Synthesis Of Nickel Oxide Nanoparticles Research Articles

Green engineering of NiO nanoparticles decorated with Arachis hypogaea shell extract for biomedical applications

Abstract We attempted to synthesize nickel oxide nanoparticles (NiO-NPs) utilizing waste Arachis hypogaea (peanut) shell extract and studied their structural, morphological, and biological performance for biomedical applications. The green engineered NiO-NPs possessed a face-centered cubic structure with an average particle size of 20 nm in highly crystalline form. NiO-NPs were shown to have an optical resonance peak at 327 nm with 3 eV as the optical band gap according to the UV–visible spectra, and the stretching band between Ni–O were evidenced from the FTIR and Raman spectrum. Utilizing green approach the stable nanoparticles were obtained with average particle size of 31 nm from SEM analysis; zeta potential value of −17.6 mV, and PDI as 0.68, revealed the formation of spherical nanoparticles with distinct morphologies without aggregation. XPS analysis confirmed the oxidation states of the elements Ni (2p) and O (1s). This approach may help to increase the surface area, increasing the possibility of nanoparticles interacting with bacterial cells. Furthermore, the presence of nickel and the oxygen oxidation state were confirmed by XPS. Proteus vulgaris, Streptococcus oralis, Bacillus subtilis, and Escherichia coli were found to be susceptible to the antibacterial action of the produced NiO-NPs, with a maximal zone of inhibition of 10.25 mm at 500 μg/ml for P. vulgaris. For P. vulgaris and E. coli, the minimum inhibitory concentrations of NiO were 5.36 and 12.55 %, respectively, at 31.25 μg mL−1. We hereby claim that green engineered NiO NPs decorated with A. hypogaea shell extract have great potential for pharmaceutical and biomedical applications.

Chemical synthesis of NiO nanoparticles from Solanum trilobatum leaf extract for antibacterial and cytotoxic properties

The chemical precipitation approach was employed to synthesize Nickel oxide nanoparticles (NiONPs) using Solanum trilobatum leaf extract as the stimulant and Nickel nitrate as the precursor. The Nickel oxide is examined using a range of characterization methods including X-ray diffraction, Fourier Transform Infrared spectroscopy, High-Resolution Transmission Electron Microscopy, High-Resolution Scanning Electron Microscopy, X-ray photoelectron spectroscopy, Thermo gravimetric Analysis/Derivative Thermo gravimetric Analysis, Diffuse Reflectance Spectroscopy, cytotoxicity and antimicrobial investigations The X-ray diffraction examination determined that the average size of the crystals increases as the quantities of leaf extract in the NiO2 composites rise. The decrease in line broadening (β) value and the increase in leaf extract concentrations may be the cause of this phenomenon. The FTIR spectrum confirms that the as-synthesized NiO-NPs are of great purity and match well with the XRD pattern. The thermal stability of the synthesized samples was determined using TGA/DTG analysis. The analysis was conducted in an air atmosphere, with the temperature increasing at a rate of 10°C per minute. The temperature range for the analysis was from room temperature to 750°C. The optical properties are determined by the use of Diffuse Reflectance Spectroscopy, which examines the coordinated movement of electrons in the conduction band when exposed to electromagnetic waves. Rat skeletal muscle cell line and SKMEL cancer cells were cultured on 96-well plates and incubated at 37°C and 5 % CO2 for 24 hours to allow them to adapt to the culture conditions. An investigation was conducted to assess the antibacterial properties of synthesized nanocomposites against two types of bacteria: gram-positive Staphylococcus aureus (MTCC No: 87) and gram-negative Escherichia coli (MTCC No: 443), in order to explore their potential for biological applications.

