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Thin film of tin oxide (SnO2) deposited by spray pyrolysis with the aim of using the samples for gas sensing. To further enhance its gas-sensing properties, NiO nanoparticles (NPs) were decorated on the SnO2 surface at various concentrations. The bare and decorated samples were subjected to thorough investigation on their properties by X-ray diffraction, field emission scanning electron microscopy, and optical absorbance spectroscopy. In particular, the NiO NP density was carefully controlled by adjusting the deposition process. The deposition of NiO NPs significantly enhanced the NO2 sensitivity of the SnO2 thin film compared to their unmodified counterparts. Our investigations also delved into understanding mechanism of sensing. The deposition of NiO NPs onto the SnO2 surface facilitated the formation of p–n heterojunctions. These heterojunctions play a crucial role in modulating the conducting channels between neighboring particles, thereby extensively enhancing the overall sensing effectiveness of the device. This study presents a new strategy for the effective utilization of NiO NPs as a strategy for enhancing the sensing efficiency of SnO2 thin films and underscores the importance of heterojunction formation in enhancing the sensor performance. [ABSTRACT FROM AUTHOR]

Green nanomaterials have been extensively used in the environmental and agricultural applications due to their advantages of biocompatibility, eco-friendly, and cost-effectiveness. In this study, we have employed P. granatum leaf extract as a capping and stabilizing agent for the biofabrication of nickel oxide (NiO) nanoparticles to remove dyes effectively. The key factors which influenced the removal of Methylene Blue (MB) and Congo Red (CR) dyes under both visible and UV light exposure were identified. The experimental findings demonstrated the significant degradation efficiencies, with MB and CR reaching degradation levels of 91.7 % and 81.2 %, respectively. Furthermore, the face-centered cubic (fcc) structure with a space group of (Fm3m) of NiO was observed from the powder X-ray diffraction (XRD) analysis. Additionally, the morphology of NiO nanoparticles were investigated using scanning electron microscopy (SEM). Morphological analysis using high-resolution transmission electron microscopes (HR-TEM) with energy-dispersive X-ray spectroscopy (EDX), revealed the formation of spherical, cylindrical, and rod-shaped, nanoparticles and their elemental composition respectively. Fourier-transform infrared spectroscopy (FTIR) analysis has provided valuable insights into the molecular vibrations and the formation of Ni-O bonds within the NiO lattice. In the PL spectrum, the observed emission peaks at 484 and 545 nm indicate the presence of defects within the NiO structure. Raman spectroscopy further confirms the 2M vibrational mode and a reduction in antiferromagnetic coupling in the samples. Additionally, investigations on NiO nanoparticles at concentrations ranging from 50 to 500 mg/ml have exhibited their influence on bacterial activity against Bacillus cereus and Bacteroides fragilis. [ABSTRACT FROM AUTHOR]

Co-precipitation, a rapid and effective technique, was used to produce Ce- and W-doped NiO nanoparticles at pH values of 10 and 12. The FT-IR, UV-visible spectroscopy, and X-ray diffraction techniques were used to examine the structural and optical characteristics. The NiO nanoparticles' distinct XRD pattern revealed their monoclinic shape and crystalline origin. According to the Debye-Scherrer formula, the crystallite size of NiO nanoparticles decreased to 5.94 nm and 7.12 nm, respectively, when 5% Ce and 5% W were added, from 20.41 nm for undoped. Using UV-VIS absorption spectra, the optical band gap and the wavelength of maximum absorption were found. It was found that both of these parameters were influenced by the pH level and the concentration of Ce and W metal dopants. It can be concluded that doping has a higher impact on Cerium compared to Tungsten and at pH 10 compared to pH 12. This work presents a comprehensive investigation of the effects of pH and dopant concentration on the properties of Ce and W-doped NiO nanoparticles. [ABSTRACT FROM AUTHOR]

In the realm of nanotechnology, the synthesis of nanoparticles using environmentally benign methods, such as using plant extracts, has garnered significant attention. This work reports a simple and eco-friendly approach for the synthesis of nickel oxide nanoparticles (NiO NPs) utilizing microwave irradiation in the presence of lemon peel extract as a green reducing agent and Ni(CH3COO)2·2H2O as a precursor. Numerous analytical techniques were employed to determine the optical, morphological, and structural properties of the green-synthesized NiO NPs. The findings revealed that the resulting NiO NPs are pure, with an average size of 34 nm and a spherical geometry, possessing a face-centered-cubic crystalline structure. The antibacterial activities of the NiO NPs were preliminarily investigated against Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus) and Gram-negative bacteria (Klebsiella pneumoniae and Salmonella typhimurium). The morphological changes in B. subtilis and S. typhimurium were also evaluated by FE-SEM analysis, which showed that some cells were partially damaged and distorted in shape upon treatment with NiO NPs, thus demonstrating their promising antibacterial activities.

NiO nanoparticles were assembled on the surface of Halloysite nanotubes, which were subsequently further functionalized by sulfonic acid, to create NiO@HNTs-SO3H composite. This composite is employed as a heterogeneous catalyst in the one-pot synthesis of 1-(benzothiazolylamino) methyl-2-naphthols starting from aryl aldehyde, β-naphthol and 2-aminobenzothiazole as well as Tetrahydrobenzo[b]pyrans starting from aldehyde, dimedone and malononitrile. The catalyst was examined using Fourier transform infrared (FT-IR), energy dispersive X-ray (EDX), X-ray diffraction (XRD) pattern, and scanning electron microscopy (SEM) images. The synthesized organic compounds were examined using 1H NMR and 13C NMR spectroscopy and mass analysis by HRMS. The most notable benefits of the current work are its straightforward setup, gentle reaction conditions, green solvents, excellent yields, ease of purification, high efficiency, and the use of a recoverable and environmentally friendly catalyst. The easy separation and reusability of NiO@HNTs-SO3H catalyst after five runs confirmed the stability and effectiveness of the catalyst. [ABSTRACT FROM AUTHOR]

A series of ethyl 2-[(1H-indol-3-yl)(phenyl)methyl]-3-oxobutanoate derivatives was synthesized via a one-pot multicomponent approach using substituted indoles, ethyl 3-oxobutanoate, and aromatic aldehydes under a conventional heating. The NiO nanoparticles used as nanocatalysts for the Knoevenagel condensation and synthesis of new indole derivatives were discussed. The XRD was used to determine the particle size of the NiO nanoparticle. NiO nanoparticles can be recycled and used again after the reaction course. The ADM analysis and drug-likeness results showed that indole derivatives satisfied the criteria for drug-likeness and Lipinski's principles. The reactivity indices and potential regions derived from the FMO investigations were effectively used in various molecular systems because they offer valuable information. The oxobutanoate derivative's potential reactivity directions were determined and the important areas were highlighted. [ABSTRACT FROM AUTHOR]

