Ni-TiO2 Composite Coatings Research Articles

Improvement of the microstructure and corrosion behavior of Ni-TiO2 composite coatings electrodeposited at various amounts of TiO2 powder

The purpose of this study was to produce efficient Ni-TiO2 composite coatings at different concentrations of TiO2 particles to enhance BS2 microstructure and corrosion resistance in 3.5 wt. % NaCl. % NaCl solution. EDS analysis shows that the Ti and O content increases by increasing the amount of TiO2. XRD results reveal that the preferential growth plane of pure Ni is (100), which corresponds to the (111) and (100) planes for Ni-TiO2 composite coatings. SEM shows that the substrates are coated homogeneously. In addition to the microstructural improvements, the corrosion resistance efficiency was enhanced significantly with the inclusion of TiO2 particles. Specifically, the study showed that 10 g/L of TiO2 provided the optimal balance, achieving a corrosion resistance efficiency of 74.6%, along with a marked reduction in porosity. Furthermore, the surface morphology confirmed a uniform and defect-free distribution of the TiO2 particles, contributing to the overall anti-corrosion properties. These findings suggest that Ni-TiO2 composite coatings are a promising candidate for industrial applications, particularly in environments where materials are exposed to harsh conditions, such as marine environments. The outcomes of this research have the potential to inform the development of advanced anti-corrosion strategies for various industries.

Effect of supercritical carbon dioxide soft particles on incorporation of titanium dioxide nanoparticles into nickel matrix

This study reports effects of physical conditions of the supercritical carbon dioxide (SC–CO2) soft particles in co-electrodeposition of Ni–TiO2 composite coatings. The SC-CO2 soft particles are SC-CO2 micelles suspending in the emulsified electrolyte capable to improve transfer efficiencies of materials in the electrolyte. Physical conditions of the SC-CO2 soft particles are manipulated by varying the applied pressure and the CO2 volume fraction in the emulsified electrolyte. The effects on the surface morphology, Ni grain refinement, incorporated TiO2 amount, TiO2 dispersity in the Ni matrix, the micro-hardness and corrosion behaviors of the Ni–TiO2 composite coatings are investigated. Following an increase in the CO2 volume fraction, the average grain size of the Ni matrix is coarsened, the TiO2 content is lowered, and a more uniform dispersion of the TiO2 nanoparticles in the Ni matrix is observed. Also, the micro-hardness decreases from 1061 HV to 872 HV as the CO2 volume fraction increases from 0.2 to 0.6. When the applied pressure increases from 9 MPa to 17 MPa, a local minimum in the average Ni grain size, a local maximum in the TiO2 content, a local maximum in the micro-hardness and a local maximum in uniformity of the TiO2 dispersity in the Ni matrix are observed.

Electrodeposition of Ni-zirconia or Ni-titania composite coatings from a methanesulfonic acid bath

The study addresses the patterns of formation of Ni-ZrO2 and Ni-TiO2 composite coatings from methanesulfonate and sulfate electrolytes at pH 3. It has been shown that the aggregative stability of the dispersed phase particles is better in the methanesulfonate electrolyte than in the sulfate electrolyte. As a result, at the same volume concentration of the non-metallic phase in both electrolytes, the concentration of particles is larger in the methanesulfonate electrolyte. This ensures the formation of composite coatings from methanesulfonate electrolyte with a content of non-metallic particles increased by 20–30 vol% compared to sulfate electrolyte. A mechanism for forming a composite coating has been proposed, which takes into account the different rates of the metal phase electrodeposition on the electrode surfaces that are free from the dispersed phase or conditionally occupied. A mathematical model of composite coating formation has been developed, which adequately describes the obtained experimental data. Incorporation of the non-metallic phase into the nickel matrix leads to a change in the coating structure and decrease in the sizes of metal grains. It has been found that the physicochemical properties of Ni-ZrO2 and Ni-TiO2 composite coatings depend on the content of non-metallic phase particles in them. It has been revealed that the microhardness of Ni-ZrO2 coatings obtained from methanesulfonate electrolyte is 10 % higher than the microhardness of coatings deposited from sulfate electrolyte, which is due to a higher content of the non-metallic phase. The photocatalytic activity of Ni-TiO2 composite coatings correlates with the content of the dispersed phase in them, which is due to the participation of TiO2 particle surfaces, accessible to irradiation, in the photocatalytic reaction. It has been found that an increased content of the dispersed phase in Ni-ZrO2 and Ni-TiO2 composite coatings obtained from methanesulfonate electrolyte leads to increased values of their microhardness and photocatalytic activity.

