Papers by Keyword: Copper Oxide

Abstract: Industrialization has led to widespread aquatic contamination, with dyes being among the most prominent pollutants found in various water bodies. Major contributors to dye pollution include the textile, printing, leather, cosmetics, and chemical industries, with the textile industry alone being responsible for approximately 13% of the dyes released into aquatic environments. This study focuses on comparing the photocatalytic degradation performance of synthesized catalysts prepared in the presence of biopolymers. Pullulan was selected as a capping agent to aid the synthesis process and promote the formation of nanosized catalysts. Three types of catalysts, namely copper oxide, zinc oxide, and a composite of both, were synthesized, and their performance was evaluated through the photocatalytic degradation of methylene blue. Among the three, zinc oxide demonstrated the highest degradation efficiency (99%), followed by the composite (27%), while copper oxide exhibited negligible photocatalytic activity (14%). Further optimization of the best-performing catalyst (zinc oxide) was conducted by varying parameters such as catalyst dosage (0.05-0.15g) and solution pH (5-9). The results showed that zinc oxide achieved the highest degradation under acidic conditions (pH 5) with a dosage of 0.15 g, requiring only 70 minutes to reach nearly 100% degradation. Overall, this study provides valuable insights into the influence of catalyst type on the photocatalytic degradation of methylene blue.

Abstract: Adoption of desalination technologies to produce fresh water in developing countries remains underutilized due to the substantial energy consumption, high operational costs, and membrane fouling associated with conventional methods. Microbial desalination cells (MDCs) have emerged as a promising alternative, offering simultaneous wastewater treatment, bioelectricity generation, and salt removal. This study aimed to evaluate the bio-templating of copper and zinc oxide nanoparticles on waste-derived eggshell membranes (CZ-ESM) and subsequently incorporated into ion exchange membranes (IEMs) for MDC applications. Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM-EDS) confirmed the presence of calcinated CZ-ESM in the IEMs. The modified and control IEMs were compared based on water uptake, mechanical strength, biofouling resistance, and salt removal. Incorporation of calcinated CZ-ESM nanocomposites enhanced membrane hydrophilicity, reflected in increased water uptake while also exhibiting reduced microbial colonization, thereby improving anti-fouling performance. However, the addition of calcinated CZ-ESM nanocomposites resulted in decreased tensile strength due to nanocomposite aggregation and heterogeneous resin distribution. Modification of the IEMs showed statistically the same salt removal as that of the unmodified counterpart. These findings demonstrate the use of CZ-ESM nanocomposites as fillers for MDC membranes, highlighting their ability to enhance hydrophilicity and antifouling properties, but improvements in the mechanical properties and salt removal must be further investigated to address practical limitations in the MDC application.

Abstract: Mineral trioxide aggregate (MTA) is a common biomaterial used for endodontic treatment. However, this material does not have antibacterial activity, and the addition of an antibacterial agent is necessary. In this research, CuO nanoparticles (CuONP) have been added to MTA to improve the compressive strength and antibacterial activity. CuONP was synthesized by mixing 25 mL CuSO₄.5H₂O 0.5 M and Na₂CO₃ 0.5 M at volume variations (15, 25, and 42 mL), sonicating the mixture at a temperature of 60 °C for 2 hours, and calcining at a temperature of 600 °C for 4 hours. MTA/CuO material was made by mixing MTA and CuONP at variations in weight percentage (1, 2, and 3%). CuONP, MTA, and MTA/CuO were characterized with Fourier Transform Infrared (FT-IR), X-ray diffractometer (XRD), and Scanning Electron Microscopy-Energy Dispersive X-ray (SEM-EDX). The compressive strength and antibacterial properties against Staphylococcus aureus and Pseudomonas aeruginosa were also tested. The results showed that CuONP was successfully synthesized with an average particle size of 21.94 nm. Adding CuONP 2% to MTA improved its compressive strength of 12.03±0.44 MPa. In addition, the presence of CuONP in the MTA gave the antibacterial property of S. aureus with an inhibition zone value of 6.69±0.67 mm for MTA/CuO-2 and 6.77±0.31 mm for MTA added with 3% of CuONP. However, adding CuONP did not increase significant antibacterial activity against P. Aeruginosa. Adding CuONP 3% increased the inhibition zone from 5.50±00 to 7.04±0.39 mm. The findings indicated that MTA modified with CuONP can potentially be applied for endodontic treatment even though further investigation is still necessary to test the biocompatibility and cytotoxicity.

Abstract: We have studied the impact of nanosized grains of copper oxides, grown by atomic layer deposition (ALD), on photocatalytic activity of thin titanium dioxide (TiO₂) films under visible-light irradiation. The size of grains and the crystal phase of copper oxide were controlled by the number of ALD deposition cycles. The x-ray diffraction and x-ray photoelectron measurements revealed preferential formation of CuO for a small number of deposition cycles, while Cu₂O forms preferentially for a larger number of cycles. The photocatalytic efficiency of pristine TiO₂ has been enhanced for copper oxide/TiO₂ structures in which the nanosized copper oxide grains do not cover the entire TiO₂ surface. At the same time, the large increase of the current measured across the copper oxide/TiO₂ structures is consistent with the charge transfer from copper oxide grains to TiO₂, essential for the observed increase of photocatalytic activity.

