Copper Oxide Research Articles

Influence of various surfactants on the stability and solidification characteristics of DI water-based CuO NFPCM for cool thermal energy storage system

The current study goals to investigate the stability and solidification characteristics of deionized water (DI water) based copper oxide (CuO) nanofluid phase change materials (NFPCMs) with a nucleating agent, different types of surfactants (SBDS, CTAB, and GA) and different weight concentration of surfactant for cool thermal energy storage systems (CTES). The stability of NFPCMs was assessed through average particle size distribution, zeta potential, and UV–vis absorbance. Among all NFPCMs, 0.1 wt% SDBS - CuO NFPCM showed prolonged stability with −42.7 mV and 212.6 nm of zeta potential and average particle size value. The heat transfer properties of NFPCMs were studied with differential scanning calorimetry (DSC), Thermogravimetric analysis (TGA) and thermal conductivity measurements. The introduction of 0.05 wt% SDBS to NFPCM resulted in a notable 17.84 % and 7.64 % increase in thermal conductivity in solid and liquid states, with a slight decrease in latent heat by 5.2 % and 6.01 % during melting and crystallization as compared to DI water. The solidification experiments of NFPCMs were investigated in a spherical encapsulation at a surrounding bath temperature of −8 °C and − 10 °C. Comparing various surfactants in NFPCMs, the SDBS–CuO NFPCM was the most efficient in reducing the solidification time by 26.3 % and 28.4 % at −8 °C and − 10 °C respectively, compared to the nucleating agent PCM (NAPCM). Further, the different concentrations of SDBS in NFPCM demonstrated that 0.05 wt% SDBS–CuO NFPCM displayed the greatest reduction in solidification time, achieving 29.4 % and 27.7 % at −10 °C and − 8 °C, respectively, compared to the NAPCM.

Hybrid Nickel‐Copper Oxide Nanoparticles: A Multiparametric Study for the Influence of Synthetic Parameters on the Optical and Physical Properties

AbstractThe hybrid nanoparticles of nickel and copper oxide are optimized by varying synthetic conditions such as precursor salt concentration, rate of reagent addition, pH, and temperature. The resulting nanoparticles are characterized by using UV‐Visible and fluorescence spectroscopy, hydrodynamic size, zeta potential, polydispersity index, SEM, EDX, XRD, and FTIR spectroscopy. The control over composition and physical properties of these hybrid oxides are analyzed through careful variations in the synthetic parameters. UV‐Vis analysis demonstrated the successful synthesis of NiO‐CuO hybrid nanoparticles at various concentrations. NiO dominant hybrids are obtained by quick addition of the reagent and at higher pH, while CuO dominant hybrids require slower addition of reagent and lower pH. The increase in the temperature causes a hypochromic shift in the UV‐Vis absorption, whereas fluorescence is enhanced with increase in the CuO concentration. The fluorescence generally remained stable by varying time of reagent addition, pH, and temperature. More stable and least‐sized NiO‐CuO hybrid nanoparticles are obtained at ratios of 75 : 25 and 25 : 75, by quick addition of reagent, at higher pH levels, and at higher temperatures. A better understanding of their physical and optical properties obtained by varying synthetic parameters may potentially result in their enhanced applications.

3D Printable Multifunctional Electrochemical Nano‐Doped Biofilament

AbstractFused deposition modeling (FDM) represents a state‐of‐the‐art 3D printing technology that holds great promise in the field of electrochemistry as a fast, in‐house, and digital fabrication method of sustainable sensors. Despite the progress in FDM, existing practical 3D printed sensors still require post‐printing treatment to improve their operational features, either through (electro)chemical surface activation or surface modification with external functional materials. Herein, a novel lab‐made conductive biofilament with integrated two different types of metallic nanoparticles (NPs) for the 3D printing of ready‐to‐use and multiplexed electrochemical sensors is introduced. The filament is composed of biodegradable polylactic acid as a base, polyethylene glycol dimethyl ether as a plasticizer, carbon black as a conductive filler, and nanopowder oxides of bismuth and copper as integrated functional precursor materials. The as‐printed sensors serve as multifunctional transducers for the direct and sensitive determinations of several analytes, by exploiting the different properties of the two co‐existing NPs. Particularly, heavy metals (such as lead, and cadmium) are voltammetrically quantified by amalgamation with BiNPs electrogenerated from Bi2O3, while biomarkers (such as glucose, and uric acid) are determined in enzymatic‐free modes. Determination of glucose takes advantage of the electrocatalytic properties of CuO, while uric acid is directly oxidized at the sensor.