Direct synthesis of nickel oxide nanoparticles from pregnant leach solution by using electrodeionization and Fenton processes in the presence of EDTA

This paper presents the results of a novel study on the direct synthesis of nickel oxide nanoparticles from a synthetic pregnant leach solution (PLS) as a middle stage product of hydrometallurgy process of nickel production. To increase the nickel proportion in the initial PLS, electrodeionization was utilized in the presence of EDTA to form an anionic complex ([Ni-EDTA]2−) with Ni2+ cations, allowing their separation from cobalt cations through the EDI process. Subsequently, the Fenton process was applied to synthesize nickel oxide nanoparticles from the complex containing solution. The proposed hybrid process was conducted in two different modes of one-stage and two-stage EDI process followed by the Fenton process. Different analysis methods including AAS, XRD, FE-SEM, and ICP were used for qualitative and quantitative evaluations. The analyses’ results revealed that by implementing one-stage EDI process followed by Fenton process resulted in producing nickel oxide nanoparticles with an average particle size of 45 nm and purity of about 98 %. Also, it was seen that about 81 % of initial nickel content of the initial PLS was recovered as nickel oxide nanoparticles. In the case of two-stage EDI process, 100 % pure nickel oxide nanoparticles with average size of 55 nm and recovery of 65 % was produced. The results showed that the innovative hybrid EDI/Fenton process can be considered as a promising approach for direct synthesis of high purity nickel oxide nanoparticles from PLS. However, it should be noted that there was a trade-off between purity of nickel oxide and nickel recovery from PLS.

Bioengineered Nickel Oxide Nanofabrication for Energy Storage Systems, Degradation of Refractory Water Toxicity, and Antibacterial Study

AbstractNickel oxide (NiO) nanoparticles were synthesized using a green method involving Pterolobium hexapetalum flower extract as the reducing agent. Synthesized nickel oxide nanoparticles (NiO NPs) were thoroughly characterized using X‐ray diffraction, UV–vis spectroscopy, Fourier‐transform infrared spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and Brunauer–Emmett–Teller (BET) surface area analysis. The XRD analysis confirmed the pure formation of NiO NPs. TEM and SEM images revealed the size, shape, and surface morphology of the nanoparticles. BET analysis indicated a high surface area, making these nanoparticles suitable for various applications. The NiO NPs were further investigated for their potential in supercapacitor applications, demonstrating excellent electrochemical performance. NiO@rGO electrode with graphene proportion showed a maximum specific capacity of 1266 Fg−1 at 1 Ag−1. Moreover, following the 3000‐cycle assessment, the specific retention of 98.2% confirmed that the electrode had high cyclic stability. Additionally, their effectiveness in dye degradation was evaluated, showing promising results in removing organic dyes from wastewater. The antibacterial activity of the NiO nanoparticles was also assessed, indicating significant inhibition against various bacterial strains. These multifaceted studies suggest that NiO NPs synthesized from plant extract hold great promise for applications in energy storage, environmental remediation, and antimicrobial treatments.

Green synthesis of nickel oxide nanoparticles using leaf extract of Mimosa pudica for killing triple-negative breast cancer MDA-MB-231 cells and bacteria

With great progress in the treatment of breast cancer, Nanomedicine is emerging as a viable option for controlled and targeted medication delivery. The present study harnessed Mimosa pudica leaf extract to synthesize nickel oxide nanoparticles (NiONPs) via aqueous phase green synthetic approach. The structural, optical properties, morphological and elemental analysis were characterized by XRD, UV–Vis spectroscopy, Field Emission Scanning Electron Microscopy (FESEM) and EDX analysis. Upon characterizing the green synthesized NiONPs, it exhibited Bunsenite NiO, with an average crystalline size of 34 nm and were pure. The energy gap of 3.71 eV has been observed in NiONPs with an absorbance peak at 355 nm, confirmed the quantum confinement effect of nanoparticle's existence. The FESEM showed the presence of closely spherical morphology with an average diameter of 43 nm. The zeta potential and PDI were recorded at −21.3 ± 0.17 mV and 0.369 respectively, indicated a stable monodisperse nano system. NiONPs proven antibacterial performance with maximum zone of inhibition of 12 mm against Klebsiella pneumoniae at 60 μg/mL and decreased bacterial growth dose-dependently recorded after 24 h of incubation at 37 °C, under visible light. The biosynthesized NiONPs exhibited maximum antioxidant activity of 56 % against DPPH with a calculated IC50 value of 103.8 μg/mL for the NiONPs. Cytotoxic studies demonstrated a substantial decrease in the growth of triple-negative breast cancer MDA-MB-231 cells in a dose-dependent manner as the concentration of NPs escalated from 5 µg/mL to 100 µg/mL after 24 h. Based on above findings, we finally conclude that utilizing a greener approach to synthesize NiONPs holds a significant potential for treating triple-negative breast cancer and associated infections.

