Doped Nickel Oxide Nanoparticles Research Articles

Enhancement of dielectric properties by modulating electroactive $$\varvec{\beta }$$-phase of copper doped nickel oxide nanoparticles incorporated thin film

Enhancement of dielectric properties by modulating electroactive $$\varvec{\beta }$$-phase of copper doped nickel oxide nanoparticles incorporated thin film

Electro-chemical studies of Zn doped nickel oxide nanoparticles synthesized via solution combustion method using green and chemical fuels.

This study presents a new green solution combustion method (aloe vera gel extract as fuel) and chemical method (glucose as fuel) to synthesise Zn-doped nickel oxide nanoparticles (Zn:NiO NPs). The face centered cubic crystal structure (FCC) phase was validated by PXRD, while the produced samples' spongy, spherical, agglomerated, and porous characteristics were shown by electron microscopy. The energy band gap values of 4.21 eV and 4.09 eV, respectively, were deduced for green and chemically synthesized Zn:NiO NPs. The reversibility was demonstrated by cyclic voltammetry with a lower EO-ER value for the green-Zn:NiO electrode. The studies on electrochemical impedance confirmed strong conductivity for the NPs by demonstrating a low charge transfer resistance. The Zn:NiO NPs are easily convertible into a stable electrode material that may be used in supercapacitors. According to the findings, Zn:NiO is an economical and promising material for use in supercapacitors in the future.

Preparation and effect of additives n-ZnO doped p-NiO Screen printed thick films on Structural and Electrical Properties

Abstract: Zinc oxide (ZnO) doped Nickel oxide (NiO) thick films prepared using glass substrate by screen printing technique successfully. Synthesis of nanoparticles was confirmed using characterisation techniques, such as X-ray diffraction (XRD), scanning electron microscopy (SEM) and static gas sensing system. The structural properties of the prepared thick films were studied by XRD analysis. The observed prepared thick film shows polycrystalline nature of the films with a cubic structure and crystallite size found to be in the range of 18.21 to 35.44 nm. SEM analysis of prepared films enabled the conclusion that the prepared films are uniform, large crystals and heavily agglomerated particles were observed spherical in shape. Also, with increase in concentration specific surface area increases. The quantitative chemical compositions were analysed by SEM-EDS and it shows nonstoichiometric in nature. The correlation between structural and morphological properties are reported. The prepared thick films of ZnO doped NiO nanoparticles were analysed for electrical parameters namely TCR, activation energy and sheet resistivity, specific surface area were evaluated at different concentration of zinc oxide that assured the prepared material has a semiconducting nature. Electrical characterization results resistivity decreases from 6283.377 to 1972.727 with increase in wt.% concentration of ZnO. Such a prepared film can be used in fabrication of optoelectronic devices.

Synthesis and Characterization of Zirconium Doped Nickel Oxide Nanoparticles Using Acalypha indica L Extract and Its Antimicrobial Activities

Synthesis and Characterization of Zirconium Doped Nickel Oxide Nanoparticles Using Acalypha indica L Extract and Its Antimicrobial Activities

Investigation of cycling effect on the enhancement of electrochemical activity of zinc doped nickel oxide

Supercapacitor activity can be greatly influenced by the doping, conductivity, and the morphology of the electrocatalyst surface. Here, we are reporting the synthesis and characterization of undoped and zinc doped nickel oxide nanoparticles for investigating the influence of doping and cyclability on the supercapacitor activity using cyclic voltammetry (CV) measurements. We found that the activity of zinc doped NiO initially increases as per increase in number of CV cycles up to the fifty cycles and beyond this it decreases further. It is interesting to note that the cyclic voltammetry changes the morphology of the electrocatalyst surface, which enhances its activity. The polarization study of the fresh and cycled electrode showed the increase of Ni +3 content for the cycled electrode is responsible for the enhanced activity. Further, the impedance and galvanostatic charge discharge analysis showed that the pseudocapacitance of the cycled zinc doped electrode is higher than that of cycled nickel oxide electrode. Phenomenologically, the presence of Ni +3 and the increased electronic conductivity due to presence of zinc, with cyclic voltammetry cycling changes the energy of the surface, which increases the supercapacitor activity.