Development of CuO Nanoparticles from the Mucus of Garden Snail Cornu aspersum as New Antimicrobial Agents

Several biologically active compounds involved in the green synthesis of silver and gold nanoparticles have been isolated from snail mucus and characterized. This paper presents a successful method for the application of snail mucus from Cornu aspersum as a bioreducing agent of copper sulfate and as a biostabilizer of the copper oxide nanoparticles (CuONPs-Muc) obtained. The synthesis at room temperature and neutral pH yielded nanoparticles with a spherical shape and an average diameter of 150 nm. The structure and properties of CuONPs-Muc were characterized using various methods and techniques, such as ultraviolet–visible spectroscopy (UV–vis), high-performance liquid chromatography (HPLC), one-dimensional polyacrylamide gel electrophoresis (1D-PAGE), up-conversion infrared spectroscopy Fourier transform (FTIR), scanning electron microscopy combined with energy dispersive spectroscopy (SEM/EDS), Raman spectroscopy and imaging, thermogravimetric analysis (TG-DSC), etc. Mucus proteins with molecular weights of 30.691 kDa and 26.549 kDa were identified, which are involved in the biogenic production of CuONPs-Muc. The macromolecular shell of proteins formed around the copper ions contributes to a higher efficiency of the synthesized CuONPs-Muc in inhibiting the bacterial growth of several Gram-positive (Bacillus subtilis NBIMCC2353, Bacillus spizizenii ATCC 6633, Staphylococcus aureus ATCC 6538, Listeria innocua NBIMCC8755) and Gram-negative (Escherichia coli ATCC8739, Salmonella enteitidis NBIMCC8691, Salmonella typhimurium ATCC 14028, Stenotrophomonas maltophilia ATCC 17666) bacteria compared to baseline mucus. The bioorganic synthesis of snail mucus presented here provides CuONPs-Muc with a highly pronounced antimicrobial effect. These results will expand knowledge in the field of natural nanomaterials and their role in emerging dosage forms.

The effect of calpain inhibitor-I on copper oxide nanoparticle-induced damage and cerebral ischemia-reperfusion in a rat model

This study aimed to investigate the effects of the calpain inhibitor N-Acetyl-Leu-Leu-norleucinal (ALLN) on neuroapoptotic cell damage caused by Copper Oxide Nanoparticles (CuO-NP) and exacerbation of damage through brain ischemia/reperfusion (I/R) in a rat model. Male Wistar Albino rats (n=80) were divided into eight groups: Control, I/R, CuO-NP, CuO-NP+I/R, I/R+ALLN, CuO-NP+ALLN, CuO-NP+I/R+ALLN, and DMSO. Biochemical markers (MBP, S100B, NEFL, NSE, BCL-2, Cyt-C, Calpain, TNF-α, Caspase-3, MDA, and CAT) were measured in serum and brain tissue samples. Histological examinations (H&E staining), DNA fragmentation analysis (TUNEL) were performed, along with Caspase-3 assessment. The ALLN-treated groups exhibited significant improvements in biochemical markers and a remarkable reduction in apoptosis compared to the damaged groups (CuO-NP and I/R). H&E and Caspase-3 staining revealed damage-related morphological changes and reduced apoptosis in the ALLN-treated group. However, no differences were observed among the groups with TUNEL staining. The findings suggest that ALLN, as a calpain inhibitor, has potential implications for anti-apoptotic treatment, specifically in mitigating neuroapoptotic cell damage caused by CuO-NP and I/R.

