Nickel Phosphate Research Articles

Plasma Enhanced Atomic Layer Deposition of Nickel and Cobalt Phosphate for Li-Ion Battery Applications

Ever since the introduction of iron phosphate as a Li-ion battery (LIB) electrode by Sony in 1991, phosphates have played an important role in various research fields. One advantage for the use of phosphates in for example LIB’s is the strong covalency in the metal-oxygen-phosphorus bonds allowing for a high structural and thermal stability. Next to this, the strong interaction between the metal atom and the phosphate anion allow for these materials to operate at a higher potential than their oxide counterparts[1]. Nevertheless, the energy density of an iron phosphate electrode is still limited, which is why the use of nickel and cobalt phosphate as electrode materials (operating at a much higher potential) is currently actively being investigated. Apart from their use as LIB electrodes, these phosphates have also shown to be of interest for a variety of other applications, such as e.g. electrocatalysis.With these applications in mind, the research towards the deposition of these materials also becomes increasingly important. The use of atomic layer deposition (ALD) has for example already allowed for the deposition of a series of metal phosphates, including iron[2] and cobalt phosphate[3]. An ALD process for the deposition of nickel phosphate is however still missing. In this work, a new plasma-enhanced ALD process (PE-ALD) was developed towards the deposition of a nickel phosphate. The process is based on earlier reported process, combining a TMP plasma (TMP*) with an oxygen plasma (O2*) and a metal precursor. When using nickelocene as the metal precursor in this work, saturated growth of an amorphous nickel phosphate was observed at a substrate temperature of 300°C, with a growth per cycle of 0.2 nm/cycle (figure 1). Using XPS, the nickel is thought to be built in with an oxidation state of 2+ while the position of the oxygen and phosphorus peak agree with the formation of a phosphate-like material.This material was then electrochemically characterised as a LIB electrode, together with cobalt phosphate (using a previously reported ALD process[3]). Both materials unfortunately did not result in the high energy (approximately at a potential of 5 V vs. Li+/Li) electrochemical activity that was expected, but did show activity at a lower voltage window (figure 2). The reason for this is expected to be due to the 2+ oxidation state of nickel (and cobalt) in the as-deposited material, while a 3+ oxidation state would be needed for the high energy redox peak to appear. Nevertheless, besides the observation of an electrochemically active nature (at a low voltage) for both materials, this work can help in the research towards enabling the higher energy variant of these phosphates (i.e. by further fine-tuning the proposed ALD processes) and/or other potential applications for these specific materials (such as electrocatalysis, for which the cobalt phosphate used in this work has already shown to result in beneficial behaviour).[1] Masquelier, C., & Croguennec, L. (2013). ChemInform : Polyanionic (Phosphates, Silicates, Sulfates) Frameworks as Electrode Materials for Rechargeable Li (or Na) Batteries. Cheminform, 44(40), no-no. doi: 10.1002/chin.201340216[2] Dobbelaere, T., Mattelaer, F., Dendooven, J., Vereecken, P., & Detavernier, C. (2016). Plasma-Enhanced Atomic Layer Deposition of Iron Phosphate as a Positive Electrode for 3D Lithium-Ion Microbatteries. Chemistry Of Materials, 28(10), 3435-3445. doi: 10.1021/acs.chemmater.6b00853[3] Rongé, J., Dobbelaere, T., Henderick, L., Minjauw, M., Sree, S., & Dendooven, J. et al. (2019). Bifunctional earth-abundant phosphate/phosphide catalysts prepared via atomic layer deposition for electrocatalytic water splitting. Nanoscale Advances, 1(10), 4166-4172. doi: 10.1039/c9na00391f Figure 1

Stable Water Oxidation Catalysts Based on in-situ Electrochemical Transition of Nickel Phosphate

Stable Water Oxidation Catalysts Based on in-situ Electrochemical Transition of Nickel Phosphate

Progress in the development of heteroatom-doped nickel phosphates for electrocatalytic water splitting

