Nickel Chloride Solution Research Articles

Mechanism of ultrasonic treatment under nickel salt solution and its effect on electroless nickel plating of carbon fibers

The carbon fibers were ultrasonically treated under nickel chloride solution, and nickel ions were attached to the surface of the carbon fibers, which replaces the nitric acid oxidation method used in the original electroless nickel plating. Electroless nickel plating was performed on the surface of the carbon fibers using a palladium-free technique successfully. Nickel-plated carbon fibers with a higher weight gain ratio than the original method was obtained. XPS was used to study the functional group changes on the surface of carbon fibers and the chemical valence of nickel element. The mechanism of ultrasonic treatment on the surface of carbon fibers was analyzed, and the effect of ultrasonic treatment on the weight gain rate of nickel-plated carbon fibers was discussed. The results show that the ultrasonic treatment under nickel chloride solution can significantly increase the content of polar functional groups on the surface of carbon fibers and can promote the bonding of the carboxyl group on the surface of the carbon fibers with the hydrated nickel ion to form CFCOONi. The formation of CFCOONi enhances the bonding strength between the nano-nickel particles and the carbon fibers, thereby increasing the bonding strength between the plating layer and the substrate. The concentration of nickel chloride solution and ultrasonic power during ultrasonic treatment has a great influence on the weight gain rate of carbon fibers after electroless plating. When the concentration is greater than 10 g/L, the higher the concentration, the smaller the weight gain rate. When the treatment concentration is less than 10 g/L, the concentration has little effect on the weight gain rate. The optimum treatment concentration obtained in the experiment was 7 g/L. As the ultrasonic power increases, the weight gain rate increases first and then decreases, and the optimal ultrasonic power is 80 W. Ultrasonic time does not have a large effect on the weight gain rate, but the too low ultrasonic time will cause a slight decrease in the weight gain rate.

Molecular Interactions of Transition Metal Chlorides in Water and Water–Ethanol Mixtures at 298–318 K on Viscometric Data

Viscosities of solutions of manganese chloride, cobalt chloride, nickel chloride, copper chloride, cadmium chloride and magnesium chloride at different concentrations have been determined in water and in ethanol + water mixtures at 303.15 K. Effect of temperature was also studied in 5% of ethanol in water at 298–318 K. The measured viscosity data has been analyzed by using Jones–Dole equation. The obtained parameters have been interpreted in terms of ion–ion and ion–solvent interactions. Activation parameters have been determined which explain the mechanism of viscous flow. In the present study all the taken transition metal chlorides and magnesium chloride were found structure promoters in water and in water + ethanol mixtures.

Synthesis and characterization of nickel aluminate nanoparticles

In the work, a simple synthesis route for obtaining NiAl2O4 nanoparticles was developed. The synthesis route used commercial aluminium foil (Al0) reacting with a solution of nickel (II) chloride (NiCl2) dissolved in a 25:75 Toluene/THF mixture in a controlled helium atmosphere. The reduction synthesis was carried out at 60 °C for 72 h. The phase transformation temperatures of the powder were determined through differential scanning calorimetry and thermal gravimetric analysis (DSC/TGA). The resulting mixture was dried at 80 °C, followed by sintering heat treatments at 500 °C, 700 °C, and 1100 °C, respectively. The powder samples were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), ultraviolet-visible spectroscopy (UV–vis), attenuated total reflectance (ATR), x-ray photoelectron spectroscopy (XPS) and high-resolution transmission electron microscopy (HR-TEM) analysis. The results showed the formation of a single NiO phase when sintered at 500 °C and a nickel aluminate (NiAl2O4)—nickel monoxide (NiO) biphasic mixture after 700 °C and 1100 °C calcinations. The NiAl2O4 nanoparticles displayed an average crystallite size of 13 to 19 nm while the NiO particles are at micrometric size due to the elevation of the sintering temperature.