A Comparative Study of Experimental and Theoretical Structural Analysis of Lithium Doped Nickel Oxide Nanoparticles

Li(x)Ni(1−x)O (x = 0.01, 0.02, and 0.03) samples were synthesized via the sol-gel process. Fourier transform infrared spectroscopy (FTIR) confirms the formation of Li(x)Ni(1−x)O (x = 0.01, 0.02, and 0.03) series. Powder X-ray diffraction technique was used for the analysis of crystallite properties. The mean crystallite size using Scherrer’s Method has been found as 21.66 nm, 20.09 nm, and 19.25 nm for Li(x)Ni(1−x)O (x = 0.01, 0.02, and 0.03) respectively, which is a rough estimate. To inspect the impact of strain induced in Li(x)Ni(1−x)O further analysis has been done. Willamson Hall Plot-Uniform Deformation Model (WH-UDM), Size-Strain (SSP), and Halder-Wagner Plot (H–W) Models were applied to determine physical and microstructural parameters i.e. crystallite size and lattice strain of Li(x)Ni(1−x)O (x = 1%, 2%, and 3%) using X-ray powder diffraction analysis. The morphology of Li(x)Ni(1−x)O (x = 1%, 2%, and 3%) has been analyzed by High-Resolution Transmission Electron Microscope (HRTEM). The outcomes of estimated mean crystallite size determined by Scherrer’s Method, WH-UDM Plot, SSP, and W–H models were compared with morphologically investigated crystallite size via TEM analysis.

Probing into the physicochemical consequences of pristine and X0.06Ni0.94O (X = Co, Fe, Cu) nanoparticles for bactericidal, antifungal and hemolytic competency

Nano-scaled transition metal oxides are massively gaining an exciting horizon of research interest among material scientists by triggering scientific attention due to its prime advancements in physico-chemical, magneto-optical, electro-chemical, bio-medical and bio-compatible characteristics. The current work highlights the fabrication and formalisation of pure and X0.06Ni0.94O (X = Co, Fe, Cu) nanoparticles via bottom-up sol-gel pathway employing citric acid as the gelling factor. The crystallite size evaluated from X-Ray Diffraction (XRD) analysis decreased with respect to doping were estimated by successive systems among which Halder-Wagner (H-W) and Wagner-Agua (W-A) approach delivered prime results. Fourier Transform Infra-Red (FTIR) spectroscopy analysis regulated at room temperature in the mid infrared frequency continuum 400–4000 cm−1 confirmed the cubic conformation and the presence of predicted functional groups in the as-synthesized nanoparticles. The bandgap energy calculated from Ultra Violet-visible (UV–vis) spectroscopy is found to decrease for Co-NiO and Cu-NiO nanoparticles and increased for Fe doped NiO nanoparticles in comparison with the bandgap of pure NPs reasoned out by the Burstein-Moss shift. The device dependent parameter Urbach energy, and other pivotal optical parameters crucial in the fabrication of optoelectronic devices were evaluated. Surface morphological features and porous network of doped nanoparticles were investigated from Scanning Electron Microscopy (SEM) technique. Energy Dispersive X-ray (EDX) spectra ascertained the molecular matrix array and elemental composition in synthesized samples. The surface area measured from Brunauer-Emmett-Teller (BET) analysis revealed higher surface area (42 m2/g) for Fe-doped NiO nanoparticles than other counterparts. The thermal decomposition and stability of the pure and doped samples were analysed by Thermo-Gravimetric (TG) studies. The fundamental kinetic and thermodynamic parameters such as entropy, enthalpy, activation and Gibb’s free energy were elucidated through six different models viz., Coats-Redfern (CR), Piloyan-Novikava (PN), Horowitz-Metzger (HM), Van-Krevelen (VK), MacCallum-Tanner (MT) and Broido methods. Vibrating Sample Magnetometer (VSM) analysis coupled with the Law of Approach to Saturation (LAS) operandi extracted two critical magnetic criteria and the saturation magnetization is noticed to reduce with doping. The antibacterial and antifungal efficacies of the as-synthesized NPs were deeply discussed by portraying the nanoparticles-microbes interface. Iron and copper doped nickel oxide nanoparticles encountered favorable antimicrobial activity against pathogenic organisms. Furthermore, the bio-compatibility nature of the NPs was examined through hemolytic activity and the samples exhibited non-toxic behavior towards human cells till 50 μg/ml.

