Structural, optical and electrochemical properties of TiO2 nanoparticles synthesized using medicinal plant leaf extract

The flower like TiO2 nanoparticles have been identified as potential electrode material for efficient next generation electrochemical energy storage devices. The present work reports, a novel green approach to synthesize high surface area TiO2 nanoparticles using medicinal plant leaf extracts namely Ocimum Tenuiflorum Plant and Calotropis Gigantea Plant. The TiO2 nanoparticles synthesized using Calotropis Gigantea plant confirmed rutile phase from X-ray powder diffraction and Raman spectra. The fourier transform infrared spectroscopy spectra of the sample indicate the presence of TiO2 vibrational bonds. The field emission scanning electron microscopy images revealed that the flower like shape of nano-granules with an average granule size of 200 nm. The presence of Ti and O elements qualitatively confirmed using energy dispersive spectroscopy spectra, which shows the good stoichiometry in the sample. The flower like shapes with nano petals were further disclosed with the help of high resolution transmission electron microscopy. The corresponding optical band gap was observed to be 3.0 eV. The electrochemical investigations of the sample exhibited a high specific capacitance of 224 F g(-1) at 0.5 A g(-1) with 71% of capacitive retention after 5000 cycles.