Single-Atom Ru Alloyed with Ni Nanoparticles Boosts CO2 Methanation.

Designing catalysts to proceed with catalytic reactions along the desired reaction pathways, e.g., CO2 methanation, has received much attention but remains a huge challenge. This work reports one Ru1Ni single-atom alloy (SAA) catalyst (Ru1Ni/SiO2) prepared via a galvanic replacement reaction between RuCl3 and Ni nanoparticles (NPs) derived from the reduction of Ni phyllosilicate (Ni-ph). Ru1Ni/SiO2 achieved much improved selectivity toward hydrogenation of CO2 to CH4 and catalytic activity (Turnover frequency (TOF) value: 40.00 × 10-3 s-1), much higher than those of Ni/SiO2 (TOF value: 4.40 × 10-3 s-1) and most reported Ni-based catalysts (TOF value: 1.03 × 10-3-11.00 × 10-3 s-1). Experimental studies verify that Ru single atoms are anchored onto the Ni NPs surface via the Ru1-Ni coordination accompanied by electron transfer from Ru1 to Ni. Both in situ experiments and theoretical calculations confirm that the interface sites of Ru1Ni-SAA are the intrinsic active sites, which promote the direct dissociation of CO2 and lower the energy barrier for the hydrogenation of CO* intermediate, thereby directing and enhancing the CO2 hydrogenation to CH4.

Revealing the Kinetic Balance between Proton-Feeding and Hydrogenation in CO2 Electroreduction.

Electrocatalytic reduction of CO2 to high-value-added chemicals provides a feasible path for global carbon balance. Herein, the fabrication of NiNP x @NiSA y -NG (x,y = 1, 2, 3; NG = nitrogen-doped graphite) is reported, in which Ni single atom sites (NiSA ) and Ni nanoparticles (NiNP ) coexist. These NiNP x @NiSA y -NG presented a volcano-like trend for maximum CO Faradaic efficiency (FECO ) with the highest point at NiNP2 @NiSA2 -NG in CO2 RR. NiNP2 @NiSA2 -NG exhibited ≈98% of maximum FECO and a large current density of -264 mA cm-2 at -0.98 V (vs. RHE) in the flow cell. In situ experiment and density functional theory (DFT) calculations confirmed that the proper content of NiSA and NiNP balanced kinetic between proton-feeding and CO2 hydrogenation. The NiNP in NiNP2 @NiSA2 -NG promoted the formation of H* and reduced the energy barrier of *CO2 hydrogenation to *COOH, and CO desorption can be efficiently facilitated by NiSA sites, thereby resulting in enhanced CO2 RR performance.

Reactivation of Ni-TiO2 catalysts in hydrogen flow and in supercritical 2-propanol-Comparative study by electron spin resonance in situ.

Highly dispersed Ni-TiO2 catalyst has been studied in the process of preparation and under catalytic transfer hydrogenation reaction conditions in supercritical 2-propanol (250°C, 70 bar) using electron spin resonance in situ. Electron spin resonance in situ has been used to study the process of the catalyst passivation and subsequent reduction of the oxide layer in the gas flow. Reduction of the NiO layer on the surface of passivated Ni nanoparticles has been detected in supercritical 2-propanol, which is in agreement with kinetic modeling data. It has been found that the reduction of the nickel oxide layer in supercritical 2-propanol occurs at a lower temperature compared with the reduction in hydrogen flow, according to in situ electron spin resonance study.

A-site deficient La0.52Sr0.28Ti0.94Ni0.06O3by low-pulsed electric current treatment: achieved exsolution of B-site Ni nanoparticles and significant improvement of electrocatalytic properties.

Perovskite materials with exsolved nanoparticles have a wide range of applications in energy conversion systems owing to their unique basal plane active sites and excellent catalytic properties. The introduction of A-site deficiency can help the formation of highly mobile oxygen vacancies and remarkably enhance the reducibility of Ni nanoparticles, thus significantly increasing electronic conductivity and catalytic activity simultaneously. Herein, we adopt pulsed electric current (PEC) treatment, a novel approach instead of the long-time high-temperature reduction technique, and for the first time review that the exsolution of minuscule Ni nanoparticles (8-20 nm) could be facilitated on Ni-doped La0.52Sr0.28Ti0.94Ni0.06O3(LSTN) anodes with A-site deficiency. Encouragingly, finding that low PEC can successfully lead to nanoparticle exsolution and show a significantly improved oxygen evolution reaction performance of LSTN-PEC (LSTN after PEC treatment) possessing A-site deficiency, the onset potential of LSTN-PEC (500 V) (LSTN after PEC treatment with 500 V-4 Hz-90 s) was advanced by 0.173 V, theRctvalue was reduced by 82.38 Ω·cm2, and the overpotential was also reduced by 73 mV.