Optimization of Rhizoclonium hieroglyphicum extract for enhanced synthesis of nickel oxide nanoparticles using response surface methodology and its potential exploration in biological application.

The study investigates the potential of Rhizoclonium hieroglyphicum as a novel source for synthesizing nickel oxide nanoparticles (RH-NiONPs) and evaluates its biological applications. Phytochemicals in the algal extract serve as capping, reducing and stabilizing agent for nickel oxide nanoparticles. The process variables were optimized using BBD based RSM to obtain maximum RH-NiONPs. Characterization of RH-NiONPs using UV-Vis and FT-IR spectroscopy reveals the plasmon resonance peak at 340 nm and the functional groups responsible for reduction and stabilization. XRD confirmed the crystalline nature while the stability and size of the RH-NiONPs were determined by DLS and zeta potential. Toxicity assessments demonstrated the effect of RH-NiONPs against Vigna radiata, Allium cepa and Artemia salina was low. RH-NiONPs revealed significant zone of inhibition against the selected bacteria and fungi. The results of larvicidal activity showed that RH-NiONPs are toxic to 4th instar larvae of Daphnis nerii. Also, RH-NiONPs efficiently decolorized Reactive Violet 13 (92%) under sunlight irradiation and the experimental data well fits to Langmuir isotherm along with pseudo second order kinetic model. The thermodynamic studies enunciate the exothermic and non-spontaneous photocatalytic decolorization of reactive violet 13. Thus, the current study assesses the eco-friendly and cost-effective nature of RH-NiONPs along with its biological applications.

Green synthesis of undoped and Ag-doped NiO nanoparticles: Evaluation and their synergetic effect on antimicrobial, anticancer, and antioxidant activities

In this investigation, we successfully synthesized nickel oxide nanoparticles (NiO NPs) using a combustion method with Acacia nilotica gum as a biofuel, and systematically altered silver (Ag) concentrations within the NiO matrix. Post-calcination at 400 °C, various characterization techniques confirmed the formation, surface morphology, and crystalline characteristics of NiO NPs. The Ag-doped NiO NPs, particularly the NiAg4 sample, demonstrated remarkable antimicrobial efficacy, with superior activity against both fungal and bacterial pathogens. The NiAg4 sample also exhibited potent cytotoxicity against HT-29 human colon cancer cells, achieving an IC50 value of 1.5 mg/mL. Toxicological assessments revealed that both undoped and Ag-doped NiO NPs maintained biocompatibility with human red blood cells, indicating their potential for biomedical applications. Additionally, the NPs showed strong antioxidant activity and protein kinase inhibition, further supporting their therapeutic potential. These findings suggest that Ag-doped NiO NPs synthesized through a green protocol possess enhanced bioactivities, making them promising candidates for future in vivo studies and diverse biomedical applications.

