trans-4-Methoxycinnamic acid (t-4MCA), an important intermediate for preparation of pharmaceutical products or sunscreens, requires efficient processes for its separation. This work systematically explored how functional monomers (acidic methacrylic acid (MAA) vs basic 4-vinylpyridine (4-VP)) and porogenic solvents (chloroform vs acetonitrile) control MIP extractive performance of the acidic t-4MCA template. The MIPs were prepared with t-4MCA as the template, functional monomer and ethylene glycol dimethacrylate (EDGMA) as the cross-linker using the precipitation polymerization process in a 1:4:20 M ratio. Non-imprinted polymers (NIPs) and the corresponding MIP with paracetamol as a dummy template were prepared for comparison. MAA-MIP characterizations were carried out by BET, FTIR, TGA and SEM analysis which indicated that amorphous mesoporous polymers were formed as thermally stable materials. The washed MAA-MIP had a large surface area of 175.2 m2 g −1 than that of the NIP (7.9 m2 g−1). Binding studies with the MAA-based MIP exhibited an adsorption capacity of 1.59 mg g−1 and imprinting factor of 1.02. The 4-VP-based MIP, however, displayed high selectivity, albeit a lower overall adsorption capacity of 1.01 mg g−1, over the paracetamol dummy templated MIP with an imprinting factor of 1.3. Competitive selectivity studies with ferulic acid, trans-4-hydroxycinnamic acid (t-4HCA) and ethyl (E)-3-(4-methoxyphenyl) acrylate (Et-MOPA) confirmed analogue dependent recognition by the t-4MCA MIP, with the strongest discrimination observed against t-4HCA. This work presented two distinct sorbents, a conventionally selective 4-VP MIP (IF = 1.3) and a high-capacity MAA-MIP (1.59 mg g−1).
Two new ruthenium(II) complexes with triphenylphosphine and tridentate benzimidazole-based ligands were synthesized and structurally characterized. The complexes were tested as homogenous catalysts for the hydration of nitriles to amides under mild and sustainable conditions. FT-IR, UV–visible, 1H, 31P, 13C NMR and High-resolution mass spectrometry confirmed the coordination of ligands to the Ru (II) centre. The complexes exhibited high catalytic activity in the hydration of aromatic and aliphatic nitriles to give the corresponding amides in excellent yields. The catalytic performance was further supported by turnover number (TON) and turnover frequency (TOF) studies, indicating good efficiency of the catalytic system. Use of very low catalyst loading (0.05 mol%) and sub-stoichiometric amounts (0.5 equivalents) of base has rendered the method highly sustainable. Catalytic activity was found to be strongly dependent on ligand architecture; one complex was shown to be a better performer than the others due to lower steric hindrance and better electronic delocalization. These results demonstrate the potential of rational ligand design for modulation of the activity of Ru(II)-triphenylphosphine complexes towards atom-economical amide synthesis.
Efficient utilisation of CO2 as a carbon source is a promising approach for reducing greenhouse gas emissions and producing value-added chemicals. In this work, Fe2O3-SiO2 core–shell nanocomposite was synthesized through a facile precipitation method and investigated as an electrocatalyst for CO2 reduction. The structural and morphological analyses confirmed the successful formation of a well-dispersed core–shell architecture. Electrochemical studies demonstrated enhanced CO2 reduction activity of the Fe2O3-SiO2 electrode compared with individual SiO2 and Fe2O3 components. The cyclic voltammetry analysis showed an enhanced cathodic response under CO2-saturated conditions, indicating improved CO2 activation. Electrochemical impedance spectroscopy revealed a significant decrease in charge-transfer resistance from 0.238 kΩ (before CO2 saturation) to 0.074 kΩ (after CO2 saturation), confirming improved interfacial electron transfer and catalytic kinetics. Product analysis after electrochemical CO2 reduction confirmed the formation of methanol (CH3OH), formate (HCOO−), carbon monoxide (CO), and methane (CH4) as reduction products, demonstrating the capability of the Fe2O3-SiO2 catalyst for multi-electron/proton CO2 conversion pathways. The enhanced performance is attributed to the synergistic effect of the Fe2O3 active sites and SiO2 shell, which promotes CO2 adsorption, charge separation, and stabilisation of reaction intermediates. The Fe2O3-SiO2 core–shell nanocomposite shows potential as an efficient catalyst for sustainable electrochemical CO2 conversion.
