Nickel Oxide NiO Research Articles

Structure and properties of powders obtained by electrodispersion of pure Nickel metal waste in distilled water

Purpose. Investigation of the composition, structure and properties of powder materials obtained by electrodispersion of nickel waste of the PNK-0T1 brand in an oxygen-containing medium – distilled water.Methods. To determine the composition, structure and properties of powder materials, samples of powders obtained from waste nickel grade PNK-0T1 were studied. The powder material was obtained by electroerosive dispersion in distilled water. Microanalysis of powder particles was carried out using a scanning electron microscope, an analysis of the size distribution of powder particles was obtained using a particle size analyzer, an X-ray spectral microanalysis of powder particles was carried out using an energy-dispersive X-ray analyzer embedded in a scanning electron microscope, an analysis of the phase composition of powder particles was carried out using X-ray diffraction on the diffractometer.Results. During the study, it was revealed that the shape of the particles obtained from nickel powders is spherical and elliptical, and agglomerates of smaller particles are also noted on the increase. Oxygen and nickel are present in the composition of powder materials. The phases of pure nickel and nickel oxide NiO are marked in the phase composition. From the analysis of the granulometric histogram, it follows that the particle size spread varies in the range of 0.26...18.62 microns, the average volume diameter of the particles was 5.2 microns.Conclusion. The obtained research results can be used to develop a new heavy pseudo-alloy using metal waste from expensive raw materials by the method of electroerosive dispersion, followed by improvement and optimization of the composition and structure of the alloy.

Enhancement of NiO/Si solar cell by adding porous silicon and a silicon dioxide SiO2 carrier selective layer

In this work, we fabricated a novel heterojunction, Silicon-based solar cell. We used nickel oxide NiO thin films on porous silicon PS separated by a thin silicon dioxide SiO2 carrier-selective layer p-NiO/(SiO2) PS/(n+) Si (Silicon). For comparison, we also manufactured a p-NiO/(n+) Si device. The Atomic Force microscopy AFM and scanning electron microscopy SEM images highlighted the nanoporous pyramidal like structures for p-NiO/(SiO2) PS/(n+) Si devices that decreased the optical reflectivity to 2 %. From the electrochemical study, low resistance and high minority carrier lifetime (1.44 ms) were estimated for p-NiO/(SiO2) PS/n+-Si. The results are promising and agree with a high power conversion efficiency of 19.52 % for p-NiO/(SiO2) PS/n+-Si versus 3.8 % for p-NiO/Si.

Green Synthesis of Nickel Oxide NPs Incorporating Carbon Dots for Antimicrobial Activities.

A biosynthesis composite using the green synthesis of titled metal nanoparticles (nickel oxide nanoparticles, NiO NPs, and carbon dots, C-dots) was produced, characterized, and then applied for antimicrobial activities. NiO NPs were produced using the Croton macrostachyus (Bakkannisa) plant leaf extract and nickel nitrate (III) hexahydrate [Ni(NO3)2·2H2O] as precursors, while C-dots were produced using citric acid and o-phenylenediamine (o-OPD). The distribution of the average particle size of the NiO NPs and NiO NPs@C-dots was 25.34 ± 0.12 and 24.95 ± 0.22 nm, respectively. The antimicrobial effects of the prepared materials were tested against the selected bacterial and fungal strains. Based on the outcomes of the bioassay, it was realized that both the bare and composite materials were effective against all bacterial strains. The composite's high surface area with strong inhibitive effective antimicrobial effects against bacterial and fungal strains were observed. Therefore, strong inhibitive effects of 21-24 and 22-26 mm were observed with NiO NPs and NiO NPs@C-dots, respectively.

Study of the Synthetic Characteristics of Pure Cobalt - Tinged Nickel Oxide (Nio) Membranes (Co)

The pure nickel oxide ((NiO) doped with cobalt (Co) in different atomic ratios (at.% 3.6.9.12) were prepared by spraying on glass bases at a temperature of (550ºC), where a solution of nickel nitrate (Ni(NO3) 2.6H2O) is a source of nickel (Ni) with a molar concentration (0.2mol/L) and a cobalt chloride solution (CoCl 2.6H2O) with the same molar concentration as the previous source of the grafting element (Co), The effect of cobalt grafting on the structural Characteristics has been studied. The results of the X-ray examinations showed that the prepared Devices were of polycrystalline cubic structure, and the predominant orientation (111) for all the prepared Devices. It was found that cobalt grafting led to an increase in the intensity of the top of the trend (200) and its relative stability relative to the top of the preferential direction in the X-ray diffraction pattern, while there is a discrepancy in the values of the grain size with an increase in the proportion of cobalt grafting, as the results of the (FTIR) assays showed the emergence of the two chemical bonds (Ni-O) and (Co-O) which appear in the wavelength range (400-500 nm).

