In this study, the modification of palm kernel shell-based Agro-Waste into an electrocatalytic material has been successfully carried out. The green hydrothermal method through temperature and time variations was chosen in the process of modifying PKS carbon into nanoporous carbon (NC-PKS). SEM-EDX, XRD, and FTIR characterization data show the success of this process, which is marked by fundamental changes in morphology, elemental composition, diffractogram peaks, and IR absorption of functional groups that make up carbon. The morphology of NC-PKS is characterized by honeycomb-shaped hexagonal pores with constituent elements including 85.111
In this work, the electrochemical efficiency of copper based layered double hydroxides (Cu-LDH) towards CO2 electroreduction (CO2ER) was investigated. Cu2Al-CO3 LDH was synthesized by coprecipitation and characterized using powder X-ray diffraction (PXRD), atomic pair distribution functions (PDFs) and electron microscopies (SEM-TEM). The CO2ER performance of Cu2Al-CO3 LDH was evaluated in a three-electrode cell under potentiostatic conditions. The influence of key electrolysis parameters, including electrolyte composition, concentration, pH and applied potential, was systematically examined. Cyclic voltammetry was used to characterize the Cu-LDH modified electrode and revealed an electrochemical activation of the copper atoms occurred in the presence of CO2 at Eapp ≤ -1.3 V vs. SCE. Optimal conditions were identified in 0.5 M KCl at Eapp = -1.4 V vs. SCE with a final pHf in the range 5.5-6.0 leading to formation of formate. The evolution of the structure and the composition of the Cu-based LDH particles after electrolysis was investigated by XRD, PDF and XPS to provide insight into the active phases formed under CO2ER conditions.
Ammonia is a vital industrial chemical, predominantly produced through the energy-intensive Haber–Bosch process, which is associated with substantial carbon dioxide emissions due to its reliance on fossil-fuel-based energy sources. Therefore, the development of sustainable alternatives for ammonia synthesis is of significant importance. Electrochemical ammonia synthesis via the nitrogen reduction reaction (NRR) under ambient conditions has emerged as a promising approach; however, the development of highly active, selective, and stable electrocatalysts remains a major challenge. In this context, this review systematically examines β-Mo2C and its MXene derivative β-Mo2CTx as emerging electrocatalysts for NRR, highlighting their unique electronic structures, surface terminations, and strong nitrogen adsorption capability. Recent advances in synthesis strategies, including heteroatom doping, defect engineering, and composite formation, are critically analyzed to elucidate structure–performance relationships. Both theoretical and experimental studies indicate that rationally engineered β-Mo2C/β-Mo2CTx catalysts can markedly enhance NRR performance. Reported Faradaic efficiencies vary broadly depending on the catalyst design and testing parameters, while the NH3 yield rates fall within the range of 1.41 to 95.1 µg h− 1 mg− 1 under different experimental conditions. By correlating catalytic pathways with structural and electronic modulation, this review identifies current limitations and outlines future design strategies toward scalable green ammonia production. Review of β-Mo2C and β-Mo2CTx electrocatalysts for NRR. Evaluation of synthesis routes including doping, defects, and composites. Identification of key structure–activity relationships in Mo-based catalysts. Summary of experimental and DFT insights into NRR mechanisms. Outlook on current challenges and future strategies for NRR.
This study explores a morphology-controlled synthesis strategy for an innovative hybrid nanostructure composed of carbon quantum dots (CQDs) integrated with NiMn₂S₄ nanosheets, designed to enhance the oxygen evolution reaction (OER) performance. Uniform, ultrathin, and regular discrete nanosheet arrays were grown on nickel foam via hydrothermal synthesis followed by calcination at 400 °C. The low thickness of the nanosheets increases the number of active sites for the OER. Moreover, the interconnected nanosheet framework facilitates the transport of electrolyte ions and enables efficient bubble release during OER. In addition, the intimate integration of ultrathin nanosheets with the substrate promotes efficient electron transfer and improves long-term stability. Notably, the CQDs/NiMn2S4 hybrid exhibits a low overpotential of 350 mV at a current density of 10 mA cm− 2, along with excellent stability over 55 h of operation. The structure and morphology of the CQDs/NiMn2S4 composite were characterized by field-emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and Raman spectroscopy. This work provides an innovative strategy for enhancing the OER performance of NiMn2S4 through surface decoration with carbon quantum dots for water-splitting applications.