Biosynthesized copper oxide nanoparticles by Psidium guajava plants with antibacterial, antidiabetic, antioxidant, and photocatalytic capacity

AbstractWith an increasing focus on green technologies, this research aimed to synthesize copper oxide nanoparticles (CuO-NPs) using leaf extracts from Allahabad Safeda and Hisar Safeda for environmental and health protection. A range of concentrations of leaf extracts were employed in the synthesis of nanoparticles, utilizing 1–9% extract from Allahabad Safeda and 3–11% extract from Hisar Safeda. The synthesized CuO-NPs were characterized by UV–visible spectrophotometry, Dynamic light scattering, Fourier transform infrared spectroscopy, and Scanning electron microscope with energy-dispersive X-ray spectroscopy. CuO-NPs synthesized using 3% Allahabad Safeda extract and 5% Hisar Safeda extract exhibited a particle size of 15.88 nm and 14.05 nm, respectively. CuO-NPs synthesized with Allahabad Safeda extract exhibited superior antibacterial, antioxidant, antidiabetic, and photocatalytic properties. Their antibacterial tests demonstrated significant inhibition zones against Staphylococcus aureus (20.5 cm), Streptococcus latis (20.7 cm), Escherichia coli (19.5 cm), and Pseudomonas aeruginosa (19.7 mm). Additionally, CuO-NPs from Allahabad Safeda extract (70 µg/mL) exhibited 68.23% of scavenging activity against 2,2-diphenyl-1-picrylhydrazyl. Moreover, the same CuO-NPs at 100 µg/mL concentration showed 67.32% α-amylase inhibition and 75.18% α-glucosidase inhibition, confirming their antidiabetic activities. Furthermore, these nanoparticles demonstrated high performance in photocatalytic degradation, by degrading 82.31% methylene blue and 88.54% crystal violet within 150 min of UV irradiation. Overall, the findings highlight the feasibility of CuO-NPs synthesis using Allahabad Safeda extract and their potential applications in antibacterial treatment, combating diabetes, antioxidation, and environmentally friendly dye photodegradation process. Graphical Abstract

Synthesis and characterization of myristic acid - infused Al2O3/CuO/MWCNT nanocomposites for energy storage and cooling applications

Phase change materials are highly effective in improving the thermal efficiency of a heat exchanger, making them a choice for enhancing renewable energy to achieve a feasible environment. In this study, myristic acid (MA) was used as a phase change material and aluminium oxide (Al2O3), copper oxide (CuO) of 2.5, 5, 10 wt % and multi-walled carbon nanotubes (MWCNT) of 1.0, 1.5, and 2 wt % were used as the nanoparticles to produce MA-embedded nanocomposite phase change material (NCPCM). The characterization studies, namely x-ray diffraction, Thermal Conductivity, field emission scanning electron microscope (FESEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, Differential Scanning Calorimetry (DSC) and Thermogravimetric analysis (TGA) were performed on nanocomposite phase change materials to ensure their homogeneous distribution and property enhancement of the fabricated samples. In addition, a Computational Fluid Dynamics (CFD) analysis was conducted to assess the impact of NCPCM on the rates of solidification and melting. The field emission scanning electron microscopy analysis confirms the homogeneous distribution of micro/nanoparticles Al2O3, CuO, and MWCNT with MA. From the x-ray diffraction (XRD) analysis, the homogeneous nature of the fabricated NCPCMs was identified. Fourier transform infrared spectroscopy (FTIR) and Raman Spectroscopy results confirmed the absence of new particle formation due to the physical interaction between nanocomposites and myristic acid. The fabricated NCPCM samples were undergone 500 thermal cycles to ensure their thermal reliability. It is evident from the test results that the addition of nanoparticles to base PCM enhances the thermal properties. The thermal performance of 2 wt% MWCNT-embedded MA was superior to that of aluminium oxide and copper oxide. DSC results revealed that the 2 wt% MWCNT added MA possessed the highest variation of 8.6% in its latent heat storage value compared to pure MA and had a significant variation compared to other fabricated NCPCM compositions. Adding 2 wt% MWCNT to MA has increased the thermal conductivity of pure PCM from 0.15 W mK−1 to 0.38 W mK−1.

