Z. Shahri, S.r. Allahkaram,
Volume 9, Issue 4 (12-2012)
Abstract
Metal matrix composite coatings reinforced with nano-particles have attracted scientific and technological interest due to the enhanced properties exhibited by these coatings. Cobalt/hexagonal boron nitride nano-composite coatings were prepared by means of the pulse current electroplating from a chloride electrolyte on copper substrates and a comparison was made with the pure cobalt in terms of structure and tribological properties. Effects of particles concentration (5-20 gL-1) and current density (50-200 mA cm-2) on the characterization of electroplated coatings were investigated via X-ray diffraction analysis, energy dispersive spectroscopy and Vickers micro-hardness. Moreover, the tribological behavior was studied using pin-on-disc method. The results showed that cobalt/hexagonal boron nitride nano-composite coatings have higher hardness, wear resistance and lower friction coefficient than pure cobalt and the plating parameters strongly affect the coating’s properties
Y C Goswami,
Volume 21, Issue 0 (3-2024)
Abstract
CuS nanoparticles (NPs) with dimensions in the nanometer range were synthesized using a wet chemical approach. The comprehensive characterization of these NPs involved an analysis of their structure, composition, and optical properties, primarily conducted through X-ray diffraction (XRD) analysis. The XRD pattern conclusively confirmed the presence of the hexagonal phase in the CuS particles, a result corroborated by the accompanying Raman spectrum. The investigation further determined an estimated bandgap energy of 2.05 eV for the slightly sulfur-rich CuS NPs. Notably, this energy value exceeds that of bulk CuS (1.85 eV), indicating a noticeable miniaturization effect. The novel CuS NPs exhibited outstanding photocatalytic activity in the degradation of methyl Red (MR), particularly under visible light. This impressive performance is attributed to surface-bound OH ions on the CuS nanostructures, facilitating the adsorption and acceleration of the degradation process for MR molecules under visible light irradiation. The research presented in this article highlights the significant promise and efficiency of the synthesized CuS NPs as photocatalysts. These nanoparticles are particularly responsive to stable visible light, making them highly suitable for purifying chemically contaminated wastewater. Specifically, their effectiveness in degrading stable azo dyes, exemplified by MR, underscores their potential in practical applications.