An aza‑borondipyrromethene (aza-BODIPY) DE was synthesized and studied for chemosensor properties for selective ion detection. Compound DE bearing two dimethylaniline moieties selectively binds with Zn2+ in solution phase. Spectroscopic properties and binding abilities of DE with Zn2+ were investigated via spectroscopic titration by gradual addition of zinc chloride into the DE solution. The new absorption band appeared and the color changing of DE had occurred due to the Zn2+ inhibited charge transfer of dimethylaniline with aza-BODIPY core. In addition to conventional spectroscopic analysis, a custom-built Arduino-based colorimeter was developed and applied for Zn2+ detection using DE as the sensing probe. The results from both spectroscopic and Arduino colorimeter were compared. The limit of detection (LOD) values of spectroscopic technique and colorimeter were determined from the calibration curves as 2.74 mM (179 ppm) at 753 nm and 1.68 mM (110 ppm), respectively. In addition, DE was successfully applied as a colorimetric test strip and demonstrated qualitative sensing capability in aqueous media as proof-of-concept demonstration. These results demonstrate the potential of DE as a colorimetric sensor for Zn2+ detection and highlight the feasibility of combining low-cost, portable colorimetric devices with aza-BODIPY-based chemosensors as a low-cost, proof-of-concept detection platform. All quantitative calibration and limit-of-detection determinations in this work were performed in CHCl3/EtOH (95:5); the aqueous experiments (test strip) are qualitative only.
In this study, we report a novel magnetically recoverable acid-base bifunctional catalyst constructed by decorating iron‑cobalt layered double hydroxide (FeCo-LDH) onto zinc and nitrogen co-doped porous carbon derived from chitosan (denoted as ZNC/FeCo-LDH). The core innovation lies in the synergistic integration of the ZNC support with FeCo-LDH active phase provides hierarchical porosity for enhanced mass transfer and tunes Lewis acid-base sites and intrinsic magnetism. Comprehensive characterization using SEM, XRD, BET, temperature-programmed desorption CO2/NH3-TPD, TGA, FT-IR, and vibrating sample magnetometry confirmed the successful formation and favorable physicochemical properties of the catalyst. In the conversion of soybean oil, the ZNC/FeCo-LDH catalyst demonstrated exceptional performance, achieving a high biodiesel yield of 97.59% under optimal conditions (molar ratio of Fe/Co = 3:1, mass ratio of FeCo-LDH/ZNC = 5:1, molar ratio of methanol/oil = 6:1, reaction time = 6 h, reaction temperature = 65 °C, and catalyst loading = 0.5 wt%). The catalyst exhibited excellent versatility toward alcohols and fatty acids. Kinetic analysis revealed a low activation energy of 8.67 kJ/mol, confirming the facile reaction kinetics. Furthermore, the produced biodiesel met international standards. This work provides a feasible strategy for designing multifunctional biomass-derived catalysts, advancing sustainable biodiesel production via synergistic regulation of structure and active sites.
With ongoing investigations into materials for sodium-ion batteries (SIBs) to replace lithium-ion batteries (LIBs), it is necessary to develop new fabrication techniques that offer greater selectivity and lower material waste to produce high-quality, reproducible battery electrodes. In recent years, molybdenum disulfide (MoS2) has gained considerable attention as a promising anode material for SIBs because of its two-dimensional (2D) layered structure and high theoretical capacity. This paper presents an analysis of the printability window of liquid-phase exfoliated MoS2 and MoS2/CNT-based inks, onto copper substrates, with respect to ink rheological and inkjet-printing conditions. The surface roughness of the copper substrate and of both electrodes after ink deposition are presented. Electrochemical impedance spectroscopy (EIS) studies confirm a reduction in the overall impedance of the MoS2/CNT electrode compared to the MoS2 electrode. This work highlights a proposed strategy for the inkjet-printed battery electrode process, from ink characterisation to printing, and motivates further development toward optimising SIB electrodes.