Preparation of Ni-TiO2 Composite Coatings on Q390E Steel by Pulse Electrodeposition and their Photocatalytic and Corrosion Resistance Properties

Preparation of Ni-TiO2 Composite Coatings on Q390E Steel by Pulse Electrodeposition and their Photocatalytic and Corrosion Resistance Properties

Dispersity and Mechanical Strength Ni-TiO2 Composites Electrodeposited Via Supercritical CO2 Emulsified Electrolyte

Electrodeposition of metal matrix composites (MMCs) is an effective method to enhance physical and chemical properties of materials by allowing dispersion of nanoparticles into the metal matrix. Various kinds of metals including Au, Cu and Ni have been reported as the metal-matrix depending on their target application. In co-electrodeposition with nanoparticles, uneven distribution of the nanoparticles in the metal matrix caused by aggregation of nanoparticles in the electrolyte would lead to an unevenly local enhancement of the desired property. Therefore, in co-electrodeposition of MMCs, controlling the dispersity, such as the size and space distribution, of the particles in the metal matrix is always a research topic of interest. Supercritical carbon dioxide (SC-CO2) is a state of CO2 exists when the temperature and pressure are above its critical point. SC-CO2 has low surface tension and low viscosity, which are advantageous in co-electrodeposition of metal matrix composite. Dispersed phases in the SC-CO2 emulsified electrolyte would improve transfer of materials in the electrolyte and expect to influence incorporation amount and distribution of suspension particles in the electrolyte then eventually affect the dispersity in the electrodeposited metal matrix. In this study, Ni-TiO2 composite coatings are electrodeposited with SC-CO2 emulsified electrolyte. The effects of SC-CO2 emulsion on the amount and distribution of TiO2 particles incorporated in the Ni matrix, and the mechanical property of the Ni-TiO2 composite coatings are evaluated for applications in miniaturized electronics.Ni-TiO2 composite coatings are deposited on cold-worked Cu plates with 3.5 cm2 in surface area through a two-electrode deposition cell. Ni plates are used as counter electrode. Ni Watts bath-based electrolyte, which composed of NiSO4‧6H2O, NiCl2‧6H2O, and H3BO3, with and without addition of 30 g/L TiO2 nanoparticles are used for the electrodeposition process. Since SC-CO2 molecules are non-polar, 0.2 g/L of sodium dodecyl sulfate (SDS) is added to emulsify SC-CO2 with the Ni electrolyte. Pure Ni and Ni-TiO2 composite coatings fabricated from conventional electrodeposition method without addition of SC-CO2 are prepared as comparisons. Pure Ni coatings are named as Ni-S-# (# represents the concentration of SDS in electrolyte) and the Ni-TiO2 composite coatings prepared by conventional method are named as CV-S-#. For the composite coatings prepared from the SC-CO2 emulsified electrolyte, the samples are designated as SC-S-#. For all electrodeposition processes, the temperature is maintained at 50 °C, the deposition time is 40 min, and the applied current density is 30 mA/cm2. Conventional electrodeposition of pure Ni and Ni-TiO2 composite are conducted under ambient pressure, and 15 MPa is used for the electrodeposition with SC-CO2. Volume fraction of SC-CO2 in the reaction cell is 20 vol.%. Surface morphologies of the as-deposited films are observed with a scanning electron microscope. The element composition are characterized by energy dispersive X-ray spectrometry (EDS). The crystalline structure annd grain size are measured by X-ray diffraction spectrometer (XRD). Local density of TiO2 particles in Ni matrix are quantified by a python-based convolution process from Ti EDS mapping datasets. The Ti local density data is revisualized as heatmap and its coefficient of variation is calculated to evaluate the dispersity of TiO2 in composite coatings. Hardness of the films is evaluated by Vickers hardness measurement.TiO2 content and Vickers hardness of Ni-TiO2 composite coatings fabricated with representative electrodeposition conditions are shown in Fig. 1. Benefit from the accelerated mass transfer in SC-CO2 emulsified electrolyte, a significant increase of TiO2 incorporation amount could be found between SC-S-02 and CV-S-02. As a result of grain refinement and high incorporation amount of TiO2 in Ni-TiO2 composite coatings, the Vickers hardness of SC-S-02 is found at about 1150HV, which is threefold of the hardness of CV-S-02. Rest parts of the data, including the influence of SC-CO2 on surface morphology of Ni-TiO2 composite coatings and grain refinement of Ni matrix, and the effect of SC-CO2 on the improvement of dispersity of TiO2 particles incorporated in Ni matrix, will be presented in the ECS meeting. Figure 1

