Nickel Research Articles

Synthesis and characterization of ZnO–NiO binary nanocomposites by hydrothermal technique for gas sensing and photocatalytic applications

Inorganic photocatalytic materials exhibiting a highly efficient response to ultraviolet-visible light spectrum have become a subject of widespread global interest. Nanocomposite metal oxides, particularly Nickel Oxide (NiO) and Zinc Oxide (ZnO), have gained attention for their diverse applications in gas sensing and photocatalytic processes. In this work, ZnO-NiO (ZnO0.6NiO0.4 and ZnO0.4NiO0.6) binary nanocomposites were synthesized by hydrothermal technique. The binary nanocomposites were analyzed by UV-Visible spectrophotometer, X-ray diffraction (XRD), photoluminescence (PL), Fourier transform infrared spectrophotometer (FTIR), energy dispersive X-ray spectroscopy (EDX), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The XRD pattern revealed that the nanocomposites, the peaks of both ZnO and NiO are present indicating the presence of both crystal structures hexagonal wurtzite and cubic. The miller indices, crystallite size, microstrain and dislocation density were determined from the XRD plot. FESEM and TEM analyses showed the spherical morphology of the synthesized composites with an approximate size of 10[Formula: see text]nm. The detailed analysis of ZnO–NiO binary nanocomposite sensor characteristics in terms of sensitivity, selectivity, response and recovery time were carried out and the nanocomposites were found to be highly sensitive to CO2 100 ppm at 350∘C and Cl2 at 200∘C. The photocatalytic degradation outcome showed 52% degradation of methylene blue at 10 ppm and 90[Formula: see text]w/m2. These results suggest the potential utility of these binary nanocomposites in photocatalytic applications for the degradation of organic pollutants.

Assessment of Essential Trace Elements Cu, Zn, Mn, and Ni in Mediterranean Mussels (Mytilus galloprovincialis) from the Algerian Coast.

The aim of this study was to determine the levels of essential trace elements copper, zinc, manganese, and nickel in two size groups of mussels, Mytilus galloprovincialis, sampled from three sites along the Algerian coast with different levels of pollution. The results of this work are very interesting for determining the effect of mussel size on the variation of contaminant levels in environmental monitoring studies. Thirty individuals from 2 size groups, less than 4-cm and more than 4-cm shell length, were collected over 4 seasons at each site studied. The samples were dissected, and copper, zinc, manganese, and nickel were measured in the whole soft tissues by inductively coupled plasma mass spectrometry (ICP-MS). The maximum concentrations of copper, zinc, manganese, and nickel expressed in mg/kg dry weight at the three sites were 54.01, 146.25, 20.69, and 8.85, respectively. A clear distribution pattern of the studied elements was observed in the two size classes. In fact, significantly higher concentrations (P < 0.05) were found in individuals with a shell length of less than 4 cm. Significantly, higher concentrations (P < 0.05) were found in individuals with a shell length of less than 4 cm due to their high filtration and low excretion activities compared to long individuals. In addition, metal pollution index (MPI) values were higher in small bivalve individuals. The trace element contents found in the mussel samples of the present study showed large spatial and temporal variations among the different sites studied, highlighting the typical exposure of marine sites to different marine pollutants. Notably, elevated concentrations of copper were observed in the port of Zemmouri, likely due to port activities. Conversely, the highest levels of manganese and nickel were recorded at Boudouaou El Bahri, potentially attributable to the use of fertilisers by agricultural activities. Some shellfish samples had exceeded the permissible concentration levels of copper and manganese, thereby posing a danger to bivalve consumers.

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.