A novel hybrid catalyst, (n-Bu₄N)2 [Mo₆O₁₉] @MOF-801, was successfully fabricated via post-synthetic Immobilization of the Lindqvist-type polyoxomolybdate anion (n-Bu₄N)2 [Mo₆O₁₉] into the mesoporous cages of MOF-801(Zr). The material was comprehensively characterized by FT-IR, SEM-EDS, N₂ adsorption–desorption, PXRD, and TGA, confirming the preservation of the MOF framework and the uniform dispersion of the polyoxometalate species. The catalyst exhibited outstanding activity in the solvent-free esterification of carboxylic acids with a broad range of alcohols, affording high yields for diverse substrates including primary alcohols within 8–10 h at 80 °C. Notably, the hybrid system exhibited excellent recyclability, retaining >89% catalytic efficiency over six consecutive cycles, with negligible Mo leaching (0.002 mmol·g−1 by ICP-OES) and no detectable structural degradation. This work provides a sustainable and scalable route to ester-based chemical intermediates under mild, solvent-free conditions, fully aligned with the principles of green chemistry.
Research on Parkinson's disease (PD) treatment through monoamine oxidase B (MAO-B) enzyme inhibition has continued for many years. Deprenyl has been prescribed as a drug to treat the symptoms of Parkinson's disease; however, there is an urgent need for new anti-Parkinson drugs due to reduced long-term efficacy and severe side effects. Therefore, this study aimed to identify plant compounds through computational studies to identify potential MAO-B inhibitors. ADMET analysis and Lipinski filter highlighted the drug similarity and pharmacokinetic properties of the selected molecule Piperine (PIP). Molecular docking results showed the highest binding affinity with increased hydrophobic interactions for PIP compared to the co-crystal ligand. Molecular dynamics (MD) simulation results showed that PIP could be considered as a prominent candidate. PCA and FEL results recorded structural changes in the presence of PIP. PIP showed the highest number of aromatic interactions (pi–pi stacking) compared to Deprenyl, which are crucial for ligand binding. The binding free energies for PIP (−142.12 ± 11.34 kJ/mol) were significantly higher than for the co-crystal (−86.21 ± 11.15 kJ/mol), in accordance with the frontier molecular orbital energies (HOMO-LUMO) obtained from DFT results; PIP exhibited electronically softer, higher reactivity and increased molecular dipole moment than the cocrystal. Although these results can be useful in the search for new, effective, and selective MAO-B inhibitors to modify lead and develop new drugs for the treatment of Parkinson's; however, it is necessary to conduct in vitro and in vivo experiments to confirm and validate these findings in future studies.
The single-nucleotide polymorphism (SNP) rs144012689 has been validated to exhibit high sensitivity and specificity for the detection of the HLA-B*1502 allele in both American and Chinese populations. Therefore, we designed a detection system for rs144012689 single base mutation detection based on double primer pairs enzymatic recombinase amplification (D-ERA) isothermal amplification and the optimized CRISPR/Cas12a system. First, we screened candidate crRNAs and optimized the D-ERA and CRISPR-Cas12a reaction conditions. Second, we determined the limit of detection (LOD) of the assay to be 0.1 ng/μL (equivalent to approximately 66 target copies per reaction) and established a fluorescence threshold of 500 arbitrary units (a.u.). Finally, we implemented a detection strategy that enables HLA-B*1502 genotyping within 30 min. Compared with the results of sanger sequencing, this method provided completely consistent results for clinical samples testing. So, this method provides a new pathway for rapid detection of single base mutation.