Tailoring photocatalytic performance: Lanthanum doping in nickel oxide for efficient degradation of some industrial cationic dyes in visible light radiation

Metal oxide nanoparticles have emerged as an important component in heterogeneous photocatalysis, which uses light-induced reactions on the surface of a catalyst to drive chemical transformations. The improved photocatalytic activity of lanthanum-doped metal oxide nanoparticles has been the subject of research due to their special qualities, which include enhanced photocatalytic performance, stability and absorption of visible light. This study involves co-precipitation approach to synthesize nickel oxide nanoparticles and nickel oxide nanoparticles doped with lanthanum. The nanoparticles were determined using UV-Visible absorption spectrophotometry, X-ray diffraction spectroscopy, Energy-disperse spectroscopy, Photoluminescence spectroscopy and Field emission scanning electron microscopy. For the photodegradation of malachite green and rhodamine B dyes, synthesized nanoparticles were employed as photocatalysts. Compared to pure NiO, the photochemical activity of 4 % Lanthanum-doped NiO was higher. The degrading efficiency of 4 % La-doped NiO is 89 % effective towards rhodamine B and 87 % for malachite green. In addition, entrapment was done to identify primary active species responsible for photocatalytic activity. The present study likely provides new insights and novelty into the photocatalytic mechanisms at play, including how lanthanum doping affects the generation and dynamics of reactive oxygen species (ROS) like hydroxyl radicals and superoxide anions, which are responsible for the breakdown of dye molecules.

Catalytic effect of nickel oxide nanoparticles from Lupinus Albus extract on green synthesis and photocatalytic reduction of methylene blue: kinetics and mechanism

Green synthesis of nanomaterials is advancing due to their ease of synthesis, cheapness, nontoxicity, and renewability. An environmentally friendly biogenic method has been developed for the green synthesis of nickel oxide nanoparticles (NiO NPs) using phytochemical-rich bioextract. They are rich in bioextract phenolics, flavonoids, and berberine. These phytochemicals successfully reduce and stabilize NiNO3 into NiO NPs. In this study, NiO NPs were synthesized by the green synthesis method from Lupinus Albus. Characterization of NiO NPs was carried out by TEM, XRD, SEM, UV, XRF, BET, and EDX analyses. According to XRD analysis, TEM results also support this, where the NiO NPs particle size diameter is 5 nm. It was determined by the Tauc equation that the band energy gap of NiO NPs is 1.69 eV. It was determined that the BET surface area of NiO NPs was 49.6 m2/g. NiO nanoparticles synthesized from Lupinus Albus extract by the green synthesis method were used as catalysts in the photocatalytic reduction of methylene blue with NaBH4. In the photocatalytic reduction of methylene blue with NaBH4, it was determined that there was no color change in 48 h without a catalyst, and in the presence of NiO nanoparticle catalyst, methylene blue was reduced by 97% in 8 min. The kinetics of the photocatalytic reduction of methylene blue with NaBH4 is a pseudo-first-order kinetic model and the kinetic rate constant is determined as 0.66 min−1, indicating that the catalytic effect of NiO NPs is very high at this value. NiO NPs were used five times in the photocatalytic reduction of methylene blue with NaBH4 and it was determined that the reduction of methylene blue was over 90% in each use.

Chitosan-sunflower meal biochar hydrogel incorporated with green synthesized NiO nanoparticles for enhanced catalytic reduction of anthropogenic water pollutants.