Chemical black nickel coatings on steels

Having high corrosion resistance and hardness, black conversion coatings are used as functional, as well as protective and decorative coatings. Black chrome and nickel electroplated coatings are mainly used for these purposes. The main drawbacks of the chromium plating processes are related to the fact that they are rather difficult to realize and control and that they consume a great amount of energy as the solutions need to be heated up and some of the heat gets lost during hydrogen evolution reaction. The known black nickel plating processes are less energy intensive and easier to implement, however they have their drawbacks, such as low protective ability and wear resistance and poor adhesion to the substrate, especially to steel. This paper describes certain processes that were tested, as well as two plating techniques for producing black wear-resistant coatings with a high protective ability on chemically deposited nickel-phosphorus layers. It was found that the treatment of black coatings with nitric acid and anodic treatment with phosphoric acid lead to increased roughness and porosity of the coatings. Nickel oxides NiO, Ni2O3, as well as nickel phosphates were found in the final coating. It was established that heat treatment enhances the wear resistance and protective ability of black nickel-phosphorus coatings and they even outperform black chrome and nickel electroplated coatings. The properties of the resulting coatings were studied using an OLYMPUS LEXT4100 confocal laser microscope, a Taber Elcometer 5135 rotary abraser, an EDX-7000 energy-dispersive spectrometer, an HB100 Auger microscope (Vacuum Generators, GB), and a 410 Quick Start Guide reflectometer. The paper demonstrates the possibility of using a safer chemical nickel plating process instead of chromium and nickel electroplating processes.The authors would like to thank the Mendeleev Shared Knowledge Centre for support of this research.

NON-THERMAL PLASMA EFFECT OF LI DOPED NIO THIN FILMS PREPARED BY THE SPRAY PYROLYSIS TECHNIQUE FOR SENSOR APPLICATIONS226

In, this research, pure nickel oxide NiO and Lithium-nickel oxide NiO:Li films were prepared on to glass substrates at a temperature of 450°C, by using the spray pyrolysis technique to develop the gas sensor, utilizing nickel and lithium chlorides as precursors. The effect of non-thermal plasma at (3,5,7sec) on the structural, optical, and electrical properties for NiO:Li thin films were studied. XRD pattern shows all films are polycrystalline belonging to cubic structure and the intensity was around the plane of (111).In addition, using SEM images, all samples exhibit porous with nanoparticles in the range (16-33nm ) as size. Optical measurements revealed that pure NiO and NiO:Li films have direct energy gaps (Eg) and decrease (from 3.65eV to 3.60eV), respectively. The optical energy gap was reduced after exposure to non-thermal plasma for 3,5,7 seconds (3.50, 3.45, 3.30eV) respectively. The results of Hall effect showed that the electrical conductivity of all films were of the p-type. The gas sensing performance of the prepared films towards NO2 gas was studied at various working temperatures, including (RT, 100 oC, 200 oC, and 300 oC). The current study found that pure NiO and NiO:Li films deposited can detect nitrogen dioxide gas at low work temperatures, where showed pure NiO, NiO:Li films sensitivity towards nitrogen dioxide NO2 gas at an operating temperature RT about 26.1% , 36.8% respectively. After exposure to non-thermal plasma at (3,5,7sec), the sensor NiO:Li showed an increase in sensitivity, and the best sensitivity was towards NO2 gas at room temperature for the sample exposed to non-thermal plasma at (7 sec) (49.9 percent ). The same sample showed a maximum sensitivity towards NO2 gas at 200 oC about (80.2%) with moderate response and recovery time. The influence of non-thermal plasma leads to good sensing performance for NiO:Li films, as shown in the study.