Simulation of quantum states in solid-state ferromagnetic nanostructures

Purpose of the article. Identification and analysis of mathematical expressions for the energy spectrum of charge carriers in nano-sized magnetic films of nickel and Ni-Cu (substrate), as well as NiO-Ni-Cu (substrate) structures.Methods. In this work, based on basic quantum mechanical concepts and taking into account the boundary conditions for coupled quantum wells, expressions for the energy spectrum of electrons are obtained. The ferrimagnetic properties of nickel are taken into account through the effective mass value. The solution of nonlinear equations that determine discrete energy levels was achieved by numerical methods using the Mathcad mathematical package.Results. Transcendental expressions for the energies of free charge carriers in quantum wells of ferromagnetic nickel films are obtained, and the influence of the position of nickel on the copper substrate is shown. It has been shown that the use of a copper substrate leads to an increase in the density of energy levels in the nickel nanofilm. The influence of the oxide layer on single-electron states in nanofilms of nickel and its oxide is considered within the framework of the Anderson model. Based on the numerical solution of the transcendental equations obtained in the work, the influence of the ratio of the thicknesses of a ferromagnetic metal and its oxide on the energy levels of electrons localized in the oxide layer is shown.Conclusions. The formulas presented in the work for the energy spectrum take into account the energy relief of a complex quantum well, the dimensions of the film, surface oxide, and the significant effective mass in the region of the ferromagnetic film. It has been shown that an increase in the effective mass in magnetic heterostructures leads to an increase in the electron density of states. It was found that the density of electronic states in the region of surface nickel oxide is practically independent of the thickness of the nickel film. The results and conclusions of the work can be used for theoretical prediction of the physical properties of magnetic nanostructures, in particular spintronic elements.

Interfacial Dipole Engineering for Energy Level Alignment in NiOx-Based Quantum Dot Light-Emitting Diodes.

The solution-derived non-stoichiometric nickel oxide (NiOx) is a promising hole-injecting material for stable quantum dot light-emitting diodes (QLEDs). However, the carrier imbalance due to the misalignment of energy levels between the NiOx and polymeric hole-transporting layers (HTLs) curtails the device efficiency. In this study, the modification of the NiOx surface is investigated using either 3-cyanobenzoic acid (3-CN-BA) or 4-cyanobenzoic acid (4-CN-BA) in the QLED fabrication. Morphological and electrical analyses revealed that both 4-CN-BA and 3-CN-BA can enhance the work function of NiOx, reduce the oxygen vacancies on the NiOx surface, and facilitate a uniform morphology for subsequent HTL layers. Moreover, it is found that the binding configurations of dipole molecules as a function of the substitution position of the tail group significantly impact the work function of underlying layers. When integrated in QLEDs, the modification layers resulted in a significant improvement in the electroluminescent efficiency due to the enhancement of energy level alignment and charge balance within the devices. Specifically, QLEDs incorporating 4-CN-BA achieved a champion external quantum efficiency (EQE) of 20.34%, which is a 1.8X improvement in comparison with that of the devices utilizing unmodified NiOx (7.28%). Moreover, QLEDs with 4-CN-BA and 3-CN-BA modifications exhibited prolonged operational lifetimes, indicating potential for practical applications.

Design of CO2-Resistant High-Entropy Perovskites Based on Ba0.5Sr0.5Co0.8Fe0.2O3-δ Materials.

High-entropy perovskite materials (HEPMs), characterized by their multi-element composition and highly disordered structure, can incorporate multiple rare earth elements at the A-site, producing perovskites with enhanced CO2 resistance, making them stay high performance and structurally stable in the CO2 atmosphere. However, this modification may result in reduced oxygen permeability. In this study, we investigated La0.2Pr0.2Nd0.2Ba0.2Sr0.2Co0.8Fe0.2O3-δ (L0.2M1.8) high-entropy perovskite materials, focusing on enhancing their oxygen permeability in both air and CO2 atmospheres through strategic design modifications at the B-sites and A/B-sites. We prepared Ni-substituted La0.2Pr0.2Nd0.2Ba0.2Sr0.2Co0.7Fe0.2Ni0.1O3-δ (L0.2M1.7N0.1) HEPMs by introducing Ni elements at the B-site, and further innovatively introduced A-site defects to prepare La0.2Pr0.2Nd0.2Ba0.2Sr0.2Co0.7Fe0.2Ni0.1O3-δ (L0.1M1.7N0.1) materials. In a pure CO2 atmosphere, the oxygen permeation flux of the L0.1M1.7N0.1 membrane can reach 0.29 mL·cm-2·min-1. Notably, the L0.1M1.7N0.1 membrane maintained a good perovskite structure after stability tests extending up to 120 h under 20% CO2/80% He atmosphere. These findings suggest that A-site-defect high-entropy perovskites hold great promise for applications in CO2 capture, storage, and utilization.

