NiO Nanostructures Research Articles

Marine alga-mediated facile green synthesis, antibacterial and enhanced catalytic activity of highly stable superparamagnetic NiO nanostructure

Marine alga-mediated facile green synthesis, antibacterial and enhanced catalytic activity of highly stable superparamagnetic NiO nanostructure

Hydrogen and oxygen production on Ag2O/NiO hybrid nanostructures via electrochemical water splitting

Among the different available methods, hydrogen production by electrocatalytic water splitting is the most attractive method. Here, Ag2O/NiO hybrid nanostructures with different molar ratios of silver and nickel ions were synthesized by co-precipitation method. Nickel oxide and silver oxide nanostructures was also prepared to compare with Ag2O/NiO nanocomposites. Investigations indicated that the as-prepared Ag2O/NiO nanocomposite with an equal molar ratio of metal ions shows high water splitting activity in 1 M KOH solution and only 430 and 140 mV are needed as overpotentials under a current density of 10 mA cm−2 for oxygen and hydrogen evolution reactions (OER and HER), respectively. Ag2O/NiO has the largest electrochemically active surface area, the lowest Tafel slope, the smallest semicircle diameter in the Nyquist plots, and the lowest charge transfer resistance for both OER and HER among all tested nanomaterials. Furthermore, Ag2O/NiO showed excellent stability for OER and HER for at least 30 h.

Synthesis of Nickel Oxide Nanoarchitecture Crystals as an Advanced Electrode Material for Supercapacitors

A NiO nanoarchitecture with a chain-like structure material was synthesized using a CTAB-assisted sonochemical method and then applied as an electrode in supercapacitors. Spectral analysis like XRD, FTIR and SEM was used to characterize the crystalline nature, internal structure and morphological properties of NiO nanoarchitecture. At a scan rate of 5 mV s-1, the NiO material exhibits a pseudocapacitive charge storage mechanism and provides a specific capacitance of 562 with good rate capabilities. Moreover, the chain-like NiO material exhibits outstanding cycle stability, retaining 96% of the original capacitance after 3,000 cycles at a scan rate of 100 mV s-1. The high-performance, chain-like nanostructured NiO material is easy to make and is of great interest for improved energy storage devices.

Exploring the growth kinetics of novel and diverse morphologies in nickel oxide nanostructures

This study focuses on the synthesis and characterization of nickel oxide (NiO) nanostructures with diverse morphologies, including nanoflowers, nanocapsules, and nanosnakes, achieved through a cost-effective hydrothermal method. Structural analysis using X-ray diffraction (XRD) confirmed the face-centered cubic crystal (FCC) structure of the NiO nanostructures, with accurate fitting of diffraction peaks achieved through Rietveld refinement within the Fm-3 m space group. The Ni-O bond lengths were determined as 2.0789 Å for nanocapsules, 2.1039 Å for nanoflowers, and 2.0824 Å for nanosnakes based on the 1D profile. The calculated average crystallite size, microstrain, and crystallite size using the Scherrer formula ranged from approximately 6 nm to 20 nm. The study investigates the formation mechanisms underlying the observed diverse morphologies of NiO nanostructures, which were further confirmed by field emission scanning electron microscopy (FESEM). Additionally, the electrochemical properties of the synthesized NiO nanostructures were evaluated using cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS). Notably, the nanoflowers demonstrated a higher specific capacitance compared to the nanocapsules and nanosnakes. This comprehensive investigation provides valuable insights into the growth kinetics, structural properties, and electrochemical behavior of novel NiO nanostructures, offering potential applications in energy storage.

Facile synthesis of Pd nanoparticles dispersed polypyrrole-carbon black/NiO nanocomposite with enhanced photocatalytic degradation of colored and colorless organic pollutants

