Ratio Of CuO Research Articles

Preparation and photo fenton-like activities of CuO/nanocellulose composite

A combination between the nanostructured photocatalyst and cellulose-based materials promotes a new functionality of cellulose towards the development of new bio-hybrid materials for water treatment and renewable energy applications. In this study, nanocellulose (CNC) was synthesized from sugarcane bagasse (SCB) biomass via formic /peroxyformic acid process treatment and acid hydrolysis at an atmospheric pressure. The resulting CNC of sugarcane bagasse were characterized by crystallinity index, chemical structure and morphology. X-ray diffraction (XRD) analysis revealed that the crystallinity increased with successive treatments. Images generated by TEM showed that CNC was rod-like in morphology, average diameter and length of 10 nm and 410 nm, respectively. The obtained CNC was used as a biotemplate for the synthesis of copper oxide (CuO) nanostructures through in - situ solution casting method. The photo-Fenton catalytic activity was evaluated via the degradation of methylene blue under sunlight irradiation with H2O2 as a oxidizing agent. The methylene blue degradation ratio of CuO/ CNC composite could achieve 98% in 150 min. The addition of H2O2 enhanced photocatalytic activities of the CuO/CNC. H2O2 not only prevented the recombination of charge carriers by accepting the photogenerated electrons and holes effectively but also produced additional OH.

Electrochemical synthesis of CuO–ZnO for enhanced the degradation of Brilliant Blue (FCF) by sono-photocatalysis and sonocatalysis: kinetic and optimization study

The purpose of this study was to improve the synthesis condition of the CuO–ZnO nanocomposite using a two-step protocol. Initially, an electrodeposition method was used to synthesize CuO nanoparticles (Nps) at different current densities (25–40–53A/dm2) then assembled with ZnO Nps via a milling process to obtain different catalysts. The performance of this new composite was evaluated by characterizing the nanocomposite with XRD, FE-SEM, FTIR, BET, BJH, pHzpc, UV-DRS and then comparing it with the sonocatalysis and sonophotocatalysis degradations of dye Brilliant Blue FCF (BBF). The preliminary results of the kinetic study and a structural characterization of the nanocomposite showed that the CuO–ZnO synthesis at low current density was an efficient catalyst to degrade BBF with a bigger surface area of 50.63 m2 g−1 and a pH zpc of 8.2. Furthermore, the optimization of operational parameters such as the synthesis temperature (300–500 °C), the mass ratio of CuO:ZnO (2–10%) and the catalyst dose (0.5–2 g L−1) was studied by a central composite design (CCD) using the NEMROOD Software. The adjustment of the model demonstrates an agreement between the experimental and predicted data as shown by the high values of the correlation coefficient (R2photosono = 0.999, R2sono = 0.998).

Effect of intergrowth and coexistence CuO-CeO2 catalyst by grinding method application in the catalytic reduction of NOx by CO

Abstract Heterogeneous symbiosis and coexistence CuO-CeO2 catalyst is prepared by simple grinding method to explore the symbiosis effect and the influence of different ratios of CeO2 and CuO on the catalyst structure and catalytic performance. All samples were characterized using XRD, TEM, N2 adsorption-desorption, LRS, H2-TPR, XPS, in situ FT-IR, the catalytic performance of the catalyst is evaluated by the CO + NO model reaction. Among them, Cu1Ce2 catalyst shows excellent catalytic performance, and testing for SO2 or/and H2O resistance. In the catalytic reaction, Cu+ in the catalyst plays an important role, and it is related to the active site where the NO molecule dissociates. Combining all the characterization results, it is shown that the introduction of CuO in the two-phase coexistence catalyst can effectively improve the oxygen vacancy content and the catalytic activity. Simultaneously, we proposed a possible mechanism for two-phase coexisting catalysts of reduction NO by CO to further understand the catalytic process.

