Effect of Er doping on flame-made SnO2 nanoparticles to ethylene oxide sensing

In this research, 0.05-2 wt% Erbium (Er)-doped SnO2 nanoparticles were synthesized for the first time by flame spray pyrolysis and their gas-sensing properties were methodically characterized. The structural analyses based on scanning/transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, nitrogen sorption analysis, and photoluminescent spectroscopy suggested that nanocrystalline SnO2 nanoparticles were substitutionally doped with Er+3 species. The sensing films were prepared by powder pasting and spin-coating processes and their gas-sensing performances were evaluated in the temperature range of 200-400 degrees C under dry and humid air conditions. The test results reported that the optimum Er content of 0.1 wt% provided the optimally high and selective response of 347 to 30 ppm C2H4O with a short response time of similar to 2 s and a low detection limit of 18 ppb, which were substantially better than those of undoped one at the best working temperature of 350 degrees C. The high selectivity was confirmed against CH2O, C3H6O, C2H5OH, NH3, C2H2, C2H4, H-2, CH4, H2S, H2O and CO. Besides, the influence of humidity on C2H4O response of Er-doped SnO2 sensor was moderately low over a wide relatively humidity range of 0-80 %. The gas-sensing mechanisms were proposed with a new model describing the catalytic roles of p-type Er dopants to ethylene oxide adsorption.

Automated summary

Erbium-doped SnO2 nanoparticles with different Er concentrations were synthesized and their gas-sensing properties were investigated. The sample with 0.1 wt% Er exhibited the best response to C2H4O, showing significantly improved performance compared to the undoped sample.