Sm2O3 doped-SnO2 nanoparticles, very selective and sensitive to volatile organic compounds

Sm2O3-doped SnO2 nanoparticles were prepared by a chloride solution combustion synthesis method and their gas sensing properties for detection of various VOCs, i.e. acetaldehyde, acetone, ethanol, toluene and trichloroethylene (TCE) were investigated. The samples were characterized by XRD, BET specific surface area, SEM, EDS, and photoluminescence (PL). Sm2O3-doping causes reduction in surface area, suppression of SnO2 crystal growth, and increase in degree of agglomeration (dBET/dXRD). According to PL spectra, concentration of oxygen vacancies increases dramatically with an increase in Sm2O3 content of the samples. .% Sm2O3-doped SnO2 sample is the most sensitive sensor to acetaldehyde, ethanol and acetone and its response is about 5.5, 2.4 and 2.2 times higher than pure SnO2 for these gases, respectively. In the case of toluene and TCE, 10.0 wt.% Sm2O3-doped SnO2 sample shows the highest response and its response is about 3.0 and 3.7 times higher than that of pure SnO2 for these gases, respectively. The optimum operating temperature of Sm2O3-doped SnO2 sensors, is about 50–100 °C lower than that of pure SnO2 sensor. Moreover, with addition of 5.0 wt.% Sm2O3, selectivity to some VOCs at different temperatures improves considerably compared to pure SnO2.