SOFC, RI-SOFC, and TI-SOFC increased by 4.9%, 9.7%, and 11.7%, respectively, compared with SI-SOFC. The connected-rib interconnectors mainly reduced cathode-side activation and concentration overpotentials by improving oxygen redistribution beneath the ribs. Among the four configurations, the TI-SOFC showed the highest power density and the strongest under-rib transport enhancement, while the RI-SOFC provided a better compromise between flow uniformity and pressure drop.

Article
Chemistry and Materials Science
Electrochemistry

Norah F. Alotaibi

,

Hussam M Alzahrani

,

Saud M. Alosaimi

,

Mohammed A. Alhajji

,

Abdullah M. Alqahtani

,

Tahani A Alrebdi

,

Abdullah M. Alotaibi

Abstract: Aerosol-assisted chemical vapor deposition (AACVD) was used to prepare thin film of heterojunction WO3/MnO2 onto FTO glass substrate. The WO₃/MnO₂ heterojunction thin film exhibited a monoclinic WO₃ structure characterized by a nanorod-like shape and substantial interfacial bonding. The detected surface area of WO3/MnO2 thin film is 33.14 μm2, while the values of Ra and Rq are 24.8 nm and 31.3 nm, respectively, which are higher than pure MnO2 while lower than pure WO3 thin films. The UV-Vis spectra demonstrated extensive absorption in the visible to near-infrared range. The absorption spectrum of UV-vis (200–900 nm) displayed a distinct absorption edge under 400 nm. The band gab of the pure WO3 thin film equals 2.79 eV. Whereas, an effective band gap of WO3/MnO2 was observed equals 1.51 eV, that is significantly smaller than that of the individual oxides (MnO2 = 4.04 eV and WO3 = 2.79 eV). PL verified robust interfacial electronic interaction. The investigation of PEC performance exhibited the best performance and the greatest photocurrent under illumination than either pure component. Additionally, a good enhancement and improvement in charge separation due to the combining catalytic MnO2 thin film with photoactive WO3 owing to effective charge transfer and decreased recombination.

Article
Chemistry and Materials Science
Electrochemistry

Jiuyi Wang

,

Xiao Lv

,

Mengjie Yang

,

Xiaogang Lin

,

Zhizeng Wang

,

Jie Jayne Wu

Abstract: Cortisol, as a crucial biomarker reflecting psychological stress and physiological status, requires rapid and sensitive detection for health assessment and disease diagnosis. Conventional methods are time-consuming, operationally complex, and costly, limiting their use for point-of-care testing. This study reports a flexible, aptamer-based capacitive biosensor that exploits alternating current electrokinetics for ultrafast detection of cortisol in small-volume samples. Aptamers are immobilized via Au-S self-assembly on gold interdigitated electrodes on a PET substrate, and ACEK-induced fluid motion and dielectrophoresis rapidly enrich cortisol at the electrode interface, producing measurable interfacial capacitance changes ΔC/C0. Experimental results demonstrate detection limits of 0.412 ng/mL in PBS and 0.337 ng/mL in artificial sweat, with response times within 1 minute and excellent linear response across 1-1000 ng/mL concentrations. Requiring only 10 μL of sample, the sensor exhibits good repeatability, specificity, and interference resistance, making it suitable for rapid cortisol level detection. To enhance detection stability, this study designed and integrated a microfluidic chip, enabling efficient sample delivery and stable detection. The system demonstrates strong interference resistance, revealing potential applications in health management and disease monitoring.

