NiO Samples Research Articles

The influence of calcination temperature on the optical, magnetic and capacitive properties of NiO nanocrystals prepared with gas–liquid diffusion method

• The morphology of NiO samples evolve with increasing calcination temperature. • The hydrophilicity of nickel oxide decreases with the increase of calcination temperature. • The magnetic susceptibility of NiO samples decreases with decreasing defects and oxygen vacancies. Three NiO nanocrystals have been obtained by calcinating nickel-based precursor synthesized with a gas–liquid diffusion method. The characterization methods such as XRD, SEM, TEM and BET were used to analyze the structure and morphology of NiO samples. XRD data analysis indicated the crystallites size of three NiO samples increased with increasing calcination temperatures. SEM and TEM characterization can also demonstrate an increase in the size of the nano-microspheres. The optical properties were investigated by Ultraviolet–visible (UV–vis) analysis. Surface wettability test was realized by measuring the contact angle. The magnetic measurement was conducted with vibrating sample magnetometer. The electrochemical testing technologies such as CV and GCD were used to evaluate electrochemical behavior of three NiO samples in 2 mol L −1 KOH. The test results showed that surface area, hydrophilicity, magnetic susceptibility and specific capacitance all decreased with the increase in calcination temperatures. The optical properties study indicated that there were both red shift and decreasing intensity for absorption peaks of the NiO samples with the increase in calcination temperature.

Controlled growth of Mo-Doped NiO nanowires with enhanced electrochemical performance for supercapacitor applications

To cope with energy crises occurred owe to over-consumption in the domain of industrial and domestic, researchers are focusing to design some efficient energy storage devices specially supercapacitors. Here, Mo-doped NiO nanowires based electrode material for supercapacitors have been fabricated. XRD, SEM, TEM, FTIR, BET and XPS studies revealed the successful growth and doping of molybdenum in nickel oxide. Their corresponding CV studies revealed that among the 1-7 wt% Mo-doped NiO nanomaterials, the 5 wt% Mo-doped NiO nanomaterial showed highest value of CV (1096.64 Fg−1). GCD studies showed an excellent change retention (80.95 %) and EIS exhibited highly conductive nature. The capacitance of 5 wt% Mo-doped NiO sample is 874.02 Fg−1 after 3000 cycles, which is 79.7% retention and coulombic efficiency at the end of 3000th cycle is 92.20%. On the basis of these above-mentioned abilities, this best sample is proposed to be used for practically application for supercapacitors.

Bandgap engineering of NiO, and enhanced photocatalytic performance by Ca doping

Wide bandgap NiO is vital for the photodegradation of organic molecules like dyes, bacteria, viruses, and for water decontamination. Calcium oxide is another efficient catalyst due to the presence of greater active sites. In this study, CaO molecules were incorporated into the NiO matrix by calcium doping. It was assumed that the incorporation of CaO would enhance the photocatalytic performance of NiO. Pure and calcium substituted NiO samples were prepared by simple co-precipitation method. The samples were characterized by X-ray diffractometer, SEM, UV–visible, and FTIR spectrometer. XRD profiles show the successful formation of NiO and Ca-doped NiO cubic nano crystallites. UV–visible spectroscopy revealed a shift in absorbance peaks toward longer wavelengths and decreased bandgap in Ca-doped samples. Photodegradation study revealed superior photocatalytic performance of doped samples under similar conditions. The improved photocatalytic performance of Ca-doped NiO is attributed to greater active sites and decreased bandgap due to the formation of new energy levels by the impurity addition. This study demonstrates that calcium doping in nickel oxide has enhanced the photodegradation efficiency from 45 % to 98.15 %.

Direct In Situ Vertical Growth of Interlaced Mesoporous NiO Nanosheets on Carbon Felt for Electrocatalytic Ammonia Synthesis.