This study investigated the catalytic CO2 methanation using nickel oxide (NiO) nanoparticles and nickel oxalate (NiC2O4) as catalysts. The NiC2O4 precursor was synthesized through a chemical precipitation reaction between nickel (II) nitrate hexahydrate (Ni(NO3)2.6H2O) and oxalic acid (H2C2O4.2H2O). Nickel oxide (NiO) nanoparticles were synthesized through thermal decomposition of NiC2O4 precursor at 450 °C in air. The samples were characterized by XRD, FTIR, BET, SEM, and EDX. The XRD and FTIR analyses revealed that the NiO nanoparticles were well‐crystallized having size 17.30 nm. The BET analysis of the NiO sample revealed mesoporous NiO nanoparticles with a specific surface area (SBET) of 29.08 m2/g and a narrow distribution of pore sizes. The catalytic performance of NiO and NiC2O4 catalysts studied for the CO2 methanation in tubular packed bed reactor at 150–550 °C and 1 atm. The reduced NiO nanoparticles exhibited more catalytic activity than the decomposed NiC2O4 catalyst. At 380 °C, 1 atm, and gas hourly space velocity (GHSV) of 9000 mL g−1 h−1, the reduced NiO nanoparticle catalyst showed high catalytic activity, with a maximum CO2 conversion of 85.54 %, 99 % CH4 selectivity, and 84.69 % CH4 yield. Furthermore, the NiO nanoparticle catalyst demonstrated excellent stability after 12 h of streaming at 380 °C. [ABSTRACT FROM AUTHOR]

The main objective of the present study was to develop flexible conductive biopolymer blend nanocomposites using polyindole (PIN) and carboxymethyl chitosan (CMC) with various nickel oxide (NiO) nanoparticles by in-situ polymerization techniques. Different techniques were used to study the effect of NiO content on the structural, optical, morphological, thermal, mechanical and electrical characteristics of PIN/CMC blend nanocomposites. Fourier-transform infrared spectroscopy (FT-IR) demonstrated that the introduction of NiO nanoparticles resulted in chemical bonding with the PIN/CMC blend, as evidenced by the formation of a new peak at a wavenumber of 603 cm− 1. The lowest optical bandgap energy was found in 10 wt% composites. The increased crystallinity of the blend nanocomposites was evident from X-ray diffraction (XRD) patterns. The scanning electron microscopy (SEM) and the energy dispersive X-ray (EDX) analysis confirmed the presence of NiO nanoparticles in the PIN/CMC blend. High-resolution transmission electron microscopy (HR-TEM) images revealed that the NiO particles were homogeneously dispersed in the blend matrix at a manometer scale. The thermogravimetric analysis (TGA) demonstrated that the reinforcement of NiO significantly improved the thermal stability of PIN/CMC blend from 202 to 223 °C. Electrical conductivity improved significantly as the temperature and nanoparticle dose increased. The tensile strength of the 7 wt% NiO-loaded PIN/CMC blend nanocomposite was 102% higher than that of the pure PIN/CMC blend. This PIN/CMC/NiO nanocomposite has high tensile strength, thermal stability, dielectric constant and electrical properties, making it suitable for a wide range of applications, including energy storage and flexible nano-electronic devices. [ABSTRACT FROM AUTHOR]

Background: Integrating nanomedicines for targeted cancer treatment and pursuing medicinally valuable components from nature are crucial for sustainable, potent alternatives to synthetic drugs in combating fatal diseases like cancer. Hence, a green synthesis of nickel oxide (NiO NPs) and zinc oxide nanoparticles (ZnO NPs) has been carried out by using the leaf extract of medicinally important plant Abutilonindicum. This sustainable approach to medical developments not only reduces the environmental effect of standard synthesis methods and offers new options for novel cancer therapeutics, but it also advances public health by using natural resources in a sustainable manner. Methods: The synthesized nanoparticles were characterized by employing spectro-analytical techniques like UV–vis, FT-IR, SEM and powder XRD. Synthesized nanparticles were evaluated in the human cervical cancer cells (HeLa). Results: Ni-O stretching vibrations were observed at 402 cm−1, whereas that of Zn-O stretching was observed at 409 cm−1in the FT-IR spectrum, confirming the formation of nanoparticles. The XRD pattern revealed the crystallite size range of 1.35–2.84 nm for NiO NPs and 7.71–56.80 nm for ZnO NPs. The morphology of the nanoparticles, as indicated by the SEM images, was rod-like for NiO NPs and rock-shaped for ZnO NPs. Further, the cancer cell growth inhibition activity of the nanoparticles was examined by MTT assay against human cervical cancer cells (HeLa) proliferation and compared with cisplatin. MTT assay elucidated the significant anticancer efficacy of the synthesized nanoparticles, showcasing low IC50 values of 29±0.5 µg/ml for NiO NPs and 32±0.7 µg/ml for ZnO NPs. Furthermore, the anticancer activity of the NiO NPs was investigated using the Trypan blue dye exclusion technique, emphasizing the pronounced cytotoxic impact of NiO NPs on cancer cell viability. The outcomes underscore the notable anticancer properties of plant extract mediated metal nanoparticles as promising contenders for advancing cancer treatment modalities.

Metal oxides are recognized as exemplary materials for photocatalytic dye degradation attributed to their unique characteristics such as tunable electronic structure, prolonged stability, and cost-effectiveness. However, the wide band gap inherent to most of these materials often limits their light absorption to the ultraviolet (UV) region. Consequently, the doping of noble metal nanoparticles into the metal oxide nanostructures has been proposed to significantly improve their light-harvesting ability. This enhancement is primarily ascribed to the localized surface plasmon resonance (LSPR) effect associated with noble metal nanoparticles, which facilitates more effective utilization of light. Thus, in this study, we synthesized silver-doped nickel oxide (Ag:NiO) with varying Ag concentrations (0, 1, 2, 4, 6 wt%) to evaluate their photocatalytic performance. The X-ray diffraction (XRD) spectra revealed that NiO possesses a cubic crystalline structure, and a peak shift to a higher angle was noted for Ag doping, indicative of compressive strain. Further analyses of morphological, vibrational, and absorption properties were conducted through the acquisition of scanning electron microscopy (SEM) images, Raman spectra and UV–Vis absorption spectra, respectively. The photocatalytic degradation of methylene blue (MB) and rhodamine B (RhB) dyes was assessed, revealing that NiO with 4.wt.% Ag doping exhibited enhanced photocatalytic activity, achieving 99% degradation of MB and 90% degradation of RhB. Notably, Ag doping significantly enhances the light absorption capabilities and modifies the electronic structure of the NiO, thereby improving its performance in photocatalytic dye degradation. • A novel strategy is proposed to improve the photo-catalytic ability of wide bandgap NiO. • Different concentration of Ag was doped into the NiO lattice. • The LSPR properties of Ag dopants will significantly improve light absorption in the visible region. • Most importantly, 99 % of MB degradation and 90 % of RhB degradation were achieved by Ag dopants. • Catalyst's high degradation efficiency towards MB Dye can be highly useful in wastewater treatment. [ABSTRACT FROM AUTHOR]