Biochar descriptors that favor aqueous heavy-metal adsorption do not necessarily maximize gas-phase CO₂ adsorption. This study develops an interpretable machine-learning framework to quantify those cross-target relationships within a common material-design space. A synthetic dataset calibrated to published ranges and broad relationships contained 1047 observations, 24 inputs and five targets-Pb2+, Cd2+, Cr(VI), As(III) and CO₂-and was analysed using Random Forest, Gradient Boosting Regressor and their arithmetic ensemble. Across two repeats of fivefold cross-validation, mean ensemble R2 values were 0.843, 0.805, 0.730, 0.748 and 0.835, respectively. Signed ensemble SHAP classified Fe loading as a conflict descriptor: it contributed positively to all four metal targets but negatively to CO₂. At the prespecified 0.02 materiality threshold, oxygen was heavy-metal-specific, BET area was cooperative, and nitrogen, micropore volume and pyrolysis temperature were CO₂-specific. Fe, BET and nitrogen classifications were stable across all repeated folds; secondary classes were more sensitive at lower thresholds. Fe-loading partial dependence showed a continuous decrease in mean predicted CO₂ capacity from 5.114 to 4.363 mmol/g, with modest steepening around 6–7 wt% Fe rather than a universal threshold. An empirical-support-constrained 1000-trial Pareto search produced 27 nondominated candidates across CO₂-oriented, balanced and heavy-metal-oriented regimes. Seed and support-threshold diagnostics preserved broad objective coverage but showed that exact knee points and regime occupancy are stochastic. Because the dataset is synthetic and no reconciled external experiment is available, the outputs are computational hypotheses for separate or sequential validation.
Water depollution is an important issue for which interest has increased significantly in recent years. From the methods used to solve this problem, adsorption is the best method to remove pollutants from water. Biochar-based materials are sustainable adsorbent materials that can be produced by pyrolysis from wastes at low cost. This study is focused on the preparation and characterization of biochar materials from apple waste that are activated (A-ac) and further functionalized with metal oxides (iron and nickel oxides), as well as, the removal of pollutants from water through adsorption on these new materials. The metal oxides were synthesized through a green method using Urtica dioica L. plant extracts (ext). In previous studies it wasn't reported the use of apple waste biochar for dual-oxide functionalization using plant extracts, so we decided to research this new field. The prepared materials were characterized morphologically and compositionally through XRD, TEM, SEM, EDX, FTIR, and BET techniques. The prepared materials were preliminarily tested for the adsorption of drugs (ciprofloxacin, tetracycline, trimethoprim, paracetamol) and dye (tartrazine). This combination of pollutants that were tested also gives this study uniqueness, as in previous works these pollutants were studied separately or just a combination of two of them. From the preliminary adsorption tests was determined that the materials obtained with the plant extract that have the highest adsorption efficiency are: A-ac-Fe3O4-ext-1:2 for trimethoprim (94%) and paracetamol (88.67%), and A-ac-Fe3O4-NiO-ext-1:2:2 for tartrazine (90.60%), tetracycline (92.83%), and ciprofloxacin (57.65%). Overall, the A-ac-Fe3O4-1:2 material prepared without plant extract showed the best adsorption efficiency for ciprofloxacin (99.26%), tetracycline (94.54%), trimethoprim (99.33%), and paracetamol (96.86%). Even if the material prepared without plant extract demonstrated a better adsorption efficiency, the materials obtained by green synthesis are preferable. This preference is given because these green synthetized materials are harmless for the environment, present a comparable efficiency to the non-green ones, and the synthesis process uses a renewable raw material.