Metal oxide nanomaterials directly grown on conductive substrates are optimal electrode materials because their structures allow for rapid ion and electron transport and thereby reduce internal resistance in the electrode. The development of such binder-free, self-supporting electrodes is of great significance for applications in electrocatalysis. In this work, a simple hydrothermal in situ self-assembly reaction and annealing process was developed to prepare three kinds of nickel oxide @ carbon felt (NiO@CF) nanocomposites with different morphologies. The influence of different precipitators (strong or weak bases) on the morphology of the resulting nano-sized nickel oxide nanocomposites was investigated. The microstructures of the NiO@CF samples were characterized with field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). When ammonia was used as the precipitator, NiO grew vertically on the surface of the carbon felt and formed a mesoporous nanosheet-like structure (NiO NSs@CF). As an electrocatalytic nitrogen reduction reaction (e-NRR) electrode, the NiO NSs@CF sample showed an excellent NH3 yield (71.3 μg h-1 mg-1 cat. ) and Faradaic efficiency (17.9 % at -0.5 V vs. RHE) in 0.1 M Na2 SO4 . The good performance was attributed to the vertical interleaved mesoporous sheet-like structure (with the pore size of 15 nm and the thickness of ∼30 nm) and the relatively high concentration of oxygen vacancies. First-principles calculations with strong on-site Coulomb interactions demonstrated that the presence of oxygen vacancy on NiO sample leads to a significantly stronger N binding over the surface, benefiting for the nitrogen gas adsorption and reduction. The e-NRR performance of this binder-free, flexible electrode material is superior to that of other reported nickel-based nanomaterials. This study highlights the potential of such binder-free carbon felt electrodes for use in e-NRR that could meet the needs of industrial production.

Two-step fabrication of lanthanum nickelate and nickel oxide core-shell dandelion-like materials for high-performance supercapacitors

LaNiO3 and NiO are promising materials for supercapacitor applications. However, it is still challenging to design special structures based on these materials to improve the electrochemical performances of supercapacitor electrodes. In this work, a two-step method with low cost and convenient operation was developed to prepare dandelion-shaped LaNiO3/NiO (CSD-LaNiO3/NiO) with core-shell structure. The as-obtained CSD-LaNiO3/NiO showed high conductivity due to the core LaNiO3, which helped to provide an efficient electron transmission path for the shell NiO, producing a strong synergistic effect. The results of electrochemical properties of CSD-LaNiO3/NiO, LaNiO3 and NiO samples revealed the superior specific capacitance of CSD-LaNiO3/NiO (326.8 F g−1) at 1 A g−1 compared to LaNiO3 (166.5 F g−1) and NiO (44.2 F g−1). The as-obtained CSD-LaNiO3/NiO material was then mixed with activated carbon and assembled into an asymmetric supercapacitor, which exhibited a wide potential window of 1.8 V, energy density of 30.4 Wh kg−1 at 1800 W kg−1, and specific capacity retention of 97.7% after 3000 cycles. In sum, the as-obtained core-shell nanostructure prepared by the proposed synthesis method is very promising for future development of high-performance supercapacitors.

Effect of morphology and oxidation state of nickel on diesel soot oxidation activity

NiO sample is synthesized using the EDTA citrate complex method and calcined at 600 °C/5 h. Ni sample was acquired by reducing NiO to Ni at 600 °C in 4% H2/N2 atmosphere. Its physicochemical properties were obtained by XRD and Raman spectroscopy analysis, where it confirmed the complete reduction of NiO to Ni. SEM and TEM micrographs revealed a drastic particle growth for the Ni, indicating NiO sintering during the reduction process and a considerable surface morphology change. Ozawa and KAS methods were used to calculate the mean activation energy (Ea) value. NiO displayed lower Ea than Ni. Hence, NiO showed better catalytic activity than Ni.

Influence of La3+ ion doping on electrical conduction and thermal stability of NiO nanostructures

Ni1-xLaxO (x = 0.00, 0.01, and 0.03) nanostructures have been synthesized by the conventional sol-gel method, and further the electrical conduction and thermal stability have been investigated. It is observed that ε′ decreases with increasing frequency and does not exhibit any significant change with temperature T < 150 °C. It attains a high value ε′ ∼103-104 (75 kHz and 300 °C) for NiO sample. The high value of ε′ in pure and LNO samples might be explained via electron relaxation–mode-coupling model, associated with oxygen vacancies (OVs) which become dominant at high temperature. The high-temperature dielectric relaxation behavior was also observed in all the samples. The calculated activation energies (Ucond and Uac) from DC and AC conductivities, revealing that the relaxation behavior associated with the migration of OVs as confirmed by the EPR spectroscopy. On the other hand, a highly doped (x = 0.03) LNO sample shows high thermal stability than pure NiO, which needs a much higher degradation temperature, i.e., above 500 °C. The thermal activation energy was also determined in the temperature range of 80–150 °C.

