Highly Sensitive Platinum Doped Nano SnO2 Based Thick Film CO Sensors

Abstract

Synthesis of nanocrystalline SnO₂ is carried out in a quartz tube furnace using thermal oxidation process at optimized temperature of 900 ºC. Synthesized nanophase SnO₂ powder is used to fabricate thick film resistors using screen printing technology. The surfaces of the thick film resistors are modified by dip coating in platinum chloride solution of optimized 0.15 M for time period of 5 min. Sintering of the films is carried out at 750 ºC in a muffle furnace. The sensors are tested for 100 ppm concentration of CO. The sensors shows highest sensitivity towards CO at 120 ºC and it is five times higher than undoped SnO₂ sensors. The characterization of the sensors is done using XRD, EDAX and SEM. The sensors are found to be extremely stable and repeatable with a response and recovery time of 10 and 52 s.