NiMoO4 Nanoparticles Research Articles

Outstanding oxygen evolution reaction properties released at the interface of NiMoO4 and FeNi layer double hydroxide heterostructures

For the alkaline oxygen evolution reaction (OER), FeNi layered double hydroxide (FeNi LDH) exhibits good activity and stability. For the sake of saving freshwater, the use of abundant seawater as an electrolyte poses new requirements for its OER performance. A novel method was designed based on a corrosion reaction to convert commercial Fe foam into a high-performance OER catalyst (FeNiM), which consisted of FeNi LDH layers and NiMoO4 nanoparticles modified on its surface. FeNiM exhibited excellent OER activity, only requiring an overpotential of 250 mV to achieve a current density of 100 mA cm−2. Experimental results indicated that the heterostructures formed by NiMoO4 and FeNi LDH was conducive to exposing active sites, promoting the adsorption of active intermediates, and generating highly active oxyhydroxides. In addition, the heterostructure was beneficial to stabilizing the electrode surface structure and inhibiting seawater corrosion. Therefore, FeNiM could maintain high current density activity in both alkaline freshwater and alkaline seawater, which only required low overpotentials of 326 mV and 304 mV to achieve a high current density of 1500 mA cm−2, respectively. This catalyst preparation method has the advantages of economic efficiency, industrial compatibility, and significantly promoting the development of green hydrogen economy and industrial seawater desalination.

Investigating the performance of nickel molybdate nanostructure in dye sensitized solar cells: Computational and experimental analysis

This study explores both computational and experimental aspects of third-generation solar cells, specifically dye-sensitized solar cells (DSSCs) using Nickel Molybdate (NiMoO4) as both a new alternative electron transport layer (working electrode, WE) and counter electrode (CE). The synthesized NiMoO4 nanoparticles have an average size of 800 nm with crystalline size of 24.12 nm using Scanning electron microscopy (SEM) and X-ray diffraction (XRD) spectroscopy. The results indicate that the DSSCs based on NiMoO4 exhibit low photovoltaic performance due to poor photocurrent production. However, when NiMoO4 is employed as the WE (with platinum serving as the CE); it yields a better short circuit current (Jsc = 20.04 μA/cm2) and overall photovoltaic performance compared to TiO2 WE (with NiMoO4 serving as the CE) (Jsc = 0.23 μA/cm2). Interestingly, the DSSCs with NiMoO4 as WE featured the lowest performance degradation (90 % efficiencies has been maintained after 250 h). Additionally, this study investigates the distribution of electrolyte between NiMoO4/Pt and TiO2/NiMoO4 slabs using molecular dynamics (MD) simulations, highlighting its effective contribution to ionic conductivity (Λ), ultimately leading to an increase in photocurrent for the NiMoO4/Pt system (Λ of 27.51 10−4 S.m2/mol) compared to the TiO2/NiMoO4 (Λ of 13.45 10−4 S.m2/mol). Interestingly, the iodide ions interact more tightly with the TiO2 semiconductor (at a distance of 0.32 nm) than with NiMoO4.

Fe-Doped NiMoO4 Nanoparticles as New Non-Enzymatic Catalyst in Glucose Sensing

In this work, a new non-enzymatic sensor for the determination of glucose was constructed using Fe-doped NiMoO4 nanoparticles (NiFeMoO4). Hydrothermal and calcination techniques were successfully used to synthesis different proportion nanoparticles of Ni1−xFexMoO4 (x = 0, 0.01, 0.03, 0.05). A set of electrochemical measurements demonstrated that all of the Ni1−xFexMoO4 have electrocatalytic properties to glucose. Especially, Ni0.99Fe0.01MoO4 (x = 0.01) displayed the most excellent amperometric response to glucose in the range of 0.01∼13 mM with a limit of detection (LOD) of 0.29 μM (S/N = 3). This amperometric sensor also showed satisfactory anti-interference performance and stability. More significantly, the sensor’s applicability was tested using a glucose assay in actual serum samples with acceptable results.