Electrochemical Corrosion Behavior of Ni–TiO2 Composite Coatings Electrodeposited from a Deep Eutectic Solvent-Based Electrolyte

The need to develop new electrochemical energy storage and conversion devices requires the creation of new, available, low-cost and high-performance electrocatalytic materials, which can be produced as coatings by electrodeposition technique. The electrodeposited composite coatings based on nickel seem to be very promising in this context. We studied the corrosion resistance of electrocatalytic Ni–TiO2 composite coatings fabricated by electrodeposition method using a plating solution based on deep eutectic solvents, a new environmentally friendly and affordable type of room-temperature ionic liquids. We investigated the corrosion behavior of Ni and Ni–TiO2 coatings (5 and 10 wt.% of TiO2) in a 3% NaCl aqueous solution as a corrosive medium. The corrosion parameters were determined by linear voltammetry and electrochemical impedance spectroscopy. It was established that the inclusion of titania particles in the Ni matrix and an increase in their content in the coating leads to a shift in corrosion potential towards positive values, a decrease in corrosion current density and an increase in polarization resistance. The observed effects of improving the corrosion resistance of coatings are associated with the barrier action of particles of the dispersed phase and the formation of corrosion microcells contributing to the inhibition of local corrosion.

Composition, topography and electrocatalytic properties of Ni-TiO2 composite coatings

Ni-TiO2 composite coatings were electrodeposited from the Watts electrolyte under different operating conditions. Chemical and phase composition, surface topography and roughness of composite coatings were investigated by X-ray fluorescence spectroscopy (XRF), X-ray diffraction (XRD), atom force microscopy (AFM). It was found that increasing current density and temperature results in more incorporation of TiO2 into nickel. The estimated percentage of a dispersed phase in coatings reaches 12–14 wt%. Ni-TiO2 composite coatings electrodeposited under lower current density and temperature differ in surface topography, in particular, they have a globular morphology. The results of cyclic voltammetric measurements indicate that Ni-TiO2 composite coatings showed higher electrocatalytic activity towards the oxidation of methanol compared to the pure Ni coatings.Selection and peer-review under responsibility of the scientific committee of 4th ISE Satellite Student Regional Symposium on Electrochemistry in Ukraine.