Due to the adverse effects of heavy metal ions on living organisms, a novel Sn(MoO₄)₂-modified carbon cloth (Sn(MoO₄)₂/CC) electrode is designed for the sensitive and selective electrochemical detection of Pb²⁺, Cu²⁺ and Hg²⁺ ions. The Sn(MoO₄)₂ nanostructures were synthesized hydrothermally, exhibiting a needle-like morphology with high crystallinity and uniform elemental distribution, as confirmed by structural and morphological studies. The average length and breadth of the nanostructures were calculated to be 1000 and 167 nm, respectively. The Sn(MoO₄)₂/CC electrode demonstrated excellent electrochemical performance toward the simultaneous and individual detection of Pb²⁺, Cu²⁺, and Hg²⁺ as depicted from the square wave anodic stripping voltammetry. The limit of detection (LOD) for the simultaneous detection of Pb²⁺, Cu²⁺, and Hg²⁺ is 40.78 nM, 15.44 nM and 13.34 nM, and when studied individually, is 8.62 nM, 15.8 nM, and 60 nM, respectively. Well-resolved, distinct stripping peaks were observed for all three metal ions, with no significant overlap, ensuring simultaneous detection. The linear dependence of the response current over a wide concentration range (0-2.2 µM) ensures high sensitivity and strong selectivity even in the presence of common interfering ions, further enabling its reliability. Overall, this study shows that Sn(MoO₄)₂/CC is a cost-effective, reliable sensor material for detecting toxic heavy metals in the environment. Its straightforward fabrication process, adaptability, and excellent analytical capabilities make this electrode ideal for on-site water quality testing and real-time environmental monitoring.
Benefiting from high technical maturity and cost competitiveness, alkaline water electrolysis (ALK) has become the mainstream technology for large-scale global green hydrogen production. This paper systematically reviews water electrolysis technologies for hydrogen production in China. It compares the technical routes, market distributions, and competitive landscape of four mainstream electrolysis techniques, elaborates on the classification and structure of ALK electrolyzers, and focuses on key performance indicators, including cell voltage, Faradaic efficiency, specific energy consumption, energy efficiency, and hydrogen production rate. The effects of core material components (electrodes, diaphragms, and bipolar plates) and critical operating parameters (current density, operating temperature, electrolyte flow rate, system pressure, electrode-diaphragm gap, and cell voltage) on the performance of ALK electrolyzers are comprehensively analyzed. Two key bottlenecks restricting ALK industrial development are summarized: widespread product homogenization leads to fierce price competition, and traditional steady-state designs fail to adapt to fluctuating renewable energy. Finally, prospective development directions are proposed from the aspects of material optimization, structural innovation, system control, and economic viability.
Proton exchange membrane water electrolysis (PEMWE) is a key technology for green hydrogen production, but its widespread deployment is severely constrained by the sluggish kinetics of the anodic oxygen evolution reaction (OER) and the high iridium loading required to achieve practical performance. Herein, we report an interfacial electronic modulation strategy that simultaneously enhance the activity and durability of IrO2 catalysts by engineering oxygen-deficient tungsten oxide (WO3−x) supports. The deliberate generation of abundant oxygen-coordinatively unsaturated tungsten (WOCU) sites enables strong electronic coupling at the IrO2/WO3−x interface, leading to the formation of well-defined Ir-O-WOCU motifs. Comprehensive structural and spectroscopic analyses reveal that these motifs drive pronounced electron redistribution from the WO3−x support to Ir centers, resulting in a downshift of the Ir d-band center and stabilization of catalytically active Ir3+ species. Consequently, the IrO2@WO3−x catalyst exhibits a low overpotential of 324 mV at 10 mA cm− 2 and a high mass activity of 163.3 A g−1Ir. More importantly, Ir dissolution is significantly suppressed, endowing the catalyst with enhanced structural stability during prolonged operation. In a practical PEMWE single-cell, the IrO2@WO3−x anode achieves a low cell voltage of 1.667 V at 1 A cm− 2 and stable operation for over 200 h with a low iridium loading of 0.2 mg cm− 2. This work highlights the critical role of oxygen‑coordinatively unsaturated sites in governing interfacial electronic structure and catalytic behavior, and provides a rational design strategy for cost‑effective and durable electrocatalysts for acidic water oxidation.