Highly sensitive ultraviolet photodetectors fabricated from rare earth metal ions doped NiO thin films via nebulizer spray pyrolysis method

In this report, an automated nebulizer spray pyrolysis (NSP) route was chosen to prepare pure NiO and (1%- Er, Tb, Pr) RE doped NiO thin films samples on glass slides at 450 °C using nickel chloride as a source. Through systematical investigation their microstructure (XRD), surface morphology (FESEM), composition (EDX), optical (UV-Vis absorption and photoluminescence), UV photoconduction (Keithly source meter 2450) information were obtained. The face centered cubic structure occupying the space group (Fm3m) of NiO thin films was confirmed without any impurity phase through X-ray diffraction (XRD) analysis. Also, the effect of (1%- Er, Tb, Pr) RE doping with NiO on the crystallite size confirms that the higher ionic radii Pr-doped NiO sample possess a higher crystalline size of 31 nm. The morphological studies show that the pure and RE doped with NiO thin film samples possess highly dense cloudy spherical morphology. UV studies show that the Pr doped NiO sample exhibits higher absorption and lower bandgap of 3.49 eV. The emission peaks related to the presence of defect sites were studied through the PL analysis showing higher recombination centers occur for the Pr-doped NiO sample suggesting the sample possesses a higher carrier concentration. The fabricated pure and (1%- Er, Tb, Pr) RE doped NiO thin film photodetectors were analyzed through I-V, photo sensing parameters, and transient characteristics. The results show that the Pr-doped NiO photodetector sample possesses higher photocurrent, better responsivity (3.45 ×10−1 AW−1), detectivity (1.20 ×1010 Jones), EQE (81%), and the photo transient characteristics shows better response and repeatability of the photodetector samples under varying UV light intensities (1–5 mW/cm2). From the photo sensing results, it is confirmed that the Pr doped NiO photodetector sample can be better suited for the application of photodetectors.

Assembly of In2O3 nanoparticles decorated NiO nanosheets heterostructures and their enhanced gas sensing characteristics

In this work, a series of In2O3/NiO composites with hierarchical structure were prepared through an efficient synthesis method based on electrospinning technique and ion exchange reaction. Material characterization confirmed that the composite was composed by one-dimensionally aligned NiO nanosheets with In2O3 nanoparticles evenly attached to them. Gas sensing properties of the In2O3/NiO series composites were systematically investigated, accompanying with pristine NiO sample for comparison. An obvious enhancement in ethanol sensing performance was discovered for the NiO based sensor via decoration with In2O3 nanoparticles. The gas sensing mechanism of In2O3/NiO composite towards ethanol based on the formation of nanoscale p-n heterojunction structure was discussed. Besides, gas response properties of the In2O3/NiO series sensors to some harmful gases (including ethanol, DMF, acetone and ammonia) were found out to be highly dependent on the component content within the composites. The different gas sensing patterns of In2O3/NiO series sensors could be utilized to discriminate among these target gases.

Hydrothermal preparation of iron doped nickel oxide for electrochemical sensing of urea

This study is devoted to the synthesis of iron-doped nickel oxide nanomaterials with the help of the hydrothermal technique, to study the effect of different dopant concentrations on the structural, morphological, and Direct current properties. Various testing has been performed on the materials for their utilization in some potential chemical applications. X-ray study showed that the material is pure single phased NiO. A cubic crystalline structure was shown by pure NiO Morphology and was analyzed by SEM revealed oval/spherical crystallites of Fe-doped NiO samples where concentration was much low i.e., 2%. The materials showed unsymmetrical morphology when dopant concentration was increased (4% to 8%). Doped NiO material (8%) was utilized to modify the glassy carbon electrode (GCE) for electrochemical sensing of various chemical analytes. The results show that as-synthesized material exhibits a good sensing response towards urea (CH4N2O) detection with high selectivity and sensitivity as compared to different interfering compounds.