Article
Chemistry and Materials Science
Electrochemistry

Kerista Tarigan

,

Rikson Siburian

,

Nuni Widiarti

,

Lisnawaty Simatupang

,

Yosia Gopas Oetama Manik

,

Joys Alisa Angelina Hutapea

,

Jingfeng Huang

,

Alfred Iing Yoong Tok

Abstract: Research on the effect of ammonium chloride (NH₄Cl) electrolyte on graphene nanosheet (GNS) electrodes derived from candlenut shells (Aleurites moluccana (L.) Willd) as primary battery cathodes has been conducted. GNS was synthesized via pyrolysis and modified with NH₄Cl to produce G–N 0.5 M, G–N 1.0 M, G–N 2.0 M, and G–N 3.0 M samples. The materials were characterized using XRD, SEM-EDX, and electrical measurements at 0.5–1.5 V. XRD results show peaks at 2θ ≈ 25° and 44.27° corresponding to C(002) and C(100) planes, while G–N samples exhibit new diffraction peaks at (111), (200), (220), (311), (222), and (400), indicating NH₄Cl incorporation. SEM analysis reveals a transition from layered GNS morphology to more wrinkled and agglomerated structures with increasing NH₄Cl concentration, supported by EDX showing decreasing carbon content and the presence of chlorine (up to ~5.9%). Electrical conductivity increases significantly from commercial battery to GNS and further to G–N samples, reaching ~1.30 S·cm⁻¹ for G–N 2.0 M, along with energy density (~605 Wh·kg⁻¹) and power density (~605 W·kg⁻¹). These results indicate that NH₄Cl modification enhances electrochemical performance and highlights the importance of electrolyte variation in optimizing GNS-based electrodes for primary battery applications.

Article
Chemistry and Materials Science
Electrochemistry

Hao Miao

,

Cong Shao

,

Jinqiao Zheng

,

Hao Yu

,

Heqian Wang

,

Kui Xiao

Abstract: 6061 aluminum alloy is lightweight and has good thermal conductivity, while 304 stainless steel possesses excellent mechanical properties and corrosion resistance; both have broad application prospects in cooling circuits. Propylene glycol coolant shows great potential in liquid cooling systems due to its low toxicity and good antifreeze properties. However, during operation, galvanic corrosion may occur when the two metals come into direct contact within the coolant, thereby threatening system safety and service life. This study focuses on 6061 aluminum alloy, 304 stainless steel, and their galvanic couples. Using electrochemical testing, SEM, 3D confocal microscopy, and XPS to systematically investigate their self-corrosion and galvanic corrosion behavior in propylene glycol coolant at pH values of 4.8, 6.8, and 8.8. The results indicate that 6061 aluminum alloy is more sensitive to pH changes; its corrosion resistance first increases and then decreases as pH rises, with the least corrosion occurring at pH = 6.8 and the most severe at pH = 4.8. 304 stainless steel exhibited lower corrosion rates at pH 6.8 and 8.8, but corrosion significantly worsened at pH 4.8. For the 6061 aluminum alloy/304 stainless steel couple, the galvanic current first decreased and then increased with rising pH, while the galvanic potential first increased and then decreased. The 6061 aluminum alloy consistently acted as the anode, and the 304 stainless steel consistently acted as the cathode, with the highest sensitivity to galvanic corrosion observed at pH 4.8. XPS analysis shows that under different pH conditions, the corrosion products of 6061 aluminum alloy are Al(OH)3 and Al2O3, while the main components of the passivation film on 304 stainless steel remain unchanged.