Anthropogenic activities have been one of the crucial driving factors for water pollution globally, thereby warranting a sustainable strategy for its redressal. In this study, we have developed a hydrogel-biochar nanocomposite for catalytic reduction of water pollutants. To begin with, green synthesis of nickel oxide nanoparticles (NiO NPs) was accomplished from waste kinnow peel extract via the environmentally benign microwave method. The formation of NiO NPs was affirmed from different analytical techniques namely ultraviolet-visible (UV-Vis), Fourier transform infrared (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and energy-dispersive spectroscopy (EDS). The FESEM images revealed spherical nature of NiO NPs. The average particle size was found to be 15.61 nm from XRD data. A novel hydrogel-biochar nanocomposite comprising the green NiO NPs, sunflower meal biochar and chitosan was prepared (Cs-biochar@ NiO) and explored as a nanocatalyst towards catalytic reduction of pollutants such as 4-nitrophenol, potassium hexacyanoferrate (III) and organic dyes methyl orange (MO), Congo red (CR), methylene blue (MB) in the presence of a reducing agent, i.e. NaBH4. Under optimized conditions, the reduction reactions were completed by 120 s and 60 s for 4-NP and potassium hexacyanoferrate (III) respectively and the rate constants were estimated to be 0.044 s-1 and 0.110 s-1. The rate of reduction was found to be faster for the dyes and the respective rate constants were 0.213 s-1 for MO, 0.213 s-1 for CR and 0.135 s-1 for MB. The assessment of the nanocatalyst in the reduction of binary dye systems depicted its selectivity towards the anionic dyes CR and MO. The nanocatalyst displayed effective reduction of dyes in real-water samples collected from different sources. Taken altogether, this study validates the design of sustainable hydrogel-biochar nanocatalyst for the efficient reduction of hazardous anthropogenic water pollutants.

Green Synthesis of Nickel Oxide Nanoparticles via Imperata cylindrica Extract for Dual Application in Photocatalytic Degradation of Rhodamine B Dye and Antibacterial Activity

Green Synthesis of Nickel Oxide Nanoparticles via Imperata cylindrica Extract for Dual Application in Photocatalytic Degradation of Rhodamine B Dye and Antibacterial Activity

Harnessing hyperaccumulator (Brassica oleracea var. alboglabra) extract for green synthesis of nickel oxide nanoparticles: A prospective route for post-phytoremediation

Even though phytoremediation is considered a green technology for remediating heavy metals, there are some problems with the application of this technology, particularly when it comes to managing the biomass that is used. So, processing biomass needs to be given a lot of attention. This study outlined the utilization of extracts obtained from the hyperaccumulator plant Brassica oleracea var. alboglabra to synthesize nickel oxide nanoparticles. Subsequently, the nanoparticle underwent testing to determine its suitability as an absorbent for heavy metals, specifically lead, as well as its efficacy as an antifungal agent against Fusarium sp. strain. The characterization of nickel oxide nanoparticles involved several measurements, such as scanning electron microscopy analysis, high- and low-resolution transmission electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and hysteresis curve acquisition. The research findings indicate that the extract from hyperaccumulators can be utilized for the synthesis of NiO, which exhibits an absorption capacity exceeding 98% and serves as an efficient antifungal agent against Fusarium sp. pathogens. The approach utilized in this study not only prioritizes "green" and sustainability factors but also takes into account the economic aspects associated with the items being manufactured. The research has important implications in two areas. Firstly, it demonstrates the utilization of natural resources (B. oleracea var. alboglabra) in the production of nickel oxide, which serves as a safer and more eco-friendly substitute for dangerous chemicals. Furthermore, it aids in the advancement of novel techniques for effectively managing biomass hyperaccumulators.

Green Synthesis of Nickel Oxide Nanoparticles and its Application in the Degradation of Methyl Red

Environmental pollution is a threat to human health, with methyl red dye used in printing and textile dyeing being a notable pollutant that can cause eye, skin, and digestive system irritation. This study investigates the degradation of methyl red dye using nanoparticles of Nickel Oxide (NiO NPs) as photocatalysts. NiO NPs were synthesised at room temperature through thermal decomposition using antioxidant-rich extracts from strawberries (Fragaria ananassa), grapes (Vitis vinifera), and grapefruits (Citrus paradisi). Characterisation of the NiO NPs was performed using FTIR, UV-Vis spectroscopy and SEM. FTIR spectra confirmed the formation of NiO NPs with peaks between 577 – 585 cm–1. UV-Vis spectroscopy showed absorption wavelengths between 322-326 nm for the synthesised NiO NPs and a blue shift to 422-470 nm during methyl red degradation. This study presents a sustainable method for synthesising NiO nanoparticles and demonstrates their effectiveness in environmental remediation, specifically for the removal of pollutant dyes.