In this study, one-pot sol-gel/auto-combustion method was applied to fabricate Bi2O3/MoO3 nanocomposites as a direct Z-Scheme electrocatalyst. The manufactured composite’s structural, surface, and morphological characteristics were comprehensively investigated by XRD, FTIR, SEM/EDX, HR-TEM analyses, and UV–Visible spectroscopy. Results demonstrated that Z-scheme BMO-5 NCs’ low band gap energy is found at 3.027 eV, with a high electrocatalytic activity. The electrocatalytic performance of BMO electrocatalyst was investigated via degradation of Methyl blue (MB), Brilliant green (BG), and mixed dyes under current voltage irradiation. Meanwhile, degradation efficiency of MB and BG dyes with BMO-5 NCs demonstrated around 96.16 ( • OH) and superoxide radical (O 2•− ) significantly affect electrocatalytic degradation of BG dye. Bi2O3/MoO3 is a potential material for environmental remediation and wastewater treatment, due to its dual functionality.
In bipolar alkaline water electrolysis, electrocatalyst degradation due to a reverse current during shutdown is a serious problem. In this study, the effect of the substrate material on the degradation of commercial Ru–lanthanide oxide cathode catalysts due to a reverse current during repeated startup/shutdown (SU/SD) operations was investigated. The causes of catalyst degradation were discussed based on spectroscopic and mass data of the electrolyte and cathode before and after SU/SD operation. In the case of the Ni substrate, the current density for the hydrogen evolution reaction (HER) decreased rapidly during the initial 200 cycles of SU/SD operations. In contrast, for the Ti substrate, the HER current density decreased by 20
Electrochemical water splitting serves as a promising approach to realize large-scale renewable energy conversion and storage for green hydrogen production. HER electrocatalysts with earth-abundant composition, low cost, high activity and superior stability determine the performance of large-scale water electrolysis. Self-supported catalysts are one of the most promising electrodes for practical hydrogen production, due to their merits of rapid charge/mass transfer, high active site density, well-regulated catalyst–substrate interface, strong adhesion and excellent HER performance. This review systematically summarizes recent advances in diverse substrates (metal foils/foams, carbonaceous materials, 3D-printed supports) for self-supported electrodes, including morphology/structure engineering, doping, interfacial regulation and crystallographic modulation, and presents conclusions and insights on scalable synthesis of high-performance self-supported electrocatalysts.
Developing efficient, durable, and cost-effective electrocatalysts for the oxygen evolution reaction (OER) is crucial for sustainable energy systems. NiFe-LDH is a promising OER catalyst but suffers from limited conductivity, agglomeration, and moderate intrinsic activity. Herein, we stabilize Ce within NiFe-LDH via a unique CeCO3F phase resulting (CeCO3F-NiFe-LDH/NF) as improved OER catalyst. This induces (i) nanoscale exfoliation into thinner nanosheets, (ii) oxygen deficient surface specie, and (iii) high-valence Ni/Fe species. Consequently, catalyst achieving an overpotential of 193 mV and 234 mV to deliver a current density of 10 mA cm-2 and 100 mA cm-2 respectively with a small Tafel slope of 70 mV dec-1. Comprehensive characterization reveals that the synergistic co-doping of Ce and F induces multifaceted enhancements: Ce promotes high-valence Ni/Fe species and according to XPS analysis, the formation of oxygen-deficient surface specie, which aid the charge compensation, while F⁻ incorporation creates atomic-level point defects and induces lattice strain. Furthermore, the in-situ formed CeCO3F phase acts as a structural modifier, leading to nanoscale exfoliation into thinner nanosheets and the creation of a conductive framework. These synergistic effects collectively enhance charge transfer kinetics, increase the number of active sites, increase the electrochemically active surface area, and boost the intrinsic activity of active sites. The catalyst also demonstrates excellent stability over 27 h of operation. This work highlights rational heteroatom co-doping as a promising strategy for designing high-performance, non-precious metal-based electrocatalysts.