Design a tunable glasses optical filters using CuO doped fluoroborate glasses

Successfully, the glass composition (80% B2O3-15% NaF-5%CaF2) was prepared using the melt quenching technique. Different CuO ration from 0.3 wt% up to 12 wt% was added to the prepared glass composition at the expense of B2O3. The X-Ray diffraction pattern reveal the amorphous structure of the prepared glasses samples. The UV–Vis-NIR optical absorption spectrometer was used to investigate the optical properties of the glass samples. The structure was examined using the FTIR absorption spectroscopy. The optical absorption measurements reveal that the glasses sample from 0.30 wt% up to 3.60 wt% of CuO ratio produces band-pass glass filter samples. In addition, the CuO content of 6.0 wt% and higher concentrations up to 12.0 wt% give cut-off filters in the NIR region. The origin of the two types of filtering property was discussed in the frame of optical absorption and the changes in the glasses samples structure were discussed in the frame of FTIR absorption spectroscopy.

Decomposition of dye pigment via photocatalysis process using CuO-TiO2 nanocomposite

In the present work, the degradation efficiency of dye pigment was enhanced by using of CuO-TiO2 nanocomposite. It was synthesized via sol–gel method under various ratios of CuO:TiO2 including 0.001:1 (as named 0.1%CuO-TiO2), 0.005:1 (as named 0.5%CuO-TiO2), 0.01:1 (as named 1.0%CuO-TiO2). The physico-chemical properties of nanocomposite were characterized by X-ray diffractometer (XRD), scanning electron microscopy (FE-SEM) and energy dispersive spectroscopy (EDS). The degradation efficiency was tested with methylene blue (MB) as a dye pigment and compared to pure synthesized TiO2 and P25. The 0.10%CuO-TiO2 obtained the best MB degradation efficiency (approximately 100% under 30 min UV-A irradiation) as similar as P25. The pure synthesized TiO2 obtained the lowest MB degradation efficiency of 70%.

Effect of FSP-inserted Cu on Physicochemical Properties of Cu/Al2O3 Catalyst

The copper inserted on Cu/Al2O3 catalysts with various Cu loading (10-40 wt%) were synthesized via flame spray pyrolysis (FSP). These catalysts were characterized using X-ray diffraction (XRD), N2 physisorption, temperature programmed reduction (TPR) and X-ray absorption near edge spectroscopy (XANES). The XRD results confirmed the formation of copper aluminate spinel (CuAl2O4) on the FSP-inserted Cu catalyst. The CuO crystallite size of the Cu/Al2O3 catalysts was increased with increasing Cu loading during the flame spray pyrolysis step. The incorporation of copper and aluminum precursors during the flame spray pyrolysis step can inhibit the growth of Al2O3 particles resulting in higher BET surface area and smaller particle size than pure Al2O3 support. The data from TPR and XANES results can predict the ratio of CuO and CuAl2O4 in the FSP-made support. Less than 20 wt% loading of the FSP-inserted Cu showed high concentration of CuAl2O4 phase in the FSP-made material. The composition of CuO and CuAl2O4 phase can be controlled by varying Cu loading in flame spray pyrolysis step. This is a promising alternative way to synthesize the desired catalyst. An example was the catalytic testing of the selective hydrogenolysis of glycerol. The presence of both CuO and CuAl2O4 phases in the Cu/Al2O3 catalyst enhanced the catalytic activity and promoted the selectivity to acetol product. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Β-Cu2V2O7 Thin Films By a Hybrid Electrochemical/Thermal Route: Preparation and Characterization