Investigations on the microbial activity and anti-corrosive efficiency of nickel oxide nanoparticles synthesised through green route

Abstract Researchers have shown considerable interest in the environmentally friendly synthesis of several nanoparticles particularly metal nano particles due to their multifaceted applications. The target of the current research includes the synthesis of nickel oxide nanoparticles (NiO-NPs) through the green route using the bark extract from Acacia Nilotica, and analyzed their chemical and surface morphological features using XRD, SEM, EDX, IR, UV–vis and photoluminescence spectroscopy. In addition, the corrosion inhibition ability and antimicrobial activity of the extract were also studied. The XRD analysis indicated that the NiO exist in the form of nanoparticles. It showed the formation of pure cubic NiO-NP with a prominent peak at 43.28° reflected from the plane (200). The crystallite size was found to be 15.83 nm. The SEM micrographs revealed that NiO-NPs appeared to be a bulk cluster-like structure on their surface.The EDX analysis displayed the presence of Ni and oxygen atoms. The photoluminescence spectrum demonstrated that the green synthesized metal oxide nanoparticles have a modified emission band due to the presence of oxygen deficiencies and induced surface imperfections. The Fourier transform infrared spectroscopy (FTIR) confirmed the association of peaks with the C–H and Ni–O bonds. The UV–vis study showed a maximum absorption at 264 nm. A study on the inhibition efficiency towards microbes confirmed that the prepared NiO-NPs have a good inhibition against selected microbes such as S. aureus, E. coli, Candida albicans, A. Niger. The mass loss system showed restraint 93.68 % effectiveness in the mild steel, and the electrochemical study supported the formation of a defensive protective layer on the cathodic locales of the carbon steel surface inhibiting corrosion.

Microwave assisted synthesis of nickel oxide nanoparticles at different pH via sol gel method: Experimental and first-principles investigations

Nickel oxide (NiO) nanoparticles were synthesized at different pH levels via a sol–gel method and calcined using microwave assistance. The study explored the effects of pH on NiO nanoparticles morphology, structure and electronic properties. Density functional theory (DFT + U) calculations were employed to investigate the structural and electronic properties of the material. NiO synthesized at pH 8 displayed superior crystallinity and particle size distribution, with spherical-like nanoparticles averaging 3 nm in size. DFT + U calculations revealed a band gap of 4.07 eV and a surface energy convergence of 51 meV/Å2, indicating stability. These findings suggest pH 8 as the optimal condition for NiO synthesis. Electrochemical tests demonstrated a high specific capacitance of 87.7F g−1 at a scan rate of 10 mV s−1, indicating promising electrochemical properties for supercapacitor applications.

Phytosynthesis of Nickel Oxide Nanoparticles and Their Antioxidant and Antibacterial Efficacy Studies.