Highly dispersed PVP-supported Ir–Ni bimetallic nanoparticles as high performance catalyst for degradation of metanil yellow

Bimetallic nanoparticles, a new class of materials for catalysis, were intensively investigated. Highly dispersed Ir–Ni bimetallic nanoparticles with varying mole fractions were synthesized by modified polyol reduction method from the solution of iridium trichloride and nickel chloride in ethylene glycol, which acts as both solvent and reducing agent. The particles were characterized for their size, morphology and composition using various techniques like UV–Vis, Fourier transform infrared (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM) and X-ray photo electron spectroscopic (XPS) techniques. The synthesized nanoparticles were in pseudo-spherical morphology and utilized as catalyst for the degradation of dyes. The feasibility of degradation of an azo dye i.e., metanil yellow (MY) in aqueous alkaline medium by hexacynoferrate (III) ions using Ir–Ni bimetals as catalyst, prepared in different molar ratios, was investigated. Results show that Ir–Ni (2:1) bimetals have good catalytic activity and degradation as compared to Ir–Ni (1:2) due to their small size and high stability for the oxidation of MY.

ZnO/Polytyramine nanocomposite film: Facile electrosynthesis and high performance electrocatalytic activity toward methanol oxidation

In the present study, the methanol oxidation reaction was investigated on a nickel ion incorporated to the zinc oxide-sodium dodecyl sulfate-polytyramine (ZnO-SDS-Pty) nanocomposite film by cyclic voltammetry and chronoamperometry. ZnO-SDS-Pty nanocomposite was prepared by using the repeated potential cyclic voltammetry in a solution containing ZnO nanoparticles and tyramine in an acidic solution of SDS by cycling the potential. The electrochemical oxidation of methanol was investigated by a stable redox behavior of the Ni(III)/Ni(II) couple at the potential of 0.4 V, after the immersion of the modified electrode (ZnO-SDS-Pty/G) in an alkaline media (i.e. NaOH 0.1 molL−1) of nickel chloride solution. The electrochemical characterization of the modified electrode exhibited that the ZnO-SDS-Pty nanocomposite, electrodeposited on the electrode surface, improved the catalytic efficiency of the dispersed nickel ions toward methanol oxidation. The catalytic rate constant and diffusion coefficient of the methanol oxidation reaction were calculated by chronoamperometry. The Ni-ZnO-SDS-Pty nanocomposite displayed a highly stable response during the oxidation of methanol, proving to be a suitable electrode material in methanol fuel cells.

Nickel extraction from nickel matte

In present work, the results of research activities to make nickel metal from nickel matte are presented. The research activities were covering a) nickel matte characterization using Inductively Couple plasma (ICP), Electron Probe Micro Analyzer (EPMA) and X-Ray Diffraction (XRD), b) nickel matte dissolution process to dissolve nickel from nickel matte into the spent electrolyte solutions that contains hydrochloric acid, c) purification of nickel chloride leach solution by copper cementation process to remove copper using nickel matte, selective precipitation process to remove iron, solvent extraction using Tri normal octyl amine to separate cobalt from nickel chloride solutions and d) Nickel electro winning process to precipitate nickel into the cathode surface from purified nickel chloride solution by using direct current. The research activities created 99, 72 % pure nickel metal as the final product of the process.

Stabilization of Ni2+ dimers in hexacyano Mo6 cluster-based Prussian blue derivatives: experimental and theoretical investigations of magnetic properties.

Herein, two new octahedral molybdenum cyanide cluster compounds, namely [{Ni(NH3)6}4{Ni2(NH3)8}1][Mo6Br6Q2(CN)6]3·12H2O, Q = S (1) and Se (2), have been synthesized as single crystals by slow diffusion of a solution of nickel chloride into aqueous ammonia solutions of a K2Cs2[Mo6Br6Q2(CN)6] molybdenum cyanide cluster-based compound. Both 1 and 2 were structurally characterized by single-crystal X-ray diffraction. They are isostructural and crystallize in the cubic system (Im3[combining macron]m (no. 229); Z = 2, a = 18.147(1) Å, and V = 5976(1) Å3 and a = 18.188(2) Å and V = 6016(2) Å3 for 1 and 2, respectively). 1 and 2 are based on the association of [Mo6Bri6Qi2(CN)a6]4- (Q = S, Se) cluster anions with Ni2+ dimer-based cubic [Ni2(NH3)8]4+ and octahedral [Ni(NH3)6]2+ cations. The structure is based on 2-fold interpenetrated [{Ni(NH3)6}4{Ni2(NH3)8}1][Mo6Br6Q2(CN)6]3 frameworks related to each other by [½, ½, ½] translation. The unit cell is based on a body-centered cubic framework of cubic [Ni2(NH3)8]4+. The [Mo6Bri6Qi2(CN)a6]4- (Q = S, Se) cluster units are located in the middle of the edges and at the center of the faces of the cell. The [{Ni(NH3)6}]2+ cations are located at the center of the cubes of the a/2 edge. The dimers [Ni2(NH3)8]4+ are stabilized by hydrogen bonds between the cyanide ligands of the cluster unit and the hydrogen atoms of the ammonia molecules. Both compounds exhibit a weak antiferromagnetic coupling within the [Ni2(NH3)8]4+ dimer entities at low temperatures together with a paramagnetic behavior originating from the cations of the octahedral [{Ni(NH3)6}]2+ complexes.

