Impact of CeO2 incorporation in electrodeposited Ni-Fe on structure and physical properties of multifunctional nanocomposites (original) (raw)
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Influence of CeO 2 nanoparticles on the corrosion behavior of electrodeposited Ni coatings
Nickel-Ceria (Ni-CeO 2) nanocomposite coatings were developed on mild steel (MS) substrate using electrodeposition method. The codeposition of the nanoparticles was achieved from the optimized Ni plating bath loaded with CeO 2 nanoparticles (particle size <20 nm). Ni and Ni-CeO 2 coatings were achieved at a wide current density (c.d.) range from 1.0 to 5.0 A/dm 2 under optimal conditions, and their corrosion protection efficacy was examined in 5% NaCl medium. The material property of Ni coatings towards corrosion was found to be enhanced by the incorporation of the distributed phase, CeO 2 nanoparticles, into the Ni matrix. Potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) techniques were used to examine the corrosion behaviors of metal and nanocomposite coatings. The obtained results showed an improvement in corrosion resistance for Ni-CeO 2 coatings compared with Ni, and the nanocomposite coating obtained at 4.0 A/dm 2 was found to be optimal with least corrosion rate (CR = 1.8 10 2 mm/y). The coatings have been characterized using diverse instrumental methodologies such as SEM, EDS and XRD study, and results are discussed.
Journal of Rare Earths, 2018
A simple electrodeposition technique was used to prepare Ni-CeO 2 nanorods composite coating (Ni-CeO 2 NRs) using Watt's nickel plating bath containing CeO 2 nanorods (NRs) as the reinforcement phase under optimized process conditions. The X-ray diffraction analysis (XRD) was used for the structural analysis of Ni-CeO 2 NRs composite coatings and their average crystalline size is ~22 nm for pure Ni and ~18 nm, respectively. The crystalline structure is fcc for the Ni-CeO 2 nanocomposite coatings. The surface morphology of the electrodeposited Ni-CeO 2 NRs composite coatings was analyzed by scanning electron microscopy (SEM). Microhardness of pure Ni, and Ni-CeO 2 NRs composite coatings are found to be 253 HV and 824 HV, respectively. The inclusion of CeO 2 NRs increases the microhardness of Ni-CeO 2 NRs composite coatings. The corrosion resistance behavior of Ni-CeO 2 NRs composite coating was evaluated by Tafel polarization and AC impedance methods. It is revealed that CeO 2 NRs reinforced Ni matrix shows higher microhardness and corrosion resistance than existing reported electrodeposited pure Ni and CeO 2 nanoparticles reinforced Ni coatings.
Electrodeposition of Ni–Co composites containing nano-CeO2 and their structure, properties
Applied Surface Science, 2010
One of the most powerful rare earth oxides, ceria CeO 2 was incorporated in Ni matrix and the effect of cobalt addition in the matrix, on the structure and properties has been studied. The amount of cobalt incorporated in the Ni matrix was in the range of 25-85 wt.%. The presence of cobalt resulted in a marginal variation in CeO 2 content from 5 to 8 wt.%. The microhardness studies revealed that a maximum value of 540 Hk 50gf was obtained in the presence of 25 wt.% cobalt in Ni-CeO 2 matrix compared to 50 and 85 wt.% addition. The presence of 25 wt.% cobalt in Ni-CeO 2 matrix also improved its wear resistance as seen from Tribology studies. The wear products were identified using Raman Spectroscopy. The X-ray diffraction (XRD) studies showed that an increase in cobalt content from 25 to 85 wt.% resulted in a change in crystal structure from fcc to hcp. A change in surface morphology with variation in cobalt content was seen from scanning electron microscopy (SEM). It was perceived from the thermal stability studies that the presence of 85 wt.% cobalt in Ni-CeO 2 matrix imparted better stability in microhardness at temperatures up to 800 • C. Although, the incorporation of cobalt in Ni-CeO 2 matrix enhanced the microhardness, wear resistance and thermal stability it did not improve the corrosion resistance as noticed from immersion corrosion studies.
Materials
The Ni-TiO2 and Ni-CeO2 composite coatings with varying hydrophilic/hydrophobic characteristics were fabricated by the electrodeposition method from a tartrate electrolyte at ambient temperature. To meet the requirements of tight regulation by the European Chemicals Agency classifying H3BO3 as a substance of very high concern, Rochelle salt was utilized as a buffer solution instead. The novelty of this study was to implement a simple one-step galvanostatic electrodeposition from the low-temperature electrolyte based on a greener buffer compared to traditionally used, aiming to obtain new types of soft-matrix Ni, Ni-CeO2, and Ni-TiO2 coatings onto steel or copper substrates. The surface characteristics of electrodeposited nickel composites were evaluated by SEM, EDS, surface contact angle measurements, and XPS. Physiochemical properties of pure Ni, Ni-CeO2, and Ni-TiO2 composites, namely, wear resistance, microhardness, microroughness, and photocatalytic activity, were studied. Poten...
