Search Results (110)

Metal–organic frameworks (MOFs) exhibit high specific surface area and porosity, which may facilitate electron transfer during electrochemical reactions. Therefore, it is clear that MOFs are promising materials for the development of electrochemical sensors. In particular, zinc (Zn) based MOFs offer several advantages such as high specific surface area, porosity, environmental friendliness and low cost. Thus, Zn-based MOF materials and their composites have been extensively utilized in the detection of various pollutants, biomolecules and food additives. The Zn-MOF-based materials have been extensively utilized in electrochemical and fluorescence sensing applications. Previously, various Zn-MOF-based sensing systems such as pristine Zn-MOF, carbon-supported Zn-MOF composites, MXene hybrids with Zn-MOF, and bimetallic/trimetallic Zn-based MOFs were explored to enhance sensing performance. Such materials exhibit remarkable analytical performance, such as a low limit of detection (LOD) (nM to pM range), wide linear response range (LR), fast response times, and high selectivity in the presence of interfering species. In electrochemical sensing, Zn-MOF-modified electrodes demonstrated improved charge-transfer kinetics and sensitivity, enabling accurate determination of the biomolecules, drugs and heavy metal ions in real samples. Similarly, Zn-MOF-based fluorescence sensors showed high luminescent properties and displayed sensitive detection of pollutants and biomolecules. Despite such promising sensing performances, some challenges, such as low stability, reproducibility and selectivity in real-time monitoring, etc., remain that need to be overcome. This review article summarizes the previously reported literature on the fabrication of Zn-MOFs, their composites and Zn-MOF-derived materials for the development of electrochemical and fluorescence sensors. We have also discussed the future directions for the rational design of the high-performance Zn-MOF-based sensing systems for environmental and biomedical applications. We believe that the present review article would be useful for the scientific community working on the fabrication of Zn-MOF-based sensors. Full article

Developing bifunctional non-noble metal electrocatalysts with high activity, stability, and cost-effectiveness is essential for large-scale sustainable water splitting, yet remains challenging. Herein, 2P-FeCoNi-MOF was synthesized via hydrothermal reaction of FeCoNi-LDH followed by phosphidation. Its layered structure, integrated with 3D nickel foam, creates a hierarchical porous architecture that increases surface area and accelerates electron transport. Synergistic effects among Fe, Co, Ni in the trimetallic phosphides, together with an amorphous carbon layer, boost catalytic performance. Moreover, superhydrophilic and superaerophobic surfaces enhance mass transfer. In 1 M KOH, 2P-FeCoNi-MOF achieves low overpotentials of 70 mV for HER and 225 mV for OER at 10 mA cm⁻², with excellent stability for 100 h at 100 mA cm⁻². For the overall water splitting, it requires only 1.54 V to reach 10 mA cm⁻² and maintains stability for 100 h at 100 mA cm⁻². Therefore, this study provides a new approach for the preparation of high-performance self-supported non-noble metal-based electrocatalysts for water splitting. Full article

The development of highly sensitive and reliable strategies for microcystin-LR (MC-LR) monitoring remains critical for environmental safety and public health protection. Herein, we report a metallene-enabled electrochemiluminescence (ECL) biosensing platform based on ultrathin PdMoCu trimetallic metallenes for femtogram-level MC-LR detection. The two-dimensional PdMoCu metallenes provide abundant active sites and accelerated interfacial charge-transfer kinetics through synergistic electronic modulation among Pd, Mo, and Cu atoms, significantly enhancing the Ru(bpy)₃²⁺/TPrA ECL efficiency. By integrating a programmable H1–aptamer duplex interface, electrostatic enrichment of Ru(bpy)₃²⁺ was achieved, enabling target-responsive luminophore release via aptamer-triggered structural switching. This cooperative amplification mechanism, combining catalytic acceleration and DNA-mediated signal modulation, results in a sensitive signal-off detection mode. Under optimized conditions, the biosensor exhibited a wide linear response from 0.1 pg mL⁻¹ to 50 ng mL⁻¹ with a detection limit as low as 37 fg mL⁻¹. The platform demonstrated excellent selectivity against structural analogues, high reproducibility, and satisfactory recovery (99.3–102.0%) in real tap water samples. This work not only highlights the catalytic potential of trimetallic metallenes in ECL systems but also establishes a generalizable interfacial engineering strategy for ultrasensitive detection of trace environmental contaminants. Full article