Nickel oxide nanoparticles (NiO NPs) are synthesized using olive leaf extract (OLE), which contains a range of polyphenols. These polyphenols serve as both reducing and capping agents, stabilizing the nanoparticles. Aqueous nickel acetate is employed as a precursor. Simultaneously, exfoliated graphene (EG) is obtained via electrochemical exfoliation of graphite in aqueous solutions. These materials were employed as electroactive components in supercapacitor applications. Characterization of NiO and EG involved thermogravimetric analysis (TGA), X-ray diffraction (XRD), Raman spectroscopy (RS), X-ray photoelectron spectroscopy (XPS), and scanning/transmission electron microscopy (SEM/TEM), alongside Brunauer−Emmett−Teller (BET) analysis, confirming the formation of crystalline NiO NPs with a cubic phase and Fm-3m space group. Micrographs revealed nanoscale dimensions for both NiO and EG with a substantial surface area, as verified by BET analysis. Symmetric (NiO/NiO, EG/EG) and asymmetric (NiO/EG) supercapacitors were fabricated using the doctor blade method. Electrode evaluation, employing field-emission scanning electron microscopy FESEM, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS), demonstrated promising morphological and electrochemical characteristics. At low scan rates, both symmetric and asymmetric supercapacitors exhibited a notable gravimetric capacitance (221, 111, and 162 F g–1 at 1 mV s–1). Additionally, they revealed higher power density (173, 137, and 161 W kg–1 at 10 mV s–1), showcasing pseudocapacitive and electric double-layer capacitor (EDLC) behavior for NiO NPs and EG, respectively. This research significantly contributes valuable insights by presenting a sustainable synthesis route for NiO NPs, developing high-performance supercapacitor electrodes, and achieving a comprehensive understanding of the electrochemical behavior of NiO NPs and EG. [ABSTRACT FROM AUTHOR]

Metal and metal oxide nanoparticles (NPs) embedded in glass matrixes exhibit special optical, electrical, or magnetic properties. Despite various approaches of encapsulating NPs in different kinds of glasses to prepare functional composite materials, there still exist challenges in fabricating efficiency and performance for silica glass made by traditional methods, such as sol–gel or melt quenching. Herein, the authors report a facile way to fabricate metal oxide NP‐doped silica glass by digital light processing (DLP) 3D printing technology for the first time. Different from common ion doping in silica glass, metal acetylacetonates that can be thermally decomposed to corresponding metal oxides innocuously, are chosen as a general precursor. Then, the representative nickel(II) acetylacetonate is introduced during the 3D printing process. The subsequent heat treatment generates a homogeneous distribution of NiO NPs in silica glass and it also exhibits optical nonlinear effect. The results provide a facile method for developing functional metal oxide‐doped glasses as well as the freeform fabrication of optoelectronic devices based on them. [ABSTRACT FROM AUTHOR]

In this research, nickel oxide (NiO) nanoparticles with different concentrations of 1, 2, 3, and 4 wt% were added to a zinc-rich ethyl silicate (ZRES) coating containing 90 wt% zinc dust particles to promote the cathodic and barrier performance of coating systems. FTIR, XRD, and EDX analysis indicated the chemical composition and created bonds in ZRES coatings. SEM, AFM and TEM images showed the surface roughness and particle size in ZRES structure. Also, TEM confirmed the uniform dispersion of NiO nanoparticles in the coating matrix loaded with 3 wt% NiO particles. The effect of NiO content and the anticorrosion behavior of nanocomposite coatings were investigated by different techniques, including open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP) and salt spray tests. Results revealed that ZRES coatings containing 3 wt% NiO nanoparticles had boosted sacrificial anode and barrier protection during 120 days of immersion in a 3.5 wt% NaCl solution. The addition of 3 wt% NiO into the coating system significantly reduced corrosion products and blisters while increasing corrosion resistances from 3069 Ω cm2 to 16482 Ω cm2 compared with the control ZRES sample. This high-performance anticorrosion behavior of the nanocomposite coatings is mostly due to the NiO nanoparticles, which have the capability to moderate the zinc dissolution rate in addition to improving the barrier by filling porosity and creating tortuous paths.

Metal and metal oxide nanoparticles (NPs) embedded in glass matrixes exhibit special optical, electrical, or magnetic properties. Despite various approaches of encapsulating NPs in different kinds of glasses to prepare functional composite materials, there still exist challenges in fabricating efficiency and performance for silica glass made by traditional methods, such as sol–gel or melt quenching. Herein, the authors report a facile way to fabricate metal oxide NP‐doped silica glass by digital light processing (DLP) 3D printing technology for the first time. Different from common ion doping in silica glass, metal acetylacetonates that can be thermally decomposed to corresponding metal oxides innocuously, are chosen as a general precursor. Then, the representative nickel(II) acetylacetonate is introduced during the 3D printing process. The subsequent heat treatment generates a homogeneous distribution of NiO NPs in silica glass and it also exhibits optical nonlinear effect. The results provide a facile method for developing functional metal oxide‐doped glasses as well as the freeform fabrication of optoelectronic devices based on them.

Present work that maximizes how lithium ions (Li) acting as a dopant affect the structure, morphology, optical, and electrical characteristics of nickel oxide (NiO) nanoparticles by co-precipitation method.It also reveals the face-centered cubic (FCC) structure of the yield material, as also evident by Transmission electron microscopy (TEM) results. Li ion observed TEM studies evident the size reductions of the NiO nanoparticles after capping processes. FTIR and UV-vis absorption spectroscopy reveals the functional behaviour of the composite elements and confirms the elemental existence. Photocatalytic observations reveal the dye degradation efficiency of NiO-Li composite nearly 96% against visible light irradiations. [ABSTRACT FROM AUTHOR]

High‐performance composite electrode materials for supercapacitors were developed by two‐step electrochemical deposition of nano‐NiO and poly(3,4‐ethylenedioxythiophene) (PEDOT) on nickel foam (NF). NF is considered an excellent conductive substrate for preparing porous electrode materials due to its high conductivity and porosity. The electrodeposited NiO nanoparticles were uniformly and densely coated on the pore of NF to fill in the internal voids, which provides an abundant active site for the electrodeposition of PEDOT. PEDOT was prepared by simple electrodeposition and was uniformly coated on the substrate surface which has high conductivity and reversible electrochemical redox properties, as well as excellent cyclic stability. The loose surface morphology not only provides abundant redox active sites for electrode material but also contributes the good pseudocapacitance property. As expected, the maximum mass‐specific capacity of PEDOT/NiO@NF composite electrode material can reach up to 129.7 F g−1 at the current density of 1 A g−1. Moreover, the composite electrode material shows excellent electrochemical cycling stability that the specific capacity has no obvious decay compared with its initial capacity after 200 cycles of cyclic voltammetry and 100 cycles of galvanostatic charge–discharge (GCD). This work demonstrates that the composite material PEDOT/NiO@NF could be a candidate flexibility electrode material for high‐performance supercapacitor applications. [ABSTRACT FROM AUTHOR]