Electrooxidation Study of Amoxicilline Using Nano ZSM-5 Modified Carbon Paste Electrode

Introduction: This study investigated the electrocatalytic oxidation of amoxicillin on the surface of carbon paste electrode modified with synthesized nano zeolite which was doped with nickel ion in the basic solution. This electrode functions as a sensor to determine amoxicillin. Materials & methods: At first, the percentage of nano zeolite via carbon paste and the flotation of the modified electrode in the nickel chloride solution (1.0 M) for determination of drug were optimized. Then, the determination of amoxicillin in the 0.1 NaOH was conducted using cyclic voltammetry and chronoamprometry techniques. Findings: Obtained results show that the produced NiOOH on the surface of modified electrode acts as an electrocatalyst for the oxidation of amoxicillin. The linear dynamic range and the limit of detection for amoxicillin determination via the proposed electrode were 8.2* 10-5 M - 2.46* 10-4 M and 2.3*10-5 M. The catalytic rate constant for the electro-oxidation of amoxicillin was obtained 4.2*105 cm3s-1mol-1. Discussion & conclusions: Finally obtained results reveal that introduced procedure was simple, fast, available, repeatable, and sensetive.

Improved electron emission properties of the porous silicon emitter by chemical surface modification

A new chemical dipping method using nickel chloride (NiCl2) solution is proposed to improve the characteristics of an electron emitter based on porous silicon (PS). Two groups of PS samples were prepared, one group was then left untreated, while the other group was treated by the chemical dipping method. Energy dispersive x-ray (EDX) and x-ray photoemission spectroscopy (XPS) studies confirm the uniform filling of the reduced Ni and the formation of the SiO2 in the chemically dipped sample. The gold electrode was sputtered on the modified PS surface and the study of J-V characteristics show that the modified samples have more favorable rectifying behavior and longer-term durability than the unmodified one. The measured results showed that the voltage threshold ∼8 V, PVCR value ∼1.08, emission current density ∼48 μA cm−2, emission efficiency ∼0.72%, and stable emission were achieved for the modified sample; most of these electron emission characteristics were better than those from the unmodified emitter. Such improvements are mainly due to the decrease of the contact barrier height between the PS and the gold electrode, as is evident from analyzing the logarithmic J-V characteristics. The chemical dipping method is therefore expected to be a valuable technique to enhance the electron emission characteristics of the PS emitter.

Электроосаждение никеля из растворов, содержащих жидкие кристаллы

The possibility of obtaining structured nickel coatings by chemical and electrochemical deposition was investigated. Deposition was performed from electrolytes containing liquid crystals. The electrolytes were prepared from a saturated (aqueous or ammoniac) solution of nickel chloride and nonionic surfactant OP-10 at a weight ratio of solutions 1:1. The chemical deposition of nickel was performed on aluminium substrate, and electrochemical deposition was performed on nickel, copper and titanium substrates. Deposition on aluminum and nickel was performed from electrolyte composed of a saturated aqueous solution of nickel chloride and OP-10. During the deposition on copper and titanium the aqueous solution of nickel chloride was replaced by ammoniac one. The purpose of the replacement was to increase the pH of the solution and, as a consequence, to decrease the hydrogen evolution and increase output of nickel. Studies of the coatings by scanning electron microscope showed that in the case of deposition of nickel from aqueous solution coating contains mainly nickel hydroxochloride. When replacing a water solution by ammoniac, the precipitated coating comprises nickel metal in the form of dendrites with a size from 50 to 1000 nm.