CREATION AND PROPERTIES OF CERAMICS FROM NICKEL OXIDE NANOPOWDER

By means of the method of the spark plasma sintering (SPS) on the basis of nanodimensional powder of nickel oxide (with an average particle size of about 100 nm), the fine-grained (of 250 – 500 nanometers approximately), dense (5.93 g/cm3), strong ceramics with the high microhardness Hv = 8.2 GPa, ultimate compressive strength ?B = 0.4 GPa and Young?s modulus of elasticity E = 140 GPa is created. The obtained ceramic sample was nickel oxide NiO (73-1519) with cubic structure, space group Fm3m (No. 225) and lattice size a = 4.168 ?.

Study the surface morphology and the chemical composition of NiPc:NiO nanocomposite thin films

The synthesis of organic and inorganic thin films based on nickel phthalocyanine (NiPc) and nickel oxide NiO nanoparticles. the thin films prepared by spin coating technic. The volume of the solution dropped on each slide is 50 micro liter at room temperature. Nanocomposites thin films NiPc:NiO with different percentage 1:0 75:25, 50:50, 25:75 and 0:1 are analysed using FESEM and EDX. The study of morphology and chemical composition of the synthesized thin films revealed the formation of NiPc in the form of rods and nickel oxide similar to spherical clusters. The EDX spectra revealed the appearance of oxygen in a high percentage in some samples, perhaps as a result of the chemical and physical adsorption. This is the first study on the combination and description of NiPc:NiO nanocomposite.

The structure, segregation and microhardness of the structural components of the Al – Ni – Zr alloys synthesized from nickel oxide NiO and brazilite concentrate by means of SHS metallurgy

Intermetallide Al – Ni alloys can potentially be used to create materials with unique properties. Alloying with refractory transition metals plays an important role in building a strong combination of physico-mechanical and performance properties in alloys. Such alloys serve as an innovative material in various fields of technology. Aluminothermic reduction of oxides of various metals (including mineral concentrates such as scheelite, brazilite and other concentrates) and the use of SHS metallurgy help obtain complex alloyed aluminides of nickel. Thus, the production process becomes much simpler and the cost of producing new high-temperature materials decreases. The authors applied the technique of ladle aluminothermic reduction to nickel oxide NiO and brazilite concentrate to obtain zirconium alloys with the following concentrations of zirconium: 0.47, 1.05, 1.67 and 3.52 wt %. Optical and scanning electron microscopes were used to study the microstructure of the alloys. It was found that the addition of 0.47 wt % Zr leads to a dramatic refining of the structural components of nickel aluminides Al3Ni2 and Al3Ni. Nickel aluminide AlNi is quite rare to be found. A further increase in the addition of zirconium to 3.52 wt % resulted in slightly coarser structural components of the Al – Ni – Zr alloys. With the help of scanning electron microscopy and electron probe microanalysis, a multiphase structure was established and the structural components of the Al – Ni – Zr alloys were identified. It was established how the distribution of elements (segregation processes) and the microhardness of the structural components tend to change in the Al – Ni – Zr alloys.1. Apart from nickel aluminide AlNi, which solidifies primarily as small compact inclusions, Al3Ni2 and Al3Ni form in the initial Al – Ni alloy. The crystals of Al3Ni envelope the grains of Al3Ni2.2. The conducted research helped establish how elements tend to distribute in the structural components, and the structural components were identified – nickel aluminides AlNi, Al3Ni2 and Al3Ni with strengthening phases – alloyed with nickel aluminides with Zr, Si and others, as well as with aluminium zirconides.3. A relationship was established between the changing microhardness and the distribution of elements in the structural components of the Al – Ni – Zr alloys.This research was funded by the Ministry of Education and Science of the Russian Federation under the Governmental Assignment No. FEME-2020-0010 “Physico-chemical and process basis of metallothermic synthesis of metals in ion melts of alkaline metals and complex alloyed nickel aluminides by SHS metallurgy”. The research was carried out as part of research and development covered by the Scholarship of the President of the Russian Federation: SP-1904.2019.1 (2019–2021) using the equipment of the Shared Knowledge Centre “Applied Materials Science”, a part of the Pacific National University.