A Comparative Study of Experimental and Theoretical Structural Analysis of Lithium Doped Nickel Oxide Nanoparticles

Li(x)Ni(1-x)O (x = 0.01, 0.02 and 0.03) samples were synthesized via sol-gel process. Powder X-ray diffraction technique was used for the analysis of crystallite properties. The mean crystallite size using Scherrer’s Method has been found to be 21.66 nm, 20.09 nm, and 19.25 nm for Li(x)Ni(1-x)O (x = 0.01, 0.02 and 0.03) respectively, which is a rough estimate. To inspect the impact of strain induced in Li(x)Ni(1-x)O further analysis has been done. Willamson Hall Plot-Uniform Deformation Model (WH-UDM), Size-Strain (SSP), and Halder-Wagner Plot (H-W) Models were applied to determine physical and microstructural parameters, i.e. crystallite size and lattice strain of Li(x)Ni(1-x)O using X-ray powder diffraction analysis. The morphology of Li(x)Ni(1-x)O has been analyzed by High-Resolution Transmission Electron Microscope (HRTEM). The outcomes of estimated mean crystallite size determined by Scherrer’s Method, WH-UDM Plot, SSP, and W-H models were compared with morphologically investigated crystallite size via TEM analysis.

Uncovering the replacement of Zn2+ ions on nano-structural, opto/magneto/electrical, antibacterial and antifungal attributes of nickel oxide nanoparticles via sol-gel strategy

Transition metal oxides have gathered momentum among the scientific community on account of their peculiar procession in physico-chemical, opto-electronic, magnetic, electro-chemical, and biological attributes resulting from anisotropic charge distribution of partly filled d-orbitals, non-stoichiometric behaviour, and diverse oxidation states of the cations. The current work emphasize on the systematic synthesis and characterization of pristine and zinc (Zn) incorporated nickel oxide (NiO) nanoparticles in varying concentrations ZnxNi1-xO (x=0, 0.1, 0.2, and 0.3) via a scalable sol-gel approach assisting citric acid (C6H8O7) as a congealing factor. A series of extensive analyses were executed to investigate the structural, opto-electrical, and magnetic characteristics of prepared nanoparticles. X-Ray Diffraction (XRD) studies confirmed the face-centered cubic structure of as-synthesized samples and the corresponding crystallite size is found to decrease with an increasing dopant concentration as estimated from the Scherrer method. Scanning Electron Microscopy (SEM) studies portrayed the spherical structure and porous nature of NiO nanoparticles. Particle size calculated from SEM shows the decreasing trend with dopant discrepancy which is in accordance with crystallite size measured from XRD results. Energy Dispersive X-ray (EDX) spectra revealed the presence of estimated molecular assembly in synthesized samples. The cubic configuration and the presence of functional groups existing in synthesized nanoparticles were endorsed from Fourier Transform Infra-Red (FTIR) spectroscopy operated in the vibrational IR frequency region. The optical absorption spectrum examined from Ultra Violet-visible (UV–vis) spectroscopy evaluates the energy bandgap and it is noticed to increase from 2.48 to 2.87 ​eV affirming the Burstein Moss shift. The energy dispersion of optical parameters plays a crucial contribution in optical materials pursuant to its prominence in optical communications and in fabricating novel devices for spectral dispersion. Optical and energy dispersion parameters evaluated from Wemple-DiDomenico (WDD) model and non-linear optical parameters were deliberated from optical studies. The performance of integrated optical systems such as monochromatic filters, optical and electrical switches, laser diodes, detectors, and amplifiers can be controlled by the dispersion parameters. Urbach energy and another pivotal optical criterion highly correlated with the bandgap energy anchored in the fabrication of optoelectronic devices were assessed. The electrical characteristics such as dielectric constant, loss, and conductivity exhibited by pure and Zn doped nickel oxide nanoparticles were reported. Molecular electronic polarizability assessed through elementary solid-state parameters is in better concurrence with diverse relations like Clausius-Mossotti, Lorentz-Lorent, bulk modulus, optical electronegativity, and energy band gap. The pore size distribution of substance matrix and the associated surface area were elucidated from Brunauer-Emmett-Teller (BET) analysis. Dispersive magnetic properties and two pivotal parameters were derived from the Law of Approach to Saturation (LAS) operandi. Further, microbial cell mechanism was illustrated through nano-architecture design, and the antibacterial and antifungal activity encountered by undoped and zinc doped NiO nanoparticles against different microbial strains were deeply discussed for pilot production of antimicrobial agents.

