Journal of Nanoanalysis

6

Authors: M. Khalid Alamgir, M. Zaka Ansar, M. Shoaib,G. Murtaza, Javaid Ahsan Bhatti, Usman Asghar

Water splitting for hydrogen production under sunlight using TiO2 as photo catalyst provides a better route for solar energy and attracts the attention of many researchers. The photo catalytic activity of TiO2 under sunlight irradiation depends on the band gap energy. The transition metal doped TiO2 shows an edge over TiO2 in optical absorbance and photo catalytic activity. Thin film of Cr doped TiO2 was deposited by Electron beam evaporation deposition process on glass substrate, the band gap of sample was measured with UV-Vis spectroscopy. In order to provide theoretical ground to our experimental band gap results the first principle (ab-initio) calculation was performed using the computer code WIEN2K with Full Potential Linearized Augmented Plane Wave method (FP-LAPW) based on the density functional theory (DFT).

15

Authors: J. Jasmine Ketzial, A. Samson Nesaraj

Solid electrolytes based on doped cerium oxide, Ce(M)O2-δ (M = rare-earth cations), are of considerable interest for potential use in low temperature solid oxide fuel cells (LTSOFCs) due to its higher ionic conductivity than YSZ based solid electrolyte. In this research work, crystalline, pure Ce1-xMxO2-δ (where M = Gd or Sm, x = 0.10 or 0.20) based nanoparticles were prepared by chemical precipitation method in presence of surfactant (polyvinyl pyrollidone). The intermediate compound (mixture of hydroxides) was subjected to TGA/DTA in order to find out the temperature at which the pure phase product is formed. Then, the as prepared materials were heat treated systematically at 300, 450 and 600o C for 2 h each to get phase pure materials. The resultant nanoparticles were subjected to physical characterization techniques such as, XRD, FTIR, particle size analysis and SEM. XRD results confirmed that all the powders had single-phase fluorite structure. Characteristic vibration mode of CeO2 was proved by FTIR. The presence of nanoparticles (50 – 100 nm) in the prepared materials was found out by particle size measurements and SEM. The results of physical characterization of the above materials are found to be good for application as alternate electrolytes in SOFC. However, these materials can be considered as suitable alternate electrolytes in LTSOFC systems only after studying their electrical characteristics.