In the present study, pure NiO NPs (Nickel oxide nanoparticles) along with their SWCNT (Single-walled carbon nanotubes) supported binary nanocomposites containing optimized wt% (weight percentages) of NiO 10%, NiO 20%, NiO 30%, and NiO 40% were synthesized via chemically controlled one-pot approach. The presence of characteristic Ni-O peak at 467 cm−1 in FTIR and fairly intense peaks in XRD data implied that synthesized NiO NPs exhibit crystallinity and don't involve impurity basis from pure Ni metal NPs. Further, the influence of variable NiO loadings on optical, morphological, photocatalytic, and antibacterial properties of the composites was explored using SEM, TEM, EDAX and UV-Visible spectroscopy. The composites were used as an effective photocatalyst for degrading MB (methylene blue) dye under UV illumination. The overall degradation behaviour of SWCNT/NiO nanocomposites initially increased with increase in NiO loading upto 30% and then showed a rapid downfall for catalyst with 40% NiO loading. The NiO 30% catalyst degraded 92.4% of the dye, whereas NiO 40% reduced the dye upto 84.2% of its initial concentration within 100 min of irradiation time. They showed better biocidal efficiency with determined activity against S. aureus and E. coli. The toxicity of NiO 40% was more pronounced against E. coli and S. aureus, as it exhibited 16.4 mm and 16 mm diameter of ZOI respectively against these strains. Overall, SWCNT/NiO 30% composites possess comparatively superior properties than pure NiO NPs and other NiO-loaded composites for their application in advancement of photocatalysis and anti-bacterial agents, thereby flooring an idea towards synthesis of multifunctional nanocomposites in the near future. [ABSTRACT FROM AUTHOR]

To counter the concern of the future availability of fossil fuel due to ever‐increasing energy demand and the emission generated due to its utilization, alternative renewable fuels, such as biogas and fuel additives in the form of nanoparticles emerge as viable alternative fuels. To date, no research has been carried out on the optimization of the co‐addition rate of nanoparticles and biogas. In this study, engine load (0.7–3.5 kW), Nickel oxide (NiO) Nanoparticles doped rate (NDR, 0–50 ppm), and Biogas Flow Rate (BFR, 0.5–1 kg/h) were selected as independent input variables to optimize compression ignition (CI) engine emission and performance outputs through the response surface methodology (RSM) approach. The F‐value of the RSM model indicates that the engine load variable has the greatest impact on engine output responses, with the BFR and NDR variables following in importance. At 2.54 kW engine load, 47.48 ppm NDR, and 0.747 kg/h BFR, the best engine output response was seen when the RSM model including the desirability function was optimized. Based on the optimization results, an assertion can be made that the use of nanoparticles in conjunction with biogas has a substantial impact on the emissions and efficiency of CI engines. [ABSTRACT FROM AUTHOR]

Green synthesis of nanoparticles (NPs) has attracted the researcher's attention due to its rapid, cost-effective, sustainable and eco-friendly nature. Current studies were carried out to perform and investigate the green synthesis of NiO NPs with aqueous (NiO(aqueous)) and ethanolic extracts (NiO(ethanolic)) of Acacia nilotica leaves, respectively. The NPs were characterized by spectroscopic, microscopic and thermometric techniques including FTIR, Raman, XRD, SEM, TGA and DSC. The electrochemical properties, antibacterial potential and haemolytic activities of the synthesized NPs were also examined. XRD patterns revealed the face-centred cubic structures of NiO NPs and a high degree of crystallinity. The average crystallite size of NiO(aqueous) NPs was significantly smaller (16 nm) than that of NiO(ethanolic) NPs (28 nm). SEM images show that NiO NPs are spherical. The synthesized NiO NPs demonstrate good electrochemical stability at an operating potential of −0.5-0.5 V. The inhibition effect of NiO NPs(ethanol) against B. subtilis, was comparable to the ciprofloxacin.

Recently, the preparation of smart multifunctional hybrid nanoparticles has captured significant interest in versatile areas, including medicine, environment, and food, due to their enhanced physicochemical properties. The present study focuses on the synthesis of Fe-doped NiO nanoparticles by the coprecipitation method using the sources of nickel (II) acetate tetrahydrate and iron (III) nitrate nonahydrate. The prepared Fe-doped NiO nanoparticles are characterized by X-ray diffraction, Fourier transform infrared spectroscopy, UV–visible spectroscopy, field-emission scanning electron microscopy, transmission electron microscopy, and X-ray photon spectroscopic analysis. The XRD results clearly confirm the face-centered cubic structure and polycrystalline nature of the synthesized Fe-NiO nanoparticles. The Tauc plot analysis revealed that the bandgap energy of the Fe-doped NiO nanoparticles decreased with the increasing concentration of the Fe dopant from 2% to 8%. The XPS analysis of the samples exhibited the existence of elements, including Fe, Ni, and O, with the absence of any surplus compounds. The FE-SEM and TEM analyses proved the formation of nanostructured Fe-NiO with few spherical and mostly unevenly shaped particles. Further, the photocatalytic efficiency of the prepared Fe-doped NiO nanoparticles were identified by using the cationic dye rhodamine B (Rh-B). The photocatalytic results proved the 8% of Fe doped with NiO nanoparticles achieved 99% of Rh-B degradation within 40 min of visible-light irradiation. Hence, the results of the present study exemplified the Fe-doped NiO nanoparticles have acted as a noticeable photocatalyst to degrade the Rh-B dye. [ABSTRACT FROM AUTHOR]

In the present study, a novel biosynthetic process of NiO-NPs is described using an economical reducing/capping agent (Cordia myxa fruit mucilage) by the simple sol–gel method, and Ni(NO3)2.6H2O as a nickel precursor. The nanoparticles were calcinated at different temperatures of 500, 600, and 700 °C. The structure, size, and morphology of these nanoparticles were characterized by FT-IR, XRD, FESEM, and EDS spectroscopy. The thermal manner of the composition has been studied by the utilization of TGA. Analyses of XRD verified that the pure and single-crystalline phase of NiO-NPs was formed when the sample was calcinated at 700 °C. The average particle size of 15 to 27 nm was obtained which showed that increasing the calcination temperature could lead to an increase in the size of NiO-NPs. The result from FESEM revealed that nanoparticles were uniformly distributed while being homogenous and nearly spherical as well. Further, NiO-NPs showed excellent catalytic activity through a three-component condensation reaction for the synthesis of 3,4-dihyropyrano[c]chromenes and 2-amino-4H-chromene derivatives. This effective catalyst could be recovered and reused several times without any significant loss of activity. [ABSTRACT FROM AUTHOR]

