A new approach: Synthesis of cobalt aluminate nanoparticles using tamarind fruit extract

Abstract

The nanostructured cobalt aluminate (CoAl2O4) was obtained through an eco-friendly precursor method using aqueous extract of tamarind fruit. The use of plant extracts is a simple and effective approach for the preparation of CoAl2O4 nanoparticles. The polynuclear complex precursor was characterized by Fourier transform infrared spectroscopy (FTIR), ultraviolet–visible spectroscopy (UV–VIS) and thermal analysis. The cobalt aluminate was investigated by: X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), FTIR, UV–VIS and colour measurements by reflectance spectroscopy (RS). X-ray diffraction patterns confirmed the formation of cubic CoAl2O4 spinel phase with good crystallinity. The average particle size from TEM is about 71 nm. Chromatic coordinates indicate that the bluest colour was obtained for the cobalt aluminate obtained by subsequent heat treatment.