Sponge Assembled by Graphene Nanocages with Double Active Sites to Accelerate Alkaline HER Kinetics.

Elaborate design of novel hybrid structures for hydrogen-evolution electrocatalysts is a crucial strategy for synergistically accelerating the reaction kinetics of water splitting. Herein, we prepare a three-dimensional (3D) sponge assembled by graphene nanocages (SGNCs) in which Ni nanoparticles and Ni single atoms coexist via a facile one-pot self-templating and self-catalytic strategy. Driven by simultaneous atomization and agglomeration under higher temperature, dual active sites of single atoms and nanoparticles are formed on graphene nanocages. Benefiting from the unique 3D porous structure and dual active sites, the SGNCs exhibit excellent hydrogen evolution reaction (HER) performance, which affords the current density of 10 mA cm-2 at a low overpotential of 27 mV. Theoretical calculations reveal that the interaction between single atoms and nanoparticles promotes HER kinetics. The controlled engineering strategy of non-noble metal-based hybrid materials provides prospects for innovative electrocatalyst development.

Carbon Microsphere-Supported Metallic Nickel Nanoparticles as Novel Heterogeneous Catalysts and Their Application for the Reduction of Nitrophenol.

Nickel nanoparticles are gaining increasing attention in catalysis due to their versatile catalytic action. A novel, low-cost and facile method was developed in this work to synthesize carbon microsphere-supported metallic nickel nanoparticles (Ni-NP/C) for heterogeneous catalysis. The synthesis was based on carbonizing a polystyrene-based cation exchange resin loaded with nickel ions at temperatures between 500 and 1000 °C. The decomposition of the nickel-organic framework resulted in both Ni-NP and carbon microsphere formation. The phase composition, morphology and surface area of these Ni-NP/C microspheres were characterized by powder X-ray diffraction, Raman spectroscopy, scanning electron microscopy and BET analysis. Elemental nickel was found to be the only metal containing phase; fcc-Ni coexisted with hcp-Ni at carbonization temperatures between 500 and 700 °C, and fcc-Ni was the only metallic phase at 800-1000 °C. Graphitization and carbon nanotube formation were observed at high temperatures. The catalytic activity of Ni-NP/C was tested in the reduction of 4-nitrophenol to 4-aminophenol by sodium borohydride, and Ni-NP/C was proved to be an efficient catalyst in this reaction. The relatively easy and scalable synthetic method, as well as the easy separation and catalytic activity of Ni-NP/C, provide a viable alternative to existing nickel nanocatalysts in future applications.

Single-Step Formation of Ni Nanoparticle-Modified Graphene-Diamond Hybrid Electrodes for Electrochemical Glucose Detection.

The development of accurate, reliable devices for glucose detection has drawn much attention from the scientific community over the past few years. Here, we report a single-step method to fabricate Ni nanoparticle-modified graphene-diamond hybrid electrodes via a catalytic thermal treatment, by which the graphene layers are directly grown on the diamond surface using Ni thin film as a catalyst, meanwhile, Ni nanoparticles are formed in situ on the graphene surface due to dewetting behavior. The good interface between the Ni nanoparticles and the graphene guarantees efficient charge transfer during electrochemical detection. The fabricated electrodes exhibit good glucose sensing performance with a low detection limit of 2 µM and a linear detection range between 2 µM-1 mM. In addition, this sensor shows great selectivity, suggesting potential applications for sensitive and accurate monitoring of glucose in human blood.

Reductive transformation of profenofos with nanoscale Fe/Ni particles.