Nickel oxide nanoparticles (NiO NPs) were effectively prepared from nickel nitrate salt using sonication-assisted chemical (S-NiO NPs) and green (G-NiO NPs) approaches with the effect of reagents sodium hydroxide and Araucaria columnaris leaf extract. To study the role of reducing and stabilizing agents employed, the physiochemical properties of prepared S-NiO and G-NiO NPs were evaluated using XRD, PSA, FTIR, FE-SEM, TEM, BET, UV–Vis, and TG–DTA analysis. The highly reactive phytochemical constituent of leaf extract had significant control over the size and morphology, which produced spherical-shaped NiO NPs with a mean particle size of 23 nm and a high specific surface of 88.191 m2g−1. The above result was tuned to the active UV–Visible absorption band gap of 3.39 eV and 3.15 eV, respectively, for S-NiO NPs and G-NiO NPs. The prepared NiO NPs were promoted to real-time application in treating severe pharmaceutical residuals of Naproxen and Carbamazepine through visible light photocatalytic degradation. The highest degradation efficiency was achieved with green synthesis NiO NPs against Carbamazepine at 98.82% and Naproxen at 98.22%. The proposed lower concentration of 0.5 g/L NPs with specific physicochemical and optical properties may address pharmaceutical pollution, especially in municipal water bodies and protect the aquatic environment. [ABSTRACT FROM AUTHOR]

The blooming requirement of high‐performance energy storage systems has aroused the thirst for advanced energy storage materials. As a high capacity anode, however, the application of NiO nanoparticles (NiO NPs) is hindered by intractable issues of dramatic volume change, intrinsic low electronic conductivity, and severe aggregation tendency during lithiation/delithiation. Herein, a polydopamine (PDA) assisted bi‐functionalization strategy for fabricating of PDA@NiO‐CNT composites for fast and durable lithium storage is reported. In this composite, CNTs intertwine to form a network to ensure sufficient electrolyte infiltration and act as a highly conductive system to motivate fast charge transmission. The strong binding affinity of PDA facilitates bonding between NiO NPs and CNTs, which not only forms uniform and flexible PDA coating but also ensures homogeneous distribution of NiO NPs on CNTs network. Therefore, the bi‐functional modified PDA@NiO‐CNT electrode possesses high conductivity, alleviates volume change and aggregation of NiO NPs during cycling, achieves a reversible capacity of 1326 mAh g−1 at 100 mA g−1, a rate capability of 215 mAh g−1 at 2000 mA g−1 and a cycling stability with 78% capacity retention after 250 cycles. This bi‐functional modification approach manifests its prospective potential for architecting other electrode materials toward high‐performance electrochemical devices. [ABSTRACT FROM AUTHOR]

Current attention has been given on health effects of combined exposure of nanoscale materials and organic pollutants. Nickel (II) oxide nanoparticles (NiO NPs) displays exceptional properties and is being used in various areas such as batteries, diesel–fuel additives, and biomedicals. Benzo[a]pyrene (BaP) is a ubiquitous pollutant. Cigarette smoke, diesel exhaust, and grilled foods are main sources of BaP exposure. Therefore, combined exposure of NiO NPs and BaP to humans is unavoidable. There is a dearth of knowledge on combined effects of NiO NPs and BaP in humans. This study was aimed to investigate co-exposure effects of NiO NPs and BaP in human liver cells (HepG2) and primary rat hepatocytes. We observed that individual and co-exposure of NiO NPs and BaP induced cytotoxicity, lactate dehydrogenase leakage, lipid peroxidation, depletion of mitochondrial membrane potential, and activation of caspases (-3 and -9) in both types of cells. Individual and co-exposure of NiO NPs and BaP further accelerated the generation of free oxygen radicals (reactive oxygen species and hydrogen peroxide) and depletion of antioxidants (glutathione and various antioxidant enzymes). Remarkably, NiO NPs and BaP exerted synergistic toxicity to both HepG2 cells and primary rat hepatocytes. Moreover, combined toxicity of NiO NPs and BaP in both cells was mediated through free oxygen radicals induced oxidative stress. This work warrants further research on risk assessment of co-exposure effects NiO NPs and BaP in an appropriate in vivo model.

Abstract The blooming requirement of high‐performance energy storage systems has aroused the thirst for advanced energy storage materials. As a high capacity anode, however, the application of NiO nanoparticles (NiO NPs) is hindered by intractable issues of dramatic volume change, intrinsic low electronic conductivity, and severe aggregation tendency during lithiation/delithiation. Herein, a polydopamine (PDA) assisted bi‐functionalization strategy for fabricating of PDA@NiO‐CNT composites for fast and durable lithium storage is reported. In this composite, CNTs intertwine to form a network to ensure sufficient electrolyte infiltration and act as a highly conductive system to motivate fast charge transmission. The strong binding affinity of PDA facilitates bonding between NiO NPs and CNTs, which not only forms uniform and flexible PDA coating but also ensures homogeneous distribution of NiO NPs on CNTs network. Therefore, the bi‐functional modified PDA@NiO‐CNT electrode possesses high conductivity, alleviates volume change and aggregation of NiO NPs during cycling, achieves a reversible capacity of 1326 mAh g−1 at 100 mA g−1, a rate capability of 215 mAh g−1 at 2000 mA g−1 and a cycling stability with 78% capacity retention after 250 cycles. This bi‐functional modification approach manifests its prospective potential for architecting other electrode materials toward high‐performance electrochemical devices.

Current research focuses on the effects of nanomaterials on the human reproductive system. Nanostructures can cross the epithelial and blood-testicular barriers and pose risks to the reproductive organs. Oxidative stress has been proposed as a possible mechanism of reproductive toxicity caused by nanomaterials. Dietary curcumin could be a therapeutic drug for nanomaterial-induced reproductive toxicity. Studies on effect of commonly used nickel (II) oxide nanoparticle (NiO NPs) on male reproductive organs and their attenuation by natural antioxidant curcumin is scarce. This work intended to study the attenuating potential of curcumin against NiO NPs-induced toxicity in mouse spermatogonia GC-1 spg cells. Plausible mechanisms of alleviating effect curcumin against NiO induced reproductive toxicity was explored through oxidative stress pathway. NiO NPs was synthesized via chemical co-precipitation route and characterized by SEM, TEM, and XRD. NiO NPs was found to induce dose-dependent cytotoxicity in GC-1 spg cells (10–320 µg/ml for 24 h) whereas curcumin did not exert any effect in concentration range of 1–80 µg/ml. Interestingly, cytotoxic response of NiO NPs in GC-1 spg cells was significantly attenuated by curcumin. The higher expression of caspase-3 gene and loss of mitochondrial membrane potential after treatment with NiO NPs were effectively alleviated by curcumin. The increase in intracellular pro-oxidant levels (hydrogen peroxide, malondialdehyde, and reactive oxygen species) after exposure to NiO NPs was also mitigated by curcumin. Moreover, glutathione depletion and lower activity of several antioxidant enzymes (GPx, SOD, and CAT) after NiO NPs were further almost reverted by curcumin. We believe, this is the first preliminary study showing that NiO NPs induced cytotoxicity in mouse spermatogonia cells was mitigated by curcumin via oxidative stress. The therapeutic effect of dietary antioxidant curcumin against nanomaterial-induced reproductive toxicity is warranted further research.