The PGM-free Fe–Ni–Co trimetallic catalysts developed in this study demonstrated outstanding performance for the oxygen evolution reaction (OER), achieving overpotentials as low as 300 mV at 10 mA cm⁻² in rotating disk electrode (RDE) measurements, a value competitive with the most efficient non-noble electrocatalysts reported in the literature. This study validates the strong catalytic performance of the baseline trimetallic configuration and provides important insights into the relationships among synthesis, structure, and morphology that govern catalyst activity. In particular, the findings highlight that although organic additives can be promising modifiers, the interaction between precursors and transition metals must be carefully controlled to avoid active-site isolation when designing efficient catalysts for sustainable hydrogen production. Actually, to further enhance catalytic activity, the nitrogen-rich precursor melamine was introduced into the supported trimetallic catalyst and then carbonized. However, no improvement in OER performance was observed. During carbonization, melamine promotes the formation of tip-growth carbon nanotubes, which mechanically disrupt the catalyst structure and degrade the supported active phase. Full article

Growing interest in sustainable, high-performance energy storage has driven extensive studies on advanced electrode materials for supercapacitor applications. In this study, a FeNiCo metal–organic framework/multiwalled carbon nanotube (MOF–MWCNT) composite was synthesized and employed as a modifying layer on a carbon felt electrode (CFE) via a drop-casting method. The electrochemical performance of the composite electrode was systematically evaluated in 1 M H₂SO₄ electrolyte. Structural and electrochemical studies demonstrate that the combined effect of the conductive CFE substrate, the electric double-layer capacitance of MWCNTs, and the pseudocapacitive properties of the trimetallic FeNiCo MOF markedly enhances the charge storage performance. Cyclic voltammetry and galvanostatic charge–discharge measurements demonstrate a maximum specific capacitance of approximately 180 F g⁻¹. The electrode delivers an energy density of 73.20 Wh kg⁻¹ at a power density of 3796.17 W kg⁻¹, demonstrating a favorable balance between energy and power performance. In addition, high coulombic efficiency confirms excellent charge–discharge reversibility. Notably, 71% of the initial capacitance is retained after 900 cycles in 1 M H₂SO₄, indicating stable electrochemical behavior even under strongly acidic conditions. These findings emphasize the promise of the FeNiCo MOF–MWCNT/CFE composite as a durable electrode design for next-generation supercapacitor devices. Full article

Transition metal oxides (TMOs) have been recognized as highly prospective anode materials for lithium-ion batteries (LIBs) due to their low cost, high capacity, and distinctive lithiation mechanisms. Nevertheless, their practical adoption is constrained by significant volume changes during lithiation/delithiation, inferior electrical conductivity, severe particle agglomeration, unsatisfactory cycling stability, and limited rate performance. In an effort to mitigate these flaws, we developed a tactic employing a zeolitic imidazolate framework (ZIF) as the self-sacrificing template and tuning the Co/Fe/Ni ratio with a ZIF framework to prepare an innovative trimetallic metal–organic framework (MOF)-derived CoNiO₂/NiCo₂O₄/NiFe₂O₄ compound (CFNO422) with nano/micro hierarchical architecture. The nano/micro hierarchical structure effectively accommodates volume changes, alleviates structural stress, and offers copious active sites for lithium storage. More importantly, the synergistic interaction among multiple component oxides promotes richer redox reactions and enhances electronic conductivity. Benefiting from the structural compatibility and composition, CFNO422 delivers an outstanding reversible capacity (1301.3 mAh g⁻¹ up to 120 cycles at 0.2 A g⁻¹), enhanced rate capability (614.3 mAh g⁻¹ even at 2.0 A g⁻¹), and exceptional cycling stability (527.4 mAh g⁻¹ over 600 cycles at 1.0 A g⁻¹). This research proposes a versatile synthesis for MOF-derived polymetallic oxides as anode materials, opening a new avenue for advanced energy storage. Full article

