NiO Nanocomposites Research Articles

Deep eutectic solvents assisted synthesis of AC-decorated NiO nanocomposites for hydrogen evolution reaction

The development of renewable and efficient electrocatalysts for hydrogen evolution reaction (HER) is energetic for clean and green hydrogen production. Herein, we prepared the nanocomposites of narthangai leaves-derived activated carbon decorated-NiO (NiO/AC) by using the deep eutectic solvents (DES) process. The prepared nanocomposites showed an aggregated structure of AC-decorated NiO nanoparticles with a high specific surface area (118.6 m2/g) and large porosity. When utilizing the NiO/AC nanocomposite as an HER catalyst, the catalyst showed an excellent HER electrocatalytic behavior i.e., low overpotential (385 mV), very lower Tafel slope (127 mV/dec), and long-term stability. These owing HER features are considered accrediting to the coactive properties of the material active surface of NiO nanoparticles and the high conductivity of the AC nanoflakes. The results suggested that the DES-supported synthesized NiO/AC nanocomposites could play a significant role in electrocatalytic performance for wastewater treatment.

Fe2O3/NiO nanocomposites: synthesis, characterization and roxarsone sensing by Fourier transform infrared photoacoustic spectroscopy

Fourier transform infrared photoacoustic spectroscopic sensing of roxarsone using the Fe2O3/NiO nanocomposite.

Low-cost piezoelectric sensors and gamma ray attenuation fabricated from novel polymeric nanocomposites

<abstract> <p>This study looks at the synthesis of innovative PEO/PVA/SrTiO<sub>3</sub>/NiO nanocomposites for piezoelectric sensors and gamma shielding applications that are low weight, elastic, affordable and have good gamma ray attenuation coefficients. The impact of SrTiO<sub>3</sub>/NiO on the structural characteristics of the PEO/PVA mixture is investigated. The polymer mixture PEO/PVA received additions of SrTiO<sub>3</sub>/NiO at concentrations of (0, 1, 2, 3 and 4) weight percent by the casting method. On the top surface of the films PEO/PVA/SrTiO<sub>3</sub>/NiO NCs, scanning electron microscopy reveals several randomly distributed aggregates or fragments that are consistent and coherent. An optical microscope image collection reveals that the blend*s additive distribution of NPs was homogenous. Gamma ray shielding application results show that the attenuation coefficient of PVA/PEO/SrTiO<sub>3</sub>/NiO NCs is increased by increasing concentration of SrTiO<sub>3</sub>/NiO nanoparticles. Radiation protection is another application for it. The pressure sensor application findings of NCs show that, when the applied pressure rises, electrical capacitance (Cp) increase.</p> </abstract>

Synthesis of Nickel Oxide Nanoparticles and Copper-Doped Nickel Oxide Nanocomposites Using Phytolacca dodecandra L'Herit Leaf Extract and Evaluation of Its Antioxidant and Photocatalytic Activities.

Nanotechnology research is emerging as cutting-edge technology, and nanoparticles (NPs) and nanocomposites (NCs) have played a significant role in the bioremediation and treatment of polluted water by organic and nonorganic materials. Nanoparticles produced by plant extracts are more stable and biocompatible in comparison with those produced by physical and chemical methods. This research focuses on the synthesis of NiO NPs and Cu-NiO NCs using Phytolacca dodecandra L'Herit (P.d) leaf extract and evaluation of their antioxidant and photocatalytic activities. Cu-NiO NCs were synthesized using 50 mL of 0.1 M nickel(II) nitrate hexahydrate, 10 mL of 0.1 M copper(II) nitrate trihydrate, and 20 mL of leaf extract. The synthesized nanoparticles were characterized by UV-vis, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM) analyses to study the energy band gap, average crystallite size, functional groups, and morphology of the samples, respectively. The UV-vis analysis showed a red shift after copper doping, indicating a decrease in the optical band gap values. FT-IR characterization confirms the presence of various functional groups in samples. Crystallite sizes of the formed particles were obtained to be 14.18 and 16.10 nm from the XRD data for NiO NPs and Cu-NiO NCs, respectively. SEM showed the crystallinity of particles with a cubic structure. The photocatalytic degradation of methylene blue (MB) was found to be 78.3 and 97.8% by NiO NPs and Cu-NiO NCs, respectively. In the antioxidant test, NiO NPs and Cu-NiO NCs prevented the oxidation of 50% of the H2O2 molecules at a concentration of 363.96 and 350.29 μg/mL, respectively. Finally, the synthesized samples showed good photocatalytic and antioxidant activities.