Review
Chemistry and Materials Science
Electrochemistry

Haoran Zhang

,

Huixin Wang

,

Wen Luo

,

Tao Liu

Abstract: Anthracycline agents, principally doxorubicin and daunorubicin, are widely used in oncology yet carry a narrow therapeutic index and pronounced interindividual pharmacokinetic variability that exposes patients simultaneously to the risk of subtherapeutic dosing and cumulative cardiotoxicity. Conventional therapeutic drug monitoring (TDM) based on periodic venous sampling and offline high-performance liquid chromatography cannot resolve the sub-minute concentration dynamics that determine organ-specific drug exposure. Electrochemical aptamer-based (EAB) sensors couple nucleic-acid aptamers, self-assembled monolayers, and methylene blue redox reporters on gold microelectrodes to convert binding-induced conformational changes into real-time, reagent-free electrochemical signals. Recent advances in this field fall into five areas: signal interrogation strategies, from kinetic differential measurement to calibration-free Fourier-transform impedance spectroscopy (FFT-EIS); interface engineering including nanostructured electrodes and AI-guided aptamer design; in vivo multi-compartment pharmacokinetic monitoring and closed-loop feedback drug delivery; the mechanisms of in vivo signal drift alongside antifouling countermeasures spanning hydrogel barriers, zwitterionic brushes, and xenonucleic acid backbone substitution; and FDA premarket pathways and clinical translation, including Premarket Approval requirements and the emerging Real-Time Clinical Trial (RTCT) framework. In live rodents, dual-compartment monitoring has resolved a reproducible 30–60 minutes plasma-to-ISF lag for doxorubicin at 12-second temporal resolution; calibration-free FFT-EIS interrogation achieves inter-animal coefficients of variation below 12% without individual pre-calibration; and xenonucleic acid backbone substitution has extended continuous in vivo operation to seven consecutive days. Three gaps still separate rodent proof-of-concept work from chemotherapy patients: clinical-context validation, tumor microenvironment calibration, and anthracycline-specific XNA aptamer design.

Review
Chemistry and Materials Science
Electrochemistry

Richa Vinod Tiwari

,

C Lakshmana Rao

,

Cemal Basaran

Abstract: Lithium-ion batteries (LIBs) are widely used across a range of applications; however, they degrade over time due to various factors, including repeated charge–discharge cycling, material aging, and environmental conditions. Degradation models play a crucial role in predicting the lifespan of LIBs and in optimizing their design and opera-tional strategies. This paper presents a comprehensive review of state-of-the-art deg-radation models for LIBs. The reviewed models primarily address key degradation mechanisms, including solid electrolyte interphase (SEI) formation, lithium plating, and particle fracture. For each mechanism, the underlying modeling approaches, their development, advantages, limitations, and associated challenges are critically dis-cussed. Finally, this review identifies existing gaps in battery degradation modeling and proposes the Unified Mechanics Theory (UMT), which is the unification of laws of Newton and the second law of thermodynamics, and uses entropy as a degradation metric, as a promising alternative framework for capturing the coupled and multifac-eted nature of battery degradation processes.

Article
Chemistry and Materials Science
Electrochemistry

Virginija Ulevičienė

,

Daina Upskuvienė

,

Aldona Balčiūnaitė

,

Aleksandrs Volperts

,

Ance Plavniece

,

Giedrius Stalnionis

,

Loreta Tamašauskaitė-Tamašiūnaitė

,

Eugenijus Norkus

Abstract: In this study the development of sustainable electrocatalysts for clean energy by modifying biomass-derived activated carbon with nitrogen and transition metals is presented. Activated carbon (AWC) was synthesized using alder wood char as a precursor, while nitrogen and cobalt or copper nanoparticles were incorporated with the aim to create efficient materials for hydrazine oxidation (HzOR) and direct hydrazine-hydrogen peroxide fuel cells (DHHPFC, N2H4–H2O2). The composition, structure, and surface morphology of the created catalysts were examined using inductively coupled plasma optical emission spectroscopy (ICP-OES), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and scanning electron microscopy and energy dispersive X-ray analysis (SEM/EDX). The activity of the AWC, AWC–Co–N, and AWC–Cu–N catalysts for HzOR was evaluated by cyclic voltammetry (CV) and linear sweep voltammetry (LSV). N2H4–H2O2 fuel cell tests were carried out by employing the catalysts both as the anode and cathode. It was found that all materials retained a hierarchical porous carbon framework, while metal incorporation altered surface compactness Cobalt doping produced well-dispersed Co nanoparticles and abundant Co–N–C coordination sites, whereas Cu introduction resulted in moderately compact structures with uniformly distributed Cu-based nanoparticles. Electrochemical measurements demonstrated that both metal dopants enhanced HzOR activity, with the catalytic performance following the order AWC–Co–N > AWC–Cu–N > AWC. Fuel-cell testing further confirmed this trend: AWC–Co–N achieved the highest maximum power density (30.4 mW cm–2), outperforming AWC–Cu–N (17.7 mW cm–2). These results identify AWC–Co–N as a highly effective bifunctional electrocatalyst for DHHPFCs.