Size-controlled reverse microemulsion synthesis of Ni and Co metal nanoparticles

Microemulsion synthesis of Ni and Co metal nanoparticles with controllable size has been studied in detail to allow replacing expensive metals (Pt and Re) in promising aqueous phase reforming of bio-derivatives. Reduction of nickel or cobalt chloride and nitrate aqueous solutions with N2H4 alkaline solution in the presence of cationic cetyltrimethyl bromide or anionic sodium dodecylsulphosuccinate surfactants provided formation of series of Ni and Co nanoparticles with mean sizes from 2.6 to 3.3 nm and from 1.0 to 5.4 nm, respectively. TEM, XRD, UV-Vis spectroscopy and XPS were applied to determine Ni and Co nanocluster sizes, composition and electronic state.

TU‐AB‐BRA‐04: An Investigation of Metal Artifact Effects in Multi‐Modalities: Development of MRI‐CT Heterogeneous Head and Neck Phantom for MRI‐CT Registration

Purpose:The purpose of this investigation was to develop an CT‐MR head and neck phantom which can investigate dose calculation differences between density‐assigned MRI and CT, and to compare non‐implant inserted registered MR‐CT registered image with artifact reduced image of MR‐CT registered image. It is to identify potential limitations related to dental implants of MR image and CT image and maximize the advantages to find interactive method to use registered image.Methods:The phantom comprises half‐circled shape which shaped to simulated the anatomical structures of a human head and neck. Through applying various clinical cases, the developed phantom is closely allied to human. Developed phantom can be verified in to opened‐mouth and closed‐mouth phantom. The case of the phantom was made of acrylic, which introduces a 0.003 parts per million (ppm) phase shift, whereas the Teflon results in a 0.03 ppm shift measured at 3T which represents human bone. Both materials are considered acceptable for MR field measurements. The phantom was filled with a solution of nickel chloride and sodium chloride. The implants and teeth were imaged by means of 3T MRI system.Results:In MRI image, the metal artifact reduced and the results in improved image quality and reduction of susceptibility artifacts originate in MR images. CT and MR artifact correction method resulted in substantial artifact reduction, both quantitatively and qualitatively. On head and neck CT images, it remained anatomical conformation but it has reduced streak and dark artifact which appeared around the dental restoration. The artifact reduced MR‐CT image improved image quality and calculation accuracy for patients with severe CT artifacts.Conclusion:By using MRI/CT and the artifact‐free slice location of the phantom, we demonstrated that the proposed artifact reduction method can effectively remove streak artifacts from a metal object.

Fabrication and performance of solid oxide fuel cell anodes from core–shell structured Ni/yttria-stabilized zirconia (YSZ) powders

A core–shell structured nickel/yttria-stabilized zirconia (Ni/YSZ) powder was synthesized by the hydrazine method from an aqueous nickel chloride solution (NiCl2·6H2O) with YSZ particles, which were prepared by a hydrothermal technique. The cationic surfactant cetyltrimethyl ammonium bromide (CTAB) was added to form the core–shell structure. Nano-sized YSZ shell particles were homogeneously coated onto the surface of the spherical Ni core particles. It was found that the addition of CTAB was crucial for the formation of the core–shell structured Ni/YSZ powder. The size of the YSZ shell particles affected the morphology of the Ni/YSZ core–shell powder. Finer YSZ shell particles led to a denser coverage of the Ni core particle. During the heat treatment of the Ni/YSZ core–shell powder in air, the Ni was partly oxidized to NiO, and a three-dimensional network structure of NiO and YSZ was obtained. The enhanced electrical conductivity in the Ni/YSZ anode because of the core–shell structured powder was considered to be due to the improved connectivity between the Ni and YSZ particles. The maximum power densities and the polarization resistances of the Ni/YSZ anode from the core–shell structured powder were 0.38, 0.57, and 0.84W/cm2 and 1.01, 0.52, and 0.25Ωcm2 at 700, 750, and 800°C, respectively.