The rapid and accurate detection of Bacillus anthracis in drinking water is crucial from a public health and safety perspective. This study investigated the development of a cobalt-based metal-organic framework (Co-MOF) as a highly sensitive and selective fluorescence-based sensing platform for detecting dipicolinic acid (DPA), the unique biomarker of Bacillus anthracis. The Co-MOF was synthesized via a hydrothermal method and characterized using FESEM, EDX, FTIR, XRD, and TGA. Analytical evaluation demonstrated excellent performance, exhibiting a linear range from 0 to 100 μM (R2 = 0.98), with a remarkably low limit of detection of 0.089 μM and a limit of quantification of 0.271 μM. The effect of various parameters was investigated, and the results showed that the best detection occurred at pH of 7, Co-MOF concentration of 50 mg/L, contact time of 1 min, and DPA concentration of 50 μM. Also, the Co-MOF exhibited high selectivity for DPA against common drinking water ions and demonstrated storage stability for up to 90 days at room temperature. To assess practical applicability, a comprehensive diagnostic validation study was conducted, in which the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the Co-MOF for detecting Bacillus anthracis were 92%, 95.6%, 95.8%, 91.6%, and 93.75%, respectively. Based on these results, the synthesized Co-MOF can be used as a rapid, cost-effective, and highly reliable tool for sensing Bacillus anthracis in real water samples, with good selectivity and stability.
Skin wound healing is a complex, highly orchestrated biological process that often fails in pathological conditions such as diabetes, leading to chronic wounds with substantial global economic burdens. While conventional wound management strategies, including debridement, autografts, and topical drugs, remain the clinical standard, they exhibit significant limitations in treating chronic and infected wounds. This review critically synthesizes recent advancements in nano-architectures for wound healing, distinguishing itself by linking specific material properties to molecular-level healing mechanisms and clinical translational readiness. We systematically analyze biopolymer platforms reorganized by functional roles (structural support, moisture retention, hemostasis), and categorize nanomaterials into established systems (e.g., Ag, Au, ZnO) with strong in vivo evidence and emerging systems (e.g., CeO2, carbon-based structures) targeting specific pathophysiological barriers, such as the diabetic microenvironment. Advanced delivery platforms, including nanohydrogels, liposomes, niosomes, and electrospun nanofibers, are compared regarding encapsulation efficiency, stimuli-responsive release, and clinical practicality. Furthermore, we provide a critical evaluation of stimuli-responsive smart dressings, detailing their mechanisms in response to pH, ROS, temperature, and enzymatic cues. Unlike conventional narrative reviews, this work emphasizes long-term biosafety, nanotoxicity, biodistribution limitations, and manufacturing scalability. Concluding with a strategic translational roadmap, this review identifies the most promising nanoplatforms likely to achieve clinical validation within the next decade, offering a critical perspective for researchers and clinicians in advanced wound care.
The direct oxidation of methane to methanol (DOMTM) using H2O2 as oxidant and Cu/ZSM-5 in aqueous medium at 50 °C has emerged as a promising green alternative to conventional gas-phase stoichiometric processes. However, reliable catalytic benchmarking in this system remains limited by two methodological shortcomings: the lack of validated analytical protocols for comprehensive product quantification, and insufficient methodological guidance for accurately determining the fraction of the accessible metallic surface copper (Dcu) in Cu/ZSM-5 catalysts. In this work, both challenges are systematically addressed. Dcu was determined using a three-step sequential N2O oxidation-H2 temperature-programmed reduction (s-TPR) method, investigating the influence of key parameters on the results. Quantification of the complete oxidation product network, including methyl hydroperoxide, methanol, formaldehyde, formic acid, and dissolved CO2, was achieved through a combination of HPLC, quantitative 1H NMR spectroscopy, and potentiometric titration. Acetonitrile was identified as a more reliable internal standard for quantitative 1H NMR than the commonly employed 3-trimethylsilyl-1-propanesulfonic acid sodium salt (DSS). In addition, a novel alkaline back-trapping procedure is proposed for the quantification of dissolved CO2, which significantly improved accuracy compared with direct titration methods. Catalytic experiments employing pure intermediate oxygenated compounds (CH3OOH, HCHO, and HCOOH) as starting materials independently confirmed the sequential nature of the oxidation cascade and validated the proposed reaction network. Radical scavenger tests established that methanol is formed predominantly via direct ·CH3 + ·OH radical combination rather than through CH3OOH decomposition.