Creation and designing of efficient visible-light responsive photocatalysts requires highly precise and extremely determined efforts in order to obtain material with promising properties and efficient transfer of charge carriers. In this work, we aim to develop and manufacture a distinct visible light photocatalyst consisting of NiO nanostructures, polypyrrole doped carbon black (PPyC) and Pd nanoparticles for wastewater treatment. The Pd NPs and PPyC doped NiO trio photocatalyst was developed via simple ultrasonication and photoreduction methods. XRD analysis showed that NiO has crystalline face centered cubic structure while the successful development of ternary photocatalyst was smoothly confirmed by X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared (FTIR) studies. Transmission electron microscopy (TEM) images showed that NiO possessed fine irregular shape particles with size ranging from 20 to 50 nm grown abundantly in huge density, while the PPyC exhibited beads shape structures interconnected with each other giving chain like appearance. The diffuse reflectance UV–vis spectra showed red shift and lowering in bandgap upon Pd and PPyC doping. The newly produced Pd-PPyC@NiO photocatalyst has been exploited for the photocatalytic removal of colorless insecticide imidacloprid and colored methylene blue (MB) dye under visible light irradiation. The newly created Pd-PPyC@NiO photocatalyst removed 96.0% of imidacloprid just in 20 min representing ⁓ 3 times more efficient than bare NiO. Furthermore, Pd-PPyC@NiO photocatalyst was exceptionally well towards the destruction of MB under same visible light source, indicating its potential use in photocatalysis.

Influence of exposure time and bias voltage on the response kinetics of toluene vapour on Ho3+-doped NiO chemiresistive sensors: Yellow-emitter nanophosphors

The incorporation of rare earths (REs) into semiconducting metal oxides is advantageous for creating surface defects and manipulating electronic structures. Therefore, the hydrothermal method fabricated p-type NiO nanostructures with various holmium (Ho3+) ion concentrations of 0, 1, 2, 3, and 4 wt% are investigated. The gas sensing features of the Ho3+-doped NiO sensors were conducted at different bias voltages and exposure times. At the bias voltage of 1 V with the exposure time of 5 min, the Ho3+-doped NiO sensors displayed a relatively high response of 36.35%, detection limit and sensitivity of 449 ppb and 0.749 ppm−1, respectively towards 60 ppm toluene at 100 °C. Upon increasing the exposure time to 1 h, at the applied bias voltage of 0.5 V, the response improved by almost 6 times (Rg/Ra ∼ 201%) towards 60 ppm of toluene, showing the outstanding toluene selectivity against benzene, xylene, ethyl-benzene and acetone vapours. The gas sensing findings proved that an appropriate concentration of Ho3+ doping, exposure time and applied bias voltage have a significant influence on the sensing performances. Further tuning of these features could result in an improved sensing response. The increased sensing mechanism is assigned to the creation of oxygen vacancies.

A sensitive, selective non-enzymatic electrochemical detection and kinetic study of glucose over Pt nanoparticles/SWCNTs/NiO ternary nanocomposite

BackgroundThe coupling of inorganic metal nanoparticles, semiconductor-based metal oxide nanostructures, and carbon nanomaterials is a promising strategy to fabricate efficient electrochemical sensors. Herein, we successfully designed a sensitive and selective electrochemical glucose sensor using Pt nanoparticles (PtNPs) decorated single-wall carbon nanotubes (SWCNTs) and nickel oxide (NiO) nanostructure-based composite materials. MethodsThe nanocomposite was synthesized without applying any dispersant or stabilizer using simple ultrasonication and photo-reduction techniques. Significant findingsThe morphology of nanocomposite reveals a homogenous dispersion of CNTs and PtNPs over the NiO nanostructure. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) demonstrated that the ternary nanocomposite-modified glassy carbon electrode (Pt@CNTs/NiO/GCE) displayed enhanced catalytic activity compared to CNTs/NiO/GCE, NiO/GCE or bare GGE electrodes. Kinetics studies indicated that the glucose electrooxidation using Pt@CNTs/NiO modified GCE followed irreversible diffusion-controlled kinetics with a transfer co-efficient value (α) ≈ 0.50. Amperometric sensing investigation revealed excellent sensitivity (149.36 µA mM−1 cm−2) and a lower limit of detection value (2.16 µM). The currently fabricated sensor electrode showed appropriate selectivity in the presence of various organic and inorganic species with outstanding repeatability, reproducibility, and sensor stability. The newly fabricated nanocomposite can represent a promising electro-catalyst for the efficient sensing of glucose and other biomolecules by the electrochemical approach.

