Papers by Keyword: Cupric Oxide

Abstract: In this study, high quality monodispersed nanocrystalline cupric oxide (CuO) nanopowder was prepared through novel sol-gel green synthesis method, assisted by sodium alginate (Na-ALG) as the green ionic exchange material. The morphology and structural properties of CuO nanopowders synthesized with and without the incorporation of extrusion dripping, at different Na-ALG solution concentrations and calcination temperatures, were studied using thermalgravimetric analysis (TGA), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX) and Raman spectroscopy. Optimum synthesis conditions were identified, resulting in high-purity, monodispersed nanocrystalline CuO powder in the range of 9.92 – 12.4 nm, which could have a promising future in various applications.

Abstract: Spherical cupric oxide (CuO) was grown on copper (Cu) foil by a facile, low-temperature chemical bath deposition (CBD) under alkaline conditions. This method enables direct contact between the active materials and the cathode which is advantageous for attaining higher capacitance. The Cu products were spherical in shape and have a uniform morphology due to self-assembly and Ostwald ripening. The fabricated CuO exhibit a specific capacitance in the range of 700–800 F/cm².

Abstract: The main aim of this study was to electrochemically synthesize and characterise bismuth vanadate (BiVO₄) photoelectrodes for photoelectrochemical (PEC) water splitting. The influence of annealing temperature on the nanostructured semiconductor BiVO₄ thin film structure was studied systematically. This was followed by advanced characterisation of the BiVO₄ photoelectrodes by using field emission-scanning electron microscopy (FE-SEM), Raman spectroscopy, photoluminescence and PEC properties measurements. When the electrochemically synthesized BiVO₄ thin films were subjected to different annealing temperatures, phase transitions occurred for tetragonal BiVO₄ at 300 °C and monoclinic BiVO₄ at 400 °C. Through this study, it was found that the annealing treatment at 400 °C resulted in the highest photocurrent density (i.e. photoactivity) of 1.23 mA/cm² at 0.6 V vs. Ag/AgCl. Finally, the BiVO₄/CuO heterojunction photoelectrode was also fabricated in order to further enhance its photoactivity under visible light irradiation.

Abstract: In the paper the SiO₂CuO_x and SiO₂(CuO_xSnO_y) thin films were deposited from the alcoholic solutions employing the sol-gel technique. The films were characterized by means of SEM (scanning electron microscopy) and 2p x-ray photoelectron spectroscopy (XPS). The SEM studies found the grain shape changes from flower-like to regular shaped inorganic agglomerates as result of adding the SnCl₄ into the sol. The X-ray photoelectron spectroscopy (XPS) studies showed the presence both CuO and CuO₂ phases and formation of a double CuSiO₃ oxide phase.

Abstract: Although copper have better electrical properties than aluminum such as low resistivity and high electro-migration resistivity, aluminum has been used as an interconnect material due to the difficulty in Cu dry etching. Since CMP process has been adapted to the semiconductor fabrication, Cu became the choice of materials for interconnection. However, copper CMP process introduces new defects on the surface such as slurry particle, organic residue, scratch and corrosion [1].

Abstract: The thermal conductivity (TC) of compression moulded polycarbonate (PC) and PC filled with 2.5-5% iron oxide (α-Fe₂O₃), cupric oxide (CuO) or magnesium oxide (MgO) nanoparticles, prepared by extrusion, was studied using a thermal conductivity analyser (TCA). The effect of type and content of nanoparticles on the thermal conductivity was investigated. The experimental TC values of the PC nanocomposites showed an increase with an increase in the level of nanoparticles concentration. The TC improvement in PC/CuO nanocomposite was greater than that of other nanocomposites. Several models were used for prediction of the TC in the nanocomposites. In all nanocomposites the TC values correlated well with the values predicted by the Ce Wen Nan model up to 5wt%.

Abstract: Nanocrystalline lms of cupric oxide (CuO) produced by thermal oxidation havebeen characterised using x-ray analysis, SEM image analysis and temperature-dependent con-duction measurements.We describe in detail the x-ray di ractometer calibration, paying partic-ular attention to a function- tting procedure which enables accurate subtraction of instrumentalcontributions to the sample di ractograms. The Scherrer and Williamson-Hall models are usedto calculate crystallite size and sample strain and also give some indication of spatial inhomo-geneity. Image analysis techniques which can discern individual `grains' (the circular Houghtransform and the ImageJ particle analyser) were used to evaluate the grain size distributionfrom SEM images. An average crystallite diameter of 30 nm - determined by the ImageJ par-ticle analyser - closely agrees with the various XRD analysis approaches. Electronic conductionin our samples is found to proceed via thermally activated transport, which we attribute tothe presence of a well-de ned trap state that lies 0.2 eV from the valence band edge. Thevoltage-dependence of the activation energy additionally shows that the activation is a bulke ect and not due to Schottky barriers between the sample and the metal contact.

Abstract: ZnO is an important functional semiconductor in application of photoelectric devices. ZnO nano-tubes and the CuO-doped ZnO have been successfully fabricated via hydrothermal method and a solution routine. The samples were characterized by X-ray diffraction, scanning electron microscopy, Fourier transformation infrared spectroscopy and room temperature photoluminescence measurement. The results show that the lattice space (d-value) of the CuO-doped ZnO increases while introducing CuO into its structure. Due to the interaction between Cu2+ and the surface atoms of ZnO, a photoluminescence confinement were observed in the CuO-doped ZnO compared with that of nano ZnO.

Abstract: By a simple chemical bath method, new carambola-like structured CuO had been fabricated in a solution composed of Cu(NO3)2, NaOH and hexamethylenetetramine (HMTA). The formation of such structure was caused by in-situ dehydration and separation of flower-like petals composed of several pieces of copper hydroxide sheets. The corresponding electrochemical reactivity of structured CuO has been investigated, which demonstrated the potential application for lithium ion batteries.

Abstract: A 2.45 GHz microwave atmospheric pressure torch is employed to prepare cuprous oxide films. The sputtered copper films are firstly deposited on slide glass. After that, the films are annealed in air at 500°C for 12 h, which would directly oxidize into cupric oxide. The annealed films are then treated by atmospheric nitrogen plasma at 800 W for 10 min. The color changed significantly from black to reddish brown after nitrogen plasma treatment. The X-ray diffraction patterns show that annealed films are cupric oxide which is vanished after plasma treatment. The cuprous oxide films appeared after nitrogen plasma treatment. The resistivity of annealed films is 16.7 --cm, which reduce to 2.08 --cm after plasma treatment. The optical band gap of annealed films, cupric oxide phase, is 2.1 eV but the value shifts toward 2.4 eV after plasma treatment. The novel microwave plasma torch posses a fast and easy way to fabricate cuprous oxide films.