Development of novel flexible photodetectors based on 0.5PVA/0.5PVP/Fe:NiO nanocomposite system with enhanced optoelectronic properties

Ordinary casting technique has been used to fabricate the intrinsic films of polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP) polymer blend matrix incorporated with dissimilar weight percent contents of Fe:NiO nanocomposite (NC). X-ray diffraction (XRD) and infrared (IR) spectroscopy has been implemented to analyze NC structure of these films. Significant interaction and tuning of PVA/PVP blend matrix due to Fe:NiO NC is detected. XRD pattern reflects the structural modification and partial crystalline nature of the pristine blend matrix. The corresponding peaks of Fourier transform IR identifies the vibrational group of the synthesized samples. Atomic force microscope images indicate that a change in the Fe:NiO concentration in a pristine blend leads to an increase in the roughness and clusters. Numerous optical factors such as E g (transition band gap), refractive index (n), and E ed (absorption edge) of pure blend and blend films with different concentrations of Fe:NiO were assessed via UV–Vis optical absorption spectra. As we increased the doping concentration in pristine blends, the value of E g goes to decrease. The dispersion (E d) and oscillator (E o) energies were calculated from Wemple and Di. Domenico of a single oscillator. Although, optical susceptibilities and nonlinear refractive index were enhanced by doping with Fe:NiO NC. The change in doping content leads to modifications in the optical limiting. The photocurrent density–voltage properties of the present polymers were studied at different values of white light intensity. It was found that the photoconductivity of the PVA/PVP blend is 1.03275 × 10−8 (Ω cm)−1, while NC films varied in the range (1.03–10.6954) × 10−8 (Ω cm)−1 at 8600 lux. In addition, the photosensitivity increased from 13.82 to 24.08. The recombination process was found monomolecular process for pure and doped polymers. The present films assume the possibility of their uses in optical and photo-electric devices.

Polyaniline‐ZnO−NiO Nanocomposite Based Non‐enzymatic Electrochemical Sensor for Malathion Detection

AbstractAn electrochemical sensor based on polyaniline‐ZnO−NiO (PANI‐ZnO−NiO) nanocomposite was developed for the non‐enzymatic detection of malathion. The structure, surface morphology, and optical properties of the as‐prepared nanocomposite were studied by XRD, FTIR, SEM, and UV‐Vis spectroscopy. The electrochemical behavior of the nanocomposite based sensor was first evaluated through cyclic voltammetry (CV). Under optimum conditions, differential pulse voltammetry (DPV) was further utilized for malathion detection, which proved the PANI‐ZnO−NiO/GCE electrode as an effective electrochemical sensor. The developed electrochemical sensor showed a low detection limit of 1.0×10−8 M with a wider linear range of 10 to 70 nM for malathion.

Design and Simulation of Lead-Free Perovskite Solar Cells with a Hole Transport Layer Made of NiO Nanocomposite

Large-scale commercial manufacture and photovoltaic field use of lead halide perovskites are hampered by the toxicity of lead. For the development of ecologically acceptable lead-free perovskite solar cells, some innovative non-or low-toxic perovskite materials have been investigated. In past few years, there has been a lot of study into using lead-free perovskite solar cells and many studies have been done to improve the power conversion efficiency and sustainability of such solar cells. The effects of NiO nanocomposite as hole transport layer on, open-circuit voltage (Voc), short-circuit current density (Jsc), Fill Factor and power conversion efficiency (PCE) are studied in this study. Solar cell limiting factor such as variation of thickness in absorber layer, hole transport layer and electron transport layer, bandgap, operating temperature of solar cell have been investigated. After the simulation and optimization of proposed device 23.28% of power conversion efficiency has been achieved.