The influence of potassium oxide (K₂O) doping on the hydrodeoxygenation (HDO) performance of trimetallic CoMo–Ni/Al₂O₃ catalysts was systematically investigated using guaiacol as a lignin-derived model compound. Catalysts containing 0, 1, 3, and 5 wt% K₂O were synthesized and characterized by SEM-EDS, N₂ physisorption, XRD, FTIR, and HRTEM. SEM micrographs showed homogeneous morphologies with no significant agglomeration, while EDS analysis confirmed elemental compositions close to nominal values, with K₂O contents increasing proportionally and maintaining uniform surface distribution. Adsorption–desorption isotherms confirmed mesoporous structures with specific surface areas ranging from 258 to 184 m² g⁻¹, decreasing with increasing K₂O loading. XRD revealed γ-Al₂O₃, NiO, (NH₄)₃[CoMo₆O₂₄H₆]·7H₂O, and K₂O phases, with slight peak shifts indicating surface modification rather than lattice incorporation of K⁺. FTIR spectra evidenced characteristic polyoxomolybdate vibrations and metal–oxygen interactions with alumina. HRTEM revealed MoS₂ slab lengths between 1.85 and 2.51 nm, stacking numbers from 2.08 to 3.17, and Mo edge-to-corner ratios (f_e/fc) between 1.39 and 2.43, corresponding to dispersions of 0.45–0.57. Guaiacol conversion remained high (≥95%) for all catalysts, while HDO selectivity strongly depended on K₂O content. At 5 wt% K₂O, cyclohexane selectivity reached 81.3% with an HDO degree of 65%, compared to 52.0% and 31% for the undoped catalyst. Pseudo-first-order kinetic analysis revealed that potassium promotes demethylation and demethoxylation steps while suppressing rearrangement pathways, steering the reaction network toward direct deoxygenation. These results demonstrate that K₂O acts as an efficient structural and electronic promoter, enabling precise control of HDO selectivity without compromising catalytic activity. Full article

The present study involves the synthesis of polyvinylpyrrolidone (PVP)-stabilized iron-based trimetallic nanoparticles with different metal addition sequences (Fe/Ag/Zn, Fe/Zn/Ag and Fe/(Zn/Ag)) using the sodium borohydride reduction method. In order to investigate the catalytic reactivity of the nanoparticles, a series of batch experiments were performed using methyl orange dye as a model pollutant. It was found that the Fe/Ag/Zn system showed the maximum catalytic activity compared to the other studied trimetallic systems. About 100% of the methyl orange dye was removed within 1 min and the second-order rate constant obtained was 0.0744 (mg/L)⁻¹ min⁻¹; the rate of reaction was higher than that of the other trimetallic systems. Furthermore, the effects of pH, initial dye concentration and nanoparticle dosage on the degradation of methyl orange were investigated. The results showed that the reactivity of the Fe/Ag/Zn trimetallic nanoparticles was highly dependent on the aforementioned parameters. Higher reactivity was obtained at lower pH, lower initial methyl orange dye concentration and higher nanoparticle dosage. Lastly, liquid chromatography–mass spectroscopy (LC-MS) was used to elucidate the reaction pathway and identify by-products from methyl orange degradation. The developed catalyst demonstrated exceptionally rapid and apparent degradation of methyl orange within one minute, outperforming previously reported bimetallic and trimetallic systems. This work reports a cost-effective nZVI-based trimetallic system containing minimal silver, which shows promising reactivity toward azo dye degradation and may be suitable for future application in textile wastewater treatment. Full article