Synthesis of carbon nanofibers supported NiMoO4 nanoparticles composites used for liquid thin film solar cells counter electrode

In this paper, PVP is used as the linking agent, and the NiMoO4 nanoparticles-loaded carbon nanofibers composite NiMoO4/CNFs is prepared by the hydrothermal process, and it replaced the traditional Pt counter electrode. Obviously, NiMoO4 nanoparticles are tightly loaded on carbon fibers, which helps to increase the overall catalytic active site. The results of specific characterization tests reveal that NiMoO4/CNFs composite has excellent electrocatalytic activity and stability. In the issue, DSSCs using NiMoO4/CNFs instead of Pt counter electrode reveal a photovoltaic conversion efficiency (PCE) of 7.67% versus Pt of 7.17% and CNFs of 5.65%, and it is expected to become an efficient alternative material for traditional Pt electrodes.

Tuning the morphology and size of NiMoO4 nanoparticles anchored on reduced graphene oxide (rGO) nanosheets: The optimized hybrid electrodes for high energy density asymmetric supercapacitors

• Porous NiMoO 4 NPs/rGO composite has been prepared through a facile hydrothermal approach followed by thermal treatment. • NiMoO 4 NPs/rGO composite electrode exhibits high specific capacitance of 2056 Fg -1 and long cyclic stability of 91.4 % after 10,000 cycles. • An asymmetric supercapacitor with high energy density and long cycle life is fabricated. In order to improve the capacitive performance of supercapacitors, NiMoO 4 electrode materials were successfully prepared by a simple and low cost hydrothermal route, and the morphology, microstructure and properties of the materials were successfully optimized by adding reduced graphene oxide (rGO). Electrochemical and sophisticated physical property tests are used to examine the qualities of items. As a supercapacitor electrode material, the NiMoO 4 /rGO composite performed admirably. The specific capacitance reached 2056 Fg -1 at a current density of 2 Ag -1 , which is greater than standard NiMoO 4 at the same current density (788 Fg -1 ). After 1000 charge/discharge cycles, NiMoO 4 /rGO retains 91.1 % of its initial capacitance. NiMoO 4 /rGO composites can be used in asymmetric supercapacitors, and the asymmetric supercapacitor device offers a high power density (60. 2 Whkg -1 ) and energy density (750.5 Whkg -1 ) when used as the positive electrode and activated carbon as the negative electrode. A combination of mesoporous-NiMoO 4 nanoparticles with a high specific surface area and good interaction with conductive rGO is responsible for the improved electrochemical performance of NiMoO 4 /rGO.

A new strategy for the preparation of multi-walled carbon nanotubes/NiMoO4 nanostructures for high-performance asymmetric supercapacitors

Over the past decade, boosting the electrical conductivity of nickel molybdate materials has been established to improve their supercapacitive performance. Nevertheless, it is significant to investigate a different approach from economic efficiency and operation time perspectives. Herein, we first prepare NiMoO4 nanoparticles using a simple ball-milling technique and then serve them in two different multi-walled carbon nanotubes (MWCNTs)/NiMoO4 composites fabricated using simple blending and ball-milling. The ball-milled nanocomposite delivers outstanding supercapacitive properties because of its good surface area, outstanding conductivity, fast kinetics, and many active sites. Its specific capacitance reached 727.2 F g−1 at 1 A g−1 and 709.8 at 10 mV sec−1, and cycling stability was measured to be 86.8 % after 2000 cycles at a current density of 20 A g−1, surpassing the other two samples. An asymmetric device based on ball-milled composite nanostructure resulted in a high specific energy of 40.9 Wh kg−1, a remarkable specific power of 918.5 W kg−1, an appealing rate performance of 73.6 % at 50 A g−1 current density, and a superb cycling durability of 85.4 %. As a result, combining storage attributes of NiMoO4 and MWCNTs with the ball-milling route provides a new strategy to enhance the electrochemical properties of nickel molybdate.