Solar water splitting offers an attractive solution for renewable energy storage. Ternary copper vanadates have drawn attention for use in photoelectrochemical (PEC) water oxidation due to their low band gap and photostability.1 In particular, Cu2V2O7 with a ratio of CuO: V2O5 stoichiometry (2:1) is a visible light active n-type semiconductor with a low band gap (see below), and has seen use in PEC devices because of its high stability for PEC water oxidation.2 This paper describes the development of a hybrid electrochemical/thermal route for the preparation of Cu2V2O7 thin films. Electrodeposition is a facile, low temperature method which can be deployed to prepare thin films of a target semiconductor. Also, the optoelectronic parameters (e.g., photocurrent, flat band potential) of the thin film semiconductors prepared by electrodeposition can be measured easily without any more processing steps. In addition, the thickness of a given thin film semiconductor, a crucial factor for PEC reactions, can be controlled easily in an electrodeposition process.A two-step electrodeposition strategy for ternary oxides3 was deployed in this study, to prepare Cu2V2O7 thin films on fluorine doped tin oxide (FTO) substrate. In the first step, a copper thin film was deposited cathodically from copper(II) nitrate in a non-aqueous medium to preclude copper oxide formation. In the second step, the copper thin film was stripped anodically in ammonium metavanadate (NH4VO3) aqueous solution to generate Cu+ and subsequent in situ precipitation with VO3 - species to yield a green CuVO3 film on the substrate. Electrochemical quartz crystal microgravimetry confirmed two- and one-electron stoichiometry for the first and second steps respectively.Compositional assays by X-ray energy-dispersive analyses (EDX), averaged from different spots of as-prepared sample, were consistent with a Cu/V ratio: 0.98 ± 0.02. X-ray diffraction pattern for the as-prepared film showed that it was amorphous. Then, the green amorphous CuVO3 thin film was oxidized to a dark reddish crystalline phase-pure β-Cu2V2O7 product by thermal anneal at 450 oC for 30 min in the presence of oxygen. The direct and indirect energy band gaps of β-Cu2V2O7 were measured by diffuse reflectance spectroscopy (DRS) and Tauc analyses yielded values of 2.26 ± 0.03 and 2.08 ± 0.02 eV respectively. The PEC activity of β-Cu2V2O7 was measured at different thicknesses to find the optimum photoelectrode film thickness for water oxidation; this was found to be ~250 nm. These new results will be discussed in the context of the prospects for this semiconductor candidate for PEC water oxidation.

How Thermal Aging Affects Ignition and Combustion Properties of Reactive Al/CuO Nanolaminates: A Joint Theoretical/Experimental Study.

The paper reports a joint experimental/theoretical study on the aging of reactive Al/CuO nanolaminates, investigating both structural modifications and combustion properties of aged systems. We first show theoretically that the long-term storage (over several decades) in ambient temperature marginally affects nanolaminates structural properties with an increase in an interfacial layer of only 0.3 nm after 30 years. Then, we observe that the first thermal aging step occurs after 14 days at 200 °C, which corresponds to the replacement of the natural Al/CuO interfaces by a proper ~11 nm thick amorphous alumina. We show that this aging step does impact the nanolaminates structure, leading, for thin bilayer thicknesses, to a substantial loss of the energetic reservoir: considering a stoichiometric Al/CuO stack, the heat of reaction can be reduced by 6–40% depending on the bilayer thickness ranging from 150 nm (40%) to 1 µm (6%). The impact of such thermal aging (14 days at 200 °C) and interfacial modification on the initiation and combustion properties have been evaluated experimentally and theoretically. Varying Al to CuO ratio of nanolaminates from 1 to 3, we show that ignition time of aged systems does not increase over 10% at initiation power densities superior to 15 W·mm−2. In contrast, burn rate can be greatly impacted depending on the bilayer thickness: annealing a stoichiometric nanolaminates with a bilayer thickness of 300 nm at 200 °C for 14 days lowers its burn rate by ~25%, whereas annealing a fuel rich nanolaminates with the same bilayer thickness under the same thermal conditions leads to a burn rate decrease of 20%. When bilayer thickness is greater than 500 nm, the burn rate is not really affected by the thermal aging. Finally, this paper also proposes a time–temperature diagram to perform accelerated thermal aging.