Multidrug-resistant (MDR) bacteria are widely acknowledged as a significant and pressing public health concern. Tribulus terrestris has been used as a health tonic in traditional medicine since ancient Vedic times. It was also utilized to synthesize small, well-dispersed metal nanoparticles (NPs). Thebiosynthesized nickel oxidenanoparticles (NiO-NPs) have a broad spectrum of biomedical uses. The objective of the research was to utilize a green synthesis method to synthesizeNiO-NPsusing Tribulus terrestris, subsequently characterize, and this study aimed to assess the antioxidant and antibacterial effectiveness of these NPs against wound isolates that are resistant to multiple drugs. The synthesis of NiO-NPs was achieved through the titration method, which is a green synthesis approach, and it was characterized by using techniques such as ultraviolet-visible spectroscopy (UV), Fourier transform infrared (FT-IR), scanning electron microscopy (SEM),X-ray diffraction (XRD) analysis, andenergy dispersive X-ray (EDX). The antioxidant activity of theNPs was evaluated using the 2,2-diphenyl-1-picrylhydrazyl(DPPH) assay, and antibacterial activity was done using the agar well diffusion method. IBM SPSS Statistics for Windows, Version 21 (Released 2012; IBM Corp., Armonk, New York, United States)is used for statistical analysis. The biosynthesized NiO-NPs exhibited acolor change from dark brown to dark green, indicating the successful reduction of the NPs.UV analysis peaks were observed at 310-350 nm, whileFT-IRanalysis showed the peaks at various wavelengths such as 629.31cm-1(halo compound; C-Br stretching), 957.80cm-1(aromatic phosphates; P-O-C stretch), 1004.65cm-1 (aliphatic phosphates; P-O-C stretch), 1094.93cm-1(organic siloxane or silicone; Si-O-Si), 1328.38cm-1(dialkyl/aryl sulfones), 1604.88cm-1(open-chainazo-N=N-), 2928.68cm-1 (methylene C-H asym/sym stretch), 3268.65cm-1(normal polymeric "OH" stretch). The crystallinity of the NPs was determined to be 24.7%, while the remaining 75.6% exhibited an amorphous structure. The SEM image revealed a spherically agglomeratedstructure of the nano-ranged size NiO-NPs.TheEDX analysis indicated the presence of elemental compositions Ni (7.4%), O (39.4%), and C (53.3%)in the biosynthesized NiO-NPs. These NPs demonstrated significant antibacterial activity against Pseudomonas aeruginosa and Klebsiella pneumoniae, moderate antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA), and the lowest antibacterial activity against Enterococcus faecalis. Our in vitro results demonstrate that the biosynthesized NiO-NPsexhibit significant antioxidant and antibacterial activity. These NPs can be used as a future antimicrobial medication, particularly against MDR clinical wound isolates ofK. pneumoniae, P. aeruginosa, and MRSA.

Synthesis of Silver Nanoparticles by Solanum trilobatum L. Aqueous Extract and Their Antibacterial Activity

ABSTRACT Solanum trilobatum L. (Solanaceae), commonly known as nightshade, has been traditionally used by various populations to treat a variety of ailments. Environment-friendly alternatives to chemical and physical procedures for the synthesis of nanomaterials have been proposed. In this research, the hot plate combustion method is used to synthesize nickel oxide nanoparticles (AgNPs) from silver nitrate and S. trilobatum leaf extract. According to X-ray diffraction (XRD) tests, the cubic phase was face-centered, had good crystallinity, and had average crystallite sizes. According to morphological studies, the surface has a cylindrical and rod-like morphology, and average particle size estimates from UV-visible spectroscopy (UV), Fourier transform infrared (FT-IR), concur well with XRD, and the bio-reduced silver nanoparticles were characterized. Staphylococcus aureus, Enterococcus faecalis, Streptococcus mutans, Pseudomonas aeruginosa, and the human pathogenic microorganisms were used to investigate the antibacterial efficacy (12.5, 25, 50 μg/mL) of these biologically created silver nanoparticles.

Natural resource-derived NiO nanoparticles via aloe vera for high-performance symmetric supercapacitor