Construction of NiCoS@NiMo-LDH hierarchical composite for high-performance supercapacitors

Ni(OH)2·0.75H2O nanosheets embedded with NiMoO4 nanoparticles (NiMo-LDH) supported by nickel cobalt sulfur (NiCoS) nanorods were prepared by a multi-step hydrothermal method, which provides an effective channel for ion transport and abundant active sites for charge storage. The NiCoS@NiMo-LDH electrode exhibited a very high capacitance of 1302.5 μAh cm−2 at 10 mA cm−2, with 54 % capacitance retention observed at 50 mA cm−2. The asymmetric supercapacitor (ASC) assembled with the NiCoS@NiMo-LDH as the positive electrode and active carbon (AC) as the negative electrodes which exhibits an energy density of 1096.6 μWh cm−2 at a power density of 2.8 mW cm−2 along with good stability of 86.67 % after 5000 cycles.

Electrospun NiMoO4-encapsulated carbon nanofibers electrodes for advanced supercapacitors

NiMoO4-encapsulated carbon nanofiber (NiMoO4/ECNFs) composites have been synthesized successfully using electrospinning method and subsequent thermal treatments. The prepared specimens were examined using field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), x-ray diffraction (XRD), thermal gravimetric analyzer (TGA), and Fourier transform infrared spectroscopy (FTIR). Electrochemical measurements including cyclic voltammetry (CV), galvanostatic charge/discharge (GCD), and electrochemical impedance spectroscopy (EIS) were performed on the symmetric supercapacitors (SSCs) which were assembled from the (75 %)NiMoO4/ECNFs binder-free nanostructured electrodes. Morphological and structural investigations revealed an open 3D interconnected conductive and grain-like texture with homogeneously dispersed monoclinic NiMoO4 nanoparticles. Moreover, a high specific capacity of 122.5 Fg−1 at 1 Ag−1 and an excellent energy density of 43.9 Whkg−1 at a power density of 1567.9 Wkg−1 were obtained from the SSCs. The constructed devices also delivered outstanding cyclic stability (92 % retention after 3000 cycles). The observed electrochemical properties have been ascribed to the uniform dispersion of nanoparticles in the conductive carbon nanofiber matrix. The results suggest that as-fabricated NiMoO4/ECNFs can be considered as a promising electrode material for high-performance supercapacitors.

Low-crystalline nickel hydroxide nanosheets embedded with NiMoO4 nanoparticles on nickel foam for high-performance supercapacitor applications

Nickel hydroxide nanosheets embedded with NiMoO4 nanoparticles with controllable composition were prepared. The optimized hybrid electrode exhibits high energy density.

NiMoO4 nanoparticles embedded in nanoporous carbon nanosheets derived from peanut shells: Efficient electrocatalysts for urea oxidation

Electrochemical oxidation of urea had aroused worldwide attention in environment and energy storage fields. However, urea electrooxidation reaction still suffered from the sluggish kinetics owing to a 6e− transfer processes involvement. In this work, nanoporous carbon nanosheets (Cps) derived from peanut shells (PS) were synthesized via two pyrolysis steps along with KOH activation. NiMoO4 nanoparticles were then embedded in Cps via a facile impregnation method. The as-prepared catalyst possessed large surface area and the embedded NiMoO4 nanoparticles exhibited small size with average diameter of 10 nm. The chemical properties of NiMoO4 could be also tuned after embedded in Cps. When used as catalyst for urea electrooxidation reaction, NiMoO4 embedded in Cps exhibited superior catalytic performance. NiMoO4 nanoparticles with small size could expose more active sites, the interface interaction between NiMoO4 and Cps could promote charge transfer and the existence of Mo species could improve the stability of the catalyst. Therefore, the as-prepared NiMoO4 embedded in Cps should be a promising catalyst in wastewater treatment and energy storage.