Fabrication and characterization of supercapacitor electrodes using chemically synthesized CuO nanostructure and activated charcoal (AC) based nanocomposite

In this work, the activated charcoal dispersed with copper oxide (CuO) nanoparticles (NPs) electrode materials was proposed as electrode material for supercapacitor that is used as energy storage device. The CuO NPs were synthesized at room temperature using co-precipitation method and the nanocomposite was with activated charcoal (AC) powder for its application in an electrochemical supercapacitor. Synthesis of CuO nanoparticles was carried out at various temperatures. The optimized temperature for synthesis is 600 °C that resulted in better performance of electrode materials. Synchrotron X-ray diffraction confirms the monoclinic structure. The X-ray photoelectron spectroscopy suggests the +2 oxidation state of copper. Electrochemical properties of the prepared nanocomposite electrodes and fabricated supercapacitor cells were characterized using a.c. impedance, cyclic voltammetry, and charge–discharge techniques by using 1 M H2SO4 and 6 M KOH as electrolytes. The optimized composition is 1:1 (mass ratio) of CuO and AC. The specific capacitance of the supercapacitor cells is stable up to 2000 cycles at 100 mV cm−2, which shows that the device has good electrochemical reversibility and cycle life with 6 M KOH and 1 M H2SO4 electrolytes.

The effect of CuO on a Pt−Based catalyst for oxidation in a low-temperature fuel cell

Electrocatalytic oxidation of methanol, ethanol, and formic acid has currently attracted research attention for low-temperature fuel cells. However, the efficiencies of these fuel cells mainly depend on the electrocatalytic activities of Pt-based anodic catalysts due to the problems of low kinetics for small organic molecule electro-oxidation. An anode catalyst can be developed by the addition of some metal oxides into a Pt-based catalyst, which can effectively promote the electro-oxidation of fuels based on small organic molecules. In this work, a nanocomposite catalyst consisting of multi-wall carbon nanotubes (CNTs), copper oxide (CuO) and Pt nanoparticles was synthesized and used to improve fuel cell oxidation. Due to its low cost and oxophilic character, the metal oxide can play a major role in the oxidation of CO. The synthesis of xPt−yCuO/CNT electrocatalysts was executed through two steps: supporting of CuO nanoparticles on CNTs by the alcothermal method followed by Pt loading onto the prepared CuO/CNT by chemical reduction. The as-prepared catalysts were physically characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Raman spectroscopy, and electrochemical measurements. The results demonstrate that CuO is well dispersed onto the CNTs and that this oxide can further interact with the active Pt present on the as-prepared catalyst composites. The activity of various xPt−yCuO/CNT electrocatalysts was determined by cyclic voltammetry (CV), where x and y are the mass ratios of Pt and CuO, respectively. The presence of CuO was found to significantly contribute to enhanced electroactivity towards oxidation reactions. The 1Pt–3CuO/CNT electrocatalyst is a capable catalyst for improving low-temperature fuel cell applications.

Rapid detection of low concentrations of H2S using CuO-doped ZnO nanofibers

In this study, a sol-gel method and an electrospinning method were used to prepare CuO-doped ZnO heterojunction nanofibers. The CuO-doped ZnO nanofibers were grown on interdigitated gold electrode substrates and then used in gas sensors. We found that when the mole ratio of CuO to ZnO was 0.15: 1, the sensing response of H2S was greatly enhanced and was 25% higher than that obtained using pure ZnO nanofibers. The best H2S gas response was 83.98% at 1 ppm H2S at 200 °C, with good recovery and reproducibility.

Synthesis and Characterization of CuO-ZnO Nano Additive for Lubricant

A mixed metal oxide (CuO-ZnO) additives has been successfully synthesized in laboratory by co-precipitation technique. The optimum ratio of CuO and ZnO in mixed metal oxide was found to be 1:1. The sodium lauryl sulfate (SLS) has been used as surfactant. The obtained material was found to be crystalline having crystalline size of 18 nm. The stretching band in FTIR spectra at around 1072 cm-1 to 750 cm-1 and around 600 cm-1 indicates the presence of Zn-O and Cu-O bonds. As prepared nano-particles have been used as nano additive in base oil to improve physio-chemical parameters of lubricants. The results revealed that the additive blended base oil (lubricant) has shown excellent lubrication properties. The higher kinematic viscosity of 33.0504 and 6.0158 at 40°C and 100°C respectively showed that as prepared additive blended lubricant is of ISO-32 category according to ISO grading system for lubricants. Similarly, viscosity index was found to be improved from 101 to 129. The pour point was found to be significantly decreased from -6°C to -24°C. So it can be used as good pour point depressant and could be used even in the extreme cold environment condition. The flash point was found to be increased from 215°C to 220°C indicating that the prepared mixed metal oxide (CuO-ZnO) acts as flash point enhancer. The copper strip corrosion rating was found to be 1b for additive indicating the non corrosive nature. The absence of moisture and pH around the neutral range 6.18 showed the additive blended lubricant is not harmful for machinery devices.