This study characterized the secondary metabolite profile and the antibacterial and antimethanogenic potential of R. tomentosa leaf extract using solvents of varying polarity: ethanol, ethyl acetate, and n-hexane. LC-HRMS was used to analyse chemical profiles, and antibacterial activity was evaluated using the agar disc diffusion assay against several pathogenic bacteria. Antibacterial and methane-mitigation potential in ruminants was discussed based on identified bioactive compounds. LC-HRMS showed that polar and semi-polar constituents, including phenolic acids, flavonoids, and bioactive polar lipids, were dominant in the ethanol extract. The ethyl acetate extract showed the highest metabolite diversity, dominated by pentacyclic triterpenoids and phenolics. In contrast, n-hexane extract was dominated by non-polar to semi-polar compounds, mainly from the terpenoid and sesquiterpene such as caryophyllene oxide, (E,E)-α-farnesene, and curcumene, with some triterpenoid derivatives. The agar disc diffusion assay showed that all extracts inhibited the growth of the Gram-positive bacteria Staphylococcus aureus and Listeria monocytogenes, whereas no inhibitory activity was observed against the Gram-negative bacteria Escherichia coli and Salmonella typhimurium. LC-HRMS analysis suggested that the antibacterial activity may arise from multicomponent interactions among triterpenoids, phenolics, flavonoids, volatile terpenoids, and bioactive lipids. LC-HRMS-based phytochemical characterization revealed a triterpenoid–phenolic–lipophilic metabolite profile that may contribute to application of R. tomentosa leaf extract as a natural antimethanogenic feed additive based on results of rumen fermentation in vitro..
A detailed density functional theory (DFT) investigation has been performed to explore the mechanism underlying the synthesis of functionalised dihydrocoumarin via [3 + 3] annulation of naphthoquinones and α, β unsaturated ketone and also to understand the role of NHC, base and thiourea in carrying out this reaction. Six distinct steps have been proposed for this reaction. Thiourea assisted Michael addition steps suggest that thiourea lowers the activation barrier. NCI analysis confirms the presence of hydrogen bonding. Overall, this study identifies the mechanism of NHC catalysed [3 + 3] annulation reaction and discloses the role of thiourea in it.
The development of stable and scalable biocontrol systems remains a major challenge for post-harvest protection of fresh produce. In this study, high–molecular weight chitosan beads (HMW-CB) were evaluated as immobilization matrices for Wickerhamomyces anomalus to enhance antifungal activity against Colletotrichum gloeosporioides and Rhizopus stolonifer. Three systems were compared, HMW-CB alone, HMW-CB loaded with cell-free supernatant, and HMW-CB containing whole yeast cells. In solid media, HMW-CB combined with whole cells significantly reduced radial growth and sporulation in both phytopathogens, while beads without biocontrol elements showed limited effects. Growth kinetics revealed early inhibition at 24 h for both fungi, with sustained suppression in C. gloeosporioides. In liquid culture, treatments containing whole cells caused severe hyphal alterations, including wall thinning and fragmentation, and reduced fungal biomass by up to 75%. Increasing bead number enhanced global inhibition, reaching 57% for C. gloeosporioides and 33% for R. stolonifer. Scanning electron microscopy confirmed effective yeast immobilization within a dense fibrillar chitosan matrix and the formation of a biofilm-like structure on the bead surface. In post-harvest assays, tomatoes treated with 9 HMW-CBs exhibited markedly reduced fungal colonization and preserved tissue integrity compared with untreated controls. These findings demonstrate that HMW-CB provide structural stabilization, sustained yeast viability, and prolonged antifungal activity. The integration of chitosan's physicochemical properties with the biological antagonism of W. anomalus represents a promising and scalable strategy for post-harvest fungal control.
