Room temperature Cl2 sensing using thick nanoporous films of Sb-doped SnO2

Thick film resistive Cl-2 sensors were fabricated using SnO2 doped with Sb. The nanocrystalline powders of Sb-doped SnO2 synthesized by a sol-gel method were compressed into an 800 mu m thick pellet. The fabricated sensors were tested against gases like Cl-2, Br-2, HCl, NO, NO2, CHCl3, NH3 and H-2. The highest response to Cl-2 was achieved in 0.1% Sb doping where an exposure to 3 ppm of Cl-2 gas led to a 500-fold increase in device resistance. The high sensitivity to Cl-2 is accompanied by minor interference due to other gases at room temperature. It was found that the SnO2 doped with 0.1% Sb exhibited high response, selectivity (>100 in comparison to the gases described above) and short response time (similar to 60 s) to Cl-2 at 3 ppm level at room temperature.