Enhanced Performance of a Novel Quaternary Nanocomposite CuO/ZnO/ZnS/CuS towards Removal of Dye Pollutant under Simulated Sunlight Irradiation

AbstractThe novel quaternary nanocomposites CuO/ZnO/ZnS/CuS have been successfully synthesized via a green microwave technique using dispersed ZnS micosphere and CuO nanoleaf. More particularly, the sphere‐like ZnS and leaf‐like CuO were mainly responsive to the visible and ultraviolet light, respectively. The quaternary nanocomposites CuO/ZnO/ZnS/CuS were sensitive to both ultraviolet and visible light. When prepared at lower mass ratio of CuO to ZnS, the quaternary nanocomposites showed excellent adsorption capacity in the dark, and remarkable photocatalytic capacity towards Rhodamine B (RhB) dye under the simulated sunlight within a short irradiation time more quickly and efficiently than that of pure CuO and ZnS. The mechanism investigation indicated the photodegradation of RhB dye under the simulated sunlight was mediated by the superoxide radicals and holes. Additionally, the quaternary nanocomposite CuO/ZnO/ZnS/CuS could be easily reused with higher activity.

Stability and characterization of mixture of three particle system containing ZnO-CuO nanoparticles and clay

The aim of this study was to understand heteroaggregation of mixture of ZnO and CuO nanoparticles (NPs) with clay, for the first time as per the authors' knowledge. Aggregation studies of mixture of ZnO and CuO nanoparticles with clay was done (ionic strength =5 mM; pH 7; nanoparticles concentration = 0.1 mg/L, 1 mg/L, 10 mg/L; Clay concentration = 1, 10, and 100 mg/L and HA concentration = 0.1,1, and 10 mg/L as total organic carbon). Critical coagulation concentration (CCC) and attachment efficiency values of suspensions with ZnO: CuO ratio = 0.1, 1, 10 were also determined. Aggregation and liquid portions of mixture suspension at equal mass ratio were characterized for size, zeta potential (ZP), metal and ion contents, pH and conductivity. Results indicated that CCC was found to be 120.7 mM for ZnO: CuO ratio 10 and 1144 mM for ZnO: CuO ratio 1. Values of attachment efficiency were obtained to be 0.9 and 0.8 for these two ZnO:CuO ratio. At natural water ionic strength (IS) condition, aggregate rate constant of mixture of particles ranged from 0.281 to 8.63 nm/min for 10 mg/L NP concentration. Aggregation in suspension containing mixture of particles was found to be affected by NP concentration, clay concentration, and humic acid (p < 0.05). During a 1-h aggregation study, 2.67 mg Cu metal/g aggregate and 0.38 mg Zn/g aggregate were found in aggregates of 5 mM suspension. Overall, this study provided information on aggregation characterization of mixture of metal oxide nanoparticles (ZnO and CuO) in HA and clay presence, which is useful in understanding aggregation formation and in characterizing exposure dose for environmental risk assessment. More detailed information on a three -particle system with natural colloids is required for predicting their fate in aquatic system and defining risk.