A Review on Recent Advancements of Ni-NiO Nanocomposite as an Anode for High-Performance Lithium-Ion Battery.

Recently, lithium-ion batteries (LIBs) have been widely employed in automobiles, mining operations, space applications, marine vessels and submarines, and defense or military applications. As an anode, commercial carbon or carbon-based materials have some critical issues such as insufficient charge capacity and power density, low working voltage, deadweight formation, short-circuiting tendency initiated from dendrite formation, device warming up, etc., which have led to a search for carbon alternatives. Transition metal oxides (TMOs) such as NiO as an anode can be used as a substitute for carbon material. However, NiO has some limitations such as low coulombic efficiency, low cycle stability, and poor ionic conductivity. These limitations can be overcome through the use of different nanostructures. This present study reviews the integration of the electrochemical performance of binder involved nanocomposite of NiO as an anode of a LIB. This review article aims to epitomize the synthesis and characterization parameters such as specific discharge/charge capacity, cycle stability, rate performance, and cycle ability of a nanocomposite anode. An overview of possible future advances in NiO nanocomposites is also proposed.

Dual Z-scheme core-shell PANI-CeO2-Fe2O3-NiO heterostructured nanocomposite for dyes remediation under sunlight and bacterial disinfection

Nowadays, environmental pollution due to discharge of organic pollutants from food, textile, and pharmaceutical industries into clean water and development of contagious diseases due to pathogenic organisms provide impetus to material researcher to fabricate novel design for efficient photocatalyst and antimicrobial agents. In this regard, designing a core-shell heterojunction catalyst based on metal oxides is considered an auspicious approach. In present study, combating the problems of singular oxides, core-shell PANI-CeO2-Fe2O3–NiO nanocomposite (PCFN) and CeO2–Fe2O3–NiO nanocomposite (CFN) was synthesized through sol-gel and oxidative polymerization route with cetyletrimethylammonium bromide (CTAB) as surfactant. The XRD, FTIR, and Raman confirmed the formation of nanocomposites with core-shell morphology composed of PANI (shell) and oxides (Core) in PCFN with a particle size of 52 nm (TEM). Surprisingly, PCFN has lower band gap, e−/h+ recombination, and larger charge transfer character than CFN. The decomposition test using MB and MO dyes showed that PCFN degraded 99%, 98%, while CFN degraded only 73% and 54%, respectively, under 50 min sunlight illumination. The reusability was assessed up to 7th cycle for PCFN. The influence of operational parameters (catalyst dose, dye concentration, pH) was tested for PCFN. Further, the antimicrobial action against S. aureus (gram + ve), E. coli (gram -ve) were also tested. The supreme performance of PCFN has been credited to heterostructure dual Z-scheme formation and core-shell morphology supported with PANI, which suppresses the e−/h+ recombination process by promoting their separation. The present finding indicated that the PCFN is a promising modifier for bacterial disinfection and acts as a superb photocatalyst through core-shell formation with PANI support.

Facile synthesis and characterization of metal ions (Ce, Cu, Gd, Mn and Y) doped Nickel Oxide nanostructures for spintronic and photodiode applications

Multiphase hexagon and flower-shaped structures of NiO nanocomposites have been prepared with different metal ions (Ce, Cu, Gd, Mn and Y) using facile and low-cost co-precipitation method. The optical, structural, morphological, and magnetic properties of the synthesized nanostructures have been investigated. The XDR measurement reveals the coexistence of several crystal structures like cubic, monoclinic, tetragonal, and orthorhombic which unveils the formation of polymorphism in the nanocomposites with high crystallinity. A wideband has been located in the FT-IR spectra at around 600 cm−1 revealing the metal oxide (M-O) phase formation. DRS exhibits four large and intense absorption bands at 260, 380, 420, and 720 nm in the UV and visible domains assigned to the nanocrystalline phases of NiO, CuO, CeO, and MnO, respectively. SEM images of metal-doped nickel oxide nanocomposites show a white sponge, semi-spherical, flower-like, and hexagon-shaped particles of 15 nm size. TEM result establishes a smooth surface for samples grown from gadolinium and yttrium, contrary to other samples made off cerium and manganese demonstrate a rough surface. A ferromagnetic tendency has been located for samples prepared from copper, manganese, and gadolinium-based NiO nanocomposites with coercivities of 132, 113, and 26 Oe, correspondingly. Photodiode characteristics were also investigated on the developed devices. These outcomes signify their use in spintronic and optoelectronic industries.