The role of TiO2 nanoparticles on the topography and hydrophobicity of electrodeposited Ni-TiO2 composite coating

Pure nickel and Ni-TiO2 composite coatings were deposited on the copper substrate using Watts bath containing different contents of TiO2 nanoparticles by the electrochemical deposition method, and the morphological alterations and hydrophobicity of coatings were studied. Field emission scanning electron microscopy (FESEM) images proved that composite coatings exhibited a rougher structure than pure nickel coating. The results of the roughness measurement performed by AFM confirmed this fact. The water contact angles (WCA) of pure nickel and the composite coatings were obtained as 62.7° and 91.6–121.7°, respectively. After surface chemical modification using the different concentrations of TMPSi, WCA of pure Ni and optimized composite coatings (Ni-27.5 g.L−1) were increased to 102.1° and 140.3°, respectively.

A novel magnetoelectrochemical method of synthesis of photoactive Ni-TiO2 coatings from glycinate electrolytes

This paper reports the results of analysis of magnetic field supported electrochemical deposition of Ni-TiO2 composite coatings from electrolytes containing nickel glycinate complexes. The effect of several parameters, including electrode potential, concentration of TiO2 in the electrolyte as well as value of magnetic field induction vector on deposition rate, composition, current efficiency, structure, surface states and surface morphology was described. Electrodeposited composites contained up to 1.43 wt% of TiO2. Depending on the applied electrolysis condition, current efficiency amounted to from 38 to 55.4% for B = 0 T and from 43.1 to 64.8 for B = 1 T. The electrochemical tests performed as well as determined diffusion coefficient values indicated that the magnetic field strongly influenced the kinetics of electrode processes. Voltammetric curves as well as further characterization of deposited coatings indicated that the deposition process is accompanied by precipitation of hydrides and hydroxides during electrolysis.

Electrodeposition of Composite Ni-TiO2 Coatings from Aqueous Acetate Baths

In this paper, results concerning electrochemical deposition of Ni-TiO2 composite coatings are presented. The influence of electrode potential, concentration of TiO2 in the electrolyte, as well as the influence of magnetohydrodynamic effect (MHD) on deposition rate, composition, current efficiency, structure, surface states, and coatings surface morphology is described. Electrochemical studies were preceded by thermodynamic analysis of the system. In addition, the electrokinetic potential (ZP) of TiO2 particles in applied electrolyte was determined. Electrodeposited composites contained up to 2.15 wt. pct of TiO2. Depending on the applied electrolysis conditions, the current efficiency recorded up to 31.7 pct for B = 0 T and up to 34.2 for B = 1 T. Electrochemical studies as well as further material characterizations indicated the strong influence of the magnetic field on processes taking place at the electrode surface. Several results indicated that the synthesis process is accompanied by precipitation of nickel hydroxides and nickel hydrides as well as by hydrogen evolution reaction (HER). The obtained coatings were also characterized in order to determine their photoelectrochemical properties.

Electrodeposition of Ni–TiO2 Composite Coatings Using Electrolyte Based on a Deep Eutectic Solvent

Deep eutectic solvents are nowadays considered to be very promising analogues of room temperature ionic liquids. They can make a significant contribution to the development of novel efficient, economic and environmentally friendly processes, particularly, in surface engineering and electroplating. The electrodeposition of Ni–TiO2 composite coatings from an electrolyte based on a deep eutectic solvent, ethaline, was studied in this work. Titania particles were introduced into the plating bath in the form of Degussa P 25 nanopowder. The content of titania in electrodeposited composite coatings was shown to depend on the stirring rate, current density and TiO2 concentration in the electrolyte and can reach ca. 2.35 wt %. The microstructure and the surface morphology of the obtained composite layers were characterized. The formation of nanocrystalline nickel matrix was detected. The introduction of TiO2 particles into nickel-based coatings resulted in an increase in the microhardness of deposits. The data obtained via the electrochemical impedance spectra technique revealed an improvement in the corrosion resistance of coatings due to titania particles incorporation into deposits. The Ni–TiO2 composite coatings manifested a photocatalytic activity towards the reaction of photochemical degradation of methylene blue organic dye in water solution.