Self-assembly of NiMoO4 nanoparticles on the ordered NiCo2O4 ultra-thin nanoflakes core-shell electrode for high energy density supercapacitors and efficient oxygen evolution reaction

The scrupulous design and construction of self-ordered binder-free core-shell electrodes with numerous active sites has drawn massive attention in the field of supercapacitors and oxygen evolution reaction. We demonstrate a powerful and environment friendly two-step electrochemical engineering of the highly ordered two-dimensional NiCo2O4 nanoflakes trapped with NiMoO4 nanoparticles on Ni foam. The vertically self-assembled NiCo2O4 nanoflakes offer easiest paths for the ion and electron transport. Moreover, the synergistic effect between nanoflakes and nanoparticles provide large active surface area for electrochemical energy storage and oxygen evolution electrocatalysis. Compared to NiCo2O4 nanoflakes NiCo2O4/NiMoO4 core-shell electrode exhibited an enhanced electrochemical performance having an excellent specific capacitance (3705 F g-1 at 1.5 A g-1), high rate capability (95.1% for 20-fold increase of the current density), and a stable cycle life (94.6% for 5000 charge-discharge cycles). Moreover, it showed an overpotential of 400 mV at a current density of 50 mA cm-2, Tafel slope of 150 mVdec-1, and 100% of stability for 5 h of continuous operation in alkaline medium. Moreover, as-fabricated NiCo2O4/NiMoO4//NiCo2O4/NiMoO4 symmetric supercapacitor delivered highest energy density of 76.45 Wh kg-1 and cycle life of 88% after 5000 cycles. Thus, present study demonstrates sustainable engineering approach to fabricate highly ordered two-dimensional heterostructures for various electrochemical applications.

NiMoO4 nanoparticles decorated carbon nanofiber membranes for the flexible and high performance glucose sensors

The free-standing and flexible carbonaceous nanofiber membrane (CNF) comprising of NiMoO4 nanoparticles decorated carbon fibers were developed for glucose sensing analysis. The applicability of polymeric nanofiber membranes in electrochemical sensors is accelerated by enhancing their electrical conductivity via carbonization process. The cavities exist in CNFs accelerate the rapid diffusion of glucose and maximizes the analyte utilization efficiency. The uniform implantation of catalytic active sites of NiMoO4 on CNFs accelerates the glucose sensing kinetics further. With the synergism of bimetal active sites, porous architecture, and conductive carbon network, NiMoO4/CNF demonstrates the excellent sensitivity, low detection limit, and broad linear range, respectively, of 301.77 μA mM−1 cm−2, 50 nM, and 0.0003–4.5 mM toward glucose sensing. Also, the sensing concerts of NiMoO4/CNF are reliable, repeatable, and electrochemically stable along with the high specificity and real sample applicability toward glucose detection. Thus, the free-standing, bendable, binder-free, reusable, and cost-efficient fabrication process developed for the NiMoO4/CNF membrane realizes it’s conscription in the development of cost-efficient and high performance glucose sensors.

Synthesis of a NiMoO4/3D-rGO Nanocomposite via Starch Medium Precipitation Method for Supercapacitor Performance

This paper presents research on the synergistic effects of nickel molybdate and reduced graphene oxide as a nanocomposite for further development of energy storage systems. An enhancement in the electrochemical performance of supercapacitor electrodes occurs by synthesizing highly porous structures and achieving more surface area. In this work, a chemical precipitation technique was used to synthesize the NiMoO4/3D-rGO nanocomposite in a starch media. Starch was used to develop the porosities of the nanostructure. A temperature of 350 °C was applied to transform graphene oxide sheets to reduced graphene oxide and remove the starch to obtain the NiMoO4/3D-rGO nanocomposite with porous structure. The X-ray diffraction pattern of the NiMoO4 nano particles indicated a monoclinic structure. Also, the scanning electron microscope observation showed that the NiMoO4 NPs were dispersed across the rGO sheets. The electrochemical results of the NiMoO4/3D-rGO electrode revealed that the incorporation of rGO sheets with NiMoO4 NPs increased the capacity of the nanocomposite. Therefore, a significant increase in the specific capacity of the electrode was observed with the NiMoO4/3D-rGO nanocomposite (450 Cg−1 or 900 Fg−1) when compared with bare NiMoO4 nanoparticles (350 Cg−1 or 700 Fg−1) at the current density of 1 A g−1. Our findings show that the incorporation of rGO and NiMoO4 NP redox reactions with a porous structure can benefit the future development of supercapacitors.

