Electrochemical bulk synthesis and characterisation of hexagonal-shaped CuO nanoparticles

Abstract

A simple and efficient two-step hybrid electrochemical-thermal route was developed for the bulk synthesis of CuO nanoparticles using aqueous sodium nitrate electrolyte and Cu electrodes in an undivided cell under galvanostatic mode at room temperature. The influence of electrolyte concentration on the synthesis of CuO nanoparticles was studied at 1.0 A/dm 2 current density. Electrochemically generated precursor was calcined for an hour at different levels of temperature in the range 200-900 C. The calcined samples were characterised by XRD, TG-DTA, XPS, SEM/ EDAX, TEM, FT-IR and UV-Vis spectral methods. The crystallite sizes were estimated and the thermal behaviour of as-prepared compound was examined. Rietveld refinement of X-ray data shows results matching the monoclinic structure with the space group of C2/c (no. 15). The TEM result revealed that the particle sizes were in the order of 30-50 nm diameter and 120-200 nm length. The blue shift was noticed in UV-Vis absorption spectra. All samples of CuO exhibited randomly oriented hexagonal morphology.

The effect of cetyltrimethylammonium bromide on size and morphology of ZnO and CuO

“…The electrolytes used in the electrolyte bath should enhance the conductivity and assist the formation of metal hydroxides. The NaHCO 3 and NaNO 3 have been used in the synthesis of ZnO and CuO NP respectively [2][3][4]12]. These electrolytes facilitate the formation of metal hydroxides along with enhancing the conductivity of the electrolyte bath.…”

“…The TiO 2 , SnO 2 , Fe 2 O 3 , PdO, WO 3 , Ga 2 O 3 , In 2 O 3 , ZrO 2 , CuO and ZnO are amongst the extensively studied transition metal-oxide semiconducting nanomaterials and have potential applications in optics, optoelectronics, microelectronics, biosensors, gas sensors, chemical sensors, switching, magnetic, luminescent, electrical and acoustic devices, solar cells, catalysis and powder metal-lurgy [1][2][3][4]5]. The CuO and ZnO nanomaterials are particularly of special interest as they are cheap, easy to prepare by simple, low cost methods at normal temperatures [6].…”

“…CuO is a p-type semiconductor with band gap of 1.8 to 2.5 eV [2,7]. It is an excellent solar absorber with low emittance, which makes it a suitable candidate for solar cells as thermal collector [8].…”

“…The synthesis of ZnO and CuO thus acquires special interest. The common chemical synthetic methods adopted in the preparation of these nanomaterials are precipitation, sol-gel, hydrothermal, solvothermal, solution combustion, thermal decomposition, simple hydrolysis, wetchemical, microemulsion, non-microemulsion, microwave assisted solvothermal, ultrasonic radiation precipitation, mechanical milling, electrochemical, chemical vapor deposition (CVD), laser vaporization, exfoliation, laser ablation methods and so on [2]. However, these methods involve organic solvents, rigorous reaction conditions, demand sophisticated instruments and few of these techniques require longer time duration affording less yield than expected [4].…”

“…The ZnO [19], Cu 2 O [20], CuO [21], Au/AgI [22] have been successfully synthesized by electrochemical method. We have recently synthesized hexagonal shaped CuO NP in bulk [2], cubic shaped Zn 2 SO 4 [23] and large size ZnO NP [3,4] by hybrid sacrificial anode electrochemical-thermal route.…”