Study of mechanical and metallurgical properties of wire arc additively manufactured inconel 718 alloy

The current research work deals with the investigation of mechanical, wetting transition on grain boundary (GB) and metallurgical properties of Inconel 718 alloy used in aerospace industrial applications. The fabrication of thin-wall structure (multilayer structure) is fabricated using wire arc additive manufacturing (WAAM) technique. The novelty of this method is that gas metal arc welding (GMAW) is used as energy source and cold metal transfer (CMT) is used as mode of droplet transfer. Four tensile samples are extracted asper ASTM E8/E8M standards and three microstructure samples are extracted from thin wall structure. Optical microscopy (OM), SEM, EDAX, and EBSD analysis were carried out. In addition, Hardness and tensile tests, as well as fractography analysis were conducted. The grain boundary wetting transition (GBWT) analysis is also carried out. SEM analysis reveals that Nb-rich MC-type carbide contains grain boundaries of droplets, indicating incomplete wetting. Laves and delta (δ) phases are also identified as liquids of a continuous layer separated by Ni elements, indicating complete wetting. EBSD analysis indicates the average grain size as 251.2 μm. The average value of micro hardness as 417.3 HV and UTS as 609.75 MPa are achieved.

Flower-like nickel oxide nanostructures: Superior ammonia gas sensing and efficient dye removal behavior under UV–visible light illumination

In this study, we fabricated the NiO nanostructures using a straightforward solvothermal technique. The NiO nanoparticles were characterized using various analytical techniques. The FESEM images clearly show the flower-like structure of NiO nanoparticles. These nanostructures were then employed as a sensor to detect the presence of highly toxic ammonia (NH3) gas. The flower-shaped nanostructures of NiO played a vital role in improving sensing performance. Moreover, the NiO sensor displayed rapid response to 100 ppm ammonia at room temperature, with responses/recovery times of 40 s/44 s. This research holds promise as a viable approach for effectively sensing and detecting NH3 gas. The NiO exhibited excellent photocatalytic activity and degradation rates of 80% and 84.75% for Methyl orange (MO) and methylene blue dye (MB) respectively under UV-visible light irradiation. The NiO nanoflower remains unaffected after recycling MB dye degradation. This effective photocatalytic performance might be due to the formation of flower-like morphology. This underscores the potential of NiO as a promising candidate for applications in environmental and healthcare safety applications.

Effect of Iron Doping in Ordered Nickel Oxide Thin Film Catalyst for the Oxygen Evolution Reaction.

Water splitting has emerged as a promising route for generating hydrogen as an alternative to conventional production methods. Finding affordable and scalable catalysts for the anodic half-reaction, the oxygen evolution reaction (OER), could help with its industrial widespread implementation. Iron-containing Ni-based catalysts have a competitive performance for the use in commercial alkaline electrolyzers. Due to the complexity of studying the catalysts at working conditions, the active phase and the role that iron exerts in conjunction with Ni are still a matter of investigation. Here, we study this topic with NiO(001) and Ni0.75Fe0.25O x (001) thin film model electrocatalysts employing surface-sensitive techniques. We show that iron constrains the growth of the oxyhydroxide phase formed on top of the Ni or NiFe oxide, which is considered the active phase for the OER. Besides, operando Raman and grazing incidence X-ray absorption spectroscopy experiments reveal that the presence of iron affects both, the disorder level of the active phase and the oxidative charge around Ni during OER. The observed compositional, structural, and electronic properties of each system have been correlated with their electrochemical performance.