Hydrogen energy is expected to replace fossil fuels as a mainstream energy source in the future. Currently, hydrogen production via water electrolysis yields high hydrogen purity with easy operation and without producing polluting side products. Presently, platinum group metals and their oxides are the most effective catalysts for water splitting; however, their low abundance and high cost hinder large-scale hydrogen production, especially in alkaline and neutral media. Therefore, the development of high-efficiency, durable, and low-cost electrocatalysts is crucial to improving the overpotential and lowering the electrical energy consumption. As a solution, Ni2P has attracted particular attention, owing to its desirable electrical conductivity, high corrosion resistance, and remarkable catalytic activity for overall water splitting, and thus, is a promising substitute for platinum-group catalysts. However, the catalytic performance and durability of raw Ni2P are still inferior to those of noble metal-based catalysts. Heteroatom doping is a universal strategy for enhancing the performance of Ni2P for water electrolysis over a wide pH range, because the electronic structure and crystal structure of the catalyst can be modulated, and the adsorption energy of the reaction intermediates can be adjusted via doping, thus optimizing the reaction performance. In this review, first, the reaction mechanisms of water electrolysis, including the cathodic hydrogen evolution reaction and anodic oxygen evolution reaction, are briefly introduced. Then, progress into heteroatom-doped nickel phosphide research in recent years is assessed, and a discussion of each representative work is given. Finally, the opportunities and challenges for developing advanced Ni2P based electrocatalysts are proposed and discussed.

Microsheets like nickel cobalt phosphate thin films as cathode for hybrid asymmetric solid-state supercapacitor: Influence of nickel and cobalt ratio variation

A rational combination of metal cations is necessary to obtain a synergistic effect leading to improved electrochemical energy storage performance of bimetal compounds. So, the effect of concentration variation of reactants (nickel and cobalt ratio) in nickel cobalt phosphate material and their influence on physicochemical properties and electrochemical capacitive performances are investigated. The morphological evolution from microflowers (nickel phosphate) to microsheets (cobalt phosphate) is observed with increasing cobalt content in nickel cobalt phosphate thin films. The optimum nickel and cobalt composition (∼1:1) in nickel cobalt phosphate (Ni1.38Co1.62(PO4)2·8H2O) thin film electrode demonstrate maximum specific capacitance (capacity) of 1116 F g−1 (446 C g−1) at 0.5 A g−1 current density. Also, a fabricated hybrid asymmetric aqueous device consists of nickel cobalt phosphate thin film as cathode and rGO as an anode in 1 M KOH electrolyte delivers a higher specific capacitance of 120 F g−1 with a high energy density of 42.3 Wh kg−1 at a power density of 1 kW kg−1. Moreover, a hybrid asymmetric solid-state device fabricated using PVA-KOH gel electrolyte exhibits a maximum specific capacitance of 102 F g−1 with an energy density of 36.2 Wh kg−1 at 160 W kg−1 power density and 83.7 % initial capacitance retention after 4000 GCD cycles. Such excellent electrochemical capacitive performance of hybrid asymmetric devices is attributed to the synergy between nickel and cobalt species in nickel cobalt phosphate thin film electrodes, suggesting its potential application as a cathode in hybrid energy storage devices.

Strategically Tuned Ultrathin Nickel Phosphate Nanosheet Thin-Film Electrode as Cathode for High-Power Hybrid Supercapacitor Device

Improved capacitive performance of the electrochemical energy storage devices can be achieved by manipulating the morphology of electroactive electrode material. Therefore, in the present work, the...

Amorphous, hydrous nickel phosphate thin film electrode prepared by SILAR method as a highly stable cathode for hybrid asymmetric supercapacitor

To achieve higher supercapacitive performance of active material, several materials with precise structures and properties have been prepared using different chemical synthesis methods. Recently, amorphous materials are gaining much attention as an electrode in supercapacitor application as it provides superior electrochemical properties due to disorder in structure. So, in this investigation, a facile, binder free successive ionic layer adsorption and reaction (SILAR) method is adopted for the preparation and deposition of amorphous, hydrous nickel phosphate thin films on stainless steel substrates. The amorphous nickel phosphate shows mesoporous, clusters of particles like morphology. In the electrochemical study, the amorphous, hydrous nickel phosphate electrode demonstrates a superior specific capacitance of 1700 F g−1 (specific capacity- 814 C g−1) at 0.5 mA cm−2 current density along with excellent capacitive retention (96.55%) and coulombic efficiency (98.62%) over 5000 cycles. Furthermore, fabricated hybrid supercapacitor device using the nickel phosphate as cathode and reduced graphene oxide as anode exhibits specific capacitance of 113.5 F g−1 at 3 mA cm−2 current density with a high 40.37 Wh kg−1 energy density at 1.689 kW kg−1 power density alongwith excellent cyclic stability (95.09% retention after 5000 cycles). The obtained results illustrate that the amorphous, hydrous nature of nickel phosphate is a beneficial and superior choice as a cathode material in high-performing hybrid asymmetric supercapacitor devices.