In Situ Hydrogen Activation Inspiring Efficient One-Pot Hydrogenation of Halogenated Nitrobenzenes over Ni–Co-Based Composites

Selective hydrogenation of halogenated nitrobenzenes (XNBs) to halogenated amines (XANs) is of great importance for practical applications. Non-noble metal-based catalysts have shown prominent advantages in price and reserves accompanying low activity and selectivity toward the hydrogenation of halogenated nitrobenzenes (XNBs) even under harsh conditions. In this work, inexpensive Ni–Co-based composites (NxCC) were prepared for in situ tandem hydrogenation of XNBs to XANs by using hydrogen released from ammonia borane (AB) hydrolysis under ambient pressure. The results show these NxCC samples exhibited superior catalytic performance against Co3O4 or NiO samples. A selected N0.2CC catalyst as the mainly screened one can quantitatively convert XNBs to XANs with unprecedented activity with 100% XAN conversion. This catalyst can completely convert m-chloronitrobenzene (m-CNB) to m-chloroaniline (m-CAN), suggesting N0.2CC efficiently suppresses the further dichlorination of m-CAN. Recycling test shows the N0.2CC possesses higher stability and recyclability. The N0.2CC catalyst was found to be a dual catalyst that synergistically catalyzes both the AB dehydrogenation (about 1735 mL min–1 g–1 of hydrogen generation rate) and the subsequent hydrogenation (almost 100% conversion) of XNBs. Notably, it is the first time that the rapid in situ hydrogen activation (IHA) which facilely arouses the efficient hydrogenation of adsorbed substrate on the surface of catalyst has been elaborated. From a unique perspective, distinctive and simple control experiments were innovatively designed for testifying the advantage of tandem hydrogenation in contrast with traditional hydrogenation. This work presents an efficient and environmental strategy to selectively produce XANs from XNBs using high-performance non-noble metal composites.

Antimicrobial and antioxidant properties of biosynthesized of NiO nanoparticles using Raphanus sativus (R. sativus) extract

The aim of this study was to explore the antibacterial and antioxidant efficacy of nickel oxide nanoparticles (NiO NPs). The Raphanus sativus (R. sativus) extract mediated NiO NPs were calcined at 100, 300, 600 and 900 ℃ in a muffle furnace for 3 h. The increased intensity of diffraction bands in the X-ray diffraction (XRD) spectrum suggest that the degree of crystallinity increases with increasing calcination temperature. The desired elements was depicted in the energy dispersive X-rays (EDX) spectrum confirm the purity of the NiO Sample. The variation in surface morphology and increase in the particles size from 12.78 to 51.42nm was determined from the transmission electron microscope (TEM) micrographs. The shift toward higher wavelength was observed in the diffuse reflectance spectroscopy (DRS) spectra with increasing calcination temperature, results into a clear decrease in band gap from 3.12 to 2.86 eV. The presence of hydroxyl group along with other organic moieties were confirm through Fourier transform infrared (FTIR) spectroscopy analysis. The biological potential of the calcined NiO NPs was examined during the antibacterial and antioxidant experiments. The antibacterial effect of NiO NPs was studied using the agar well diffusion process, and the ABTS free radical scavenging potential of NiO NPs was also assessed. The activity of NiO NPs calcined at 100 °C is greater than that of those calcined at higher temperatures.

Mesoporous-assembled TiO2-NiO-Ag nanocomposites with p-n/Schottky heterojunctions for enhanced photocatalytic performance

Construction of Schottky heterojunctions with plasmonic metals and p-n heterojunctions with p-type semiconductors have been considered as two effective approaches for boosting photocatalytic activity of TiO2. Here, we report on a magnetically-recyclable TiO2-NiO-Ag p-n/Schottky heterojunction photocatalyst fabricated by a facile and two-step approach combining spark discharge generation of mixed metallic nanoparticles under a protective argon atmosphere and a suitable thermal annealing process at air. Our comprehensive characterization studies revealed the formation of a mesoporous nano-heterostructure consisting of defective TiO2 nanoparticles that were finely incorporated with well-dispersed p-type NiO and Ag nanoparticles. Thanks to its extremely high surface area (223.07 m2 g−1), reduced optical band gap (~1.88 eV), improved visible-light absorption (~26% within 400–900 nm), and suppressed charge carriers recombination rate, our structure exhibited an enhanced photocatalytic degradation efficiency of 93.8% and a mineralization efficiency of 87.5% within 90 min irradiation towards methylene blue decomposition, superior to those of pure TiO2, NiO, and TiO2-NiO samples. This nanocomposite structure shows a large potential for practical application in the areas of environmental remediation and other photocatalytic applications.