Uncovering the combining V with Ni micro-addition alloying on the mechanical properties and multiphase transformation during solidification and homogenization of Al–Zn–Mg–Cu–Sc alloy

The ultimate tensile strength of the T6-aged Al–Zn–Mg–Cu–Sc alloy is improved by 24 MPa reached 667 MPa with the addition of 0.10 % V, 0.20 %Ni and decrease 0.1 %Sc. The thermodynamic and microalloying mechanisms of phase transformation during solidification and homogenization of Al–Zn–Mg–Cu–Sc–V–Ni alloy were clarified. The phase transformation model of Al3Sc (V, Ni) structure induced by V and Ni addition during homogenization was established. The calculation radius showed that coherent L12-ordered Al3Sc(V, Ni) nanoparticles were formed in the Al–Zn–Mg–Cu–Sc–V–Ni alloy, which had a small critical nucleation radius (22.0 nm). The large thermodynamic driving force and the high kinetic energy migration energy barrier of γ-Al7Cu4Ni and Al3Sc (V, Ni) phases led to the finer microstructure of grain. V element not only promoted the formation of Al21V2 phase containing Sc but also hindered the mutual diffusion of Al and (Sc, Ni) elements in the eutectic system via segregation at the α-Al/Al3Sc (V, Ni) interface, which improved the stability of the whole alloy. The edge nucleation of γ-Al7Cu4Ni phase upon its diffusion into a Sc-containing Al21V2 phase induced the formation of Al3Sc (V, Ni) structure, whereas the segregation of V and Ni further strengthened the alloy matrix.

Enhanced Performance and Stability of Perovskite Solar Cells Through Surface Modification with Benzocaine Hydrochloride.

Current development of inverted p-i-n perovskite solar cells (PSCs), with nickel oxide as the hole transport layer, is progressing toward lower net costs, higher efficiencies, and superior stabilities. Unfortunately, the high density of defect-based traps on the surface of perovskite films significantly limits the photoelectric conversion efficiency and operational stability of perovskite solar cells. Finding cost-effective interface modifiers is crucial for the further commercial development of p-i-n PSCs. In the present work, we report a passivation strategy using a multifunctional molecule, benzocaine hydrochloride (BHC), which is shown to reduce defect density and enhance the photovoltaic performance and stability of the resultant p-i-n PSCs. It has been revealed that BHC strongly interacts with perovskite precursor components and triggers the evolution of the perovskite absorber film morphology and enables improved surface energy level alignment, thus promoting charge carrier transport and extraction. These properties are beneficial for improving open-circuit voltage (VOC) and fill factor (FF). Our results show that the photoelectric conversion efficiency (PCE) of p-i-n PSCs with nickel oxide as the hole transport layer increased from an initial 20.0% to 22.1% after being passivated with BHC, and these passivated devices also exhibited improved stability. DFT calculations reveal the unusual ability of the BHC passivant to improve band alignment while also preventing the accumulation of holes at the interface. In this work, the advantages of BHC passivation are demonstrated by linking theoretical calculations with optical and electrical characterizations.

In silico Investigations of Al2O3 and NiO Nanoparticles Interactions with Antioxidant Enzymes of Fresh Water Fish O.mossambicus

Metal oxide nanoparticles caused hazardous to aquatic organisms, especially fishes. Nanomaterials of Aluminium and nickel oxide are applied in wide range of applications. However the toxicity of these metal oxide nanoparticles on freshwater fish is very scarce. In this study, we investigated the toxic impact of these two nanoparticles through an in silico approach. The antioxidant enzymes /proteins of SOD, CAT and GST in fish O.mossambicus were docked against Al2O3 and NiO NPs. These enzymes are responsible for oxidative metabolism of a large number of nanomaterials. Induction of oxidative stress by NPs exposure leads to inhibition of these enzymes. The targeted proteins SOD, CAT and GST were retrieved from Alpha fold database and docked with ligands. Molecular docking was conducted using CB - Dock and AutoDock Vina software tools to find the binding affinity and interaction with amino acids of each protein. The target proteins found to strongly interact with ligands through hydrogen bonding and metal coordination interactions. The lowest binding energy shows strong binding of ligands with proteins. Docking results revealed that the amino acids residues of SOD, CAT and GST enzymes are strongly bind with the Al2O3 and NiO NPs in its active site and causes inhibition of the enzymes activities. CAT exhibited lowest binding affinity of (-4.0 Kcal/mol) among all enzymes and significantly inhibited by NiO NPs, followed by GST (-3.4 Kcal/mol), likewise CAT (-1.7 Kcal/mol) and GST (-1.8 Kcal/mol) was moderately inhibited by Al2O3 NPs. SOD inhibited insignificantly by both the NPs. In conclusion, NiO NPs effectively inhibit antioxidant enzymes activity than Al2O3 NPs.