Enhancing the boiling efficiency helps improve the productivity of thermal systems. Given the effects of added nanoparticles and applied magnetic field on the boiling process, this study investigates the effects of nickel oxide (NiO) nanoparticle concentration with and without applied magnetic field. The studied nanofluid was synthesized by the two-step method and approved by TEM and DLS stability tests for resistance to flocculation. Five concentrations of nanofluid, namely 0.005, 0.01, 0.05, 0.1, and 0.2), were prepared using nanoparticles with an average size of 30 nm. Moreover, a DC magnetic field with a maximum current of 10 A and a strength of 1000 G in the metal core and 300 G at the center of the core was used to evaluate the effects on nanoparticle boiling. The boiling heat transfer coefficient (BHTC) of deionized (DI) water was then compared with a plot of the Rohsenow correlation in three regions to validate the results and showed remarkable consistency. Moreover, experimental data indicated that the magnetic field affected the shape of DI water bubbles during boiling while improving the fluid's BHTC. It was also found that a 0.005 volume fraction of added NiO nanoparticles results in an average 35 % improvement, whereas at the 0.2 volume fraction, increased sedimentation drastically impacts the BHTC. The magnetic field improved the BHTC by nearly 10 % at a 0.005 volume fraction, while higher concentrations reversed the effects of the magnetic field. By hindering bubble generation, nanoparticle sedimentation on surfaces also drastically affects the BHTC. [ABSTRACT FROM AUTHOR]

4‐Nitrophenol (4‐NP) is a hazardous organic pollutant with detrimental effects on plants, animals, and humans. Detection of 4‐NP in the environment is therefore a necessary requirement. We demonstrate a facile green synthesis of nickel‐oxide (NiO) nanoparticles employing Brassica oleracea vegetable extract (cauliflower) as a green stabilizing and reducing agent. Green synthesized NiO nanoparticles were used as an efficient electrode material for the highly sensitive electrochemical detection of 4‐NP. The abundant polyphenolic component in the vegetable extract of Brassica oleracea is capable of reducing and stabilizing C2NiO4 into NiO nanoparticles. The as‐synthesized NiO nanoparticles were characterized by UV‐Vis spectroscopy, FTIR spectroscopy, Raman spectroscopy, photoluminescence spectroscopy, and X‐ray photoelectron spectroscopy (XPS), and the structural phase of NiO nanoparticles was confirmed using powder X‐ray diffraction technique. The surface morphology of the NiO nanoparticles was analyzed using scanning electron microscopy (SEM). Linear sweep voltammetry (LSV) and Differential pulse voltammetry (DPV) techniques were adopted to for the electrochemical determination of 4‐NP after drop casting the NiO nanoparticles onto the screen‐printed carbon electrode (SPCE). The developed sensor (NiO/SPCE) showed a high sensitivity of 1.055 μA/nM over a wide linear‐range from 1 to 10 nM with a detection limit of 0.519 nM for the detection of 4‐NP using DPV technique. [ABSTRACT FROM AUTHOR]

Remarkable properties of III-V semiconductors, particularly GaN nanostructured based photoelectrodes offers a potential attention in the field of photoelectrochemical water splitting (PEC-WS) for clean and sustainable hydrogen production, due to its wide bandgap, magnificent optoelectrical properties. However, the presence of inevitable surface states in GaN nanorods (NRs) leads to low solar-to-hydrogen (STH) conversion efficiency with poor stability, thereby severely limiting their practical application in PEC-WS, which can be effectively alleviated by constructing a hybrid heterostructures. Herein, we present the development of interfacial engineering of a type-II core-shell heterostructure based on p -NiO nanoparticles (NPs) loaded on n -GaN NRs photoelectrodes for PEC-WS. We assessed the impact of the NiO NPs shell density on core GaN NRs, finding that the optimized NiO@GaN NRs photoelectrode achieved a photocurrent density (J ph) of 1.38 mA/cm² at 1.23 V versus RHE and an excellent applied bias photo-to-current conversion efficiency (ABPE) of ∼0.39 %, which was 3.8 (J ph) and 4.8 (ABPE)-fold times higher than the pristine GaN NRs photoanode under 1-Sun illumination. The type-II p-n heterojunction band alignment between core-shell NiO@GaN NRs photoelectrode effectively reduced the photogenerated carrier recombination rate through surface states passivation and boost the light absorption and harvesting capacity. This facilitates a significant charge separation and transfer at the photoanode/electrolyte interface leading to enhanced redox reactions, resulting in improved PEC-WS and STH performances. These findings offer a promising strategy to design and fabricate highly efficient III-V hybrid heterostructure photoelectrodes for futuristic PEC-WS-based green energy applications. [Display omitted] • Construction of a novel hybrid p - n NiO@GaN NRs core-shell heterostructure photoanode for PEC water splitting. • The shell-NiO NPs greatly reduces the surface states of core-GaN NRs and carrier recombination effect of p - n heterostructure. • The J ph and ABPE of hybrid NiO@GaN NRs heterostructure is increased by 3.8 % and 4.8 % than bare GaN NRs. • The high PEC-WS performances are attributed to the excellent charge separation and transportation at p - n heterojunction. • A detailed mechanism is proposed to explain the high PEC-WS performances of hybrid NiO@GaN NRs photoanode. [ABSTRACT FROM AUTHOR]

In this work, resistive type photodetectors were fabricated using Gd3+ ions doped NiO nanoparticles to improve the detection of ultraviolet (UV) light. The occurrence of the simple cubic phase in NiO systems has been shown by X-ray diffraction patterns. The crystalline size of the NiO nanoparticles doped with different concentrations of Gd3+ at levels of pure, 1 %, 2 %, and 3 % were 6 nm, 8 nm, 9 nm, and 12 nm, respectively. The presence of dopants in the material was established by the Raman spectrum analysis. Transmission electron microscopy (TEM) pictures were used to validate the morphological properties of Gd3+ doped NiO nanoparticles nanoparticles at different degrees of dopant concentration (0 %, 1 %, 2 % and 3 %). The introduction and concentration of dopants alter the shape of NiO material. Based on the findings of UV–visible absorption spectroscopic studies, it can be concluded that the addition of Gd3+ ions to the system improved the absorption characteristics. The measured bandgap values for various degrees of Gd3+ doping, namely 0 %, 1 %, 2 %, and 3 %, are 3.51 eV, 3.45 eV, 3.36 eV, and 3.23 eV, respectively. According to the measured photoluminescence spectrum, Gd3+ ions may efficiently trap and maintain excited electrons within an energy level between the ground and excited states. This process greatly extends the lifespan of excitons from immediate recombination. The use of Gd3+-doped NiO sensors in UV photodetection resulted in a significant increase in conductivity and photocurrent. The photodetector fabricated using a 3 % concentration of Gd3+ doped NiO, has a responsivity of 24 × 10−2 AW−1, a detectivity of 14 × 109 Jones, and an external quantum efficiency (EQE) of 62 %. • Simple cubic phase NiO with Gd3+ doping, crystalline sizes up to 12 nm. • TEM confirms morphological changes, Ni 1-x Gd x O (x = 0 to 3). • Reduced bandgap: 3.51 eV–3.23 eV with Gd3+ doping. • Enhanced photodetection: Responsivity 24 × 10−2 AW−1, EQE 62 %. [ABSTRACT FROM AUTHOR]