Profenofos is an abundantly used organophosphate pesticide in agriculture but its excessive use may lead to hazardous effects on environment. Thus, the present study focused on the reductive transformation of this pesticide in the presence of Fe/Ni bimetallic nanoparticles by optimizing the process parameters such as stirring time, nanoparticles dose, pH, and initial pesticide concentration. The results of reductive transformation were compared with photodegradation studies. It was found that with the increase in UV irradiation time, the percent degradation was increased. After 660 min, a 78% photodegradation of 100 µM solution of pesticide was observed. On increasing the initial pesticide concentration to 200 µM, the maximum degradation was achieved in 570 min, but here, only 73% degradation was observed. The rates of photodegradation observed with 100 to 400 µM solutions were 1.4 × 10-3, 1.5 × 10-3, 1.5 × 10-3, and 5 × 10-4 min-1 respectively.In case of reductive transformation carried out in the presence of Fe/Ni bimetallic nanoparticles, the degradation was observed to be increased from 78 to 93.9% in only 180 min. A further increase in pesticide concentration led to a decrease in degradation. Under these conditions, the rate of reaction was found to be 1.09 × 10-2 min-1. A 93% degradation of profenofos was further increased to 98% when the quantity of nanoparticles was increased twice; hence, a significant reduction in time of irradiation was observed. Reductive transformation of pesticide thus provided an efficient and cheaper method for reducing the burden of profenofos from the environment.

Microstructure and Electro-Physical Properties of Sn-3.0Ag-0.5Cu Nanocomposite Solder Reinforced with Ni Nanoparticles in the Melting-Solidification Temperature Range.

The electrical conductivity of nanocomposite Sn-3.0Ag-0.5Cu alloys with two different weight percentages of Ni nanoparticles (1.0 and 2.0 wt.%) was measured over a wide temperature range. The samples were produced using a cold pressing method: Sn-3.0Ag-0.5Cu powder and Ni nanopowder were mechanically mixed and pressed into 8 mm diameter rods. Ni nanoparticles were synthesized via a chemical reduction method and characterized by a core/shell structure. Temperature dependencies of the electrical conductivity revealed a hysteresis between the heating and cooling curves in a wide temperature range above the melting temperature. This fact is connected with structure transformations accompanied by a dissolution of Ni nanoparticles, which should be retarded due to an oxide/hydroxide shell on the surface of the nanoparticles. A microstructure analysis of the samples in the solid state showed a fine distribution of intermetallic compounds in the Sn-based matrix. The Ni atoms substituted for Cu atoms in the Cu6Sn5 compound forming a (Cu,Ni)6Sn5 phase.

Dielectric Barrier Plasma Discharge Exsolution of Nanoparticles at Room Temperature and Atmospheric Pressure.

Exsolution of metal nanoparticles (NPs) on perovskite oxides has been demonstrated as a reliable strategy for producing catalyst-support systems. Conventional exsolution requires high temperatures for long periods of time, limiting the selection of support materials. Plasma direct exsolution is reported at room temperature and atmospheric pressure of Ni NPs from a model A-site deficient perovskite oxide (La0.43Ca0.37Ni0.06Ti0.94O2.955). Plasma exsolution is carried out within minutes (up to 15 min) using a dielectric barrier discharge configuration both with He-only gas as well as with He/H2 gas mixtures, yielding small NPs (<30 nm diameter). To prove the practical utility of exsolved NPs, various experiments aimed at assessing their catalytic performance for methanation from synthesis gas, CO, and CH4 oxidation are carried out. Low-temperature and atmospheric pressure plasma exsolution are successfully demonstrated and suggest that this approach could contribute to the practical deployment of exsolution-based stable catalyst systems.

Efficient composite chlorinated ethenes removal using gallic acid to enhance Fe/Ni nanoparticles activated persulfate.

As the representative volatile chlorinated hydrocarbons detected in wastewater, the removal of composite chlorinated ethenes is a major challenge in wastewater treatment. In the present study, an efficient removal system for composite chlorinated ethenes was reported, in which gallic acid was used to enhance the activation of persulfate by Fe/Ni nanoparticles. The influences of gallic acid-Fe/Ni and persulfate concentrations, initial pH value, reaction temperature, inorganic anions, and natural organic matters were evaluated in the composite chlorinated ethenes removal. Our results showed that the gallic acid-Fe/Ni-persulfate system with 9.0 mM of gallic acid-Fe/Ni and 30.0 mM of persulfate yielded about 100% trichloroethylene removal and 97.3%-98.6% perchloroethylene removal in the pH range of 3.0-12.0. Electron paramagnetic resonance analysis and radical quenching experiments indicated that SO4•- and •OH were the predominant radical species under acidic and alkaline conditions. Ultraviolet visible spectroscopy and inductively coupled plasma optical emission spectrometer tests revealed the Fe-gallic acid chelation could regulate the concentration of iron ions and improve the reactivity of gallic acid-Fe/Ni. These results demonstrated that the gallic acid-Fe/Ni-persulfate system was a promising strategy for treating composite chlorinated ethenes-containing wastewater.