Advanced corrosion resistance and mechanistic insights of electroless Ni-P-PTFE coatings on L245NS substrate in H2S-saturated environments

The extraction and transportation of oil and gas pose significant challenges due to corrosive environments, particularly hydrogen sulfide (H2S) exposure. This study investigates the use of polytetrafluoroethylene (PTFE) to enhance the corrosion resistance of nickel‑phosphorus (NiP) coatings in H2S-rich environments. Electroless deposition was employed to prepare Ni-P/PTFE coatings, which were then subjected to simulated H2S corrosion tests. Results indicate that the incorporation of PTFE led to a more uniform NiP coating with reduced porosity, significantly improving corrosion resistance. The coatings exhibited enhanced protective performance by stabilizing corrosion product layers and preventing the formation of corrosion channels. Ni-P-PTFE coatings overcame the existing research challenge of NiP coatings' corrosion in H2S environments, showing no penetration of the corrosive medium into the substrate after 720 h of immersion. The corrosion rate of the coating is only 0.0261 mm/year, only 4.27 % of the corrosion rate of the L245NS substrate in the early stage of corrosion. Moreover, after characterization by SEM, XRD and XPS, it was found that the presence of PTFE altered the corrosion mechanism, promoting the formation of stable nickel sulfide and oxide layers on the surface. This study sheds light on the mechanisms underlying PTFE-enhanced corrosion resistance in NiP coatings, offering promising implications for extending the lifespan of equipment in the oil and gas industry.

Evaluation of antioxidant, catalytic and antidiabetic activity of Phaseolus vulgaris (French green bean) mediated nickel oxide and copper doped nickel oxide bimetallic nanoparticles

In this study, nickel oxide nanoparticles (NPs) and copper doped NiO bimetallic nanoparticles (Cu@NiO BMNPs) were synthesized using Phaseolus vulgaris extracts as reducing and stabilizing agents by sol gel methods. The chemical and physical properties of synthesized NiO NPs and Cu@NiO BMNPs were confirmed by various techniques, like UV Visible spectrophotometer (UV–Vis), Fourier transform infrared spectroscopy (FTIR), Scanning Electron Microscope (SEM), Energy Dispersive X-ray (EDX), Transmission Electron Microscope (TEM) and X-ray diffraction (XRD) analysis. The optical properties of both NPs observed by UV–Vis analysis with well-defined peak and band gap value 3.2 eV & 2.62 eV. FTIR analysis confirmed the presence of functional group of NPs with fruits extract. The morphology of NPs was confirmed by SEM and TEM analysis as polygonal, rod and spherical shape. The elements present in NPs were confirmed by EDX analysis. The crystalline size calculated based on the XRD analysis was 49.78 nm and 53.66 nm for NiO and Cu@ NiO NPs respectively which were found to be slightly smaller than particle size determined from SEM and TEM micrograph. Antioxidant activity of NPs was examined using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) scavenging radicals, Catalytic activities were screened by the degradation of Methylene blue (MB) and by the inhibition of alpha-amylase enzyme, antidiabetic activity of NPs were evaluated using acarbose as standard drug. The Cu@NiO BMNPs showed 77.60 % antioxidant, 76.98 % photocatalytic and 88.86 % antidiabetic activity, which were found to be more as compared to NiO NPs. The NiO and Cu@NiO BMNPs were synthesized for the first-time using P. vulgaris extracts. This study clearly showed that P. vulgaris extracts mediated mono- and bimetallic NPs were more stable and biocompatible than their respective bulk particles.

Pros and Cons of (NH4)2S Solution Treatment of p-GaN/Metallization Interface: Perspectives for Laser Diode.