In the present study, NiO nanoparticles have been synthesized using sodium dodecyl sulfate (SDS) intercalated layered nickel hydroxides as precursors. The precursors were synthesized using homogeneous precipitation method. The SDS intercalated layered nickel hydroxide precursors exhibit hierarchical micro-flower like structures consisting of nanosheets and they were converted into NiO nanoparticles via calcination at 400 °C. The SDS intercalated nickel hydroxides and the NiO nanoparticles were characterized using various techniques. The NiO nanoparticles possess small crystallite size, large specific surface area and they retain their original morphology as that of the precursors. The NiO nanoparticles obtained via the calcination of SDS intercalated nickel hydroxides were tested as adsorbent for the removal of congo red from an aqueous solution. [ABSTRACT FROM AUTHOR]

Green synthesis of nanoparticles (NPs) has attracted the researcher's attention due to its rapid, cost-effective, sustainable and eco-friendly nature. Current studies were carried out to perform and investigate the green synthesis of NiO NPs with aqueous (NiO(aqueous)) and ethanolic extracts (NiO(ethanolic)) of Acacia nilotica leaves, respectively. The NPs were characterized by spectroscopic, microscopic and thermometric techniques including FTIR, Raman, XRD, SEM, TGA and DSC. The electrochemical properties, antibacterial potential and haemolytic activities of the synthesized NPs were also examined. XRD patterns revealed the face-centred cubic structures of NiO NPs and a high degree of crystallinity. The average crystallite size of NiO(aqueous) NPs was significantly smaller (16 nm) than that of NiO(ethanolic) NPs (28 nm). SEM images show that NiO NPs are spherical. The synthesized NiO NPs demonstrate good electrochemical stability at an operating potential of −0.5-0.5 V. The inhibition effect of NiO NPs(ethanol) against B. subtilis, was comparable to the ciprofloxacin. [ABSTRACT FROM AUTHOR]

The results of the synthesis of PAN/NiO composite fibers by the electrospinning method are presented. The electrospinning installation included a rotating drum collector for collecting fibers. Nickel oxide nanoparticles were synthesized by solution combustion synthesis from nickel nitrate and urea. It was shown that monophase NiO nanoparticles with average particle sizes of 154 nm could be synthesized by this method. NiO nanoparticles were investigated by X-ray diffraction analysis and scanning electron microscopy. Based on NiO nanoparticles, composite PAN/NiO fibers were obtained by electrospinning. The obtained composite fibers were modified with heat treatment (stabilization and carbonization) processes. Obtained C/NiO fibers were investigated by SEM, and EDAX. It was shown that obtained composite fibers could be used for the detection of acetone and acetylene in air. These results show that C/NiO based electrospun fibers have potential applications in gas sensors. [ABSTRACT FROM AUTHOR]

Quantum-dot (QD) light-emitting diodes (QLEDs) are garnering significant attention owing to their superb optoelectrical properties, but the overinjection of electrons compared to holes into the emissive layer (EML) is still a critical obstacle to be resolved. Current approaches, such as inserting a charge-balancing interlayer and mixing p-type organic additives into the EML, face issues of process complexity and poor miscibility. In this work, we demonstrate efficient InP QLEDs by simply embedding NiO x nanoparticles (NPs) into the EML which forms a homogeneous QD-metal oxide hybrid EML. Precisely changing the NiO x NPs concentration enables an effective modulation of the valence state of the hybrid EML, while controlling the exciton quenching phenomena stemming from the metal oxide additives. Moreover, the inorganic hybrid EML exhibits superior electrical stability compared to that of typical organic additives. In detail, it possesses an upshifted valence state by approximately 0.2 eV, leading the QLEDs to a 3.7-fold increase in luminance, 1.7-fold improvement in external quantum efficiency, and 3-fold extension in operational half-lifetime, simultaneously. Comprehensive analyses on the optoelectrical and morphological characteristics confirm that the hybrid EML is suitable for realizing efficient and stable InP QLEDs via a simple fabrication method. Therefore, we expect that this approach would provide valuable insights into the development of high-performance and low-cost QLEDs.

In this study, we successfully synthesized nickel oxide (NiO) nanoparticles (NPs), i.e., samples NiO 24V , NiO 36V , and NiO 48V , via an environmentally friendly one-step electro-exploding wire technique by employing three distinct voltage levels of 24, 36, and 48 V, respectively. Sample NiO 48V showed the most rugged surface and smallest particle size, which helped to enhance electrocatalytic properties. The highest Ni 3+ content of sample NiO 48V contributed to the increasing redox current and rendering highly enhanced chemical reactions and thereby improving their electrochemical properties and electrocatalytic performance in the glucose oxidation processes in alkaline (0.1 M NaOH, pH = 13) media. The NiO 48V electrode showcased an excellent linear detection range spanning from 0.1 to 1 mM, featuring a remarkable sensitivity of 1202 μA mM -1 cm -2 and an exceptionally low limit of detection (LOD) value of 0.25 μM. Remarkably, NiO NPs exhibited exceptional long-term stability, commendable reproducibility, favorable repeatability, and outstanding selectivity. This study also highlights the excellent operational performance of the NiO 48V electrode in real-world samples, such as commercially available beverages and human urine, highlighting the practical nature of these nonenzymatic sensors in real-life scenarios for the food industries, clinical diagnostics, and biotechnology applications.