Reduced graphene oxide/VSB-5 composite micro/nanorod electrode for high energy density supercapattery

Nickel Phosphate (Ni20[(OH)12(H2O)6][(HPO4)8(PO4)4]•12H2O) – VSB-5 nano/micro rods composite with reduced graphene oxide (rGO) was successfully synthesized using a Polyvinyl Pyrrolidone (PVP) aided hydrothermal technique and applied as a battery-type cathode for supercapatteries. The uniform meso/microporous structure provides more electro-active sites for surface redox reaction and nano-paths for electrolyte ion diffusion which can significantly improve the device performance. From the electrochemical analysis, it was found that VSB-5/rGO exhibited a specific capacity of 117.3 mAh g−1 (1056.1 F g−1) which was noticeably higher than the pristine VSB-5 (60.7 mAh g−1) at 5 mA cm−2. These excellent electrochemical performances may be due to rGO modification and well-defined nano/micro rods. Furthermore, supercapatteries were fabricated by pairing a commercially available activated carbon (AC) electrode with VSB-5/rGO as a positrode. The fabricated cell was tested and showed a high specific capacity of 86.8 mAh g−1 (208.4 F g−1) with 88% capacity retention after 5000 cycles. Finally, the assembled supercapattery delivered a maximum specific energy of 80.5 Wh kg−1 at a power output of 2216.5 W kg−1. In comparison with a pristine VSB-5 based device, the AC/VSB-5/rGO device shows remarkable electrochemical performance, demonstrating that VSB-5/rGO is a promising, new electrode material for high performance supercapatteries.

Cobalt-Nickel Phosphate Composites for the All-Phosphate Asymmetric Supercapacitor and Oxygen Evolution Reaction.

Recently, design of cost-effective multifunctional electromaterials for supercapacitors and oxygen evolution reaction (OER) and enhancing their functionalities have become an emphasis in energy storage and conversion. Herein, a series of cheap and functional phosphate composites with different ratios of cobalt and nickel are synthesized using a simple polyalcohol refluxing method, and their excellent capacity and OER properties are systematically studied. Notably, owing to the different major role of Co and Ni elements in the phosphate composites for capacity and OER, the optimal electroconductibility, structural adjustment, electrochemical active sites, and activities for capacity and OER are obtained from the composites with the different ratios of Co/Ni. In addition, using high-capacity BiPO4 (BPO) as the negative electrodes, the new type of all-phosphate asymmetric supercapacitor (CNPO-40//BPO) shows a high energy density and reaches 36.84 W h kg-1 at a power density of 254.52 W kg-1. Its cyclic stability is also more excellent than that of the CNPO-40//AC device using commercial activated carbon as the negative electrodes. This study is beneficial to the more in-depth research on efficient dual-function electromaterials in capacity and OER and provides a high-efficient way to improve the practicality of asymmetric supercapacitors using the high-capacity Bi-based electromaterials as the negative electrodes.

Hydrophilic nickel phosphate nanoparticles: An efficient catalyst for the hydrogenation of nitroarenes

A clean and highly efficient chemical method was developed for the synthesis of hydrophilic nickel phosphate nanoparticles and the formation of nanoparticles was confirmed by discrete spectral techniques. The synthesized nanoparticles were found to be an efficient catalyst for transfer hydrogenation of aromatic nitro compounds. The reaction was carried out at room temperature using sodium borohydride as the hydrogen donor and the reaction was successful with remarkable yields.