The microbial resistance era prompts researchers to find new effective antimicrobial agents. Trimetallic nanocomposites consisting of AuAg nanostructures and iron oxide nanoparticles can represent an efficient tool to inhibit bacterial growth as demonstrated here. The trimetallic nanocomposites, prepared by green chemistry approach, are grafted on a modified, plasma-treated, flexible polyethylene terephthalate (PET) substrate. Spectroscopic and microscopic characterization of the trimetallic nanocomposites grafted on modified PET together with antibacterial tests confirm the successful applicability of the newly developed material: a statistically significant antibacterial effect against E. coli is proven. This effect is further pronounced by a short time (5 min) UVA light (365 nm) irradiation. The present work thus reports on the feasible preparation of the brand-new material that is successfully used in E. coli colony growth regulations. The impact of small noble metal nanostructures containing Ag and UVA light-activated iron oxide particles on the bacterium can be combined and results in the improved antibacterial performance of the final material. Employing such material may represent a potential strategy for fighting against the development of bacteria resistance. Full article

This study presents a comprehensive atomistic investigation of the structural, mechanical, and thermal properties of Pd₆₀Ir_nRh_19−n trimetallic nanoclusters adopting a truncated octahedral geometry. The compositional evolution of chemical ordering, local pressure distributions, and melting behavior was systematically analyzed using Gupta potential-based basin-hopping global optimization. The accuracy of the Gupta potential predictions was further validated for all configurations using density functional theory (DFT) calculations. The surface layer consisted solely of Pd atoms and was held constant throughout the study. Meanwhile, Ir and Rh atoms were distributed within the 19-atom core region, allowing a detailed evaluation of how variations in core composition affect the energetic and thermal stability of the clusters. The Pd₆₀Ir₆Rh₁₃ configuration exhibits the minimum value of mixing energy, corresponding to the most symmetric and energetically stable atomic arrangement. Local pressure analyses showed that Ir incorporation enhances internal compressive stress and induces tensile relaxation on the Pd surface, achieving an optimal strain balance at n = 6. Melting analyses based on caloric curves and Lindemann indices revealed a non-monotonic dependence of melting temperature on Ir content, with Ir-rich clusters displaying the highest thermal resistance and Rh-rich systems showing reduced stability. These findings clarify how Ir/Rh distribution governs the energetic, mechanical, and thermal response of Pd–Ir–Rh nanoalloys, offering a coherent atomistic framework for understanding their composition-dependent stability. Full article

Metal nanoparticles (NPs) with enzyme-mimicking activities, known as nanozymes, are being actively explored for biomedical and analytical applications. Enhancing their catalytic activity and metal utilization efficiency is crucial for advancing these technologies. Here, we report an aqueous-phase, room-temperature synthesis of tetra-metallic Au@Ag-Pd-Pt NPs that exhibit superior peroxidase-like activity compared to their mono-, bi-, and trimetallic counterparts. The synthesis involves a sequential, seed-mediated approach comprising the formation of Au NP seeds, the overgrowth of a Ag shell, and the galvanic replacement of Ag with Pd and Pt ions. We systematically investigated the effects of the Au core diameter (15, 40, 55 nm), Ag precursor concentration (50–400 µM), and the Pd-to-Pt ratio on the optical and catalytic properties. By changing the particle composition, we were able to tune the absorbance maximum from 520 nm to 650 nm while maintaining high extinction coefficients (10⁹–10¹⁰ M⁻¹cm⁻¹) comparable to that of the initial Au nanoparticles. Mapping of chemical element distributions in the nanoscale range confirmed a core–shell–shell architecture with surface-enriched Pd and Pt. This structure ensures the surface-exposed localization of catalytically active atoms, yielding a more than 10-fold improvement in specific peroxidase-like activity while utilizing up to two orders of magnitude less Pt and Pd than bimetallic particles. The synthesized NPs thus combine high catalytic activity with tunable optical properties, making them promising multifunctional labels for biosensing. Full article