The Effect of Common Cations on DNA Degradation

The process of DNA degradation is important to many scientific studies. Heat treatment is the standard procedure used to degrade genetic material by heating DNA-containing media past the DNA melting temperature, but certain chemical alternatives have been explored. More specifically, the presence of cations, such as Mg²⁺, has been linked to increased stability of DNA molecules subjected to high temperatures. However, the possible effects of other ions have not been extensively studied; perhaps cations similar to magnesium may offer more versatile effects. This study examines the effects that NH₄⁺, Ni²⁺, and Li⁺ have on the heat degradation and melting temperature of DNA. Magnesium chloride, magnesium sulfate, ammonium sulfate, nickel chloride, and lithium chloride solutions of different concentrations were mixed with DNA samples; the resulting mixture was heated and subsequently analyzed using gel electrophoresis. Treatment with NH₄⁺ did not yield effects that significantly differed from Mg²⁺, while Li⁺ proved effective at preserving DNA even at high temperatures. Treatment with Ni²⁺ resulted in marked degradation of DNA. These results show that magnesium, ammonium, and especially lithium ions can be used for the preservation of DNA. The specific effects of Li⁺ and Ni²⁺ on DNA are promising subjects for future research.

Preparation and Performance of Electroless Nickel on AZ91D Magnesium Alloy

The corrosion of magnesium alloy in different plating solutions was researched. The results demonstrated that corrosive condition of the alloy immersed in nickel chloride solution and nickel sulfate solution is serious and in nickel acetate solution and nickel nitrate solution is less. Magnesium alloy was handled with four acid pickling formulas and two activation formulas and the effects of different pickling formulas and activation formulas were researched through comparative experiment. The experimental results indicated that after handed with pickling formula about 500 mL L−1 H3PO4 (85%), 110 mL L−1 HNO3 (68%), room temperature for 30 s and activation formula about 375 mL L−1 HF (40%), room temperature for 10 min, magnesium alloy could realize electroless nickel plating directly and the performance of the prepared plating was much better. The properties of the nickel-plating coating were researched by electrochemical workstation, scanning electron microscope, and X-ray diffraction. The results demonstrated that this Ni–P coating was very uniform and meticulous; the structure of Ni–P coating was amorphous; and comparing with magnesium alloy, the corrosion potential of this plating increased about 799 V and the corrosion current density declined obviously. The nickel-plating coating effectively improved the anticorrosion performance of magnesium alloy.

Metastable Ni7B3: A New Paramagnetic Boride from Solution Chemistry, Its Crystal Structure and Magnetic Properties.

We trapped an unknown metastable boride by applying low-temperature solution synthesis. Single-phase nickel boride, Ni7B3, was obtained as bulk samples of microcrystalline powders when annealing the amorphous, nanoscale precipitate that is formed in aqueous solution of nickel chloride upon reaction with sodium tetrahydridoborate. Its crystal structure was solved based on a disordered Th7Fe3-type model (hexagonal crystal system, space group P63mc, no. 186, a = 696.836(4) pm, c = 439.402(4) pm), using synchrotron X-ray powder data. Magnetic measurements reveal paramagnetism, which is in accordance with quantum chemical calculations. According to high-temperature X-ray diffraction and differential scanning calorimetry this nickel boride phase has a narrow stability window between 300 and 424 °C. It crystallizes at ca. 350 °C, then starts decomposing to form Ni3B and Ni2B above 375 °C, and shows an exothermic effect at 424 °C.

Hydrogen production by the hydrolysis of milled waste magnesium scraps in nickel chloride solutions and nickel chloride added in Marmara Sea and Aegean Sea Water

The present study reports experimental results the effectivity of hydrogen production by the hydrolysis of milled waste magnesium scraps (MWMS) in nickel chloride (NiCl2) solutions (0.5 M–2.5 M) and NiCl2 added in Marmara Sea and Aegean Sea water. A micro-batch reactor is considered as hydrogen evolution reaction in solutions with variety of conductivity. The experimental results concern about hydrogen generation tests in presence of aqueous NiCl2 solutions, NiCl2 added in Marmara Sea and Aegean Sea water and also investigation of hydrogen generation kinetics at different temperatures (22 °C–60 °C). 2.5 M NiCl2 solution shows excellent MWMS conversion and hydrogen generation performance. Addition of 2.5 M NiCl2 into Marmara and Aegean Sea water has superficial effect on the conductivity and pH of solution and, MWMS conversion.