Sonochemical decomposition effects of nickelocene aiming for low-temperature and dispersant-free synthesis of nickel fine particle.

Sonochemical decomposition effects of nickelocene, which sublimates easily were investigated to synthesize dispersant-free nickel fine particles at low temperature. In a hydrazine monohydrate and 2-propanol mixed solvent, the reduction of nickelocene was promoted by ultrasound irradiation, and nickel fine particles were synthesized while precluding the sublimation of nickelocene. Unlike the common hydrazine reduction of nickel salts, which requires multiple-step reactions, nickelocene was reduced directly without forming intermediates. The effect of the water-bath temperature (20-60 °C) was investigated, where larger fine particles were synthesized using a higher water-bath temperature (60 °C). When irradiated at 20 °C, the reduction rate of nickelocene was low, leading to the formation of nickel fine particles and organic nanoparticles via the reduction and decomposition of nickelocene. The ultrasound frequency was also investigated, where fine nickel particles were synthesized using low-frequency ultrasound irradiation. The formation of high-temperature hotspots led to the diffusion and growth of nickel on the surface of the nickel fine particles; therefore, raspberry-like nickel fine particles were synthesized. In this study, the difficult-to-handle nature of nickelocene, owing to its sublimation properties, was easily overcome by ultrasound irradiation. Instantaneous and localized reactions at hotspots contributed to inhibiting particle growth. Furthermore, Ni fine particles were synthesized via a direct reduction pathway, which differs from previous reactions. This method represents a new, dispersant-free, low-temperature process for synthesizing Ni fine particles.

Zinc Vaporization Induced Formation of Desired Ni Nanoparticles Coated with Ultrathin Carbon Shells for Efficient Electrocatalytic H2 Production Coupling with Methanol Upgrading.

The integration of the hydrogen evolution reaction (HER) with the methanol oxidation reaction (MOR) has been demonstrated to be a viable strategy for the energy-saving generation of H2 and value-added formate, which relies primarily on highly active and cost-effective bifunctional electrocatalysts. Herein, an efficient electrocatalyst consisting of controllable Ni nanoparticles (NPs) coated with ultrathin graphitic carbon shells was obtained by the pyrolysis of a Ni-Zn metal-organic framework. Intriguingly, we found that zinc vaporization not only resulted in the relatively small Ni NPs but also ultrathin carbon shells (≤3 layers). The density functional theory simulations confirmed that these ultrathin carbon shells significantly influenced electrocatalytic activity by facilitating electron transfer from the Ni core to the carbon shell. The optimized Ni1(Zn)@C demonstrated high catalytic activity for both HER and MOR, and only a low potential of 97 mV at 10 mA cm-2 was required for HER and 1.48 V at 30 mA cm-2 for MOR. In a two-electrode electrocatalytic cell measurement, a cell voltage of 1.63 V was observed at 10 mA cm-2 in the presence of methanol, 240 mV lower than that without methanol.

Nickel Nanoparticles Protruding from Molybdenum Carbide Micropillars with Carbon Layer-Protected Biphasic 0D/1D Heterostructures for Efficient Water Splitting.

It remains a tremendous challenge to achieve high-efficiency bifunctional electrocatalysts for both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) for hydrogen production by water splitting. Herein, a novel hybrid of 0D nickel nanoparticles dispersed on the one-dimensional (1D) molybdenum carbide micropillars embedded in the carbon layers (Ni/Mo2C@C) was successfully prepared on nickel foam by a facile pyrolysis strategy. During the synthesis process, the nickel nanoparticles and molybdenum carbide were simultaneously generated under H2 and C2H2 mixed atmospheres and conformally encapsulated in the carbon layers. Benefiting from the distinctive 0D/1D heterostructure and the synergistic effect of the biphasic Mo2C and Ni together with the protective effect of the carbon layer, the reduced activation energy barriers and fast catalytic reaction kinetics can be achieved, resulting in a small overpotential of 96 mV for the HER and 266 mV for the OER at the current density of 10 mA cm-2 together with excellent durability in 1.0 M KOH electrolyte. In addition, using the developed Ni/Mo2C@C as both the cathode and anode, the constructed electrolyzer exhibits a small voltage of 1.55 V for the overall water splitting. The novel designed Ni/Mo2C@C may give inspiration for the development of efficient bifunctional catalysts with low-cost transition metal elements for water splitting.

