Design of selective gas sensors using electrospun Pd-doped SnO2 hollow nanofibers

Undoped and Pd-doped SnO2 hollow nanofibers were prepared by single capillary electrospinning and their gas sensing characteristics for 100 ppm H2, 100 ppm CO, 500 ppm CH4, and 100 ppm C2H5OH were investigated. The gas responses and responding kinetics were closely dependent upon the sensor temperature and Pd doping concentration. The undoped and 0.08 wt% Pd-doped SnO2 nanofibers showed selective detection to C2H5OH at 385 and 440 °C. In the 0.4 wt% Pd-doped SnO2 nanofiber sensor, the selective detection to CH4 and H2 was optimized at 440 °C with the minimum cross-sensitivity to C2H5OH. The tuning of gas selectivity via the combinatorial control of Pd doping concentration and sensor temperature in the electrospun hollow nanofibers was discussed in relation to the gas sensing mechanism.