Surface Morphology Of Co Research Articles

Investigations on structural, morphological and electrochemical properties of Co(OH)2 nanosheets embedded carbon nanotubes for supercapacitor applications

The nanostructured cobalt hydroxide [Co(OH)2] embedded carbon nanotubes (CNT) have been synthesised by a simple chemical reflux method. The crystallinity of cobalt hydroxide has been confirmed by using powder X-ray diffraction data. The presence of CNT in the synthesised nanocomposite is also examined. Fourier transform infrared spectroscopy reveals the OH and CoO vibrations in the Co(OH)2/fCNT nanocomposite. SEM and TEM images expose the surface morphology of Co(OH)2 sheet that is embedded over carbon nanotube. The electrochemical performance of the Co(OH)2 embedded fCNT has been examined by the cyclic voltammetry in 6 M potassium hydroxide (KOH) electrolyte in room temperature. Co(OH)2 embedded fCNT nanocomposite exhibits higher specific capacitance up to 1006.8 F/g at 0.5 mV s−1 scan rate. The specific capacitance of Co(OH)2 embedded fCNT nanocomposite is calculated from the charge-discharge curve. The synthesised hybrid nanocomposite is used as a cathode, and the functionalized CNT is used as an anode. These are used to fabricate an asymmetrical supercapacitor device. The device is delivered to a high power density of 7000 W kg−1 and energy density of 17 W h kg−1 in the potential window from 0 V to 1.4 V. The results of hybrid Co(OH)2/fCNT||fCNT asymmetrical supercapacitor exhibit better cycle stability up to 5000 cycles. The usefulness of Co(OH)2/fCNT||fCNT asymmetrical supercapacitor is analysed for energy storage devices.

Microscopic study of the surface morphology of CO2 laser-treated cotton and cotton/polyester blended fabric

This paper presents how the morphology of fibers is affected by CO2 laser treatment. The change in morphology of fibers induced by a laser affects the physical and mechanical properties of the fabric, such as water absorption, dye uptake, resistance to wrinkles and adhesion to other materials, etc. The morphology of laser-treated fibers was analyzed by scanning electron microscopy (SEM). Samples of cotton twill fabric, cotton/polyester blended twill fabric and cotton knitted fabrics with different yarn counts were studied before and after laser treatment. SEM images reveal different sizes of pores and cracks on the surface of cotton fibers. In the case of cotton/polyester blended twill fabric, the two types of fibers responded differently to laser treatment; the change in cotton fibers was slightly different from the SEM images of 100% cotton twill fabric. The number of pores and cracks on the fiber surface of cotton/polyester fabric was lower than that found in 100% cotton twill fabric. Polyester fibers melt and flow while cotton fibers are encased in resolidified polyester. For 100% cotton knitted fabrics, the thickest yarn with the lowest yarn twist exhibited the largest change when compared with fabrics knitted with lower yarn counts. The degree of change of fiber surface modification was enhanced with an increase of laser processing variables.

Effect of pretreatment on the surface structure of a Co(OH)2 electrode

Structural and morphological changes of Co(OH)2 and valence modification of cobalt during the first charging by pretreatment, discharging at 57.8 mA g−1 for 7.5 h before the first charging, were investigated by transmission electron microscopy, X-ray photoelectron spectroscopy and X-ray diffractometry. Consequently, metallic Co nanoparticles were formed on the Co(OH)2 particles after pretreatment. A comparison of the results for the pretreated and untreated electrodes shows that for the pretreated electrode, the Co nanoparticles were sequentially oxidized to Co(OH)2, Co3O4 and CoOOH. Moreover, the electric conductivities of the untreated and pretreated Co(OH)2 electrodes were 3.6 × 10−5 and 2.0 × 10−3 S cm−1, respectively. The difference in electric conductivity was ascribed to that in surface morphology of Co(OH)2 by the pretreatment and the following reoxidation which led to the formation of highly conductive mosaic CoOOH. This contributes to the formation of a dense, highly conductive network on the surface, great improving the electrochemical performance.

Analyzing in-plane magnetic anisotropy from surface morphology for amorphous films

A method is developed to analyze the in-plane magnetic anisotropy from surface morphology for amorphous films. The lateral sizes along radial direction ( R RD) and tangent direction ( R TD) of rotational substrate, which are extracted from the surface morphology of Co 66.3Zr 33.7 amorphous films, are used to calculate stress anisotropy energy E σ. It is found that E σ is consistent with the magnetic anisotropy energy K μ for the samples deposited on Si (1 0 0) substrate and then a relationship K μ ∝ 1/ R RD − 1/ R TD can be obtained. This method is sensitive to the initial state of substrate so its application range is discussed.