Electrocatalytic oxidation of ascorbic acid, uric acid, and glucose at nickel nanoparticles/poly (1-amino-2-methyl-9,10-anthraquinone) modified electrode in basic medium

Poly (1-amino-2-methyl-9,10-anthraquinone) (PAMAQ) modified electrode (ME) was synthesized at glassy carbon electrode in a binary solvent mixture containing acetonitrile and 5.0 M H2SO4 (1:1) employing a continuous cyclic voltammetry (CV) technique. Nickel (II) nanoparticle ions (NiNPs) were incorporated into the polymer by immersing the ME in an aqueous 1.0 M nickel chloride (NiCl2 6H2O) solution for 30 min. ME polarization process was performed in an aqueous 0.1 M NaOH solution using CV technique by sweeping the potential between 0.0 and 0.8 V with a potential sweep rate of 0.1 V s−1 for 30 scans to improve its electrochemical response. The obtained NiNPs/PAMAQ-polarized ME was characterized electrochemically using CV technique. The surface morphology of the NiNPs/PAMAQ-polarized ME was analyzed by scanning electron microscopy which demonstrates the presence of NiNPs within the surface of the film. NiNPs/PAMAQ-polarized ME showed excellent catalytic activities toward electrochemical oxidation of ascorbic acid (AA), uric acid (UA), and glucose (Glu) using square-wave voltammetry technique in their single, binary, and ternary mixtures. The ME was applied for the determination of UA, AA, and Glu in real samples.

Preparation of rod shaped nickel oxide thin films by a novel and cost effective nebulizer technique

Nickel oxide thin films have been deposited from 0.3M aqueous solution of nickel chloride onto microscopic glass substrates, which were chemically and ultrasonically cleaned before coating. The film depositions are carried out with 1ml, 2ml, 5ml and 10ml. The substrate temperature, spray rate, distance between substrate and nozzle and air flow rate were fixed at 400°C, 0.5ml per min, ~7cm and 1.2kg/cm2 respectively after optimization of these deposition parameters. The effect of the volume of sprayed solution on structural, optical properties and surface morphology of the films was investigated using X-ray diffractrometer, UV–vis–NIR spectrometer, photoluminescence spectrometer, Raman spectrometer, scanning electron microscope and liner four probe resistivity set-up respectively. The diffraction peak along (111) plane at 2θ=37.2° for all the films was observed. Besides this other low intensity peaks were observed along (200) and (220) Miller planes. The peaks indicated that this corresponds to cubic structure of NiO thin films. Optical transmittance and absorption spectra are recorded using a UV–vis–NIR spectrometer. When the quantity of sprayed volume increased, the transmittance decreased, consequently the band-gap energy wanes from 3.64 to 3.21eV. From PL spectra, the samples show sharp and strong UV emission around 376nm corresponding to the near band-edge emission of NiO under excitation of 275nm. The surface morphology of the films was carried out using SEM to find the smooth, uniform and pin hole free surface. The composition of the films was estimated using EDAX spectrum of the films. The resistivity results show that the activation energy decreases with increase in the sprayed volume solution.

A novel, effective and low cost catalyst for formaldehyde electrooxidation based on nickel ions dispersed onto chitosan-modified carbon paste electrode for fuel cell

In this study, a novel modified carbon paste electrode (CPE) was fabricated by chitosan and then Ni2+ ions incorporated to this electrode by immersion of the modified electrode in a 0.5 M nickel chloride solution. The values of charge-transfer rate constant and electrode surface coverage for Ni(II)/Ni(III) redox couple and redox sites of modified carbon paste electrode (Ni-CHIT/CPE) were found to be 0.174 s−1 and 7.38 × 10−8 mol cm−2, respectively. The electrochemical behavior of the Ni-CHIT/CPE electrode towards oxidation of formaldehyde was evaluated by cyclic voltammetry technique as well as chronoamperometry method. It has been observed that chitosan at the surface of CPE can improve catalytic efficiency of the dispersed nickel ions toward oxidation of formaldehyde. The values of electron transfer coefficient, diffusion coefficient and the mean value of catalytic rate constant for formaldehyde and redox sites were obtained to be 0.47, 2.68 × 10−6 cm2 s−1 and 2.06 × 105 cm3 mol−1 s−1, respectively. Obtained results from cyclic voltammetry and chronoamperometric techniques specified that the electrode reaction is a diffusion-controlled process. The good catalytic activity, high sensitivity, good stability and easy in preparation rendered the Ni-CHIT/CPE to be a capable electrode for electrooxidation of formaldehyde.