Effect of anode materials of the Al-Ni-Zr system on the ESA process and wear resistance of coatings on steel 45

Composite alloys of nickel aluminides doped with zirconium were obtained from nickel oxide NiO and baddeleyite concentrate containing zirconium by the method of out-of-furnace alumothermal reduction. The multiphase structure of the ingot obtained by SHS metallurgy has been established by scanning electron microscopy and micro X-ray spectral analysis. With an increase of zirconium content in the alloy up to 3.52 wt.% the amount and variety of nickel aluminide phases doped with zirconium linearly increase. The influence of aluminum-matrix electrode alloys from Al-Ni-Zr on the ESA process and wear resistance of the coatings on steel 45 under various processing modes tsk/tp= 40/50 and 25/80 in the argon atmosphere and in air has been established and scientifically substantiated: The erosion resistance of the anode materials made of Al-Ni-Zr alloys does not change monotonously while changing the zirconium content in the argon atmosphere. The minimum erosion resistance of the anode alloy is observed at 1.05 wt.% Zr, and the maximum - at 3.52 wt.% Zr. The fact that erosion resistance of the anode materials in argon is lower than in air concerns all the Al-Ni-Zr alloys investigated and in all ESA treatment modes, except the anode material with 3.52 wt.% Zr; In all the cases, the greatest weight gain value at the formation of an alloyed coating during ESA (t = 10 μs) is observed when using the anode material with 1.05 wt.% Zr, which is characterized by low erosion resistance, and the smallest weight gain value - with 0.47 wt.% Zr with higher erosion resistance; the highest wear resistance is observed when the anode material contains 1.52 wt.% Zr at ESA in argon (it increases 2.8 times when compared to steel 45).

Structural Morphology and Optical Properties of Nanocomposites based Conducting Polymer

A simple, inexpensive, pulsed laser deposition (PLD) technique excimer source Nd:YAG laser was used for the preparation of the all films irradiation targets and deposite of nickel oxide NiO, polypyrrole PPy, carboxylic functionalized multi-walled carbon nanotubes (f-MWCNT), [PPy:(f-MWCNT)] nanocomposite, [NiO/PPy:(f-MWCNT)] and [PPy:(f-MWCNT)/NiO] films on fluorine-doped tin oxide (FTO) substrates. Surface morphology of all films and nanocomposite was investigated by Scanning Electron microscopy (SEM) display various morphology on the surface of the all films and nanocomposites, but the predominant structure is granular morphology, x-ray diffraction (XRD) indicates that the peaks of all films are broadening expect for PPy are sharp peaks, the optical absorbance spectra for the studied all films showed the maximum values around (425, 333, 347, and 397) nm refer to type transitions (π*-π) and (polaron-π*) and the maximum value of NiO around 346 nm. The optical energy gap of all films was determined and values around (2.2, 2.6, 2.8, 3, 3.2) eV. It has been observed that the measurements for films [NiO/PPy:(f- MWCNT)] and [PPy:(f-MWCNT)/NiO] may be identical and NiO nanoparticles are a good adhesion to nanocomposite films and interconnected in structure.

Application of Graphene/Nickel Oxide Composite as a Humidity Sensor

Molecular modeling analyses at Density functional theory DFT level was used to study the possible application of modified graphene (G) as gas sensor. A model molecules of graphene sheet was constructed then modified with nickel oxide NiO attached to graphene through covalent bonds forming G/NiO composite. DFT at B3LYP/6-31G(d,p) was utilized to investigate the physical properties of G; G/NiO; G/NiO/2H2O. Results show that interacting G/NiO composite with water molecules lowers the calculated energy of the formed structure reflecting the possibility of exposing G/NiO structure to humidity, since it forms more energetically stable composition that can be detected by a proper circuit. However, water addition results in significant reduction in the TDM which would enhance its stability. This would increase the efficiency of G/NiO material as a humidity sensor. Mapping molecular electrostatic potential indicated that, the impact of interacting with G/NiO composite through Ni end increases electron cloud on the terminals ensuring the great ability of this region to sense different water molecules. It is concluded that, the change in the physical properties of G/NiO under the influence of water molecules took place. Collecting these data together, it is clear that the studied G/NiO composite could act as humidity sensor.

The behavior of radioactive metals (Am, Eu, Sr) during the processing of radioactive graphite in salt melts

The behavior of Am, Eu, Sr radionuclides was investigated by thermodynamic modeling method at heating of radioactive graphite in NaCl – KCl – Na2CO3 – K2CO3 molten salt with additives of nickel oxide NiO. The integrated thermodynamic analysis was carried out by means of TERRA software in temperature range 373-3273 K to determine possible composition of condensed and gaseous phases. It was established that americium is in gaseous state in temperature range 2773-3273 K. Europium is in the forms of gaseous EuO and Eu in temperature range 2373-3273 K. Strontium is in the forms of gaseous SrCl2, SrCl, Sr, SrO in temperature range 2373-3273 K.