Enhanced electromagnetic interference shielding in nickel oxide and graphene composite nanostructures loaded polyvinylidene difluoride thin films

Polyvinylidene difluoride nanocomposites having high dielectric, microwave absorption and electromagnetic interference (EMI) shielding properties has been prepared by loading Nickel oxide (NiO) and NiO embedded graphene hybrid nanostructures into PVDF matrix, and characterized. NiO nanoparticle and NiO/graphene were synthesized from hydrothermal reactions at 80 °C. The nanocomposites are prepared by the solvent casting method of NiO and NiO/graphene hybrid nanomaterials embedded PVDF are evaluated for their thermal, morphological, dielectric, microwave absorption and electromagnetic interference shielding behavior. The TGA results revealed that the thermal permanence of the nanocomposites was improved proportional to the NiO and NiO/graphene content in the PVDF matrix. The SEM analysis revealed the dissemination of the NiO nanoparticles (3%) indicating homogeneous distribution unvaryingly throughout the PVDF matrix. The 10 wt% of NiO/Graphene/PVDF composites showed highest conductivity of 6.8 × 10-14 at 1000 Hz and a dielectric constant of 90. The reinforcement of 3% NiO in PVDF matrix leads to a tremendous enrichment in the EMI shielding value with a highest shielding effectiveness of 39 dB at 10.3 GHZ which is considerably higher than the Pristine PVDF and other samples prepared.

Remarkable effects of laser irradiation in adjusting the structural, morphological, and optical properties of spray pyrolysis-synthesized NiO nanostructured films for optoelectronic applications

Remarkable effects of laser irradiation in adjusting the structural, morphological, and optical properties of spray pyrolysis-synthesized NiO nanostructured films for optoelectronic applications

Hydrogen storage properties of surface oxidized LiBH4 system catalyzed with NiO nanorods and nanoplates

This paper highlights the hydrogen storage performance of surface oxidized LiBH4 (Lithium borohydride) system incorporated with NiO nanostructures under 250 °C. Surface oxidized LiBH4 system was impregnated with hydrothermally synthesized mesoporous NiO nanorods (NiONR) and NiO nanoplates (NiONP) using simple ultrasonication method. Hydrogen sorption and desorption studies has been investigated for LiBH4/NiONR and LiBH4/NiONP systems for the first time. The Brunauer-Emmett-Teller results showed that the specific surface area of NiONR, NiONP, LiBH4/NiONR and LiBH4/NiONP systems were 77.92, 88.12, 96.67 and 101.65 m2/g, respectively. Hydrogenation followed by isothermal dehydrogenation at 250 °C revealed that the LiBH4/NiONR and LiBH4/NiONP systems released ∼3.44 wt% and 4.02 wt% of hydrogen respectively in 60 min. Using the Kissinger's relation, the activation energy (Ea) was calculated as 69.28 and 63.23 kJ/mol for LiBH4/NiONR and LiBH4/NiONP systems, respectively. The dehydrogenation rate of LiBH4/NiONP system was found to be greater than that of LiBH4/NiONR system due to its large surface area and lower activation energy. The reported results revealed that nickel oxide nanostructures incorporated surface oxidized LiBH4 systems provide new opportunities for the solid-state hydrogen storage applications.

"Electrical and Magnetic Properties of Nanostructured NiO Thin Films Prepared by Spray Pyrolysis Method"

"Electrical and Magnetic Properties of Nanostructured NiO Thin Films Prepared by Spray Pyrolysis Method"

A two-dimensional hybrid of NiO nanowalls and reduced graphene oxide for superior field emission

The sharp and 2D nanostructure of nickel oxide (NiO) was synthesized hydrothermally on the nickel(Ni) foil and studied for field emission application. Graphene oxide (GO) and reduced graphene (rGO) is also good field emitter due to their unique electrical properties and geometry. The 2D_NiO nanostructured substrate was coated with GO solution, and it form a hetero-structure. The structure, morphology, and elemental details of as-synthesized materials, as well as hybrid samples, were determined by using X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and X-ray photoelectron spectroscopy (XPS). The field emission study of the samples was studied for NiO nanostructures samples showed field emission response. The turn-on field and maximum currents are 7.5 V/μm and 4.9 mA/cm2; for graphene oxide coated Ni foil, Ni_GO sample, 14 V/μm, and the maximum current is 2.6 mA/cm2. With a coating of GO on the NiO nanostructured surface, the field emission response enhanced abruptly. In the hybrid sample, NiO_GO, the field emission response is enhanced abruptly, the turn-on the field and the maximum current are 5.7 V/μm and 15.5 mA/ cm2, respectively. The field emission response is substantially increased than that of the individual 2D nanostructure, which has shown a low field emission. The field emission response increased further, introducing rGO on the Nanostructured substrate. In the NiO_rGO sample, the turn-on field and the maximum currents are 4.4 V/μm and 39.6 mA/ cm2, respectively.