Novel gravel-like NiMoO4 nanoparticles on carbon cloth for outstanding supercapacitor applications

Massive advancements in the energy storage devices has urged scientist to remediate physically/chemically electroactive methods for excellent supercapacitor applications. The use of binders in energy storing devices obstacles their charge carrier in redox kinetics and high internal resistances results in low electrochemical performances. Herein, we successfully decorated gravel-like NiMoO4 nanoparticles arrays onto a carbon cloth (NMO@CC) which is used as binder-free electrode for electrochemical supercapacitor measurements. The NMO@CC electrode unveils a noticeable specific capacitance of 970 F/g 2.5 A/g of current density, exceptional stability and retention of 91.34% after 5000 cycles. The outstanding electrochemical properties of NMO@CC are credited to the conductive nature of double-metal (Ni–Mo) ions and binder-free electrode that facilities rapid redox reactions and designate it as a promising pseudocapacitor in industrial applications.

Highly porous NiMoO4 tailored onto amine functionalized CNT as advanced nanocomposite electrocatalyst for supercapacitor application

In this study, the NiMoO4-carbon nanotubes (NiMoO4-CNTs) nanocomposite with interesting vertical nanosheet architecture and hierarchical mesoporous surface was synthesized via a simple hydrothermal treatment, followed by annealing process. The NiMoO4 nanoparticles were chemically tailored onto amine functionalized CNT through the reactive –NH2 group available; this noble electrode design not only resulted to remarkably high specific surface area of 181.88 m2 g−1 with numerous numbers of active sites, but also ensured outstanding mechanical and chemical stability that helped retained 91.93% capacity retention even after 5000 continuous cycles at fast scan rate. The fabricated NiMoO4-CNT electrode press deposited onto nickel foam substrate obtained specific capacitance of 611.69 F g−1 and 20.42 W h kg−1 energy density at 1 A g−1 current density. Furthermore, the annealing temperature was a critical factor during the synthesis of the modified material as it has direct effect on the structure and crystal phase, as well as to the amount of decomposed CNT; thus, the effect of using low and high annealing temperature towards the electrochemical activity of the modified material was extensively examined. The synthesized materials were investigated by using thermo gravimetric analysis, X-ray diffraction, field emission scanning electron micrographs equipped with energy dispersive X-ray spectrometer, and Brunauer–Emmett–Teller.

Microwave combustion synthesis, magneto-optical and electrochemical properties of NiMoO4 nanoparticles for supercapacitor application

Nickel molybdate (NiMoO4) nanoparticles (NPs) were synthesized by a simplistic one-pot microwave combustion method using urea as the fuel. The produced NPs have been examined by powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR) analysis, scanning electron microscope (SEM), energy dispersive X-ray (EDX), high-resolution transmission electron microscopy (HR-TEM) analysis. Further, optical and electronic properties were determined by UV-Visible and Photoluminescence (PL) analysis, respectively. The magnetic performance of the NiMoO4 NPs was investigated by vibrating sample magnetometer (VSM) and the surface chemical composition was identified by X-ray photoelectron spectroscopy (XPS). The electrochemical activities of the NiMoO4 NPs were studied by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge/discharge (GCD) analysis. From the results, the CV curves indicated the occurrence of redox couples and besides with the EIS data (Nyquist plot), confirmed the supercapacitor nature of the synthesized NiMoO4. The prepared NiMoO4 exhibits a high specific capacitance and rateability. This electrode grants a high specific capacitance of 450 F g−1 at 2 mA cm−2 and the well permanency with a cycling proficiency of 94% after 1000 cycles. These results clearly showed that the synthesized NiMoO4 NPs have potential application for the forthcoming flexible and lightweight energy storage.

