POLYOL MEDIATED SYNTHESIS OF TUNGSTEN TRIOXIDE AND TI DOPED TUNGSTEN TRIOXIDE PART 2

Polyol mediated synthesis of tungsten trioxide and Ti doped tungsten trioxide part 2

Part 2: Synthesis of NASICON—A Molecular Precursor-Based Approach

P. Porkodi, V. Yegnaraman, P. Kamaraj, V. Kalyanavalli and D. Jeyakumar

Chem. Mater., 2008, 20 (20), pp 6410–6419

DOI: 10.1021/cm800208k

Abstract

Phosphosilicate molecular precursor for the synthesis of NASICON, natrium super ionic conductor, Na1+xZr2SixP3−xO12 (x = 1 and 2) has been devised and prepared by the hydrolysis of tetraethoxysilane (TEOS) employing sodium phosphate solution. The molecular precursor was reacted with Zr(OC3H7)4 in ethanol under solvolytic condition to yield nano precursor material of NASICON. This material was annealed at high temperature to yield phase-pure NASICON. The molecular precursor was characterized using 31P NMR, FTIR spectral data, powder XRD pattern and TG/DTA studies. The structure of the molecular precursor was deduced from the powder XRD data, which indicates the presence of edge sharing tetrahedral arrangement of −O−Si−O−P−O−Si− chain. The NASICON precursor material was characterized using TG/DTA, FTIR, TEM, SEM, MAS 31P NMR and XRD. The conductivity of the synthesized NASICON material was measured using the pellet annealed at 900 °C and was found to be 5.5 x10−3 S cm−1. The details on the preliminary investigation are presented in this paper.