Confined Ni nanoparticles in N-doped carbon nanotubes for excellent pH-universal industrial-level electrocatalytic CO2 reduction and Zn-CO2 battery.

Electrocatalytic reduction of CO2 (ECR) offers a promising approach to curbed carbon emissions and complete carbon cycles. However, the inevitable creation of carbonates and limited CO2 utilization efficiency in neutral or alkaline electrolytes result in low energy efficiency, carbon losses and its widespread commercial utilization. The advancement of CO2 reduction under acidic conditions offers a promising approach for their commercial utilization, but the inhibition of hydrogen evolution reaction and the corrosion of catalysts are still challenging. Herein, Ni nanoparticles (NPs) wrapped in N-doped carbon nanotubes (NixNC-a) are successfully prepared by a facile mixed-heating and freeze-drying method. Ni100NC-a achieves a high Faraday efficiency (FE) of near 100 % for CO under pH-universal conditions, coupled with a promising current density of CO (>100 mA cm-2). Especially in acidic conditions, Ni100NC-a exhibits an exceptional ECR performance with the high FECO of 97.4 % at -1.44 V and the turnover frequency (TOF) of 11 k h-1 at -1.74 V with a current density of 288.24 mA cm-2. This excellent performance is attributed to the synergistic effect of Ni NPs and N-doped carbon shells, which protects Ni NPs from etching, promotes CO2 adsorption and regulates local pH. Moreover, Ni100NC-a could drive the reversible Zn-CO2 battery with a high power-density of 4.68 mW cm-2 and a superior stability (98 h). This study presents a promising candidate for efficient pH-universal CO2 electroreduction and Zn-CO2 battery.

Comparative Study of Exsolved and Impregnated Ni Nanoparticles Supported on Nanoporous Perovskites for Low-Temperature CO Oxidation.

This study investigated the redox exsolution of Ni nanoparticles from a nanoporous La0.52Sr0.28Ti0.94Ni0.06O3 perovskite. The characteristics of exsolved Ni nanoparticles including their size, population, and surface concentration were deeply analyzed by environmental scanning electron microscopy (ESEM), transmission electron microscopy-energy dispersive X-ray spectroscopy (TEM-EDX) mapping, and hydrogen temperature-programmed reduction (H2-TPR). Ni exsolution was triggered in hydrogen as early as 400 °C, with the highest catalytic activity for low-temperature CO oxidation achieved after a reduction step at 500 °C, despite only a 10% fraction of Ni exsolved. The activity and stability of exsolved nanoparticles were compared with their impregnated counterparts on a perovskite material with a similar chemical composition (La0.65Sr0.35TiO3) and a comparable specific surface area and Ni loading. After an aging step at 800 °C, the catalytic activity of exsolved Ni nanoparticles at 300 °C was found to be 10 times higher than that of impregnated ones, emphasizing the thermal stability of Ni nanoparticles prepared by redox exsolution.

Immobilization and Catalytic Conversion of Polysulfide by In-Situ Generated Nickel in Hollow Carbon Fibers for High-Rate Lithium-Sulfur Batteries.

Lithium-sulfur (Li-S) batteries are considered promising energy-storage systems because of their high theoretical energy density, low cost, and eco-friendliness. However, problems such as the shuttle effect can result in the loss of active materials, poor cyclability, and rapid capacity degradation. The utilization of a structural configuration that enhances electrochemical performance via dual adsorption-catalysis strategies can overcome the limitations of Li-S batteries. In this study, an integrated interlayer structure, in which hollow carbon fibers (HCFs) were modified with in-situ-generated Ni nanoparticles, was prepared by scalable one-step carbonization. Highly hierarchically porous HCFs act as the carbon skeleton and provide a continuous three-dimensional conductive network that enhances ion/electron diffusion. Ni nanoparticles with superior anchoring and catalytic abilities can prevent the shuttle effect and increase the conversion rate, thereby promoting the electrochemical performance. This synergistic effect resulted in a high capacity retention of 582 mAh g-1 at 1 C after 100 cycles, providing an excellent rate capability of up to 3 C. The novel structure, wherein Ni nanoparticles are embedded in cotton-tissue-derived HCFs, provides a new avenue for enhancing electrochemical performance at high C rates. This results in a low-cost, sustainable, and high-performance hybrid material for the development of practical Li-S batteries.

DNA/BSA interaction, anticancer, antimicrobial and catalytic applications of synthesis of nitro substituted pyrimidine-based Schiff base ligand capped nickel nanoparticles.