Improving the properties of Li4Ti5O12- a promising anode material for lithium-ion batteries

Two materials with the stoichiometric composition Li3.85Ni0.15Ti5O12and Li3.80Cu0.05Ni0.15Ti5O12were obtained by solid-state reaction using lithium carbonate Li2CO3, titanium oxide TiO2, nickel oxide NiO and copper oxide CuO. The materials were characterized in terms of phase composition, crystal structure as well as cycle performance. Phase composition and crystal structure parameters were determined using X-ray Panalytical Empyrean XRD diffractometer in the range of 10-110° with CuKa radiation. The results were analyzed using Rietveld refinement which was then implemented in the GSAS computer software. The electrochemical properties of the samples were measured by galvanostatic charge/discharge cycles at different rates over a voltage range of 1.0-2.5 V and 0.2-2.5 V. Cyclic voltammetry measurements were also carried out. It was proved that the addition of both Ni and Cu results in high specific capacity of LTO especially at high current rates (2C and 5C). The sample Li3.80Cu0.05Ni0.15Ti5O12delivers superior capacity above 200 mAh·g-1when discharged to 0.2 V.

Investigation of the properties of nanostructured nickel oxide NiO thin films irradiated at different γ-doses

Nanostructured thin films of Nickel oxide NiO were synthesized using spray coating method. The samples were irradiated at different γ-doses by Co-60 radioisotope. The obtained films were studied using X-ray diffraction (XRD), scanning electron microscopy, UV–visible spectrophotometry, Raman spectroscopy, photoluminescence (PL) spectroscopy and FT-IR. The experimental results demonstrated that the irradiation of NiO led to significant changes. XRD and Raman spectroscopy demonstrate that the as-deposited NiO samples show a cubic structure with (111) preferred orientation common at all gamma radiation doses. The optical energy gaps of the samples were found to decrease when increasing the γ ray dose, the Eg value decreases from 3.84 eV for as deposited NiO thin film to 3.60 eV for sample irradiated at 50 kGy. Scanning electron microscope (SEM) image of sprayed NiO films shows the high porosity and the presence of microcavities in surface of films.

Intelligent Modeling of Metal Oxide Gas Sensor

Due to the complexity of the gas detection process, traditional modeling techniques cannot provide accurate modeling performance to reproduce the behavior of this difficult process. In this paper, an intelligent modeling technique is utilized to develop an accurate model to represent the complex and nonlinear gas detection process. In particular, in this study nickel Oxide NiO gas sensor, which was specifically fabricated by a simple chemical spray pyrolysis technique. In the process, the nickel chloride hexahydrate salt was used at a concentration of (0.05 M) and a temperature of 350 ºC. Because of this process, the thickness of NiO was 0.1μm. Inspection was done using three different testing techniques; X-ray diffraction, scanning electron microscopy, and the sensitivity test of NiO for Methane gas CH4 in the range of (0-500) ppmv. Inspection results show that the film was crystalline, has a cubic system, and without cracks or open pores. On the other hand, the sensitivity results were disparate and low in value within the considered range. From the real-time experiment described above, training samples were gathered to develop the desired process model. The considered modeling technique was based on exploiting the wavelet network (wavenet) to represent the nonlinear function of the nonlinear autoregressive with exogenous input (NARX) structure. In model development process, the experimental data were utilized as the training samples for the wavenet-based NARX model. As the modeling accuracy, the proposed wavenet-based NARX model attained a value of 1.895 × 10-12 for the root mean square of error (RMSE) criterion.

Elimination of oxide films during Spark Plasma Sintering of metallic powders: A case study using partially oxidized nickel

We present a case study addressing the issue of surface cleaning of the particles of metallic powders from oxide films during Spark Plasma Sintering (SPS). Based on the results obtained using an intentionally oxidized powder of carbonyl nickel (O/Ni(at.)=0.2), we show that when the powder is heated in the SPS chamber but is not in direct contact with graphite foil commonly used in the SPS practice, the reduction of the oxide is limited to the surface layers of the powder bed. Comparative sintering experiments with graphite and copper foils indicate that a direct contact with a source of carbon is critical for the elimination of the oxide from the sintered compact. Compacts/regions of the compacts, in which nickel oxide NiO was reduced, showed more pronounced inter-particle necking than the regions maintaining the initial oxide concentration.