Strong third-order nonlinear response and optical limiting of α-NiMoO4 nanoparticles

In this manuscript, we demonstrate the strong resonant two photon absorption coefficient ≈71 ± 5 cm/GW at 532 nm in α-NiMoO4 nanoparticles prepared by a facile hydrothermal method. Strikingly, we have obtained the optical limiting onset threshold fluence (FON) of 36 mJ/cm2 for the linear transmittance of 0.64 with an excellent two photon absorption cross section (38 × 10−45 cm4 s), which suggests that they can be utilized as passive optical limiters. To explain the observed effects, we present a two-level rate equation model and numerically simulated the Z-scan peak shape, which is in good agreement with the experimental data. Further, we also show the normalized population density of the carriers in excited and ground states.

Enhanced performance of NiMoO4 nanoparticles and quantum dots and reduced nanohole graphene oxide hybrid for supercapacitor applications

NiMoO4 nanoparticles and quantum dots were uniformly distributed on the surface of reduced nanohole graphene oxide (rNHGO). NiMoO4@rNHGO exhibited a higher specific capacitance and better cycling stability than NiMoO4@reduced graphene oxide (rGO), which were attributed to the large surface area and high electrical conductivity. NiMoO4 nanoparticles and quantum dots (QDs) had high surface to volume ratio, which would not result in change in volume during the electro–chemical operation and induced better supercapacitor performance. Moreover, synergistic effect between NiMoO4 and the rNHGO also improved undoubtedly high specific capacitance and cycle stability.

Structurally stable hollow mesoporous graphitized carbon nanofibers embedded with NiMoO4 nanoparticles for high performance asymmetric supercapacitors

Herein, we report a facile and scalable method of synthesizing NiMoO4 nanoparticle embedded mesoporous hollow carbon nanofibers by electrospinning. We have synthesized four different NiMoO4-carbon composite nanostructures, each containing a different composition of NiMoO4 and carbon. Amongst these, the composite nanostructure with 50% (wt.) of NiMoO4 displayed an excellent specific capacity of 575Cg−1 (1438Fg−1) at 1Ag−1 current density and a capacity retention of 88% after 3000 cycles; while the pure electrospun NiMoO4 nanofibers displayed a specific capacity of 385Cg−1 (836Fg−1) and a capacity retention of only 72%. An asymmetric supercapacitor fabricated from this composite nanostructure and activated carbon displayed a high specific capacity of 135Cg−1 (85Fg−1) at 1Ag−1 and a capacity retention of 92% after 3000 cycles. A high energy density of 30WhKg−1 and a power density of 403WKg−1 have been achieved. The enhanced capacity of the NiMoO4-carbon composite nanofibers could be attributed to the mesoporous size of the hollow carbon nanofibers (∼3.4nm), their high specific surface area (∼253m2g−1) and the increased reactivity due to the nanosized metal oxide particles. The improved cyclability can be attributed to the structural stability gained by embedment of the particles into the hollow carbon matrix that acts as a buffer during the volume changes of the cycling process. Furthermore, the encapsulation of the particles by the onion-like graphitic carbon layers prevents the particles from dislodging from the carbon matrix. The synergistic effects from NiMoO4 and carbon enhances the performance that could not be obtained by either of these components alone. These results show that these NiMoO4-carbon composite nanofibers could be promising materials for high performance supercapacitors.

In Situ Synthesis of Mesoporous NiMoO4 on Ball Milled Graphene for High Performance Supercapacitors

Hydrothermal method is used to in situ synthesize mesoporous graphene@NiMoO4 nanocomposites as supercapacitor electrodes. NiMoO4 nanorods are formed on fresh graphene surface, while scattered NiMoO4 nanoparticles are obtained on the surface of ball milled graphene. graphene@NiMoO4 nanocomposites electrodes exhibit a higher electrochemical performance compared with a pure NiMoO4 electrode, and the ball milled graphene@NiMoO4 electrodes have the maximum specific capacitance of 2100 F g−1 at 1 A g−1 discharge current and maintains at least 92% of its initial capacitance after 5000 operational cycles. Such an enhanced supercapacitive performance originates from the mesoporous structure, more electroactive sites, large specific surface area, high electrical conductivity and synergistic effect between NiMoO4 and the graphene.