Structural, morphological and optical aspects of novel synthesized pristine and hafnium doped nickel oxide nanoparticles

The manuscript attempted to synthesise novel pure and Hafnium doped Nickeloxide (HNO) nanospheres using the facile co-precipitation route. Though the material is novel, a thorough enquiry on the structural, morphological and optical aspects of HNO is indeed and is carried out via various characterization techniques. The synthesis route guaranteed the production of nanosized spheres with reduced crystallite size was confirmed with structural and morphological studies. X-ray diffraction XRD) confirms the face centred cubic structure of NiO nanostructures, and it upholds the evidence of doping in NiO lattice. The morphological analysis was carried out with the scanning electron microscope (SEM) and transmission electron microscope, confirming the spherical NiO nanostructures and the effect of doping on its morphological properties. Furthermore, the UV analysis assessed the absorption spectra and the bandgap value is calculated using Kubelka–Munk plot. Moreover, PL analysis revealed that the doped samples exhibit a high bandgap above 3 eV and have strong emissions under 266 nm and 280 nm excitation wavelength.

Uncovering the consequences of Ag1+ on nano-structural, magneto-optical, antibacterial, and antifungal response of nickel oxide particles

Metal oxide nanoparticles existing in transition metal series have intensely earned high research interest among material scientists by virtue of their dispersive magnetic nature desirable for antimicrobial action. Herein, we report the unsubstituted and silver (Ag) doped nickel oxide nanoparticles with varying dopant concentrations AgxNi1−xO (x = 0.00, 0.05, 0.10, and 0.15 M) prepared via flexible sol–gel citrate route at optimum temperature. The well-resolved prominent peaks from X-ray Diffraction (XRD) pattern confirmed the micro-structural attributes of NiO particles and the corresponding crystallite size decreases from 25.67 to 10.93 nm (nm) upon doping. The bandgap energy evaluated from the Tauc plot traced an increasing trend from 2.48 to 3.09 eV affirming the blue shift reasoned with the Burstein Moss phenomenon. Scanning Electron Microscopy (SEM) analysis portrayed the formation of spherical nanoparticles and the particle size was calculated. The phase purity and the chemical composition of nanoparticles were elucidated from Energy Dispersive X-ray (EDX) spectra which endorse only the presence of Ni, Ag, and O metals. Fourier Transform Infra-Red (FTIR) spectroscopy analysis operated in an IR vibrational spectral span confirms the functional group matrix. Dielectric constant and loss of doped nanoparticles were discussed where the loss decreases with increasing dopant concentration. Saturation magnetization (Ms) and coercivity (Hc) were calculated from Vibrating Sample Magnetometer (VSM) studies where Ms perform a declining tendency from 39.96 to 2.86 emu/g which is favorable in the construction of antennas and memory storage equipment. In addition, the nanoparticles were tested against different bacterial and fungal organisms to examine their antimicrobial activity wherein the high concentration (Ag0.15Ni0.85O) doped nanoparticles exhibited a higher antimicrobial response.