Nickel oxide nanoparticles were synthesized via calcination of organometallic chelate. The adsorption of acid yellow 99 (AY99) was examined using produced NiO at temperatures of 450°C, 550°C, and 650°C. Different spectroscopic studies were used to characterize the synthesized NiO as an example (XRD) X-ray diffraction, FTIR, energy-dispersive X-ray spectroscopy (EDX), including the Brunauer–Emmett–Teller (BET) variable surface area, which was 156.036 m2 /g. Scanning electron microscopy (SEM) got accustomed to quantifying the changes on the surface. Initial pH, for example, is variable to consider, the dose of adsorbent, time of contact, temperature, and the point of zero charging (pHPZC) of NiO was designed and established to be 7.3. To discover the best adsorption conditions for extracting (AY99) from aqueous media, researchers looked into a variety of factors. Langmuir isotherm was shown to closely resemble the experimental values. To characterize the dye getting, the pseudo-second-order represents growth was adopted. This was also shown that adsorption has a high activation energy of 24.8 kJ/mol, this indicates that the adsorption obeys the chemisorption process. To determine adsorption equilibrium parameters, the Langmuir isotherm was utilized. Several thermodynamic constraints, for example, ΔG°, ΔH°, and ΔS° were calculated at various temperatures. The thermodynamics of the adsorption mechanism was discovered to be endothermic, random, and spontaneous. Compare the results of adsorption of AY99 over the NiO was 766.35 mg/g with other adsorbents and found it is the best one for removal. [ABSTRACT FROM AUTHOR]

Nickel oxide nanoparticles (NiO NPs) embedded in SiO2 matrix were prepared by the precipitation method. The different sizes of NiO NPs were achieved at various calcination temperatures (600–1000 °C) and different molar ratios of Ni/Si (1, 1.05, 1.15 and 1.24). The SEM images show the morphology and uniform distribution of NiO NPs in the prepared samples. The size, spherical shapes and good dispersion of NiO NPs in the SiO2 matrix are illustrated by TEM images. The dark spots and gray background indicated the NiO NPs and the SiO2 matrix, respectively. The crystalline structures of samples and the approximate crystalline size of the nanoparticles were achieved by XRD patterns. The paramagnetic property of the prepared sample was investigated by a vibration sample magnetometer. In this study, the observed size of the nanoparticles increased by increasing the calcination temperatures and molar ratio of Ni/Si and also SiO2 is a suitable matrix for the synthesis of small nanoparticles. Thus, this method is an appropriate method for fabricating NiO NPs. [ABSTRACT FROM AUTHOR]

Calcination method has been used to create NiO nanoparticles with a diameter of 19 to 30 nm from [NiL] [L: 2,2'-((1E, 1'E)-(1,2-phenylenebis(azanylylidene))bis(methanylylidene))bis(4-bromophenolate)]. Formation and purity of the NiO nanoparticles produced under mild conditions without any special needs are evidenced by fourier-transformed infrared (FT-IR) spectroscopy, ultraviolet visible (UV-Vis) spectroscopy, X-ray powder diffraction (XRD), energy-dispersive X-ray (EDX) spectroscopy and scanning transmission electron microscopy (STEM). According to the spectral methods, transformation of the synthesized nickel-Schiff base complex into the nanoparticles has been achieved with high purity, high crystallinity and low agglomeration by thermal decomposition which is an efficient and simple approach. The nanoparticles are employed as a catalyst for the decomposition of methylene blue, an industrial synthetic dye, and the nanoparticles exhibit mild photocatalytic activity. Furthermore, biological activity of nanoparticles has been investigated on five bacterial strains and two fungi, with promising results. [ABSTRACT FROM AUTHOR]

In this study, we described a green, sustainable, and feasible method for synthesizing 5 nm NiO nanoparticles. Eggplant skin was chosen as an appropriate bio-template with a high potential to induce its structure into the desired metal oxide. Two approaches were used and compared to synthesize NiO bio-template: hydrothermal and sol-gel. The morphology and physical properties of the obtained NiO nanoparticles were evaluated using FESEM, TEM, XRD, BET, FT-IR, TGA, and UV–Vis analyses. All these methods confirm that the hydrothermal method is a better approach for synthesizing NiO bio-template nanoparticles than the sol-gel method. UV–Vis analysis revealed that the NiO nanoparticles produced by the hydrothermal method have a low bandgap of 2.88 eV, which is a key factor for photocatalytic applications. [ABSTRACT FROM AUTHOR]

Photocatalytic CO 2 conversion, in general, requires the incorporation of expensive and noble materials to achieve a highly efficient conversion rate. Herein, the TNT/NiO/CQD ternary nanocomposites without any expensive materials and material modification are fabricated for the demonstration of efficient and economically affordable photocatalytic CO 2 conversion, to our best knowledge, for the first time. The TNT-based ternary photocatalysts are successfully prepared by a simple anodization and immersion process. The TNT/NiO/CQD ternary nanocomposites produce 1.47 μmol·cm-2·h-1 (≈ c.a. 2834 μmol·g-1·h-1) of CH 4 as the sole product under AM 1.5 illumination. This is five times higher performance than that of bare TNT and the performance is comparable to that of any other TiO 2 -based unitary, binary, or ternary photocatalysts. This highly enhanced performance results from effective junction formation between TNT and NiO NP, and the dual role of CQDs as a light absorber and charge transporter/collector in the system. The formation of Z-scheme at the TNT/NiO interface leads to efficient charge transfer via a TiO 2 /NiO bond. The light absorption of the photocatalysts is enhanced and extended by decorated CQDs due to their small band gap. The charge transfer and collection are further improved by charge depletion at the TNT/CQD interface and the charge transfer at the NiO/CQD interface. This work provides a possible model for the realization of efficient and economically affordable photocatalytic CO 2 conversion. [ABSTRACT FROM AUTHOR]

Dental decay is known in the world as the most common human infectious disease. Ascending process of dental caries index in the world shows the failure of oral disease prevention. Streptococcus mutans bacteria cause acid damage and tooth decay by producing acid over time. Nanomaterials with suitable functionality, high permeability, extremely large surface area, significant reactivity, unique mechanical features, and non-bacterial resistance can be considered as promising agents for antimicrobial and antiviral applications. In this study, nickel oxide (NiO) nanoparticles with size range from 2 to 16 nm containing Stevia natural sweetener were eco-friendly synthesized via a simple method. Additionally, their various concentrations were evaluated on S. mutans bacteria by applying the broth dilution method. The results demonstrated that these spherical NiO nanoparticles had efficient bacteriostatic activity on this gram-positive coccus. [ABSTRACT FROM AUTHOR]

Five different Nickel (II) complexes were prepared using a ONNO type Schiff base bis-N;N'(salicylidene)-1,3-propanediamine (LH2) and an ONO type Schiff base N(2-hydroxy)salicylaldimine (SAPH2) in the presence of NH3 or amine and NiO nanoparticles were obtained with thermal decomposition of this complexes in air. The prepared complexes and Schiff bases have been characterized by element analysis, IR spectroscopy, Thermogravimetry (TG), ¹HNMR and 13CNMR spectroscopy, Mass Spectrometry (MS), Atomic absorption spectrometry (AAS), and Scanning Electron Microscopy (SEM). The surface area of the obtained nanoparticle NiO material was measured by the Brunauer-Emmett-Teller (BET) method. The thermal decomposition products NiO nanoparticles were investigated with XRD, and SEM technics. SEM investigations showed that due to the very little solubility of the prepared two complexes and consequently they were precipitated in the form of nanoparticles. In addition, it observed that this very insoluble complexes are converted to NiO nanoparticles a result of thermal decomposition. [ABSTRACT FROM AUTHOR]