Development and Investigation of High Performance PVA/NiO and PVA/CuO Nanocomposites with Improved Physical, Dielectric and Mechanical Properties.

A series of polyvinyl alcohol (PVA)based composites with well dispersed nano fillers were fabricated and compared in terms of dielectric, mechanical, and optical properties. Specifically, NiO and CuO nano-fillers were utilized in a range of 0.2–0.6 wt% for thin film fabrication by solution deposition method. The characterization of nanocomposites was confirmed through FTIR, FESEM, and XRPD, whereas dielectric and mechanical properties were analyzed with respect to the filler concentrations. The bandgap of PVA/nano-filler composites reduced with an increase in NiO and CuO concentration from 0.2 to 0.6 wt%. The increase in the permittivity of the material was observed for 6 wt% of nano-fillers. The toughness of PVA/nano-filler composites was improved by increasing CuO and NiO concentration and Young’s modulus of 30.9 and 27.2 MPa for 0.6 wt% of NiO and CuO-based nanocomposite, respectively, was observed. The addition of nano-fillers showed improved optical, dielectric, and mechanical properties.

Synergistic effect of La2o3 -Nio nanocomposite based electrode for electrochemical high-performance asymmetric supercapacitor applications

Global economic growth and rapid industrial development have resulted in a severe energy problem. Renewable energy sources have been replaced by alternative and sustainable energy sources. Super capacitors are one of the most important types of energy storage devices. The development of supercapacitor electrodes with maximum performance is currently the most important research topic in this area. Here we present the results of hydrothermal research on rare earth-based nanocomposites of Lanthanum-Nickel La2O3 -NiO-based electrodes for electrochemical super capacitor applications. XRD, FTIR, TG/DTA, SEM, TEM and EDAX techniques are used to examine the physico-chemical characteristics such as crystallographic structure, vibrational characteristics, thermal stability morphology, chemical composition, and its features respectively. According to the cyclic voltammetry (CV) investigation, the prepared nanocomposite materials have a Specific capacitance of 704 F/g at scan rate of 5 mV/s. EIS analysis demonstrates the RsValues ofLa2O3 (0.11549 Ω) NiO(0.1937 Ω) La2O3 -NiO(0.641 Ω) increased conductivity of nanocomposite material. According to galvanostatic charge–discharge (GCD) tests, the La2O3 -NiO electrode has a maximum specific capacitance of 564 F/g at 1 A/g current density in 1 M KOH electrolyte. This result proved that the prepared (La2O3 -NiO Nanocomposite), electrode material used for practical application, which shows good capacitive retention of 93.4%even after 2000 cycles. More ever asymmetric device constructed superior cyclic stability of 77.2%of capacitive retention even after 2000 charge discharge cycle.

An Efficient Enzyme-Less Uric Acid Sensor Development Based on PbO-Doped NiO Nanocomposites.

Here, the voltammetric electrochemical approach was applied to detect uric acid (UA) in a conductive sensing medium (phosphate buffer solution-PBS) by using PbO-doped NiO nanocomposites (NCs)-decorated glassy carbon electrode (GCE) performing as working electrode. The wet-chemically prepared PbO-doped NiO NCs were subjected to characterization by the implementation of XRD, FESEM, XPS, and EDS analysis. The modified GCE was used to detect uric acid (UA) in an enzyme-free conductive buffer (PBS) of pH = 7.0. As the outcomes of this study reveal, it exhibited good sensitivity of 0.2315 µAµM−1cm−2 and 0.2233 µAµM−1cm−2, corresponding to cyclic (CV) and differential pulse (DPV) voltammetric analysis of UA, respectively. Furthermore, the proposed UA sensor showed a wider detection (0.15~1.35 mM) range in both electrochemical analysis methods (CV & DPV). In addition, the investigated UA sensor displayed appreciable limit of detection (LOD) of 41.0 ± 2.05 µM by CV and 43.0 ± 2.14 µM by DPV. Good reproducibility performance, faster response time and long-time stability in detection of UA were perceived in both electrochemical analysis methods. Finally, successful analysis of the bio-samples was performed using the recovery method, and the results were found to be quite acceptable in terms of accuracy. Thus, the findings indicate a reliable approach for the development of 5th generation biosensors using metal-oxides as sensing substrate to fulfill the requirements of portable use for in situ detection.