Novel [BMIM]PF6 modified flake-ANP flame retardant: Synthesis and application in epoxy resin

A novel ionic liquid-modified flake-NiNH4PO4·H2O (IL-ANP) hybrid material was prepared using a mechanochemical method with weak interactions. Characterization methods, including scanning electron microscope, Fourier transform infrared, X-ray diffraction and thermogravimetric analysis indicated the successful synthesis of IL-ANP. The prepared IL-ANP was incorporated into epoxy resin (EP) to improve the flame retardancy and mechanical properties. The limiting oxygen index (LOI) and cone calorimeter tests showed that IL-ANP enhanced the flame retardancy of EP composites. The 6 part per hundred resin (phr) IL-ANP/EP achieved excellent flame retardancy with the LOI value of 30.3% (that of pure EP was 24.4) and a significant decrease in the peak heat release rate, total heat release rate and the maximum release rates of CO production. This is attributed to the synergistic effect of the condensed phase and gas phase. During combustion, IL-ANP generated an incombustible gas (ammonia gas), nickel phosphate and nickel phosphide. On one hand, the incombustible gas diluted the concentrations of the combustible gas and oxygen in the gas phase. On the other hand, the phosphorus compounds catalyzed the carbonisation of EP to form a stable char layer and accumulated on the char layer surface as a physical barrier to delay the heat release. Additionally, the IL-ANP/EP composites exhibited excellent tensile strength, elongation at break, and impact strength, owing to their good compatibility and dispersion.

Synthesis of flower-like cobalt, nickel phosphates grown on the surface of porous high entropy alloy for efficient oxygen evolution

The development of cheap, efficient and high activity non-noble-metal oxygen evolution reaction (OER) electrocatalysts is of great interest in promoting the application of water splitting. Herein, the flower-like phosphates were grown in situ on a porous microwave sintered CoCrFeNiMo high entropy alloy (HEA) by the hydrothermal–phosphorization method. The metal phosphates can promote the formation of hydroxides with high catalytic activity on the surface of the catalyst. The obtained porous HEA phosphates exhibit a low overpotential of 220 mV at 10 mA cm−2, a small Tafel slope of 30.3 mV dec−1 and superior stability in 1.0 M KOH. Especially, after continuous cyclic voltammetry (CV) 5000 cycles, the catalyst only requires the overpotential of 210 mV at 10 mA cm−2. The enhanced OER performance of this porous HEA is be attributed to 3D internal connected nanoporous structure, high conductivity, abundant metal (oxy)hydroxide nanosheets and the presence of phosphonates, that provides a sufficiently large surface exposure and allows the acceleration of the electron transfer rate between various species.

Self-assembly of MOF on MXene nanosheets and in-situ conversion into superior nickel phosphates/MXene battery-type electrode

The low conductivity of nickel phosphate hinders its application as electrode for electrochemical energy storage applications, although its environmental and biological benign, as well as the low cost, are superior advantages compared with other transition metal based electrode materials. Herein, the “bottom-up” self-assembly of Ni-MOF amorphous nanospheres on MXene nanosheets, which provide rich nucleation sites for MOF growth, is achieved, and the MOF nanospheres are subsequently in-situ conversed into hierarchically porous nickel phosphate nanospheres through the “top-down” etching. The porous nickel phosphate nanospheres are therefore anchored on the MXene nanosheets, enabling the fast electron transportation between the nickel phosphate and MXene, addressing the low conductivity issue of nickel phosphate. Meanwhile, the porous nickel phosphate nanospheres prevent the aggregation of MXene nanosheets, and the laminar structure is maintained for fast ionic migration within the electrodes through long charge/discharge cycles. The electrode materials displays high specific capacity of 639C g−1 at 0.5 A g−1 and outstanding cycling stability of 85% capacity retention after 10,000 cycles. Asymmetric supercapacitor fabricated using p-phenylenediamine-functional reduced graphene oxide (PPD-rGO) as cathode exhibits an considerable energy density of 72.6 W h kg−1 at the power density of 932 W kg−1. This design strategy holds great guiding significance for the preparation of high performance electrode materials.