Abstract: The dealloying technique has been a well-known process since antiquity, but recently it has started to be used to produce nonporous metals and metal oxide semiconductors for various electrochemical applications. The dealloying process is carried out in both acidic and basic solutions, depending on the base material and the desired application. In this study, Cu-based amorphous ribbons were dealloyed in alkaline aqueous solution at room temperature, keeping the temperature constant and varying the concentration of the solution. This process has the advantage that both dealloying of the ribbons and nanostructured copper oxide synthesis on their surface is obtained in one step. For the preparation of copper-based amorphous ribbons, the melt-spinning process was used, and the composite obtained consisting of nanopores decorated with Cu₂O/CuO nanoparticles makes it an ideal candidate for electrochemical applications. For the investigation of the structural, morphological, and optical properties of the obtained materials, X-ray diffraction (XRD) and scanning electron microscopy (SEM).

Abstract: Titanium dioxide (TiO₂) was utilized in photocatalysis applications due to their non- toxic, cheap and high photocatalytic activity. However, its photocatalytic reaction is limited by low surface area as well as the rapid recombination of photogenerated electron-hole pairs and only has ability to absorb a small fraction (<5%) of indoor light. In this study, copper oxide coupled titanium dioxide (CuO/TiO₂) nanocomposite photocatalyst was synthesized using hydrothermal method. The synthesised photocatalyst was characterized by using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), Scanning electron microscopy(SEM), Brunauer, Emmett, teller (BET) and UV- Visible Spectroscopy. Spectra obtained from FTIR have proved that there are existence of O-H stretching, O-H vibration and metal-O bond that correlates to the functional groups of the samples. As affirmed by XRD analysis, highly crystalline rutile TiO₂ phase was obtained for pure TiO₂ samples. Rutile TiO₂ phase is remained and additional peaks belong to copper oxide was observed for CuO/TiO₂ nanocomposite photocatalyst sample. This finding suggesting that copper oxide was successfully loaded onto TiO₂. Morphological study from SEM shows the presence of short rod-like particles of copper oxide and agglomerated TiO₂ bulk particles. BET surface area for CuO, TiO₂ and CuO/TiO₂ nanocomposite photocatalysts were 20.50 m²/g, 15.26 m²/g and 17.13 m²/g, respectively. The photocatalytic degradation of methyl orange (MO) was found to be 85.0% using CuO/TiO₂ nanocomposite photocatalyst, which is better than pure TiO₂ and pure CuO after 3 hours reaction.

Abstract: Significant demand of Li-ion batteries (LIBs) is raising awareness of future LIBs wastes which are highly required to be reprocessed, reused or recycled. In this research, copper foil waste from spent LIBs are upcycled as an anode material, CuO. Hydrometallurgical route was applied to selectively dissolve copper foils where nitric acid, maleic acid and acetic acid were used as the leaching agents while oxalic acid were used to precipitate copper into copper oxalate which is a precursor to CuO. CuO was obtained by calcination of copper oxalate at high temperature. Based on XRD and FTIR analysis, Copper (II) oxalate dihydrates is successfully obtained while SEM images of the samples confirmed micron sized agglomerates which is consist of submicron primary particles. XRD analysis of CuO samples obtained from various leaching process confirmed that a pure CuO is successfully synthesized from nitric acid leaching process while CuO from acetic acid and maleic acid leaching has Cu₂O and Cu phase. CuO and 10%CuO@graphite sample from nitric acid leaching were used as sole anode and composite anode in a LiNi_0.8Co_0.1Mn_0.1O₂(NCM) battery, respectively. The initial columbic efficiency of CuO anode was far inferior to CuO@graphite. However, CuO@graphite had higher specific charge-discharge capacity with the value of 347.8 mAh/g compared to pure graphite (286.5 mAh/g). In conclusion, Cu-foils are a promising source of CuO to enhance the capacity of commercial graphite anode.

Abstract: In the present work, pure copper ferrite (CuFe₂O₄) thin film has been grown on clean glass substrate by using the spray pyrolysis deposition technique. All the necessary parameters were optimized before the deposition. The deposited thin film was annealed at 500°C for 4 h and then cooled to room temperature. X-ray diffraction (XRD) technique was used to study the phase purity and crystal structure of the sample formed on the thin film. The analysis of the X-ray diffraction pattern reveals the formation of a single-phase cubic spinel structure. The lattice constant and other structural parameters calculated from XRD data are in good agreement with the reported data.

Abstract: The aims of this study are to improve thermal characteristics and decrease electrical consumption of air-conditioning as well as, to increase the performance (COP) of cooling cycle. CuO nanoparticles (0.003 mass fraction) have been added to compressor oil of air conditioning (1 ton capacity, split-unit) used Freon gas (R22), and then compared with pure oil compressor of air conditioning under same environmental conditions. The results showed that the increasing of density ratio, COP and viscosity ratio are 3%, 50% and 1.8% respectively while the decreasing of electrical consumption is 51.2%. The experimental data are compared with previous data in the literature to be validated. It can be recommended that the nano-oil is significant utilizing in air conditioner compressors for energy consumption applications.

Abstract: The need for energy has reached a remarkable level that needs to be solved. In this study, nanoparticles of cuprous oxide (Cu₂O) doped with varying amounts of samarium (Sm) were prepared by using solution precursor route approach with the aid of ultrasonic sound. Copper chloride and Samarium (III) Chloride was used as source for copper ions and samarium ions, respectively. X-ray diffraction (XRD) measurement confirmed that the prepared nanostructures are crystalline and the dopant Sm ion did not alter the crystalline structure of the Cu₂O. The sample absorption spectrum was determined using UV-Vis spectroscopy in the wavelength range of 400nm to 700nm. The optical bandgap of the undoped and doped Cu₂O was found to fall between 1.94 eV - 2.21 eV. Scanning Electron Microscopy (SEM) paired with energy dispersive x-ray (EDX) was used to observe the morphology and the presence of samarium in the synthesized Cu₂O nanoparticles. The results show that upon adding Sm to the Cu₂O, in a facile way, it could bring an important impact on optoelectronic devices such as photodiodes and solar cells.