Copper Oxide Nanoparticles Induced Growth and Physio-Biochemical Changes in Maize (Zea mays L.) in Saline Soil

Research on nanoparticles (NPs) is gaining great attention in modulating abiotic stress tolerance and improving crop productivity. Therefore, this investigation was carried out to evaluate the effects of copper oxide nanoparticles (CuO-NPs) on growth and biochemical characteristics in two maize hybrids (YH-5427 and FH-1046) grown under normal conditions or subjected to saline stress. A pot-culture experiment was carried out in the Botanical Research Area of “the University of Lahore”, Lahore, Pakistan, in a completely randomized design. At two phenological stages, both maize hybrids were irrigated with the same amount of distilled water or NaCl solution (EC = 5 dS m−1) and subjected or not to foliar treatment with a suspension of CuO-NPs. The salt stress significantly reduced the photosynthetic parameters (photosynthetic rate, transpiration, stomatal conductance), while the sodium content in the shoot and root increased. The foliar spray with CuO-NPs improved the growth and photosynthetic attributes, along with the N, P, K, Ca, and Mg content in the roots and shoots. However, the maize hybrid YH-5427 responded better than the other hybrid to the saline stress when sprayed with CuO-NPs. Overall, the findings of the current investigation demonstrated that CuO-NPs can help to reduce the adverse effects of salinity stress on maize plants by improving growth and physio-biochemical attributes.

Utilization of Eco‐friendly Copper Oxide Nanoparticles and Iron Oxide Nanorods in Dye Removal from Real Textile Industry Effluent

AbstractTextile industry wastewater contaminated with dye effluents poses a significant environmental challenge. Numerous nanoparticles are used as adsorbents to treat similarly stimulated wastewater, but particularly nanomaterials synthesized through green methods have gained prominence. To assess their practical applicability in addressing real‐world textile wastewater pollution, studies on dye removal from authentic textile industrial effluents are recommended. As a result, a study focused on the removal of dye from real textile industrial effluent is conducted, and biosynthesized copper oxide nanoparticles and iron oxide nanorods are chosen as adsorbents. The investigation scrutinized the influence of adsorbent dosage, adsorbent‐adsorbate contact time, and wastewater pH on the percentage of dye adsorption. These findings indicate that increasing the adsorbent dosage and contact time leads to a higher percentage of dye removal. Notably, copper oxide nanoparticles exhibit superior dye removal efficiency at pH levels 5 and 7, outperforming the maximum dye removal efficiency of iron oxide nanorods at pH 12. The study achieved an impressive process efficiency of 95.24% for copper oxide nanoparticles and 62.5% for iron oxide nanorods. Response surface methodology (RSM) is employed for statistical data analysis and optimization of dye removal process parameters to maximize efficiency. Overall, the results demonstrate that biosynthesized nanomaterials offer a promising and effective solution for removing dyes from textile industrial wastewater.

Metal nanoparticle-induced effects on green toads (Amphibia, Anura) under climate change: conservation implications.

The toxicity of aluminum oxide (Al2O3), copper oxide (CuO), iron oxide (Fe3O4), nickel oxide (NiO), zinc oxide (ZnO), and titanium dioxide (TiO2) nanoparticles (NPs) on amphibians and their interaction with high temperatures, remain unknown. In this study, we investigated the survival, developmental, behavioral, and histological reactions of Bufotes viridis embryos and larvae exposed to different NPs for a duration of 10 days, using lethal concentrations (LC25%, LC50%, and LC75% mg/L) under both ambient (AT: 18 °C) and high (HT: 21 °C) temperatures. Based on LC, NiONPs > ZnONPs > CuONPs > Al2O3NPs > TiO2NPs > Fe3O4NPs showed the highest mortality at AT. A similar pattern was observed at HT, although mortality occurred at lower concentrations and Fe3O4NPs were more toxic than TiO2NPs. The results indicated that increasing concentrations of NPs significantly reduced hatching rates, except for TiO2NPs. Survival rates decreased, abnormality rates increased, and developmental processes slowed down, particularly for NiONPs and ZnONPs, under HT conditions. However, exposure to low concentrations of Fe3O4NPs for up to 7 days, CuONPs for up to 72 h, and NiO, ZnONPs, and TiO2NPs for up to 96 h did not have a negative impact on survival compared with the control group under AT. In behavioral tests with larvae, NPs generally induced hypoactivity at AT and hyperactivity at HT. Histological findings revealed liver and internal gill tissue lesions, and an increase in the number of melanomacrophage centers at HT. These results suggest that global warming may exacerbate the toxicity of metal oxide NPs to amphibians, emphasizing the need for further research and conservation efforts in this context.

CuO (111) Microcrystalline Evoked Indium-Organic Framework for Efficient Electroreduction of CO2 to Formate.