Photocatalysis is an emerging and sustainable wastewater treatment technology that utilizes light and semiconductor catalysts to degrade hazardous organic pollutants into harmless compounds. Among various photocatalysts, silica nanoparticles (SiNPs) have shown promising potential due to their chemical stability, ecofriendly nature, and tunable surface properties. In this study, SiNPs were sustainably synthesized from natural sand via an energy-efficient alkaline fusion method assisted by microwave irradiation. This approach eliminated the need for prior acid leaching while significantly reducing synthesis time and energy consumption compared to conventional thermal fusion. As a result, SiO2 purity was upgraded from 77.52% in the raw sand to 94.34% in the SiNPs, leaving Al2O3 (3.82%) as the only detected metallic impurity. XRD and FTIR confirm that the as-prepared SiNPs retain a hybrid structure combining residual crystalline quartz and cristobalite domains within a predominant amorphous silica matrix (SBET = 65.48 m2/g), together with abundant surface silanol groups. The material exhibits a reduced optical band gap of approximately 3.55 eV, a value situated within the UV region and therefore mainly responsible for near-UV absorption; defect states associated with the amorphous fraction are proposed to extend light harvesting toward the near-visible edge. Under simulated solar irradiation (pH = 3), 20 mg of SiNPs achieved complete (100%) removal of 4.79 mg/L Rhodamine B within 30 min via a surface-mediated pseudo-first-order kinetic process (k1 = 0.080 min−1, R2 = 0.931). Scavenger experiments confirmed photogenerated holes as the primary active species driving direct oxidation. The catalyst exhibited excellent stability and recyclability over five degradation cycles, underscoring its suitability for practical environmental remediation. These findings highlight the potential of microwave-assisted synthesized SiNPs as economically viable, environmentally friendly photocatalysts for wastewater treatment, with future work targeting effectiveness in real wastewater matrices and scale-up optimization.
The development of efficient and cost-effective electrocatalysts for the hydrogen evolution reaction (HER) is critically important for sustainable hydrogen production. In this study, NiCo thin film electrocatalysts were fabricated using electrodeposition technique, and the role of sodium saccharin as an additive in tuning their structural and electrocatalytic properties was systematically investigated. X-ray diffraction analysis revealed that increasing saccharin concentration refined the NiCo microstructure, producing a defect-rich nanocrystalline alloy with reduced crystallite size and increased dislocation density and microstrain. These structural modifications significantly enhanced the electrochemically active surface area, as indicated by the increased double-layer capacitance. Among the prepared catalysts, Ni75Co25 exhibited the best HER activity, delivering a current density of 30.43 mA cm−2 at 0.5 V, a low overpotential of 253 mV, and a Tafel slope of 70 mV dec−1, together with the highest ECSA and lowest Rct. The enhanced catalytic performance follows a Volmer–Heyrovsky mechanism and is attributed to the synergistic effects of defect-engineered nanostructure, optimized NiCo composition, and increased exposure of electrochemically active sites. These results highlight additive-assisted electrodeposition as an effective strategy for tailoring NiCo thin films for efficient hydrogen evolution reaction.
A series of deep eutectic solvents (DESs) with NaHCO3 as hydrogen bond acceptor and glycerol (GL) or ethylene glycol (EG) as hydrogen bond donor are prepared and used as catalyst for the synthesis of glycerol carbonate (GC) from the transesterification of GL and propylene carbonate (PC). FT-IR, NMR, TGA and DSC are used for the characterization of the physicochemical properties of prepared DESs. The effects of reaction temperature, PC to GL molar ratio, catalyst amount, and reaction time on the GL conversion and GC yield are investigated in detail. The results show that NaHCO3:GL (1:5) DES possesses the highest catalytic activity, which is attributed to the hydrogen bond network structure between NaHCO3 and GL as well as the interaction between NaHCO3:GL DES and reactants GL or PC. Under 135 °C, PC/GL molar ratio of 2:1, catalyst amount of 5 wt% (based on the GL weight), and reaction time of 4 h, the GL conversion of 99.99% and GC yield of 99.54% are obtained. NaHCO3:GL (1,5) DES can be reused five times with no obvious decline in activity. Based on the experimental results and FT-IR analysis, the reaction mechanism of transesterification of GL and PC using NaHCO3:GL (1,5) as catalyst is proposed. To the best of our knowledge, this is the first report about the application of DES catalyst for the reaction of GL and PC.