Article
Chemistry and Materials Science
Electrochemistry

Jiatong Li

,

Qiming Sun

,

Tianyi Zhang

,

Jicheng Ma

,

Dehua Li

,

Shuangxi Xing

Abstract: Developing highly efficient, stable, and cost-effective non-precious metal electrocatalysts to replace traditional platinum-based materials is of great significance for advancing the commercialization of advanced energy conversion devices, such as zinc-air batteries (ZABs). Herein, we propose a facile and highly efficient strategy to successfully prepare a defect-rich, highly active nitrogen-doped porous carbon-based electrocatalyst, U-Fe-N-C (Urea-assisted synthesized iron-nitrogen-carbon material), via a high-temperature co-pyrolysis treatment of heme in the presence of urea. The study demonstrates that urea not only acts as an excellent nitrogen source during pyrolysis, introducing abundant topological defects and heteroatom doping sites, but also prompts the carbon substrate to form a hierarchical sponge-like porous structure with a high specific surface area. This unique microenvironment effectively prevents the agglomeration of iron species at high temperatures, achieving efficient anchoring and high dispersion of catalytic active centers. Electrochemical tests indicate that under optimal synthesis conditions (precursor mass ratio of 1:3, calcination at 900 °C), U-Fe-N-C exhibits outstanding oxygen reduction reaction (ORR) catalytic activity (with a half-wave potential reaching 0.731 V vs. RHE) and possesses long-term durability far exceeding that of commercial Pt/C. Furthermore, liquid rechargeable zinc-air batteries assembled with U-Fe-N-C as the air cathode demonstrate exceptional stability, achieving up to 270 h of charge-discharge cycling without attenuation. This study not only provides profound insights into the mechanisms of pore formation and assistance but also offers a novel perspective for the rational design and scalable synthesis of high-performance metal-nitrogen-carbon (M-N-C) electrocatalysts.

Article
Chemistry and Materials Science
Electrochemistry

Lexuan Zhu

,

Guoju Wang

,

Dewen Fu

,

Zhifeng Zhang

,

Wenfei Dong

,

Yonglei Xing

Abstract: Ammonia (NH₃), as an indispensable chemical in modern agriculture and industry, has long been produced on a large scale through the traditional Haber-Bosch process. However, this process is not only highly energy-intensive but also accompanied by substantial CO₂ emissions, necessitating the development of green alternatives. Meanwhile, nitrate (NO₃−) pollution in water bodies has become increasingly severe, posing significant threats to both ecosystems and human health. In this study, we successfully designed a bimetallic iron-cobalt organic framework (FeCo-MOF) catalyst and, for the first time, applied it to the electrocatalytic nitrate reduction reaction for ammonia synthesis. Experimental results demonstrate that at a working potential of −1.5 V (vs. SCE), the catalyst exhibits outstanding catalytic performance, achieving a current density of 52.17 mA/cm² and a remarkable NH₄⁺ Faradaic efficiency of 97.90%, significantly surpassing those of single-metal Fe-MOF and Co-MOF counterparts. Through spectroscopic characterization and electrochemical analysis, we elucidated the synergistic mechanism of the Fe-Co bimetallic active sites. The scientific significance of this work lies in its dual contributions: providing an efficient electrocatalytic strategy for nitrate pollution remediation while pioneering a low-carbon-emission approach to green ammonia synthesis, thereby holding substantial environmental and energy implications.