The objective of this research was to create stable nickel nanoparticles using nickel chloride salt and a Schiff base ligand called DPMN. The synthesis process involved a two-step phase transfer procedure. Spectroscopic techniques such as UV-Visible and FT-IR were used to confirm the formation of ligand-stabilized nickel nanoparticles (DPMN-NiNPs). To analyze the size, surface morphology, and quality of DPMN-NiNPs, SEM and TEM techniques were utilized. In vitro studies were performed to investigate the potential anticancer activity of the synthesized compounds against three different cancer cell lines and one normal cell line, and the results were compared to those of cis-platin. The researchers also conducted tests to determine the ability of DPMN-NiNPs to bind to CT-DNA using various techniques such as electronic absorption, fluorescence, viscometric, and cyclic voltammetric. The results showed that the synthesized DPMN-NiNPs exhibited good DNA binding ability, which was further validated by denaturation of DNA using thermal and sonochemical methods. The researchers also investigated the antimicrobial and antioxidant activities of DPMN-NiNPs, which demonstrated better biological activities than DPMN alone. Furthermore, the synthesized nano compounds were found to selectively damage cancer cell lines without harming normal cell lines. Finally, the researchers examined the potential of DPMN-NiNPs as a catalyst in dye degradation by testing its ability to decompose methyl red dye using UV-Visible spectroscopy.Communicated by Ramaswamy H. Sarma.

Bioactive organic Schiff-base ligand having head group and tail group was synthesizedHead group interacted and stabilized the nickel nanoparticlesAverage size of the Ni nanoparticles is 45 nmSolid and stable nickel nanoparticles were prepared.Nickel nanoparticles have good biological properties as well as catalytical properties.

Ni nanoparticles supported on Al2O3 + La2O3 yolk-shell catalyst for photo-assisted thermal decomposition of methane.

Catalytic methane decomposition (CMD) has emerged as an appealing technology for large-scale production of H2 and carbon nanostructures from natural gas. As the CMD process is mildly endothermic, the application of concentrated renewable energy sources such as solar energy under a low-temperature regime could potentially represent a promising approach towards CMD process operation. Herein, Ni/Al2O3-La2O3 yolk-shell catalysts are fabricated using a straightforward single-step hydrothermal approach and tested for their performance in photothermal CMD. We show that the morphology of the resulting materials, dispersion and reducibility of Ni nanoparticles, and nature of metal-support interactions can be tuned by addition of varying amounts of La. Notably, the addition of an optimal amount of La (Ni/Al-20La) improved the H2 yield and catalyst stability relative to the base Ni/Al2O3 material, while also favoring base growth of carbon nanofibers. Additionally, we show for the first time a photothermal effect in CMD, whereby the introduction of 3 suns light irradiation at a constant bulk temperature of 500 °C reversibly increased the H2 yield of catalyst by about 1.2 times relative to the rate in the dark, accompanied by a decrease in apparent activation energy from 41.6 kJ mol-1 to 32.5 kJ mol-1. The light irradiation further suppressed undesirable CO co-production at low temperatures. Our work reveals photothermal catalysis as a promising route for CMD while providing an insightful understanding of the roles of modifier in enriching methane activation sites on Al2O3-based catalysts.

Ultrawide Hydrazine Concentration Monitoring Sensor Comprising Ir-Ni Nanoparticles Decorated with Multi-Walled Carbon Nanotubes in On-Site Alkaline Fuel Cell Operation.

A highly sensitive amperometric hydrazine monitoring sensor offering an ultrawide dynamic range of 5 µM to 1 M in alkaline media (e. g., 1 M KOH) was developed via co-electrodepositing iridium-nickel alloy nanoparticles (NPs) functionalized with multi-walled carbon nanotubes (Ir-Ni-MWCNTs) on a disposable screen-printed carbon electrode. The synergistic interaction of MWCNTs with Ir-Ni alloy NPs resulted in enlarged active surface area, rapid electron transfer, and alkaline media stability with an onset potential of -0.12 V (vs. Ag/AgCl) toward hydrazine oxidation. A limit of detection for hydrazine was 0.81 µM with guaranteed reproducibility, repeatability, and storage stability alongside a superb selectivity toward ethanolamine, urea, dopamine, NaBH4 , NH4 OH, NaNO2 , and Na2 CO3 . The sensor was finally applied to on-site monitoring of the carbon-free hydrazine concentration at the anode and cathode of a hydrazine fuel cell, providing more insight into the hydrazine oxidation process during cell operation.