Electrochemical reduction of carbon dioxide (CO2RR) to formate is economically beneficial but suffers from poor selectivity and high overpotential. Herein, enriched microcrystalline copper oxide is introduced on the surface of indium-based metal-organic frameworks. Benefiting from the CuO (111) microcrystalline shell and formed catalytic active In-Cu interfaces, the obtained MIL-68(In)/CuO heterostructure display excellent CO2RR to formate with a Faradaic efficiency (FE) as high as 89.7% at low potential of only -0.7 V vs. RHE in a flow cell. Significantly, the membrane electrode assembly (MEA) cell based on MIL-68(In)/CuO exhibit a remarkable current density of 640.3mAcm-2 at 3.1V and can be stably operated for 180h at 2.7 V with a current density of 200mAcm-2. The ex/in situ electrochemical investigations reveal that the introduction of CuO increases the formation rate of the carbon dioxide reduction intermediate *HCOO- and inhibits the competitive hydrogen evolution reaction. This work not only provides an in-depth study of the mechanism of the CO2RR pathways on In/Cu composite catalyst but also offers an effective strategy for the interface design of electrocatalytic carbon dioxide reduction reaction.

Large unidirectional magnetoresistance from the dual functionality of copper oxide in naturally oxidized light-metal Al/Cu bilayer films

Large unidirectional magnetoresistance from the dual functionality of copper oxide in naturally oxidized light-metal Al/Cu bilayer films

Dendritic copper oxide catalyst engineering weak-polarity Cu-O bond for high-efficiency nitrate electroreduction

Nitrate reduction reaction (NO3RR) is deemed a promising pathway for both ammonia synthesis and water purification. Developing a high-efficiency catalyst with excellent NH3 selectivity and catalytic stability is desirable but remains challenging. In this work, a dendritic copper oxide catalyst (Cu-B2) has been developed to efficiently catalyze NO3RR for ammonia production, the Cu-B2 exhibits excellent catalytic performance, achieving an NH3 Faradaic efficiency as high as 94 % and an NH3 yield of 16.9 mg h−1 cm−2 with a current density of 192.3 mA cm−2 at − 0.6 V (vs. RHE, reversible hydrogen electrode). During NO3RR testing, the Cu-B2 catalysts are reduced in situ to form highly active Cu0/Cu+ sites, while retaining its dendritic morphology. Compared with other catalysts, the Cu-O bond in Cu-B2 catalyst has weaker polarity, resulting in Cu0/Cu+ sites in lower oxidation states. In situ attenuated total reflection surface enhanced infrared absorption spectroscopy (ATR-SEIRAS) studies reveal the Cu-B2 catalyst exhibits a potential-independent capability for *NO3- adsorption and high conversion efficiency of NO2- intermediate into ammonia, DFT calculations reveal that Cu-B2 exhibts higher NO3- adsorption energy and lower NO3- adsorption energy barrier than Cu-B1, thus endowing it with a remarkably improved catalytic activity and durability.

The Effect of Composition on the Properties and Application of CuO-NiO Nanocomposites Synthesized Using a Saponin-Green/Microwave-Assisted Hydrothermal Method.

In this study, we explored the formation of CuO nanoparticles, NiO nanoflakes, and CuO-NiO nanocomposites using saponin extract and a microwave-assisted hydrothermal method. Five green synthetic samples were prepared using aqueous saponin extract and a microwave-assisted hydrothermal procedure at 200 °C for 30 min. The samples were pristine copper oxide (100C), 75% copper oxide-25% nickel oxide (75C25N), 50% copper oxide-50% nickel oxide (50C50N), 25% copper oxide-75% nickel oxide (25C75N), and pristine nickel oxide (100N). The samples were characterized using FT-IR, XRD, XPS, SEM, and TEM. The XRD results showed that copper oxide and nickel oxide formed monoclinic and cubic phases, respectively. The morphology of the samples was useful and consisted of copper oxide nanoparticles and nickel oxide nanoflakes. XPS confirmed the +2 oxidation state of both the copper and nickel ions. Moreover, the optical bandgaps of copper oxide and nickel oxide were determined to be in the range of 1.29-1.6 eV and 3.36-3.63 eV, respectively, and the magnetic property studies showed that the synthesized samples exhibited ferromagnetic and superparamagnetic properties. In addition, the catalytic activity was tested against para-nitrophenol, demonstrating that the catalyst efficiency gradually improved in the presence of CuO. The highest rate constants were obtained for the 100C and 75C25N samples, with catalytic efficiencies of 98.7% and 78.2%, respectively, after 45 min.