This investigation reported a one-step green synthesis of nickel oxide nanoparticles (NiO NPs) using aloe vera leaves extract solution for their application in a supercapacitor. This method used aloe vera leaves as a reducing agent, which is very simple and cost-effective. The synthesized NPs were thoroughly characterized using various techniques. The X-ray diffraction analysis unequivocally confirmed the crystalline nature; field emission scanning electron microscopy and transmission electron microscopy images showed different shapes and forms of an agglomerated cluster of synthesized NPs. The absorption spectra were recorded from UV visible spectroscopy, while Fourier transform infrared spectroscopy provided insights into the functional groups present. Electrochemical assessments were carried out via cyclic voltammetry, galvanostatic charging-discharging and electrochemical impedance spectroscopy. These experiments were performed using a 2 M KOH electrolyte within a 1.0 V potential window. Impressively, the single electrode displayed a remarkable specific capacitance of 462 F g−1 at a scan rate of 1 mV s−1 and 336 F g−1 at a current density of 0.76 A g−1. Further, a symmetric two-electrode device (NiO||NiO) has been successfully fabricated by employing a separator between the electrodes. The device exhibited an exceptional specific capacitance of approximately 239 F g−1, along with an energy density of 47.8 Wh kg−1 and a power density of 545 W kg−1 at 1 A g−1 current density within a 1.2 V potential window. The fabricated device also shows a retention capacity of 89% at 10 A g−1 after 2000 cycles with 114% of columbic efficiency. The present study underscores the effectiveness of the green synthesis approach in producing NiO NPs and establishes their potential as highly promising candidates for supercapacitor applications, showcasing both excellent electrochemical performance in a three-electrode system and remarkable stability in a practical two-electrode device. The results collectively highlight the efficacy of the green approach in producing NiO NPs, establishing its potential as a highly promising candidate for supercapacitor application.

Enhanced photocatalytic degradation of polycyclic aromatic hydrocarbons (PAHs) Using NiO nanoparticles

The oncogenic and genetic properties of anthracene, a member of the polycyclic aromatic hydrocarbons (PAHs) family, pose a significant health threat to humans. This study aims to investigate the photocatalytic decomposition of anthracene under various conditions, such as different concentrations of PAHs, varying amounts of NiO (nickel oxide) nanoparticles, and different pH levels under ultraviolet light and sunlight. The synthesized NiO nanoparticles showed surface plasma resonance at 230 and 360 nm, while XRD and SEM analysis confirmed the nanoparticles were cubic crystalline in structure with sizes ranging between 37 and 126 nm. NiO nanoparticles exhibited 79% degradation of pyrene at 2 μg/mL of anthracene within 60 min of treatment. NiO at 10 μg/mL concentration showed significant adsorption of 57%, while the adsorption method worked efficiently (72%) at 5 pH. Photocatalytic degradation was confirmed by isotherm and kinetic studies through monolayer adsorption and pseudo-first-order kinetics. Further, the absorption process was confirmed by performing GC-MS analysis of the NiO nanoparticles. On the other hand, NiO nanoparticles showed antimicrobial activity against Gram negative and Gram-positive bacteria. Therefore, the present work is one of its kind proving the dual application of NiO nanoparticles, which makes them suitable candidates for bioremediation by treating PAHs and killing pathogenic bacteria.

Surface and quantum chemical parameters of nickel oxide nanostructures suited for ultraviolet-assisted cationic dye degradation

Nickel oxide (NiO) nanostructures were synthesized through chemical precipitation and subsequently analyzed using a scanning electron microscopy (SEM) and X-ray diffraction (XRD). Rietveld refinement of XRD data revealed a cubic structure with lattice parameters of a = b = c = 4.173 Å. Fourier transform infrared spectroscopy and energy dispersive X-ray were employed to analyze the functional group and elemental composition of NiO NPs. The ultraviolet diffuse reflectance spectra indicated an optical band gap of 3.08 eV for synthesized NiO nanoparticles. Surface characteristics were evaluated using the Gwyddion open-source application, and parameters including Ra (mean roughness), Rq (mean square roughness), Rsk (surface skewness), and Rku (kurtosis coefficient) were calculated. The chemical properties of NiO were investigated through density functional theory calculations, and the results aligned well with experimental data. Furthermore, a comparative analysis of the photodegradation of methylene blue (MB) and rhodamine B (RhB) in the presence of UV light was examined, and it followed pseudo-first-order rate kinetics with degradation efficiencies of 82.62% (MB) and 71.31% (RhB), respectively. The electric energy per order for the photodegradation process was calculated to be 9.4 × 102 kWh/m3/order (MB) and 11.7 × 102 kWh/m3/order (RhB). Notably, the low electric energy consumption per order indicated a cost advantage for the reactor setup.