The impact of wet treatment using an (NH4)2S-alcohol solution on the interface state of the p-GaN/Ni/Au/Pt contact system and laser diode processing was investigated. Sulfur wet cleaning resulted in reduced surface roughness and contact resistivity. The lowest specific contact resistance (ρc < 1 × 10-4 Ω·cm2) was achieved with samples treated with an (NH4)2S-isopropanol solution, whereas the highest resistivity (ρc = 3.3 × 10-4 Ω·cm2) and surface roughness (Ra = 16 nm) were observed in samples prepared by standard methods. Annealing the contact system in an N2 + O2 + H2O atmosphere caused degradation through species inter-diffusion and metal-metal solid solution formation, irrespective of the preparation method. Standard prepared substrates developed a thin GaN-Au intermediate layer at the interface after heat treatment. Enhanced adhesion and the absence of GaN decomposition were observed in samples additionally cleaned with the (NH4)2S-solvent solution. Complete oxidation of nickel to NiO was observed in samples that underwent additional sulfur solution treatment. The intensity of metal species mixing and nickel oxidation was influenced by the metal diffusion rate and was affected by the initial state of the GaN substrate obtained through different wet treatment methods.

Reactive Blue MEBF 222 dye and textile wastewater treatment using metal-doped cobalt and nickel perovskites by batch and column adsorption process.

Water contamination is a serious issue that has an impact on the whole globe. In the current work, adsorption technique was used to remove synthetic Reactive Blue MEBF 222 textile dye utilizing Cd-doped Co (Co1-xCd1.5xFeO3), Zn-doped Co (Co1-xZn1.5xFeO3), Cr-doped Co (Co1-xCr1.5xFeO3), Zn-doped Ni (Ni1-xZn1.5xFeO3), and Cr-doped Ni (Ni1-xCr1.5xFeO3) perovskites, synthesized by sol-gel auto-combustion approach. According to the findings of batch adsorption studies, maximum adsorption was observed at pH 3 (45.62mg/g), 0.01g/50ml dosage (36.67mg/g), 60min (14.31mg/g), 100ppm dye concentration (47.41mg/g), and 308K (35.96mg/g) for Co1-xCd1.5xFeO3; at 3 pH (42.94mg/g), 0.01g/50ml dosage (35.33mg/g), 60min (12.88mg/g), 100ppm dye concentration (40.52mg/g), and 308K (31.31mg/g) for Co1-xZn1.5xFeO3; at 2 pH (38.82mg/g), 0.01g/50ml dosage (32.20mg/g), 60min (11.98mg/g), 100ppm dye concentration (33.54mg/g), and 308K (29.34mg/g) for Co1-xCr1.5xFeO3; at 2 pH (34.97mg/g), 0.01g/50ml dosage (30.41mg/g), 60min (10.46mg/g), 100ppm dye concentration (27.19mg/g), and 308K (26.12mg/g) for Ni1-xZn1.5xFeO3; and at 2 pH (31.22mg/g), 0.01g/50ml dosage (25.04mg/g), 60min (9.48mg/g), 100ppm dye concentration (21.73mg/g), and 308K (23.61mg/g) for Ni1-xCr1.5xFeO3. The pseudo-second-order model showed good fitness for adsorption kinetic data. Electrolytes, detergents/surfactants, and heavy metal ions had a substantial impact on the adsorption potential. The column adsorption experiments demonstrated optimal bed height, flow rate, and intake dye concentration to be 3cm, 1.8ml/min, and 70mg/l, respectively, in the column experiment. With an adsorption capacity of 44.1mg/g, reactive blue (RB) 222 dye was able to achieve its maximum adsorption. Detailed desorption of RB 222 dye was also achieved. The novelty of this adsorption method lies in its eco-friendliness, ease of handling, and cost-effectiveness.

NiO/AgNPs nanowell enhanced SERS sensor for efficient detection of micro/nanoplastics in beverages