Article
Chemistry and Materials Science
Electrochemistry

Antonina Andreevna Filimonova

,

Hristo Ivanov Beloev

,

Artur Maratovich Khairutdinov

,

Iliya Krastev Iliev

,

Ivan Hristov Beloev

Abstract: Electrochemical treatment of sulfide‑containing industrial effluents and gas emissions remains a pressing challenge for the development of clean technologies, whose solution requires anodes with low operating potential, stable performance, and facile, cost‑effective fabrication. The paper studies the influence of the substrate nature on the structural and electrochemical characteristics of lead dioxide anodes in sulfide-containing aqueous systems using the electrolysis of an aqueous solution of sodium sulfide Na₂S as an example. The substrates used were composite materials based on polylactic acid with the addition of 7 and 10 wt.% multiwalled carbon nanotubes, designated as PLA (7% mCNT)/PbO₂ and PLA (10% mCNT)/PbO₂, as well as a PLA (Graphite)/PbO₂ composite containing dispersed graphite as a conducting phase; PbO₂ coatings were applied to all of the above polymer substrates by electrochemical deposition. For comparison, a traditional Ti/PbO₂ anode and a graphite electrode without a lead dioxide coating, used as a standalone anode, were also considered. Cyclic voltammetry in a Na₂S solution was used to evaluate the anodic reaction overpotential, specific current densities, and current-voltage curve shapes on various substrates, as well as to analyze the influence of the conductive composite composition on the electrochemical behavior of the PbO₂ layer. It was shown that the PLA (7% mCNT)/ PbO₂, PLA (10% mCNT)/PbO₂, and especially PLA (Graphite)/PbO₂ anodes provide operating potentials, ohmic resistance, and cyclic stability comparable to or superior to those of the traditional Ti/PbO₂ anode in a sulfide-containing electrolyte, whereas the uncoated graphite electrode is inferior to the composite PbO₂ electrodes in terms of a combination of parameters. The obtained results allow us to conclude that the nature and composition of the substrate play a key role in the formation of the morphology, conductivity and electrochemical properties of PbO₂ anodes and confirm their high potential for use in electrochemical systems for treating sulfide-containing aqueous media and gas emissions.

Article
Chemistry and Materials Science
Electrochemistry

Enith Carrion Quezada

,

Pablo Garcia-Triviño

,

Luis M. Fernández-Ramírez

,

José Ibarra

,

María Jesús Aguirre

,

Galo Ramírez

,

Roxana Arce

Abstract: The growing deployment of green hydrogen technologies is increasing pressure on freshwater resources, motivating the exploration of alternative water sources that do not compete with human consumption. In this work, the direct use of untreated produced water from the Shushufindi 78 oil well (Ecuador) as an electrolyte for the hydrogen evolution reaction (HER) was experimentally evaluated. A comprehensive physicochemical characterization (ICP-OES, anions, BTEX), combined with electrochemical techniques (cyclic voltammetry, Tafel analysis, electrochemical impedance spectroscopy) and gas chromatography, was performed to correlate electrolyte composition with electrochemical performance. Despite the high salinity (~52 ± 5 g·kg⁻¹) and complex matrix composition, hydrogen production was achieved without pretreatment. Absolute hydrogen quantification yielded 10.29 µmol after 4 h of electrolysis, corresponding to a Faradaic efficiency of 43.8% and an electrical efficiency of 54.1% under non-optimized conditions. Comparative gas chromatography experiments using different electrolyte compositions revealed that alkaline systems, particularly mixtures of produced water with KOH, enhance hydrogen production, as evidenced by increased chromatographic peak areas. Impedance analysis showed reduced ohmic losses with KOH addition, while mineral scaling (CaCO₃ and Mg (OH)₂) increased interfacial resistance and reduced catalytic activity. These results demonstrate the feasibility of using produced water as an electrolyte for hydrogen production, highlighting the critical role of electrolyte composition within a circular economy framework.