Methanol sensing using Zn doped NiO nanoparticles

In the present study, we report gas sensing properties of Zinc doped nickel oxide nanoparticles. The Zn doped NiO samples were successfully synthesized by chemical co-precipitation method at room-temperature. Raman studies revealed the presence of defects such as nickel vacancies, which encourage the better sensing results. These defects are essential for providing active sites for adsorption of gaseous molecules and assists in improving the sensing parameters. Further, the sensor response of device has been found to be 7.2 when exposed to 100 ppm of methanol at 260 °C. Obtained Zn doped NiO sensor was found to be selective towards methanol as compared to other volatile compounds including, ethanol, acetone, ammonia and hydrogen.

Tuning Ni3+ quantity of NiO via doping of cations with varied valence states: The key role of Ni3+ on the reactivity

To unravel the role of Ni3+ cations in NiO-based catalysts on the reactivity, NiO samples doped by Li+, Zn2+ and Cr3+ cations were prepared to engineer different amounts of lattice and surface Ni3+ cations, and probed by CO oxidation. By using experimental and DFT calculation methods, it is disclosed that Li+, Zn2+ and Cr3+ cations have been doped into NiO lattice to generate solid solutions by replacing the lattice Ni2+ cations rather than refilling directly into the Ni2+ vacancies. Compared with pure NiO, Li+ doping promotes the generation of lattice and surface Ni3+, but Zn2+ and Cr3+ doping reduces the generation of Ni3+ cations. The quantity of surface active oxygen sites, which is critical to the reactivity, changes proportionally and linearly with the surface Ni3+ amount. As a result, the intrinsic CO oxidation activity follows the order of Ni0.9Li0.1O > NiO > Ni0.9Zn0.1O > Ni0.9Cr0.1O, which has proved strongly that the amount of surface Ni3+ controls the reactivity. Therefore, the oxidation activity of NiO can be improved by constructing a larger amount of surface Ni3+ cations.

Room temperature ferromagnetism in Zn-doped NiO nanoparticles: An experimental and DFT+U approach

Abstract We report the room temperature ferromagnetism in Zn-doped NiO nanoparticles of Ni1−x ZnxO (x = 0.00, 0.01, 0.03, 0.05 and 0.1) prepared by the sol-gel method. Zn dopant has significant influence on structural, optical, and magnetic properties of NiO crystal when there is a size reduction and lattice distortions. The crystalline nature of the samples were characterized by the room temperature X-ray Diffraction and we found that the range of crystallite size is about 7 ± 0.01 to 9 ± 0.01 nm for 3–10% of Zn doping concentration. The lattice parameter and the effective strain increases with the increase of doping concentration. Local structure and defects are probed through Raman characterization which reveals that there are no secondary or impurity peaks on the Zn-doped NiO samples. Photoluminescence spectra at room temperature shows two major emission peaks at wavelength 357 nm and 393 nm for both pure and Zn-doped NiO powder respectively. There also exists a blue shift for wavelength 357 nm emission band with the increase of Zn doping concentration. The band gap energy calculated from the PL spectra is ≈3.46 eV for pure NiO and it increases with the doping upto 3% then it decreases with further doping. To understand the effect of doping on magnetic properties, we measured the temperature dependent M-H loops and M-T curve for zero field cooled (ZFC) and field cooled (FC) condition in the temperature range 25–350 K using Vibrating Sample Magnetometer. We observed that the Ni1−x ZnxO nanoparticles are ferromagnetic in nature at room temperature with highest magnetic moment of ≈1.9 emu/g when the doping of Zn is 3% and it decreases with further increase of doping concentration. M-T data bifurcation peak was observed around 300 K and a broad peak in ZFC curve below the bifurcation. This broad peak is attributed to the thermal relaxation of uncompensated spins. We have also investigated the first-principle DFT+U calculation to study the electronic properties of the materials. The results show that the Zn-doped NiO with oxygen vacancies are ferromagnetic in nature whereas without defects the compound is non-magnetic, which agrees quite well with the experimental results. The nanoparticle with ferro-magnetic properties have potential application in the field of nanomagnetism and also its optical properties could be useful for optical device applications.