The ubiquity of plastic products has led to an increased exposure to micro and nano plastics across diverse environments, presenting a novel class of pollutants with substantial health implications. Emerging research indicates their capacity to infiltrate human organs, posing risks of tissue damage and carcinogenesis. Given the prevalent consumption of beverages as a primary vector for these plastics' entry into the human system, there is an imperative need for the advancement of precise detection methodologies in liquids. In this study, we introduce a substrate comprising a Nickel Oxide (NiO) nanosheet array decorated with Silver Nanoparticles (AgNPs) for the Surface-Enhanced Raman Spectroscopy (SERS) analysis of micro//nano plastics. This configuration, leveraging a unique nanowell architecture alongside silver plasmonic enhancement, demonstrates unparalleled sensitivity and repeatability in signal, facilitating the accurate quantification of these contaminants. Through the application of a portable Raman apparatus, this study successfully identifies prevalent micro/nano plastics including polystyrene (PS), polyethylene (PE), and polypropylene (PP), achieving detection sensitivities of 5 μg/mL, 25 μg/mL, and 25 μg/mL, respectively. Moreover, the substrate's efficacy extends to the detection of PS within commonly consumed beverages such as water, milk, and liquor with sensitivities of 25 μg/mL, 50 μg/mL, and 50 μg/mL, respectively. These findings highlight the substrate's potential as an expedient and effective sensor for the real-time monitoring of micro/nano plastic pollutants.

Investigation of Oxide Layer Development of X6CrNiNb18-10 Stainless Steel Exposed to High-Temperature Water.

The oxide layer development of X6CrNiNb18-10 (AISI 347) during exposure to high-temperature water has been investigated. Stainless steels are known to form a dual oxide layer in corrosive environments. The secondary Fe-rich oxide layer has no significant protective effect. In contrast, the primary Cr-rich oxide layer is known to reach a stabilized state, protecting the base metal from further oxidation. This study's purpose was to determine the development of oxide layer dimensions over exposure time using SEM, TEM and EDX line scans. While a parabolic development of Cr in the protective primary layer and Fe in the secondary layer was observed, the dimensions of the Ni layer remained constant. Ni required the presence of a pronounced Fe-rich secondary layer before being able to reside on the outer secondary layer. With increasing immersion time, the Ni element fraction surpassed the Cr element fraction in the secondary layer. Oxide growth on the secondary layer could be observed. After 480 h, nearly the entire surface was covered by the outer oxide layer. In the metal matrix, no depletion of Cr or Ni could be observed over time; however, an increased presence of Cr and Ni in the primary layer was found at the expense of Fe content. The Nb-stabilized stainless steel was subject to the formation of Niobium pentoxide (Nb2O5), with the quantity and magnitude of element fraction increasing over exposure time.

Dual-Functional Tungsten-Doped NiO for Highly Sensitive Triethylamine Sensor with ppb Level Detection Limit.

In this study, the W-doped Nickel oxide (NiO) nanoflowers were synthesized using a straightforward hydrothermal method, significantly enhancing the sensing performance toward triethylamine through dual-functional tungsten doping. The optimal doping concentration not only increased the specific surface area of NiO from 25.54 to 189.19 m2 g-1 but also reduced the formation energy of oxygen vacancies. The sensor containing 4 at % W-doped NiO demonstrated exceptional sensitivity to triethylamine, achieving a detection level as high as 229.0 for concentrations of 100 ppm at 237.5 °C. This triethylamine sensor represents a 135-fold enhancement over sensors fabricated from undoped NiO, and offers a rapid response/recovery time of 8 and 30 s, respectively. Furthermore, at a lower triethylamine concentration of 50 ppb, indicating a lower detection limit.

Stable and sustainable perovskite solar modules by optimizing blade coating nickel oxide deposition over 15 × 15 cm2 area

Perovskite solar cells have rapidly advanced, achieving over 26% power conversion efficiency on the laboratory scale. However, transitioning to large-scale production remains a challenge due to limitations in conventional fabrication methods like spin coating. Here, we introduce an optimized blade coating process for the scalable fabrication of large-area (15 cm × 15 cm) perovskite solar modules with a nickel oxide hole transport layer, performed in ambient air and utilizing a non-toxic solvent system. Self-assembled monolayers between the nickel oxide and perovskite layer improve the uniformity and morphology of the perovskite film. Perovskite solar modules with a 110 cm2 active area achieve a power conversion efficiency of 12.6%. Moreover, encapsulated modules retained 84% of their initial efficiency after 1,000 hours at 85 °C in air (ISOS-T-1). This study demonstrates progress in the large-scale production of perovskite solar cells that combine efficiency with long-term stability.