Exploring the influence of tin in micro-structural, magneto-optical and antimicrobial traits of nickel oxide nanoparticles

Transition metal oxide nanoparticles, especially nickel oxide (NiO) have profound interests to the scientific commune on account of their dimension-reliant attributes and peculiar progression in optical, electrochemical, and magnetic characteristics. Herein, the undoped and tin (Sn) doped nickel oxide nanoparticles of varied concentrations were synthesized by highly favourable citrate assisted sol-gel technique. An array of extensive investigations were discussed on the structural, optical, and magnetic properties of synthesized nanoparticles. The crystallite size and strain of as-synthesized samples decreased with significant augmentation in dopant discrepancy which was confirmed by Scherrer and Williamson-Hall model. The optical energy band gap was evaluated from UltraViolet-visible (UV-vis) spectroscopy analysis and a notable blue shift was observed over the wide absorption spectrum. Refractive index, Urbach energy, and other optical parameters anchored in opto-electrical applications were evaluated from optical studies. Fourier Transform Infrared Spectroscopy (FTIR) analysis conducted at room temperature from spectral span 400–4000 cm−1 affirmed the cubic configuration and elucidated bond lengths of pure and tin-doped nanoparticles. Scanning electron microscopy studies portrayed surface morphological features and slight porous particles were observed. Transmission Electron Microscopy (TEM) analysis confirmed the spherical shape of nanoparticles and the grain size estimated is in accordance with the XRD results. The surface area and porosity of pure and doped samples were deeply investigated by Brunauer-Emmett-Teller (BET) analysis. Magnetic parameters such as saturation magnetization, coercivity, retentivity, magnetic moment were enumerated from Vibrating Sample Magnetometer (VSM) investigations and two critical magnetic parameters were extracted from the Law of Approach to Saturation model (LAS). The sample with 6% of Sn shows the highest coercivity of 147 Oe. Further, synthesized pure and doped traces of nickel oxide nanoparticles were deliberated for their competent application in the domain of antibiotics independent antimicrobial activity.

Synthesis of Manganese (Mn) doped Nickel oxide nano particles, its antibacterial activity

The present work deals with the synthesized Manganese (Mn) doped Nickel oxide nanoparticles. Using hydrothermal method, the Manganese (Mn) doped Nickel oxide nanoparticles were synthesized with the concentration ranges from 1 mol% to 2 mol%. The characterization done for the synthesized nanoparticles are X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), DSC spectroscopy and UV visible spectroscopy. The XRD reveals the amorphous nature with the size ranges from 60 nm to 20 nm. The chemical bonding nature and functional group analysis of the prepared material was confirmed by FTIR Spectroscopy. The optical behaviour of the Manganese (Mn) doped Nickel oxide nanoparticle was done using UV–Visible spectroscopy. The antibacterial activity of the prepared nanoparticles was done for both gram negative and gram-positive bacterial strains. The prepared nanoparticles have proven to be promising candidates to be utilized in drug delivery and food packaging applications.

Synthesis and characterization of manganese doping on NiO nanoparticles and its supercapacitor applications

In this study, bare nickel oxide (NiO) and Mn2+ doped NiO nanoparticles (NPs) were prepared through the precipitation method. Samples were analyzed by XRD (X-ray diffraction), FT-IR (Fourier-transform infrared spectra), SEM (scanning electron microscope), EDX (energy dispersive X-ray analysis), and CV (cyclic voltammetry) techniques. The XRD result indicates that the obtained samples of bare and doped NiO NPs show a face-centered cubic structure. SEM images established that the bare NiO NPs and Mn2+ doped NiO have a spherical shape. The formation of the NiO phase was confirmed by the existence of a peak at 436 cm−1 in FTIR. Electrochemical properties of bare and Mn2+ doped NiO NPs were investigated regarding their performance as an electrode in supercapacitors. The highest specific capacitance shows on bare NiO electrode 555 Fg-1 at 10mVs−1 scan rate. it shows that is a good electrode material for the supercapacitor.