Article
Chemistry and Materials Science
Electrochemistry

Ruoxi Wu

,

Yangwei Luo

,

Jiahong Yang

,

Haoyu Cheng

,

Peng Xu

Abstract: A binder-free Co₃O₄ nanoneedle electrode grown directly on nickel foam (Co₃O₄@NF) was fabricated by hydrothermal synthesis followed by calcination and evaluated for electrocatalytic nitrate reduction to ammonium. The integrated three-dimensional architecture combines the catalytic activity of Co₃O₄ with the high conductivity and open porosity of nickel foam, thus exposing abundant active sites, shortening electron-transfer pathways, and facilitating mass transport. Among the electrodes prepared at different calcination temperatures, Co₃O₄@NF calcined at 400 °C delivered the best performance. Under the optimal conditions of −1.4 V vs. Ag/AgCl, pH 7, and an initial NO₃⁻-N concentration of 50 mg L⁻¹, the electrode achieved 84.3% nitrate removal within 480 min together with 98.7% ammonium selectivity. Electrochemical measurements revealed a markedly enlarged electrochemically active surface area and reduced charge-transfer resistance after Co₃O₄ loading. Mechanistic analyses further suggested that nitrate reduction on Co₃O₄@NF proceeded predominantly through an indirect pathway while maintaining negligible nitrite accumulation. The electrode also showed good cycling stability and retained high ammonium selectivity in real water matrices. These results demonstrate that binder-free Co₃O₄ nanoneedles supported on nickel foam constitute a promising cathode architecture for coupling nitrate removal with ammonia recovery.

Review
Chemistry and Materials Science
Electrochemistry

Alberta Carella

,

Francesco Rossella

,

Claudio Fontanesi

Abstract: The chiral-induced spin selectivity (CISS) effect enables spin-selective transport of electrons through chiral systems, linking handedness with spin polarization. This review provides a comprehensive examination of the emerging field of chiral electrocatalysis, detailing also the extensive experimental and theoretical endeavor conducted to gain a deeper understanding of the fundamental physical principles and mechanistic characteristics of this phenomenon. In particular, the CISS effect has garnered significant attention within the scientific community due to its potential for broad applicability across several fields, ranging from spintronics to biology. Among them, the prospective harnessing of CISS effect into electrocatalytic processes offers an innovative strategy to improve the performance of energy conversion and storage technologies. This review deeply examines the practical applications of the CISS effect across different electrocatalytic reactions, with particular emphasis on its influence on the oxygen reduction reaction (ORR) and its critical role in energy conversion systems where ORR reaction is a key process - such as in metal-air batteries, whose safety and performance can be enhanced through spin-selective electron transport.