Mott gap filling by doping electrons through depositing one sub-monolayer thin film of Rb on Ca2CuO2Cl2

Abstract Understanding the doping evolution from a Mott insulator to a superconductor probably holds the key to resolve the mystery of unconventional superconductivity in copper oxides. To elucidate the evolution of the electronic state starting from the Mott insulator, we dose the surface of the parent phase Ca2CuO2Cl2 by depositing Rb atoms, which are supposed to donate electrons to the CuO2 planes underneath. We successfully achieved the Rb sub-monolayer thin films in forming the square lattice. The scanning tunneling microscopy or spectroscopy measurements on the surface show that the Fermi energy is pinned within the Mott gap but close to the edge of the charge transfer band. In addition, an in-gap state appears at the bottom of the upper Hubbard band (UHB), and the Mott gap will be significantly diminished. Combined with the Cl defect and the Rb adatom/cluster results, the electron doping is likely to increase the spectra weight of the UHB for the double occupancy. Our results provide information to understand the electron doping to the parent compound of cuprates.

Performance investigation of MAPbI3/MASnI3 based all-perovskite tandem solar cell using SCAPS simulation

Due to the complexity of the fabrication process of tandem solar cells, perovskite materials provide a cost-effective and simpler fabrication solution. In this work, MAPbI3/MASnI3 Perovskite-based Tandem solar cell has been explored numerically by using SCAPS-1D. Methylammonium Lead Iodide (CH3NH3PbI3 or MAPbI3) and Methylammonium Tin Iodide (CH3NH3SnI3 or MASnI3) have been considered as wide bandgap (WBG) and narrow bandgap (NBG) absorber material for the top cell and bottom cell, respectively. WBG top cell and NBG bottom cell are both investigated through the change in the depth of perovskite materials at the current matching conditions at the illumination of Standard AM 1.5 spectrum. The all-perovskite MAPbI3/MASnI3 tandem solar cell with copper (I) oxide (Cu2O) hole transport layer has achieved excellent performance with a maximum power conversion efficiency (PCE) of 32.74% with V oc of 1.68 V, J sc of 24.6 mA cm−2, and fill factor (FF) of 79.39%, respectively.

Development of CuO nanoparticles modified electrochemical sensor for detection of salbutamol

Abstract Metal oxide structures are being utilized in an increasing variety of applications. This study used cyclic and differential pulse voltammetry technique to investigate the possible utilization copper oxide (CuO) nanoparticle modified carbon paste electrode (CPE) for the redox reactions of salbutamol (SAL). The electrochemical performance of the SAL analyte in a complex matrix environment in Ventolin was evaluated in order to assess the appropriateness of the proposed sensor in a real sample environment. CuO nanoparticles were produced via a straightforward, cost effective and efficient sol-gel method and characterization studies of synthesized CuO nanoparticles were performed by scanning electron microscopy, X-ray Diffraction (XRD) and X-ray photoelectron spectroscopy. The synthesized CuO nanoparticles had a spherical shape and particle size was found to be 74 nm. Crystal size of the CuO particles was calculated to be 21.79 nm by using the Debye-Scherrer equation. Under optimal conditions, differential pulse voltammetry demosrated a linear response in the 50 nM to 100 µM range, with a salbutamol detection limit of 50 nM (S/N=3). The SAL concentration (R2 = 0.9971) was found to have a good correlation coefficient. The reproducibility of the biosensor was investigated and evaluated with a relative standard deviation of 3% (n=8). The storage stability of CuO modified CPE for two weeks was evaluated based on the response of DP current measured at intervals every two days. According to the measurement results, the modified electrode exhibited good stability and reproducibility while maintaining 80% of its stability. It is also a rapid and dependable sensor candidate with a measurement time of approximately 20 seconds. The developed electrode has been utilized successfully to determine doping material with improved performance.