Design and fabrication of iron-doped nickel oxide-based flexible electrode for high-performance energy storage applications

In this study, we report on the synthesis of pristine and iron (Fe)-doped nickel oxide nanoparticles (NPs) using a precipitation method. The optical, magnetic, and supercapacitor properties of NPs were investigated via ultraviolet–visible absorption, vibrating sample magnetometer (VSM), and cyclic voltammetry (CV). The effect of Fe doping on the optical bandgap of NiO nanoparticles demonstrates that the bandgap increases with increasing doping concentration (x = 0.02 M, 0.04 M, and 0.06 M). The VSM exhibits ferromagnetic behavior at room temperature. Fe doped sample shows promising supercapacitor electrode material properties ensuring that NiO: Fe could act as an enhanced working electrode for the future generation of supercapacitors.

Efficient, highly stable Zn2+ doped NiO nanoparticles with enhanced magnetic and supercapacitor applications

ABSTRACT In this study, pristine nickel oxide (NiO) and Zn2+ doped NiO nanoparticles (NPs) are synthesised through the chemical precipitation method. Samples were analysed by TG/DTA, XRD, UV-DRS spectroscopy, FT-IR spectroscopy, SEM, EDX, TEM, SAED, VSM and CV techniques. The XRD result indicates that the obtained samples are face-centred cubic structure and hexagonal structure. SEM and TEM images established the spherical and hexagonal shape for the pristine and Zn2+ doped NiO NPs, respectively. A variation in the optical absorption and low energy bandgap was observed in pristine and Zn2+ doped NiO NPs. The NiO phase formation was confirmed by the existence of a peak at 492 cm−1 in FT-IR. The magnetic characterisation identifies the conversion of weak ferromagnetic to superparamagnetic behaviour of pristine and Zn2+ doped NiO NPs. The highest specific capacitance (Cs) of 667 Fg-1 at a 10 mV s−1 scan rate was obtained for 0.04 M, Zn2+ doped NiO NPs.

Structural, Optical and Antibacterial Properties of neodymium (Nd3+) doped nickel oxide (NiO) Nanoparticles using Sesbania grandiflora Leaf Extract

Objectives: To study the eco-friendly green synthesis of neodymium doped nickel oxide nanoparticles and to study their structural, optical and antibacterial activities. Method: Sesbania grandiflora herb has been used to synthesize NiO nanoparticles. With the materials present in the plant extract, such as sugar, flavonoid, protein, enzyme, polymer, and organic acid, acting as the reducing agent the green approach takes charge in bio induction of metal ions into nanoparticles. Structural and Optical Properties of nanoparticles were studied by following XRD, SEM, EDAX, FTIR and UV-Vis-NIR (DRS). The antibacterial activity of the resultant neodymium (Nd3+) doped nickel oxide (NiO) was tested on Gram negative and Gram positive bacteria with suitable standard. Findings: From the XRD analysis, it is revealed that the size of the particles is in the order of 9.2 to 23.06 nm. JCPDS data confirmed that Nd3+ ion-doped NiO nanoparticles exhibit phases of (111), (200), (220), and (311). SEM with EDAX proved that existence of Nd3+ ion-doped NiO nanoparticles. Cubical and spherical shapes of the nanoclusters having a size of 20-40 nm are shown by SEM analysis. Most promising peaks at 420 cm-1 and 657 cm-1 associated to Ni-O vibration bond and Ni-O-H stretching bond were analyzed from FTIR graph of the sample before annealing while for the sample at 500oC shows the Ni-O vibration bond at 411cm-1. The direct band gap of Nd3+ ion-doped NiO nanoparticles calculated as 3.08 eV at the concentration of NiONdO3 mol%. By doping with Nd3+ ion, energy gap increases with doping concentration proved by UVDRS spectroscopy that confirms Quantum confinement. The eco-friendly synthesized nanoparticles exhibited good antibacterial activity against pathogenic bacterial strain is an indication of antibacterial efficiency of nanoparticles. Novelty: Eco-friendly synthesis of NiO nanoparticles and characterization and doped nanoparticles exhibited good antibacterial activity. Keywords: Green synthesis; NiO particles; Characterization; Cubical; spherical shapes; Direct band gap semiconductors; NIR laser; Antibacterial activities