The electrochemical analysis of terbinafine, an antifungal drug available for oral and topical use, was investigated using poly(bromocresol purple) modified glassy carbon electrode. The surface of the bare electrodes was coated by one-step electropolymerization of bromocresol purple monomer via cyclic voltammetry in a pH 6.0 phosphate buffer solution, resulting in at least a two-fold increase in terbinafine peak current compared to the bare glassy carbon electrode. Electrochemical analysis revealed that terbinafine undergoes irreversible and diffusion-controlled oxidation. Quantitative analysis of terbinafine using differential pulse voltammetry yielded a detection limit of 19.0 nM and a linearity range of 0.08‒20.0 µM. Results with relative standard deviations below 2.0
Platinum (Pt) remains the benchmark catalyst for hydrogen evolution reaction (HER), yet its high cost and limited abundance demand strategies that maximize atomic efficiency. Single-atom catalysts (SACs) offer near-perfect Pt utilization, but their practical deployment is hindered by atom migration and support degradation, especially under harsh electrochemical conditions. This Perspective explores the recent advances in stabilizing Pt SACs for renewable hydrogen production, emphasizing the critical role of support engineering, synthetic strategies, and local atomic environments. We highlight heterostructured supports, defect-rich frameworks, and dual-atom interfaces that anchor Pt atoms with high stability and catalytic activity. Advanced synthesis methods—including atomic layer deposition, template-assisted embedding, alloying, and high-energy laser/flame techniques—are discussed for their ability to create robust Pt–support interactions. Finally, we outline future directions for designing long-lived Pt SACs, focusing on dynamic support systems, dual-function interfaces, and in situ adaptive stabilization. This Perspective aims to guide the rational design of next-generation Pt SACs for scalable, durable hydrogen generation technologies.
Nano-ferrites have recently emerged as potential candidates for application in energy storage devices due to their good redox activity, excellent chemical stability and tunable electronic properties. In this study, we report the synthesis of pristine Mn0.5Co0.5Fe2O4 (MCF) nanoparticles and their nanocomposite with reduced graphene oxide (rGO) via facile chemical co-precipitation method. In this configuration, MCF provides pseudocapacitance and structural stability while rGO contributes a large surface area and high electrical conductivity. Structural morphological analysis confirmed the formation of spinel phase of ferrites having nanoscale features. Electrochemical performance was assessed via cyclic voltammetry (CV) in three-electrode system with 1 M KOH as the electrolyte. Specific capacitance at each scan was higher for composite material. The rGO-MCF nanocomposite exhibited remarkably enhanced specific capacitance of 1228.7 F/g at 2 mV/s, compared to 448 F/g for the pristine MCF. Electrochemical impedance spectroscopy (EIS) revealed lower Charge transfer resistance for nanocomposite (36.8 Ω) than pristine MCF (59.0 Ω) which may be attributed to the high conductive nature of rGO. Moreover, the rGO-MCF composite sample exhibited superior oxygen evolution reaction (OER) activity with a lower overpotential and a Tafel slope of 78 mV/dec along with excellent cyclic stability. These findings suggest that rGO-MCF nanocomposite is a promising candidate for electrodes of supercapacitors and OER applications.