Microstructure and Oxidation Behavior of Ni–TiO2 Composite Coating at High Temperature

Ni-based composite coatings are considered to improve the oxidation resistance of stainless steel. In this study, Ni–TiO2 composite coatings were electrodeposited onto the AISI 430 stainless steel. The isothermal oxidation of bare steel and steel with Ni–TiO2 coating was performed at 800 °C for 200 h. Moreover, cyclic oxidation of the coated and bare steel was performed up to 50 cycles. The coating layer and oxide scales were investigated by X-ray diffraction and scanning electron microscopy. All the coated specimens showed good oxidation resistance during the oxidation tests. The TiO2 particles in the coating affected the stability of the protective oxide scale. Furthermore, the coated steel showed a lower oxidation rate compared with the bare steel. It is concluded that TiO2 increases oxidation resistance by blocking the outward diffusion of Cr cations.

Surface quality of the Ni-TiO2 composite coatings produced by electroplating

Composite nickel coatings on a brass substrate were produced from suspensions consisted of a conventional nickel sulphate bath and fine TiO2 particles (dp < 0.35 ?m). Characterization of coatings surface was performed by using optical and SEM micrographs, by EDS analysis and by determining the surface roughness parameters. Metallographic analysis has also been done in order to get an insight about particles distribution throughout the thickness of the coating layer. Presence of TiO2 particles in electrodeposited metal affected the surface morphology. Particles were embedded as smaller or bigger agglomerates within the coatings, as well as the individual particles. Metallographic analysis showed uniform distribution of particles and their agglomerates within the coating. Surface roughness parameters of the composites have had up to 35 times higher values than the ones of the pure nickel coatings. Roughness maxima appeared at the concentration of particles between 10 and 20 g dm-3. Then it drops down and remains constant for concentrations > 40 gdm-3. SEM micrographs showed irregularities like single-nodule, or beads of nodules on the surface. Relationship between surface roughness and current density has not been noted.

Effect of titania particles preparation on the properties of Ni–TiO2 electrodeposited composite coatings

In this paper, the effect of titania particles preparation on the properties of Ni–TiO2 electrocomposite coatings has been addressed. Titania particles were prepared by precipitation method using titanium tetrachloride as the precursor. The titanyl hydroxide precipitate was subjected to two different calcinations temperatures (400 and 900 °C) to obtain anatase and rutile titania particles. These particles along with commercial anatase titania particles were separately dispersed in nickel sulfamate bath and electrodeposited under identical electroplating conditions to obtain composite coatings. The electrodeposited coatings were evaluated for their microhardness, wettability, corrosion resistance, and tribological behavior. The variation of microhardness with current density exhibited a similar trend for all the three composite coatings. The composite coating containing anatase titania particles exhibited higher microhardness and improved wear resistance. However, the corrosion resistance of the composite coating containing commercial titania powder was superior to that of plain nickel, Ni–TiO2 composite coatings containing anatase and rutile titania particles. The poor corrosion resistance of these composite coatings was attributed to the higher surface roughness of the coatings. This problem was alleviated by incorporating ball-milled titania powders. The composite coatings with higher surface roughness were modified with a low surface energy material like fluoroalkyl silane to impart hydrophobic and superhydrophobic properties to the coatings. Among these coatings, Ni–TiO2–9C coating exhibited the highest water contact angle of 157°.

Corrosion Resistance and Antibacterial Activity Performances of Ni-TiO2 Composite Coatings

Abstract The novel properties for the corrosion resistance in a 5% NaCl salt-spray-test and the inhibitory capability of Ni-TiO2 composite coating for the growth of pathogenic bacteria (E. faecalis, E. coli, and P. aeruginosa), under fluorescent irradiation and using a “drop-method” antibacterial experiment was set forth in this paper. The antibacterial activity of Ni-TiO2 composite coating became more significant by increasing the TiO2 contents in the composite coatings.