Gas sensing properties of platinum dispersed-TiO2 thin film derived from precursor

Metal-organic precursor solution for coating glass substrates was synthesiz ed using a Ti alkoxide derivative, amino acid, platinum salt and methanol a s a solvent. Suitable addition of TiO2 sol remarkably increased the gas sen sitivity of the resultant platinum dispersed-TiO2 thin film because of the formation of fine pores around nano-sized TiO2 grains. A thin film fired at 450 degrees C under a reducing atmosphere was not sensitive to reducing ga ses such as CO and CH4, but revealed high selectivity and sensitivity to H- 2 at 200 degrees C. This thin film also showed high selectivity to trimethy lamine (TMA) and NH3. The selection of an appropriate starting metal-organi c precursor and addition of titania sol were very effective in forming the desired microstructure with improved gas sensing properties. (C) 2000 Elsev ier Science S.A. All rights reserved.