Lanthanide coordination polymers [Ln(C18H12N3O7)2(OH)(H2O)]n (Ln = Nd, La, Ce) of tricarboxylic acid functionalized 1,2,3-triazole based linker were synthesized by solvothermal synthesis of Ln(NO3)3.6H2O and 5-((1-(4-carboxyphenyl)-1H-1,2,3-triazol-4-yl)methoxy)isophthalic acid in DMF. The formation of the coordination polymers and their chemical formula were proposed from the combination of different characterization techniques such as FTIR, ICP-OES, SEM-EDX, TGA, CHN-elemental, acid digestion HNMR spectroscopy and PXRD analysis. The materials were investigated for their electrochemical detection of epinephrine (EP) and dopamine (DA) at a scan rate of 50 mV/s in the voltage range of -0.4–0.8 V in 10 mM PBS. Nd trz CP/GCE exhibited highest activity for sensing of dopamine and epinephrine with limit of detection 1.8 µM and 1.84 µM and sensitivity of 5.18 µAµM−1cm− 2 and 9.9 µAµM−1cm− 2, respectively and performed well at pH 7. The Nd trz CP/GCE exhibited small charge transfer resistance (Rct) than La trz CP and Ce trz CP/GCE when measured using electrochemical impedance spectroscopy (EIS). Chronoamperometry study was conducted for testing the selectivity of the Nd trz CP modified electrode in the presence of 5 µM of ascorbic acid, uric acid, Ɣ-aminobutyric acid, cysteine, and glucose and the results showed that the catalyst is only responsive towards epinephrine and dopamine.
The electrochemical reduction of carbon dioxide (CO2RR) into multi-carbon (C2+) products is emerging as a promising pathway for sustainable fuel and chemical synthesis. Copper (Cu)-based catalysts remain uniquely capable of facilitating C–C coupling due to their favorable binding with key CO2RR intermediates. Recent advances in catalyst design—encompassing surface engineering, molecular modifiers, doping and alloying strategies, and tandem catalyst architectures—have substantially enhanced C2+ selectivity under laboratory conditions. However, translating these gains into large-area electrodes suitable for industrial operation remains a major bottleneck. Challenges include scalable catalyst synthesis, maintaining structural stability under high current densities, and developing reliable fabrication methods for uniform, high-performance electrodes. This mini review summarizes recent progress in Cu-based CO2RR catalyst development, a holistic overview of the electrolyzer configurations and examines the key limitations hindering scale-up in both synthesis and electrode manufacturing, and discusses potential solutions informed by mature electrochemical technologies. Overcoming these challenges will be essential to bridge the gap between laboratory advancements and commercial deployment, enabling the large-scale production of low-carbon fuels and chemicals from CO2.
Efficient oxygen evolution reaction (OER) is vital for water electrolysis, rechargeable metal–air batteries, and regenerative fuel cells. This study has highlighted a modest and straightforward approach for the preparation of 3-aminopropyl trimethoxysilane (APTMS)-functionalized graphene oxide (GO-APTMS) and its composites with cobalt (GO-APTMS/Co) and nickel (GO-APTMS/Ni). The prepared catalysts were utilized for the oxygen evolution reaction (OER) in a basic medium (0.1 M KOH). The prepared composites, GO-APTMS/Ni and GO-APTMS/Co, are characterized using spectroscopic methods, such as Fourier transform infrared (FT-IR), ultraviolet (UV-vis), powder X-ray diffraction (P-XRD), FT-Raman, X-ray photoelectron spectroscopy (XPS), and energy dispersive X-ray spectroscopy (EDS). It was also characterized with transmission electron microscopy (TEM) and selected area electron diffraction (SAED). The nanocomposites GO-APTMS/Ni and GO-APTMS/Co are deposited on the surface of a glassy carbon (GC) electrode to study their electrochemical behavior. It is observed that GC modified GO-APTMS/Ni (GC/GO-APTMS/Ni) and GO-APTMS/Co (GC/GO-APTMS/Co) have efficient OER activity. The Tafel slopes of nanocomposite materials GC/GO-APTMS-Co and GC/GO-APTMS-Ni are 74 and 183 mV/dec, respectively, in a 0.1 M KOH solution. GC/GO-APTMS/Co and GC/GO-APTMS/Ni exhibit remarkable OER activity with low onset potentials of 1.63 and 1.65 V, respectively, with satisfactory operational stability. This indicates that GC/GO-APTMS-Co could be a promising, cost-effective electrode material for OER. This study demonstrates a novel way of creating an active nanocomposite catalyst for OER in alkaline media. Hence, it could be a suitable alternative for the replacement of a high-cost electrocatalyst in the fuel cells, metal-air batteries, water electrolyzers, etc.