Physical properties of La-doped NiO sprayed thin films for optoelectronic and sensor applications

Lanthanum-doped nickel oxide NiO:La thin films were deposited onto glass substrates at 450°C, by the spray pyrolysis technique using nickel and lanthanum chlorides as precursors. These films belonging to cubic structure, crystallize preferentially along (111) plane. First, Raman study shows the presence of bands corresponding to NiO structure. The same study confirms the presence of both Ni(OH)2 and LaNiO3 as secondary phases. Moreover, using SEM observations, all samples exhibit porous microstructures with rough surfaces and spherical nanoparticles of about 40nm as size. Second, NiO:La films present a direct band gap energy value lying in the range of 3.63–3.84eV. Also, the effect of the La incorporation in NiO matrix on the disorder is studied in terms of Urbach energy. Some optical constants (refractive index, extinction coefficient, dielectric constants, and dispersion parameters) are reached. On the other hand, the photoluminescence spectroscopy reveals the presence of peaks related to the electronic transition of the Ni2+ ions and others confirming the presence of some defects in NiO matrix in terms of La content. Finally, it has been found that La doping allows the improvement of the electrical conductivity as well as Haacke’s figure of merit of NiO sprayed thin films by at least, three orders of magnitude.

Enhanced lead-free solder wettability of oxidized-nickel by Ar–H2 plasmas for flip chip bumping

Solder wettability (SW) of oxidized-nickel (ON) with liquid lead-free solder (LFS) (96.5Sn–3.5Ag) is notably improved by Ar–H2 plasmas from 0 % wetting of nickel substrate oxidized in air gases at 200 °C for 2 h to 100 % wetting of ON substrate treated by Ar–H2 plasmas at certain plasma settings. The SW of ON substrates with LFS is dependent on the surface characteristics of ON substrates. The enhanced SW of ON substrates with LFS by Ar–H2 plasmas is mostly due to a decrease in polar surface free energy and an increase in dispersive surface free energy on the surfaces of ON substrates. The ratios of the compositions of O to Ni are critical to the SW of ON substrate with LFS. The atomic compositions of Ni and O on ON substrates are analyzed by an energy-dispersive X-ray spectroscope. The nickel oxides NiO and Ni2O3 on the surfaces of ON substrate are identified by an X-ray photoelectron spectroscope.

Effect of Doping with Nickel Ions on the Electrical Properties of Poly(aniline-co-o-anthranilic acid) and Doped Copolymer as Precursor of NiO Nanoparticles

Poly(aniline-co-o-anthranilic acid) (PANAA) and its nickel composite (PANAA–Ni) are successfully prepared based on oxidative chemical polymerization via two comparative in situ and ex situ polymerization methods. PANAA copolymer contains aniline, and o-anthranilic acid moieties, were doped with different concentrations of nickel ions. The ratios of aniline, o-anthranilic acid, and nickel chloride were (1:1:0.5) and (1:1:1), respectively. The effect of nickel moiety on the properties of polyconjugated polymers, and their spectral characteristics (UV–Vis absorption spectra, FTIR, thermal stability) were recorded. TGA analysis confirmed that the poly(aniline-co-o-anthranilic acid)/nickel (PANAA–Ni) composites, which were prepared by in situ or ex situ polymerization method, are more thermally stable than the pure PANAA copolymer. The XRD revealed that the pure and PANAA–Ni (prepared by ex situ polymerization method) is completely amorphous structure, while the PANAA–Ni composite (prepared by in situ polymerization method) is a mixture of crystalline and amorphous phases. The temperature dependence of dielectric constants (er and ei) as well as AC conductivity (σac) were investigated in the temperature range of 300–383 K and test frequency range of 0.1–100 kHz. All the tested samples showed semiconductor behavior. The values of thermal activation energies ΔE1 and ΔE2 for PANAA copolymer are calculated, and found to be in the range of 0.03–0.1 eV and 0.58–1.88 eV, respectively. We calculated ΔE1 and ΔE2 for PANAA–Ni composite, and we found their values in the range of 0.14–0.27 eV and 0.41–0.58 eV, respectively. Moreover, Nanocrystalline nickel oxide NiO powder was prepared by thermal decomposition route of (PANAA–Ni) composites, which was prepared by in situ polymerization method. The size of the obtained nickel oxide nanoparticle was determined by transmission electron microscope .