Fast organic degradation on Ti- and Bi-based photocatalysts via co-deposited Pt and Ni3(PO4)2 nanoparticles

Environmental remediation via semiconductor (SC) photocatalysis has attracted great attention over the past three decades. However, prospect for large scale application is still under debate, basically due to the bottleneck of fast charge recombination and/or slow surface reaction. Herein we report a universal solution of speeding up organic degradation simply via co-deposited Pt and nickel phosphate (NiP). Several representative SCs have been examined, including TiO2 (anatase, rutile, and brookite) under a 320 nm light, and Bi-based SC (BiVO4, Bi2WO6, and Bi2MoO6) under a 420 nm light. In all cases, the rates of phenol degradation in aqueous solution always varied not only in the order of NiP/Pt/SC > Pt/SC > NiP/SC > SC, but also NiP/Pt/SC > (Pt/SC + NiP/SC + SC). Meanwhile, hydroquinone and benzoquinone were produced as the main intermediates, but their concentration was much lower than that of phenol decreased, especially for NiP-containing sample. The solid was characterized with several techniques, including photoluminescence and (photo)electrochemical measurement. It is proposed that Pt and NiP act as co-catalysts for O2 reduction and phenol oxidation, respectively. Such electron and hole transfer promote each other, additionally improving the efficiency of charge separation, and further increasing the rates of surface reactions. This work highlights the necessity of a versatile co-catalyst in SC photocatalysis.

A novel approach to investigate the synergistic inhibition effect of nickel phosphate nanoparticles with quaternary ammonium surfactant on the Q235-mild steel corrosion: Surface morphology, electrochemical-computational modeling outlines

Novel quaternary ammonium Surfactant, namely, N,N-dimethyl-N-(3-((2-nitrophenyl)sulfonamido)propyl)dodecan-1-aminium iodide (QAS-12) has been prepared and characterized. The inhibition performance of the individual QAS-12 surfactant and blended with nickel phosphate nanoparticles (NiPNPs) in 15% HCl on the Q235-mild steel was investigated by means of EOCP-t profiles potentiodynamic, LPR corrosion rate and EIS measurements. The findings display that the corrosion rate of Q235-mild steel is considerably decreased with rise in the surfactant dose where the protection power of QAS-12 extents a maximum value of 93.1% at 0.5 mM. Synergistic protection effect was detected between the cationic QAS-12 and the NiPNPs additives, with the maximum protection capacity as high as ~98.6%. The adsorption behavior obeyed the Langmuir isotherm model with competitive of physical and chemical adsorption between the surfactant and metal. The individual surfactant and mixed with NiPNPs performed as mixed type inhibitors. Surface morphology analysis using XPS, SEM/EDX, and UV–vis absorption studies verified the high efficiency of the cationic surfactant on the inhibition of Q235-mild steel in 15% HCl solution, and the synergistic effect on corrosion protection among the QAS-12 and the NiPNPs was confirmed. Correlation of Computational Modeling with empirical findings of the current work is discussed based on the DFT calculations and MC simulation. The proposed mechanism for the synergism resulting from both addition of the cationic surfactant and NiPNPs was also discussed according to the obtained outcomes.

Understanding the Reduction of Transition-Metal Phosphates to Transition-Metal Phosphides by Combining Temperature-Programmed Reduction and Infrared Spectroscopy.

Temperature-programmed reduction of transition-metal phosphate precursors is the most commonly used method for the preparation of transition-metal phosphides (a new class of versatile metal catalysts), but the reduction processes are still not clear. Here we describe the construction of a temperature-programmed reduction-infrared spectroscopy apparatus (TPR-IR) to analyze the gas flows during the reduction of nickel, molybdenum, and tungsten phosphates. PH3 and Pn+ species already appeared in the gas flows at low temperature (ca. 200 °C), and PH3 was involved in the formation of phosphides. The emission of PH3 and Pn+ during the reduction of the molybdenum and tungsten phosphates was smaller than that of the nickel phosphate. Ni2 P drastically accelerated the formation of the PH3 and Pn+ . These results explain why excess phosphorus is needed for the preparation of Ni2 P, and also demonstrate that the TPR-IR technique is an efficient method to understand the complex processes of catalyst preparation.

