Titanium Dioxide and Tin Oxide Composite for so2 Gas Sensors

Wednesday, 27 May 2015
Salon C (Hilton Chicago)


We present the synthesis and utilization of semiconducting metal oxide composites of SnO2 and TiO2 composites (ST) to serve as a SO2 sensor for a range of applications including carbon capture and storage (CCS), enhance oil recovery (EOR) etc. ST-series pellets were prepared by conventional solid state synthesis approach (~700 oC in air), where the size of the pellet was ~1 cm in diameter. The chemical and thermal stability was demonstrated by employing scanning electron microscopy (SEM) and powder X-ray diffraction (PXRD). The average grain size of as-prepared ST composites was obtained in few nanometers. The as-prepared ST pellets were tested for the sensing properties of SO2 gas in ppm level. The effect of temperature was studied to optimize the operating temperature using Pt electrodes as current collector by applying a constant external potential (~100 mV). As-prepared ST2575 with 0.25 mol % SnO2 exhibited an excellent sensing properties for SO2 (10-40 ppm) at 450 oC. For the sensing measurements, SO2 gas was diluted in N2 gas by maintaining the total flow rate at 100 sccm. The t90 (90% of response time) for ST2575 was found to be ~5 mins. The stability of the sensor was satisfactory for gas sensing measurements in optimized conditions.