The present work aims to synthesize trimetallic catalysts supported on mixed oxides such as Al₂O₃-TiO₂. These mixed oxides have been synthesized via the hydrothermal method, which enables us to determine the favorable textural properties that facilitate the oxide in achieving a high dispersion of the NiMoWS active phase. The synthesis of NiMoW supported on Al₂O₃-TiO₂ with varying morphological characteristics presents a wide range of research opportunities related to catalysts for HDS. The knowledge generated by the proposed parametric studies will be essential in establishing a scientific basis for preparing catalysts with suitable properties in this field. Moreover, this study provides two key contributions to the field of hydrotreating catalysis. First, we demonstrate that hydrothermal synthesis assisted by Triton X-100 enables the formation of Al₂O₃–TiO₂ nanostructures with controlled defect density and Ti distribution, features not attainable through conventional sol–gel or mechanical mixing methods. Second, we show that these defect-rich mixed oxides uniquely modulate the dispersion and electronic structure of NiMoW sulfide phases, revealing a nonlinear dependence of activity on W incorporation. These findings offer new guidelines for the rational design of mixed oxide supports for deep hydrotreating applications. Full article

The increasing demand for sustainable chemical processes has fostered the development of advanced catalytic systems for biomass valorization. In this work, a series of mono-, bi-, and trimetallic oxides (FeO, FeCuO, FeZnO, and FeCuZnO) were successfully synthesized using MIL-101-based MOFs as sacrificial templates. The obtained materials were thoroughly characterized by N₂ adsorption–desorption, XRD, FTIR, and TEM/STEM-EDX to investigate their structural, morphological, and textural properties. Their catalytic performance was evaluated in the selective oxidation of benzyl alcohol, a lignin-derived platform molecule, into benzaldehyde under microwave irradiation as a sustainable heating strategy. The results demonstrate that MOF-derived oxides exhibit superior activity compared to their parent MOFs, highlighting the beneficial effect of thermal treatment on the exposure of active sites. Among the catalysts, heterometallic oxides showed enhanced performance due to synergistic effects between metals. In particular, FeZnO reached a maximum yield of 62.1% towards benzaldehyde at 150 °C and 30 min, outperforming the monometallic oxide. Recycling tests revealed that FeZnO retained higher overall performance than FeCuO, which suffered from progressive copper leaching. These findings confirm the potential of MOF-derived multimetallic oxides as efficient and reusable heterogeneous catalysts for selective biomass-derived alcohol oxidation. The combination of microwave-assisted processes and the tuneable nature of MOF-derived oxides provides a promising pathway for designing sustainable catalytic systems with industrial relevance. Full article

Nickel-based metal–organic frameworks (Ni-MOFs) have received enormous amounts of attention from the scientific community due to their excellent porosity, larger specific surface area, tunable structure, and intrinsic redox properties. In previous years, Ni-MOFs and their hybrid composite materials have been extensively explored for electrochemical sensing applications. As per the reported literature, Ni-MOF-based hybrid materials have been used in the fabrication of electrochemical sensors for the monitoring of ascorbic acid, glucose, L-tryptophan, bisphenol A, carbendazim, catechol, hydroquinone, 4-chlorophenol, uric acid, kaempferol, adenine, _L-cysteine, etc. The presence of synergistic effects in Ni-MOF-based hybrid materials plays a crucial role in the development of highly selective electrochemical sensors. Thus, Ni-MOF-based materials exhibited enhanced sensitivity and selectivity with reasonable real sample recovery, which suggested their potential for practical applications. In addition, Ni-MOF-based hybrid composites were also adopted as electrode modifiers for the development of supercapacitors. The Ni-MOF-based materials demonstrated excellent specific capacitance at low current densities with reasonable cyclic stability. This review article provides an overview of recent advancements in the utilization of Ni-MOF-based electrode modifiers with metal oxides, carbon-based materials, MXenes, polymers, and LDH, etc., for the electrochemical detection of environmental pollutants and biomolecules and for supercapacitor applications. In addition, Ni-based bimetallic and trimetallic catalysts and their composites have been reviewed for electrochemical sensing and supercapacitor applications. The key challenges, limitations, and future perspectives of Ni-MOF-based materials are discussed. We believe that the present review article may be beneficial for the scientific community working on the development of Ni-MOF-based materials for electrochemical sensing and supercapacitor applications. Full article