Article
Chemistry and Materials Science
Electrochemistry

Antonina Andreevna Filimonova

,

Hristo Ivanov Beloev

,

Artur Maratovich Khairutdinov

,

Andrey Chichirov

,

Egor Sergeevich Mayorov

,

Alena Vlasova

,

Ruzina Farsilovna Kamalieva

,

Andrey Artemovich Filimonov

,

Iliya Krastev Iliev

,

Ivan Hristov Beloev

Abstract: Sulfide-alkaline wastewater (SAW) from petrochemical plants, particularly from pyrolysis and hydrotreating units, presents a significant environmental challenge due to its high toxicity, extreme alkalinity (pH > 12), and high concentrations of sulfides and organic pollutants. Traditional treatment methods like acid neutralization or air oxidation are often inefficient, generate secondary waste, or fail to recover valuable components. This study investigates the effectiveness of a novel electrochemical system for the simultaneous treatment of SAW and recovery of valuable products. A lab-scale four-chamber bipolar electrolyzer, equipped with cation-exchange membranes and nickel electrodes, was designed and tested using real industrial wastewater. The wastewater was characterized by a pH of 13.06, chemical oxygen demand of 12600 mg/l, and a sulfide content of approximately 5000 mg/l. The process leverages anodic oxidation to convert sulfide ions into elemental sulfur, while sodium cations migrate through cation-exchange membranes to the cathodic compartments. There, water reduction generates high-purity hydrogen (≥99.9%) and a concentrated, purified sodium hydroxide solution. The results demonstrate the ineffectiveness of conventional electrodialysis with anion-exchange membranes due to rapid membrane degradation. In contrast, the proposed bipolar membrane electrolysis achieved excellent performance: a caustic soda solution with a concentration of 2.3–2.5% was recovered with a current efficiency of 83–85%, containing only trace amounts of sulfides (0.0052%) and organic impurities (0.053%). The process completely removed the original sulfide alkalinity. The study confirms the chemical and mechanical stability of the cation-exchange membranes under harsh SAW conditions. The proposed technology offers a path towards a closed-loop system in refineries by enabling the reuse of recovered caustic, utilization of hydrogen, and potential recovery of sulfur, aligning with the principles of green chemistry and circular economy.

Review
Chemistry and Materials Science
Electrochemistry

Paolo Yammine

,

Ali Al-Zein

,

Tony Tannous

,

Hanna El-Nakat

,

Doris Homsi

,

Elie Atieh

,

Zeinab Matar

,

Pierre J. Obeid

,

Ayman Chmayssem

Abstract: This paper serves as a practical guide to help the readers select electrochemical instruments with a focus on potentiostats / galvanostats. It is dedicated to professionals in industry, students and researchers from various fields. We provide an overview of the main potentiostats / galvanostats and related electrochemical instruments currently available on the market and the main suppliers worldwide. For each device, we summarize its technical specifications including current and potential ranges as well as the methods the instrument is able to support. We also discuss the limitations of each instrument in order to provide the readers with a clear and comprehensive understanding. Finally, the paper aims to help the readers in selecting the most suitable instrument for their needs while considering performance and budget.

Article
Chemistry and Materials Science
Electrochemistry

Paolo Yammine

,

Nouha Sari-Chmayssem

,

Hanna El-Nakat

,

Darine Chahine

,

Moomen Baroudi

,

Farouk Jaber

,

Ayman Chmayssem

Abstract: Water pollution is one of the most critical societal, environmental challenges and remains a persisting problem worldwide. The origin of this pollution is diverse while organic matter occupies a significant portion originating from different sources. This creates major environmental and health risks, requiring reliable and sensitive analytical tools for effective monitoring. The permanganate index stands as a conventional assessment method for organic pollution, but it demonstrates compound non-specificity toward compounds and limited sensitivity to various contaminant structures. This research introduces cyclic voltammetry as a standalone electrochemical method which provides sensitive detection and characterization of organic oxidizing compounds. Six organic compounds including gallic acid, phenol, oxalic acid, ascorbic acid, salicylic acid and p-benzoquinone were used as model compounds and studied in aqueous media. These compounds were analyzed individually, in single-compound mode, to characterize its redox behavior and to identify the voltammetric peaks. Subsequently, a multi-compound analysis was studied to check for the validity of the concept in a more complex matrix. Notably, a strong linear correlation was observed between the measured charge and the theoretical permanganate index, highlighting the quantitative reliability of the electrochemical method. Comparing the obtained results with the permanganate index method confirmed the superiority of cyclic voltammetry in terms of response time and detection capability. The outcomes demonstrate that cyclic voltammetry functions as a robust alternative to the classical chemical oxidation method for environmental water assessment.

of 18

Prerpints.org logo

Preprints.org is a free preprint server supported by MDPI in Basel, Switzerland.

Subscribe

© 2026 MDPI (Basel, Switzerland) unless otherwise stated

Accessibility

Disclaimer

Terms of Use

Privacy Policy

Privacy Settings