Effects of precursor salts on the morphological, optical, and structural properties of NiO synthesized using a hydrothermal route

A typical transparent conductive oxide with inherent p-type conductivity is nickel oxide (NiO). Recently, due to its intriguing properties such as chemical stability, morphology, optical properties, and electrical properties, NiO has been recognized as one of the most auspicious oxides developed via various techniques and employed in optoelectronic applications. For this study, nickel chloride and nickel nitrate were used as precursors to create NiO nanostructures through a simple hydrothermal technique. XRD, FTIR, FESEM, and UV–Visible spectroscopy were used to analyze the nanostructures. XRD showed the phase identification and the lack of impurities in the cubic NiO nanostructures. FESEM showed the formation of irregular shaped nanoparticles of different sizes. FTIR suggested the presence of M – O bonds. Tauc's plots were used to calculate the direct optical band gaps of the samples, which were between 3.05 and 3.27 eV. The mechanism of formation and the reasons for the observed effect were discussed. This technique can be used to control the optical and morphological characteristics of NiO and can be used for various applications.

Synthesis, Structural, Optical and Electrical Properties of Pure and Doped NiO Nanostructures Prepared via The Co-precipitation Method

Here, we report the synthesized high purity NiO nanostructures using simple and inexpensive chemical route. NiO NPs and (Cu, Zn) single and dual doped NiO NPs prepared by co-precipitation technique and annealed at 350 ℃ for 2 hours. Structural properties of prepared samples were investigated by X-ray diffraction (XRD). The optical characterizations and electrical conductivity were characterized by UV-vis spectrophotometer and I-V measurement. The crystallite size for dual doped NiO samples was 7.9 ± 0.9 nm compared to pure NiO, which had 9.52 nm. These results are consistent with the ionic radii of the doped metals. The obtained values of the band gap energy increased from 3 eV for pure sample to higher values (3.14 ± 0.06 eV) for doped samples due to the quantum confinement effect. These results agreed with the DC conductivity of samples. The ionic conductivity σ_ionic was developed with dual doping. The characterization of the doped samples makes them good candidates for photoelectronic applications.

Tuning the structural, magnetic, and electrochemical properties of Mo-doped NiO nanostructures prepared by coprecipitation method

Tuning the structural, magnetic, and electrochemical properties of Mo-doped NiO nanostructures prepared by coprecipitation method

Green Synthesis of NiO Nanoflakes Using Bitter Gourd Peel, and Their Electrochemical Urea Sensing Application

To determine urea accurately in clinical samples, food samples, dairy products, and agricultural samples, a new analytical method is required, and non-enzymatic methods are preferred due to their low cost and ease of use. In this study, bitter gourd peel biomass waste is utilized to modify and structurally transform nickel oxide (NiO) nanostructures during the low-temperature aqueous chemical growth method. As a result of the high concentration of phytochemicals, the surface was highly sensitive to urea oxidation under alkaline conditions of 0.1 M NaOH. We investigated the structure and shape of NiO nanostructures using powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). In spite of their flake-like morphology and excellent crystal quality, NiO nanostructures exhibited cubic phases. An investigation of the effects of bitter gourd juice demonstrated that a large volume of juice produced thin flakes measuring 100 to 200 nanometers in diameter. We are able to detect urea concentrations between 1-9 mM with a detection limit of 0.02 mM using our urea sensor. Additionally, the stability, reproducibility, repeatability, and selectivity of the sensor were examined. A variety of real samples, including milk, blood, urine, wheat flour, and curd, were used to test the non-enzymatic urea sensors. These real samples demonstrated the potential of the electrode device for measuring urea in a routine manner. It is noteworthy that bitter gourd contains phytochemicals that are capable of altering surfaces and activating catalytic reactions. In this way, new materials can be developed for a wide range of applications, including biomedicine, energy production, and environmental protection.

