dc and ac response of SnO2 sensor to CO

A SnO2 layer was prepared by an electrodeposition process, followed by an oxidation step. The SnO2 layer was porous, highly pure and of cubic crystalline structure. dc potential and ac impedance methods were used to detect the sensor response of the SnO2 layer to CO in air and in H2SO4 (aq). In air the sensor response increased with increasing temperature and revealed the largest values at 623 K and in H2SO4 (aq) the response started from room temperature and sensed a CO concentration as low as 100 ppm. The ac impedance method was promising to detect the sensor response of SnO2 to CO.