Influence of CuO on crystallization and electrical properties of B2O3-Bi2O3-GeO2- CaF2 glass system for thermoelectronic applications

Germanium bismuth-borate glasses with varying concentration of CuO of [(55-x)B2O3-20Bi2O3-5GeO2-20CaF2:xCuO] composition were prepared with melt-quenching method. The structure and thermal behavior of the samples were described through DTA, XRD, FTIR spectroscopy. The low energy of formation phases Bi44GeO68, CaGeO3 and CuGe3O9 were crystallized by the incorporation of CuO. [BO3] and [BO4] units are the main building groups of the glass matrix with some sharing of BiO6 and GeO4 units as FTIR analysis indicated. The electrical and dielectric characteristics were studied by broadband dielectric spectroscopy upon a wide-ranging of frequency (10-1 -107 Hz) and at temperatures 240 and 330 K. The heat-treated samples reveal higher conductivity than glass, by about three decades, at 330 K as the ratio of CuO increases to be in the range of semiconducting materials. The enhancement of dielectric properties of heat-treated samples over considered glass samples makes them better choices for the energy storage glass-dielectrics.

Metal–organic framework-derived nanocomposite metal-oxides with enhanced catalytic performance in thermal decomposition of ammonium perchlorate

Abstract In this work, CuO@NiO nanocomposites have been prepared using a 3D metal-organic framework, [Ni(μ3-tp) (μ2-pyz)]n as precursor, where H2tp and pyz corresponds to 1,4-benzenedicarboxylic acid and pyrazine, respectively. Calcinations of the precursor at two different temperatures (400 and 500 °C) following precipitating copper nitrate by NaOH (Cu:Ni molar ratio of 1:2) resulted in metal oxide nanocomposites with different characteristics (CuO@NiO-400 (2:1) and CuO@NiO-500 (2:1), respectively). Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM) coupled with EDS mapping, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and dynamic light scattering (DLS) analyses have been used to obtain compositional and morphological features of the prepared samples. The effect of calcination temperature on textural characteristics of the nanocomposites have been examined by Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) methods. It was found that higher calcination temperature destroyed the porous structure of the nanoparticles due to agglomeration. Catalytic performance of the nanocomposites was investigated toward thermal decomposition of ammonium perchlorate (AP) by means of differential scanning calorimetry (DSC) and thermogravimetry analysis (TGA). The results showed that the composite metal oxides (CuO@NiO) had more catalytic activity compared with CuO and NiO nanoparticles. CuO@NiO-400 (1:2) nanocomposites with larger surface area and smaller particle size exhibited significant catalytic activity compared with CuO@NiO-500 (1:2). The decomposition temperature was notably decreased from 420 to 310 °C. The released heat from AP decomposition was increased from 450 J g−1 to 1535 J g−1 over CuO@NiO-400 (1:2) nanocomposites. Also, the effect of different molar ratios (1:1 and 2:1) of CuO and NiO was investigated on AP thermal decomposition. The obtained nanocomposites are promising enough for further catalytic studies on the thermal decomposition of AP.

New coating synthesis comprising CuO:NiO/C to obtain highly selective surface for enhancing solar energy absorption

A novel nano coating was synthesized by spin and casting methods to obtain high-performance selective surfaces to enhance solar energy absorption. Nanomaterials (CuO:NiO) and carbon (fly ash) were used to provide a cost-efficient coating with high absorption efficiency. The materials were prepared with different carbon doping content, and the coating of the nanocomposite film was deposited by these techniques on pre-cleaned copper and glass substrates. Energy dispersive X-ray analysis was used to determine the component element for carbon (fly ash), and its diameter was measured using scanning electron microscopy. The optical properties were investigated by UV spectrometry and reflectivity tests in a range of 250–1300 nm at room temperature. The absorbance coefficient, transmittance, reflectance, skin depth, optical density, optical energy gap and Urbach’s parameters of the nanocomposite thin films were also determined. The data were analyzed and interpreted in terms of the theory of phonon-assisted direct electronic transitions. The Eg of the doped carbon was measured in different composition ratios of CuO:NiO (A = 0.5:2.5, B = 1:2, C = 1.5:1.5, D = 2:1, E = 2.5:0.5) wt.%, and fixed carbon content at 7 wt.%. The results of the doped samples revealed an energy gap value of 2.5–3.9 eV. When the ratio of the CuO content ranged from 0.5 to 2.5, composition B was found to have three regions in its figure that were dependent on the CuO content in the nanocomposite mixture. The optical band gap values were highly dependent on the CuO content in the nanocomposite films.