Rapid selective adsorption of hazardous dyes using charge controlled NiO layers encapsulated SiO2 core-shell nanostructures

SiO2/NiO based composites possess extra ordinary chemical stability for employment in catalytic adsorption. In this study, we report on, SiO2/layered NiO nanocomposite processed through successive ionic layer adsorption and reaction (SILAR) process using appropriate surfactant as a template along. The nanocomposites have been synthesized with different concentration of cationic (Ni2+) and anionic (OH-) solution. The surface morphology, structural behavior, surface area and absorption properties were analyzed by XRD, FE-SEM, TEM, BET, FTIR and UV–vis studies. The nitrogen absorption-desorption curve shows that the composite exhibits the larger surface area (576.71 m2/g) in comparison to NiO (89.75 m2/g) and SiO2 (245.2 m2/g). The synthesized nanocomposites were examined for the elimination of Rhodamine B (RhB). The adsorption efficiency of the composite was observed to be 99.5% within 6 min and also, investigated as a function of contact time, adsorbent dosage, effect of initial concentration, selectivity, recyclability and reusability. Additionally, the kinetics and isotherms were evaluated to understand the surface interactions among the adsorbent and adsorbate. The nanocomposite was well-known to obey pseudo-second order kinetics (R2 = 0.99) and follow monolayer adsorption with maximum adsorption capacity of 35.33 mg/g. The studies approved the processed composite effectively adsorbed Rhodamine B, suggesting them as a better adsorbent in other frontiers.

One pot facile flash-combustion synthesis of ZnO@NiO nanocomposites for optoelectronic applications

Herein, the synthesis of the ZnO and NiO nanocomposites is reported for the first time through a facile one-pot flash-combustion. The structural, vibrational, optical, dielectric, and electrical properties of these prepared nanocomposites are systematically examined. X-ray diffraction and energy-dispersive X-ray spectroscopy studies confirm the presence of a combined phase of ZnO and NiO in the final product. The mean crystallite size, no. of dislocations, and strain values were determined to be in the range between 17 and 23 nm, 1.94 to 3.11 ( × 10−3) nm−2, and 4.17 to 5.35 ( × 10−3), respectively. TEM/HRTEM analysis was also performed on the sample prepared with higher citric acid concentration. The noticed elemental composition of Zn and Ni was 26 and 22%, respectively. The morphological study confirms the cubic crystals of NiO and nanoparticles of ZnO in the final products. The energy gap was determined using Kubelka-Munk relation and found to range between 3.19 and 3.53 eV for all studied ZnO@NiO nanocomposites. High dielectric constant and electrical conductivity while sustaining low loss values approved the promising utilization of the prepared nanocomposites in optoelectronic applications.

Effects of Electron-Beam Radiation on the Dielectric Properties of PVA/xNiO Nanocomposite for Energy Storage Applications

For energy storage applications, a material that has high dielectric permittivity, low loss factor, strong thermal resistance, easy processability, and low cost is highly desirable. In the present study, PVA/xNiO nanocomposite films with different NiO contents of (0, 10, and 50) wt% were prepared by casting technique. The PVA/xNiO of 50 wt% NiO has been irradiated with 3 MeV electron beam at a dose of 50 kGy at room temperature in order to investigate the modifications induced in its dielectric properties. The results show that the NiO nanoparticles are well incorporated inside the PVA matrix and the crystallite size of NiO has been decreased upon doping by 50 wt% NiO from 15.45 to 11.44 nm. Also, PVA/(50%)NiO nanocomposite shows indirect allowed optical transition (3.43 eV) with relatively high dielectric constant (7.60 to 9.55) and low loss factor (<0.1) at high frequency (1 MHz) and the entire indicated range of temperature which proposes to use this material in energy storage applications. The electron beam radiation has increased the dielectric constant (10.52 to 13.94) which is preferable. However, a slight increase is observed in the loss factor (<0.109).

