The peaks were indexed using JCPDS card no 00-024-0734. The morphology of the samples was observed using JEOL (JED 2300) scanning electron microscope under high vacuum with an accelerating voltage of 20 kV and a current of 7.475 nA. Transmission electron microscopy (TEMFEI -TECHNAI G220S-Twin operated at 200 kV) was utilized to obtain high resolution micrographs. Atomic Force Microscopy (AFM) was done using Agilent Technologies Model No 5500. Drop deposition technique was used for sample deposition on monocrystalline silicon substrate. Particle size measurements were performed using a DLS based Horiba Scientific Nano Particle Analyzer SZ-100. The size distribution is determined by photon correlation spectroscopy (PCS) comparing the scattered light intensity at some reference and delay time. UV-vis absorption spectroscopy was carried out on the dispersion in transmittance mode. The voltage output was measured using a Textronix TBS1072B digital oscilloscope (70 MHz, 1GS/s) and Sigma 3A digital multimeter unit. To investigate oxidation states and surface composition of the materials, XPS ThermoFisher Scientific Nexsa was used, with Al-Kα radiation (λ=1486.71 eV) as source.