Electrochemical analysis of CuO-AC based nanocomposite for supercapacitor electrode application

In the present work, the activated charcoal-dispersed with Copper Oxide (CuO) nanoparticles (NPs) electrode materials has been proposed as electrode materials for supercapacitor that is used as energy storage device. The CuO NPs have been synthesized using co-precipitation method and the nanocomposite has been with activated charcoal (AC) powder for its application in an electrochemical supercapacitor. CuO nanoparticles calcination has been carried out at three different temperatures (400, 500, and 600 °C). The optimized temperature for synthesis is 600 °C that resulted into better performance of electrode materials. The Synchrotron X-ray diffraction (SXRD) confirms the monoclinic structure with space group C2/c (15). Electrochemical properties of the prepared nanocomposite electrodes and fabricated supercapacitor cells have been characterized using a.c. impedance, cyclic voltammetry (CV) and charge discharge (CD) techniques by using 6 M KOH as an the electrolyte. The optimized composition is 1:1 (mass ratio) of CuO and activated charcoal. The specific capacitance of the supercapacitor cell is stable up to 2000 cycles at 100 mV cm−2, which show that the device has good electrochemical reversibility and cycle life with 6 M KOH electrolyte.

Synthesis of copper oxide nanoparticles using tree gum extract, its spectral characterization, and a study of its anti- bactericidal properties

The synthesis of Copper Oxide nanoparticles was carried out using tree gum extract as a template. The nanoparticles were characterized by UV–Vis, SEM and XRD. Scanning electron microscopy shows a beautiful needle like structure implanted inside the gum framework. Tree gum acts as a good binding agent. X ray diffraction patters show the formation of both CuO and Cu2O nanoparticles of size in the range of 25.40 and 51.56 nm for Moringa Olifera and Acacia Nilotica. The CuO nanoparticles showed good antibacterial activity against two bacterial strains which increase its potential applications. Though the characterization studies of CuO nanoparticles with two different gums showed different ratios of Cu2O and CuO, the antibacterial studies showed fairly similar results.

Influence of Ga2O3, CuGa2O4 and Cu4O3 phases on the sodium-ion storage behaviour of CuO and its gallium composites.

CuO and its gallium composites with various compositions are successfully fabricated by using a hydrothermal technique followed by calcination at 900 °C. The added Ga precursors formed oxides in the composites, such as Ga2O3, CuGa2O4 and Cu4O3, as confirmed through the X-ray diffraction patterns as well as the HRTEM and SAED patterns. Further HRTEM analysis also confirmed that Cu4O3 and CuGa2O4 phases reside on the surface of CuO in the composites with a CuO : Ga ratio of 90 : 10. The contents of various oxide phases varied when we increased the amount of Ga in the CuO composites. Changing the ratios of CuO and Ga precursors in the composites is quite effective in tailoring the sodium-ion storage behaviour of CuO. The resultant CuO/Ga composites exhibit remarkable electrochemical performance for sodium-ion batteries in terms of capacity, rate capability and cycling performance. The composite containing 90% CuO and 10% Cu/Ga oxides delivers the highest charge capacity of 661 mA h g−1 at a current density of 0.07 A g−1 with a capacity retention of 73.1% even after 500 cycles. The structure and morphology of the composite (90% CuO and 10% Cu/Ga oxides) was successfully retained after 500 cycles, which was confirmed through ex situ XRD, SEM and HRTEM analyses. The composite also exhibited remarkable rate capability in which it delivered 96 mA h g−1 even at a high current density of 6.6 A g−1. The enhanced electrochemical performances of CuO and its gallium composites are attributed to the presence of Cu4O3 and CuGa2O4 phases. The Cu4O3 phase is actively involved in the redox reaction and the CuGa2O4 phase stabilizes the CuO phase and buffers the volume expansion of CuO during cycling. The present approach eplores great opportunities for improving the electrochemical performance of oxide based anode materials for sodium-ion batteries.