Synthesis and properties of electrodeposited Ni/ceria nanocomposite coatings
Surface and Coatings Technology, 2006
Composite plating is a method of co-depositing fine particles of metallic or non-metallic compounds or polymers in the plated layer to improve material properties such as lubrication, wear resistance and corrosion resistance. In the present study, Ni was chosen as the matrix material and ceria nanoparticles were chosen as the distributed phase. Nanocrystalline ceria powder was synthesized by the solution combustion process and characterized by powder X-ray diffractometry (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The nanosize ceria particles were co-deposited with nickel from a nickel sulfamate bath using conventional electrodeposition method. The electrodeposition was carried out at current densities of 0.23, 0.77, 1.55, 3.1 and 5.4 A/dm 2. The microhardness of the Ni matrix was enhanced by the incorporation of ceria particles. Potentiodynamic polarization, electrochemical impedance spectroscopy and SEM were used to characterize the corrosion behaviour of Ni and Ni/CeO 2 coatings. These studies showed improved corrosion resistance for Ni/CeO 2 when compared to Ni. The microhardness, corrosion resistance and wear resistance of Ni and Ni/CeO 2 were compared.
Structure and Properties of Electro Co-Deposited Ni-Fe/ZrO2 Nanocomposites from Ethylene Glycol Bath
2014
Ni-Fe/ZrO2 nanocomposite coatings were prepared by electrodeposition under direct current condition from nickel sulfamate and ferrous sulphate bath with ZrO2 nanopowder using ethylene glycol as a solvent. Plating parameters like current density, concentration of ZrO2 particles and electrolytes, temperature and agitation were optimized in terms of particle incorporation, microhardness and brightness of the deposits. Morphology, composition, micro and crystallographic structures of the coatings were investigated by SEM, EDAX, XRD and TEM. The iron content in the deposit varies from 38.2% to 19.1% showing fcc lattice by the Ni-Fe alloy matrix. Due to incorporation of ZrO2 particles in Ni-Fe matrix average crystallite size of the deposit reduces to ≈11 nm. The effect of current density and annealing temperature on microstructure, texture and microhardness was studied. With increasing current density from 1.0 to 5.0 A/dm 2 there is shifting of preferred orientation from (111) to (220) cr...
Applied Sciences
The composite of ceria has been widely studied as an electrode material for supercapacitors applications due to its high energy density. Herein, we synthesize CeO2/NiO nanocomposite via a hydrothermal route and explore its different aspects using various characterization techniques. The crystal structure is investigated using X-ray diffraction, Fourier transform infrared, and Raman spectroscopy. The formation of nanoflakes which combine to form flower-like morphology is observed from scanning electron microscope images. Selected area scans confirm the presence of all elements in accordance with their stoichiometric amount and thus authenticate the elemental purity. Polycrystalline nature with crystallite size 8–10 nm having truncated octahedron shape is confirmed from tunneling electron microscope images. Using X-ray photoelectron spectroscopy the different oxidation states of Ce and Ni are observed which play the role of active sites in the electrochemical performance of this nanoc...
Digest Journal of Nanomaterials and Biostructures
Ni-TiO2 nanocomposites coatings with a layer thickness of 21 μm have been obtained by electrocodeposition. Incorporation in nickel matrix of TiO2 nanoparticles (10 nm), affects the morphology of the nickel matrix as indicated from scanning electron microscope (SEM) and atomic force microscope (AFM) results. The chemical composition was studied by energy dispersive X-ray spectroscopy (EDS). Analysis by X-ray diffraction (XRD) revealed the inclusion of nickel particles in the matrix and their effect on nickel matrix crystal size changes.
THICKNESS DETERMINATION AND CONTROL OF FUNCTIONAL Ni–COMPOSITE ELECTRODEPOSITED COATINGS
Vietnam Journal of Science and Technology, 2018
Surface electrochemically plated with nickel and highly inert particles provides useful applications: Ni-CeO 2 as chemical catalysts, high hardness Ni-CBN (cubic boron nitride) as grinding tools, among others. The plating's inert particles-100 μm in size-on nickel surface need to be tightly adherent and evenly dispersed; it is therefore necessary to determine and control the coating layer's thickness corresponding to the inert particles' size by parameters like electrical current density and time. With 40-60 nm CeO 2 particle size, Ni plating thickness is 12 μm. With 60-100 μm CBN particles, Ni plating thickness is up to 60 μm. Weight and plating thickness were determined by the weight method and Faraday's law. The difference between the two methods showed the presence of inert functional particles on composite coating. EDX method and SEM image also showed the alignment as well as the distribution of particles on the coating surface. Catalytic ability of Ni-CeO 2 coating and abrasive properties of Ni-CBN coating were tested by special methods, proving composite plating method useful as catalyst sand grinding metal surface.