Removal of methomyl in water by leaves-generated biochar: Effect of metallic coating, kinetics, and important role of hydroxyl radical

Methomyl (MET) can exist as fatal water pollutant due to its high leachability, and solubility, which is urgently to be efficiently removed. This work investigated its removal in water by cost-effective biochar; in which, the efficiencies of leaves-generated biochar (BC) as non-modified adsorbent, and copper oxide coated BC (COBC) and hematite (Fe2O3) coated BC (MBC) as modified adsorbents were compared. At initial concentration of 20.0 mg/L in purified water, the respective removals by BC, COBC, and MBC were 21.3 %, 16.4 %, and 18.9 % within 360 min at 0.5 g/L dosage, which were increased to 33.8 %, 18.9 %, and 26.1 % at an increased dosage of 1.0 g/L. However, the removal efficiencies of combined method with non-modified, and the modified adsorbents were increased less. The removal was increased from 33.8 % to 47.0 % by increasing BC dosage to 1.5 g/L, and removal was further increased to 54.0 % when MET concentration was decreased to 10.0 mg/L. The removal of MET by BC was pH-dependent as it could be increased up to 80.0 % at pH 11.0; while, the influence of temperature was slight. With analyses of the effect of dissolved oxygen, and free-radical quenching experiment, both the adsorption, and hydroxyl radical (•OH) induced degradation were found responsible for removal. Finally, removal in tap water (TW) was investigated, which indicated that the leaves-generated BC was suitable for MET removal in real water.

Friction and wear behavior of C implanted copper via ion beam-assisted bombardment

This work modified the surface of copper using physical vapor deposition and investigated the wear behavior of the modified copper at low load and sliding speed. The results of the study showed that the adhesion between the thin film prepared using the ion beam deposition technique and the substrate was insufficient, leading to an increased wear rate of copper after surface modification. However, when carbon particles were injected using ion beam-assisted bombardment, the friction properties of copper were significantly improved, with a decrease in wear rate from 1.6 × 10−4 to 8 × 10−6 mm3/N m and a 40% reduction in friction coefficient. This improvement can be attributed to the amorphous carbon layer on the copper surface, as well as the injection of carbon particles into the substrate, which enhanced the adhesion between the film and the substrate. Furthermore, a continuous copper oxide film formed during the friction and wear process, providing lubrication and protection to the substrate in conjunction with the amorphous carbon layer. Additionally, the primary wear mechanism of copper shifted from abrasive and adhesive wear to oxidation wear after ion beam-assisted bombardment with carbon injection. This study provides new insights and methods for material design and engineering applications by investigating the effects of ion beam-assisted bombardment technology on the wear resistance of copper materials.

Synergistic removal of toxic anionic reactive red dye Me4BL (RRME4BL) from aqueous media using chemically synthesised nano-adsorbents (ZnO, CuO, NiO and CoO); equilibrium, kinetics and thermodynamic studies

ABSTRACT This study explores the efficient removal of the synthetic anionic dye-reactive red Me4BL (RRMe4BL) from an aqueous medium which is a significant contributor to environmental pollution. The present study investigates the synthesis of zinc oxide, nickel oxide, cobalt oxide and copper oxide nano adsorbents (ZnO (II), NiO (II), CoO (II), CuO (II)) through the co-precipitation method and their effectiveness in eliminating the reactive red dye Me4BL(RRMe4BL). Maximum adsorption capacities were achieved at pH 2 for ZnO (96.1 mg/g), NiO (86.9 mg/g), CoO (93.4 mg/g) and at pH 6 for CuO (76.3 mg/g) under a 0.05 g/50 mL nano-adsorbent dose, 50 mg/L dye initial concentration and 25°C T and 90 min of contact time. The fitness of the pseudo-2nd-order model explained the kinetics, while Langmuir and Temkin adsorption isotherm highlighted the efficiency of the dye adsorption. Thermodynamic studies revealed the spontaneous and exothermic nature of adsorption. The influence of electrolytes, surfactants and desorption was also analysed. Characterisation of the nanoparticles was done through SEM, XRD and FTIR which revealed the morphology and functional groups of nano-adsorbents. The adsorption method used for eliminating this anionic red dye shows several benefits, including affordability, simplicity of use and the presence of intelligent adsorbents for environment-friendly removal of industrial dyes from wastewater.