Oxytetracycline (OTC), a tetracycline antibiotic frequently detected in aquatic environments, poses persistent ecological risks due to its resistance to conventional biodegradation. In this study, a novel iron-modified titanium suboxide electrode (Fe/Ti4O7) was successfully developed via a facile high-temperature solid-phase reduction method, and its electrocatalytic performance for the removal of OTC from wastewater was systematically evaluated. X-ray photoelectron spectroscopy (XPS) analysis revealed that the introduction of the Fe2+/Fe3+ redox couple significantly enhanced the interfacial charge transfer kinetics of the electrode. Under optimized conditions (pH = 7, 100 mM Na2SO4, current density of 20 mA·cm-2), the Fe/Ti4O7 electrode achieved 99.7
Crizotinib (CZT) is an anaplastic lymphoma kinase (ALK) inhibitor used for the treatment of lung cancer. The selective detection of CZT in human biological samples is crucial for therapeutic studies. Electrochemical sensors have become essential in pharmaceutical analysis due to their high selectivity, fast response, low costs, simplicity, and portability. Here, an effective and novel electrochemical sensor based on a perovskite hydroxide CoSn(OH)6/carbon black (CB) nanocomposite was designed for the highly selective detection of CZT on a glassy carbon electrode (GCE) surface. Characterization techniques such as field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), and electrochemical methods such as electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and differential pulse voltammetry (DPV) confirmed the structural and electrochemical properties of the nanocomposite. The sensor exhibited a wide linear range of 0.001 to 2400 nM, a limit of detection (LOD) of 0.0003 nM, and acceptable selectivity, reproducibility, repeatability, and stability for CZT detection. Finally, the designed electrode was used to determine CZT in a real sample, displaying its promise for pharmaceutical and biomedical applications.
Widespread adoption of electrolytic water splitting for hydrogen production is limited by the high overpotential and slow kinetics of the oxygen evolution reaction. This work presents a bifunctional electrocatalyst of cobalt phosphide-doped porous carbon electrocatalyst (CoP/Co2P/C). The catalyst was synthesized via direct pyrolysis of a composite precursor (denoted as Co/Zn-PO@Co-MOF), which consisted of spherical cobalt/zinc phosphate (Co/Zn-PO) coated with Co-based metal-organic framework. The spherical Co/Zn-PO served as a novel and safer phosphorus source, eliminating the need for conventional NaH2PO2 carbonization which releases toxic gases. Although minimally incorporated into the composite precursor, Ni2+ played two key roles: it primarily functioned to assist the coordination of Co2+ with 2-methylimidazole on the surface of Co/Zn-PO, and additionally modulated the resulting CoP/Co2P ratio. Moreover, the carbonization temperature was a critical variable in converting Co/Zn-PO@Co-MOF into CoP/Co2P and affected the final ratio between them. Based on the interfacial synergistic effect between CoP and Co2P, along with three catalytic active sites of Co, P and Pyridinic N, the optimized CoP/Co2P/C achieved a current density of 10 mA cm− 2 at low overpotentials (η10) of 204 mV for HER and 339 mV for OER. The performance of CoP/Co2P/C remains comparable to that of most recently reported cobalt phosphide-based catalysts.