Fabrication of sodium and MoS2 incorporated NiO and carbon nanostructures for advanced supercapacitor application

Transition metal oxides and carbonaceous nanocomposites have triggered enormous interest in the application of high-performance supercapacitors due to the outstanding electrical conductivity and superior theoretical capacitance. In this study, we prepared highly porous nanostructured NiO/C yolk-shell nanocomposites via a simple calcination of nickel-based metal-organic frameworks. The porosity and electrochemical property were further enhanced by incorporating sodium and hierarchical MoS2 nanostructures via a facile hydrothermal method. It was found that the as-synthesized Na-doped MoS2@NiO/C nanocomposites with hierarchical porosity exhibited superior electrochemical performance. Particularly, the delivered electrochemical capacitance of NiO/C yolk-shell structure was 1779.50 F g−1 in an aqueous electrolyte (2 M KOH), and a superior specific capacitance of 2540.63 F g−1 was acquired after the incorporation of sodium and 2D layered MoS2 into the nanocomposite. When a symmetrical supercapacitor was fabricated, a remarkable energy density of 36.93 Wh kg−1 was recorded in an environmental-friendly aqueous-based electrolyte. More significantly, the outstanding delivered capacitance retention and coulombic efficiency were 111.92 % and 97.6 %, respectively after 4000 continuous GCD cycles. Hence, the Na-doped MoS2@NiO/C with hierarchical porous nanostructures and extraordinary electrochemical performance was explicitly demonstrated in this study and can be utilized as electrode active materials in realizing high-performance supercapacitors.

Tailoring on p-type conductivity of nickel oxide nanostructures by palladium for the detection of 2-methoxy ethanol

Tailoring on p-type conductivity of nickel oxide nanostructures by palladium for the detection of 2-methoxy ethanol

Prospective of Agro-Waste Husks for Biogenic Synthesis of Polymeric-Based CeO2/NiO Nanocomposite Sensor for Determination of Mebeverine Hydrochloride.

The remarkable properties of nickel oxide (NiO) and cerium oxide (CeO2) nanostructures have attracted considerable interest in these nanocomposites as potential electroactive materials for sensor construction. The mebeverine hydrochloride (MBHCl) content of commercial formulations was determined in this study using a unique factionalized CeO2/NiO-nanocomposite-coated membrane sensor. Mebeverine-phosphotungstate (MB-PT) was prepared by adding phosphotungstic acid to mebeverine hydrochloride and mixing with a polymeric matrix (polyvinyl chloride, PVC) and plasticizing agent o-nitrophenyl octyl ether. The new suggested sensor showed an excellent linear detection range of the selected analyte at 1.0 × 10-8-1.0 × 10-2 mol L-1 with regression equation EmV = (-29.429 ± 0.2) log [MB] + 347.86. However, the unfunctionalized sensor MB-PT displayed less linearity at 1.0 × 10-5-1.0 × 10-2 mol L-1 drug solution with regression equation EmV = (-26.603 ± 0.5) log [MB] + 256.81. By considering a number of factors, the applicability and validity of the suggested potentiometric system were improved following the rules of analytical methodological requirements. The created potentiometric technique worked well for determining MB in bulk substance and in medical commercial samples.

Tuning the p-type conductivity of NiO for the room temperature formaldehyde detection

The present research synthesizes pure Nickel Oxide (NiO) nanostructures via a coprecipitation route with exceptional surface modification by temperature treatment. The morphological, structural, elemental and gas sensing tests of the prepared NiO were done carefully. The study unveils the sensing performances of various volatile organic compounds (VOCs), specifically for HCHO. Furthermore, gas sensor testing of prepared samples was carried out at room temperature (RT) and at different concentrations of the target gas. For 100 ppm of target gases, NiO (300 ℃), NiO (500 ℃), and NiO (700 ℃) gas sensors exhibited 83.43, 5616, and 196 gas responses, respectively, at RT. Hence, NiO nanoparticles at 500℃ sintering temperature-based HCHO sensor showed a significant response than other NiO sensors.