Understanding the Reduction of Transition‐Metal Phosphates to Transition‐Metal Phosphides by Combining Temperature‐Programmed Reduction and Infrared Spectroscopy

AbstractTemperature‐programmed reduction of transition‐metal phosphate precursors is the most commonly used method for the preparation of transition‐metal phosphides (a new class of versatile metal catalysts), but the reduction processes are still not clear. Here we describe the construction of a temperature‐programmed reduction‐infrared spectroscopy apparatus (TPR‐IR) to analyze the gas flows during the reduction of nickel, molybdenum, and tungsten phosphates. PH3 and Pn+ species already appeared in the gas flows at low temperature (ca. 200 °C), and PH3 was involved in the formation of phosphides. The emission of PH3 and Pn+ during the reduction of the molybdenum and tungsten phosphates was smaller than that of the nickel phosphate. Ni2P drastically accelerated the formation of the PH3 and Pn+. These results explain why excess phosphorus is needed for the preparation of Ni2P, and also demonstrate that the TPR‐IR technique is an efficient method to understand the complex processes of catalyst preparation.

Amorphous Bimetallic Phosphate–Carbon Precatalyst with Deep Self-Reconstruction toward Efficient Oxygen Evolution Reaction and Zn–Air Batteries

Amorphous transition-metal compounds (a-TMC) have attracted more and more attention due to their high electrocatalytic activity for the oxygen evolution reaction (OER). However, it is still a challenge to in situ synthesize a-TMC-carbon nanocomposites at elevated temperature and figure out the exact advantages of the amorphous structure. Here, an amorphous iron-doped nickel phosphate–carbon hollow nanocomposite (a-NiFePO-C) has been simply prepared by coprecipitation of metal ions and phytic acid, followed by a controllable annealing process. The results show that a-NiFePO-C can achieve a low overpotential of 268 mV at 10 mA/cm² and maintain 91.3% of the initial current density after a 9 h chronoamperometry test in a 1 M KOH solution with low mass loading of 0.1 mg/cm². The excellent performance of a-NiFePO-C is attributed to the low charge-transfer resistance, bulk self-reconstruction, and synergetic oxidation of the bimetallic sites during cyclic voltammetry (CV) activation, resulting in the formation of a highly OER-active Fe(III)-Ni(oxy)hydroxide-carbon nanocomposite. Moreover, the rechargeable Zn–air batteries powered by the a-NiFePO-C + Pt/C electrode can present a lower charging voltage and superior cycle performance than that powered by a commercial RuO₂ + Pt/C electrode.

Graphene oxide @ nickel phosphate nanocomposites for photocatalytic hydrogen production

The graphene oxide @nickel phosphate (GO:NPO) nanocomposites (NCs) are prepared by using a one-pot in-situ solar energy assisted method by varying GO:NPO ratio i.e. 0.00, 0.25, 0.50, 0.75, 1.00, 1.25, 1.50, and 2.00 without adding any surfactant or a structure-directing reagent. As produced GO:NPO nanosheets exhibited an improved photocatalytic activity due to the spatial seperation of charge carriers through interface, where photoinduced electrons transferred from NiPO4 to the GO sheets without charge-recombination. Out of the series, the system 1.00 GO:NPO NC show the optimum hydrogen production activity (15.37 μmol H2 h−1) towards water splitting under the visible light irradiation. The electronic environment of the nanocomposite GO-NiO6/NiO4-PO4 elucidated in the light of advance experimental analyses and theoretical DFT spin density calculations. Structural advanmcement of composites are well correlated with their hydrogen production activity.

Hollow cuboidal MnCo2O4 coupled with nickel phosphate: a promising oxygen evolution reaction electrocatalyst.

The growth of hierarchical morphologies of complex metal oxides directly on the substrate is a challenging task. Herein we report a unique hollow-cuboidal MnCo2O4 (h-MCO) morphology that offers insights into the efficient charge-transfer and surface kinetics for the oxygen evolution reaction. h-MCO coupled nickel phosphate under alkaline conditions outperforms the benchmark RuO2.

Microwave Assisted Synthesis of Amorphous Cobalt Doped Nickel Phosphate as Electrode Materials for Supercapacitor

Microwave Assisted Synthesis of Amorphous Cobalt Doped Nickel Phosphate as Electrode Materials for Supercapacitor