Chemical Synthesis and Antipseudomonal Activity of Al-Doped NiO Nanoparticles

Synthesis of efficient antibacterial agents has become extremely important due to the emergence of antibiotic resistant bacteria. This is especially true for Pseudomonas aeruginosa, an opportunistic pathogen having ability to rapidly develop resistance to multiple classes of antibiotics thus limiting the efficacy of antibiotics approved for clinical use. Aluminum (Al)-doped NiO nanoparticles are of special interest due to their enhanced antipseudomonal properties at certain Al-doping levels. The composite hydroxide mediated (CHM) approach was opted for the synthesis of pure nickel oxide (NiO) and Al-doped nickel oxide (Ni1–xAlxO; x = 5, 10, 15, 20, 25, and 30 wt.%) nanoparticles. X-ray diffraction (XRD) technique was used for structural analysis of these nanoparticles. Morphology and elemental composition of these nanoparticles were investigated by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectroscopy, respectively. The optical properties were investigated by using UV-visible spectroscopy and Kubelka-Munk Theory and Tauc relation were employed for energy bandgap calculation of these nanoparticles. The antibacterial activity of representative Al-doped NiO nanoparticles was assessed on multidrug-resistant clinical P. aeruginosa strains. The agar well and disc-diffusion methods were used to assess the antibacterial efficacy of (Al)-doped NiO compared to pure NiO nanoparticles. Interestingly, a gradual increase in the antibacterial activity was observed with increasing Al-doping concentration and the highest antibacterial activity was observed at x = 15 wt.% Al-doping concentration. The antipseudomonal efficacy of Ni1–xAlxO nanoparticles was comparable to aztreonam antibiotic, primarily used for Gram-negative bacterial infections. Hence, it is proposed that these nanoparticles can be used for coating surgical devices, bone prostheses, medical implants, antibacterial clothing and in pharmaceutical formulations as burn ointments to produce the antimicrobial effect.

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.

Enhanced photocatalytic activity on Vanadium-doped NiO nanostructures in natural sunlight

The contamination of water from industrial pollutants is the most significant concern for environment. Semiconductors have been at forefront of effective elimination of pollutants from waste water, with the tuning of bandgap and improving the photocatalytic activity. This work elaborates the hydrothermal synthesize of highly stable Nickel Oxide (NiO) and Vanadium-doped Nickel Oxide (V-NiO) nanoparticles. The undoped and doped Nickel Oxide nanoparticles were characterized for structural, morphological, thermal and optical properties. X-ray diffraction pattern reveals the V-NiO stabilized in cubic structure. Morphological analysis demonstrates that upon Vanadium doping NiO particles transform from network like structure to spherical nanoparticles. NiO and V-NiO nanoparticles have an average crystallite size of 42 nm and 26 nm which are well matched with particle size calculated from transmission electron micrographs. The photoluminescence study reveals that the Vanadium substitution specifically reduces the rate of recombination in NiO. The V-NiO catalysts exhibited noticeable red shift of absorption spectrum to the visible region in comparison with pure NiO. The functional groups were studied using Fourier Transform Infrared Spectroscopy (FTIR). The photocatalytic study by degradation of Xylenol Orange (XyO) under sunlight irradiation unveils that photocatalytic activity of NiO is enhanced on vanadium doping. Reaction kinetics investigation of XyO degradation revealed that the reaction obeys the pseudo-zero-order model with improved rate constant of 0.115 mol L−1S−1 and 0.225 mol L−1S−1 for NiO and V-NiO, respectively. The retention of high performance and structural stability of photocatalysts after four consecutive degradation cycles implies the reusability of the catalyst. Consequently, the V-NiO with high photocatalytic activity with improved cyclic stability is able to provide as a promising material in the field of environmental remediation.