Studies on Co3O4–NiO nanocomposites for potential electrocatalyst for alkaline water electrolysis

Studies on Co3O4–NiO nanocomposites for potential electrocatalyst for alkaline water electrolysis

Microwave-assisted sol-gel synthesis of CeO2–NiO nanocomposite based NO2 gas sensor for selective detection at lower operating temperature

The progress in the development of gas sensors has considerably grown using some novel nanomaterials of metal, metal oxide and composite. In the current study, we intended and evaluated the properties of nanomaterials like CeO2, NiO, and CeO2–NiO composite and its application as NO2 gas sensor. Sensing of low concentration of NO2 gas at optimum functional temperature was succeeded using CeO2–NiO nanocomposites (NCs) film. The working temperature ranges in between 100 and 225 ​°C. Highly crystalline nanomaterials (CeO2, NiO and CeO2–NiO) have been prepared by applying microwave-assisted sol-gel route. The as-prepared nanomaterials are characterized for their structure, size, morphology and constitution by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray analysis. XRD studies of nanoparticles reveal the formation of nanoscale CeO2 and NiO with crystallite size 26, 23 ​nm, respectively. Both are having a face centered cubic structure. The nanocomposite (NC) Ce:Ni ​= ​60:40 has crystallite size of 13 ​nm. XRD study of NCs shows assimilation of Ni metal into the ceria and proves physical similarities of two phases. It can be observed from SEM that prepared NC has a porous surface which enables more surface active sites for adsorbing oxygen. The optical properties are measured with the help of UV–Vis. Spectroscopy. Optical band gaps of 3.19, 3.41 and 2.9 ​eV were observed for CeO2, NiO nanoparticles (NPs) and CeO2–NiO NC, respectively. Gas sensing properties state that the NC material shows a higher gas response % of 67.34% for NO2 gas (25 ​ppm) at comparatively low operating temperature (125 ​°C). It gives response time as (∼28 ​s) and the recovery (∼54 ​s). NiO incorporation in CeO2 results in a decline of operating temperature of NC and improves the sensing features.

Dual drug delivery system based on biodegradable modified poly(3-hydroxybutyrate)-NiO nanocomposite and sequential release of drugs

Dual drug delivery system based on biodegradable modified poly(3-hydroxybutyrate)-NiO nanocomposite and sequential release of drugs

Investigation of the dielectric and electrochemical properties of Co3O4–NiO nanocomposites with varying NiO content

A facile sol-gel ultrasonication route has been adopted for synthesizing Co3O4/NiO nanocomposite series, which has been analyzed for their dielectric and electrochemical properties and compared with their components i.e. NiO & Co3O4. The synthesised specimens were characterized using various experimental techniques such as X-Ray diffraction (XRD), Scanning electron microscope (SEM) with Energy dispersive X-Ray Spectroscopy (EDX), X-Ray Photoelectron Spectroscopy (XPS), Transmission electron Microscopy (TEM). The frequency dependence of dielectric parameters in the range varying from 75 kHz to 5 MHz at room temperature has been explored. The variation of the a. c. conductivity, dielectric constant and loss factor with frequency were investigated. The loss tangent and dielectric constant exhibited a decreasing behaviour with increasing frequency. The samples having low values of loss at higher frequency indicate that these synthesised samples can be employed in high frequency applications. The nanocomposite samples exhibit improved electrochemical properties than their components. They were used as electrode materials of energy storage devices and found to deliver improved specific capacitance and cycling stability. The synthesised samples were found to exhibit high values of power and energy density. The nanocomposite sample (with 40% NiO) has lowest value of charge transfer co-efficient indicating the anodic current is dominant.