Multiple doped ZnO with enhanced thermoelectric properties

ZnO has a large thermal conductivity that hinders its satisfactory thermoelectric performance. In this work, we add multiple dopants including S, C, Fe and Ni to ZnO simultaneously. A low thermal conductivity ∼3 W m−1 K−1 is obtained, with an initial composition ZnO-1%S-0.15 %C-4%Fe2O3-3%NiO (sample #7), and comparable to the lowest reported values of ZnO-based bulk samples. We attribute the reduction to the Ni induced lattice distortion and the Fe induced microstructural changes. This composition also shows the highest power factor that is ∼60% higher than ZnO due to its highest charge carrier concentration and mobility. The overall dominant carrier scattering is through acoustic phonons rather than impurities. The resultant zT is 2.4 times higher than that of undoped ZnO at 973 K. We find multiple doped ZnO exhibits better thermoelectric performance than any single doped counterpart, providing an effective way to improve the thermoelectric properties of ZnO and other oxides.

Gasochromic properties of thin film oxides in terms of surface physics

A novel gasochromism phenomenon is descried using thin films of the ZnO, NiO and WO3 oxide semiconductors under hydrogen exposition, exhibiting rather advantageous properties than previously used fiber optic coating. The oxides were fabricated on glass substrates by RF Magnetron Sputtering technique. Structural and optical characterizations of the semiconductors were completed with XRD, Raman, SEM and optical absorption measurements. To investigate the optical response of these semiconductors to hydrogen gas, an optical gas sensor test system was prepared and programmed during the studies, using charged coupled device (CCD) signal processing. A nano-layer metal sensitizing of Pd and Pt up to 340% on the thin film surfaces of the various oxide samples of ZnO, NiO and WO3 have also been observed in the range of 450–850 nm wave lengths, covering the VIS-IR range. Overall optical response is rather amphoteric for n and p-type materials, having correlation with the resistivity responses. Present applications of the obtained devices on the hydrogen sensing up to low concentrations of 200 ppm, with relatively low response times around 70 s and that of recovery around 200 s, even at the room temperature execution. It is predicted that this extraordinary situation can also be used for various other applications such as smart windows and solar technology, especially in air and oxygen exposure.

Electro‑crystallized NiO nanoparticles for river‑water treatment applications

There is a fundamental relationship between properties of nanoparticles and their preparation method. In this study, NiO nanoparticles were electro-crystallized in an electrochemical cell containing two nickel electrodes, and an electrolyte solution of tetramethylammonium chloride and NaOH. The optimized reaction parameters obtained for the effective electro-crystallization of NiO nanoparticles were applied potential of 10 V, electrolyte concentration of 0.075 M, bath temperature of 20 °C, and annealing temperature of 400 °C. XRD results approved the formation of cubic structure of NiO. SEM images showed the mean particle size of spherical particles ranging from 12 to 47 nm. Based on UV–visible results, the value of band gap for typical NiO nanoparticles was obtained ~ 3.56 eV. The photoluminescence spectrum of a typical NiO sample showed two peaks at 370 nm and 670 nm, related to 3d8 electron transition, recombination between electrons and holes, or defects in NiO nanoparticles. The magnetization curves showed that all samples are magnetically soft and the specific magnetization is dependent on the particle size. The electro-oxidation of Ni was particularly effective for cobalt and cadmium removal from laboratory water at high voltages. This protocol was also successful for removing cobalt and cadmium from two rivers in Iran. Based on atomic absorption spectroscopy analysis, it is possible to remove ~ 100% of cobalt and cadmium from water using obtained nanoparticles. The method could be economically scaled up to industrial capacity.

Biomorphic NiO/Ni with a Regular Pore‐Array Structure as a Supercapacitor Electrode Material

AbstractPromoting the electronic conductivity and constructing regular porous structures are of high importance for increasing the electrochemical performance of oxides as supercapacitor electrodes. Herein, a simple biotemplating method is explored to synthesize NiO/Ni with regular pore‐array structures. The specific capacitance of the biomorphic NiO/Ni (381.4 F g−1 at 1 A g−1) is higher than that of the nontemplated NiO sample (251.2 F g−1 at 1 A g−1). Moreover, good rate capability and cycling stability are also demonstrated. The enhanced electrochemical performance should be attributed to the improved electronic conductivity of hybridized NiO/Ni component and the efficient mass/charge transport in the biomorphic pore‐array architecture.