NiO nanoparticle decorated SnO2 nanosheets for ethanol sensing with enhanced moisture resistance
In a high relative humidity (RH) environment, it is challenging for ethanol sensors to maintain a high response and excellent selectivity. Herein, tetragonal rutile SnO2 nanosheets decorated with NiO nanoparticles were synthesized by a two step hydrothermal process. The NiO decorated SnO2 nanosheet based sensors displayed a significantly improved sensitivity and excellent selectivity to ethanol gas. For example, the 3 mol% NiO decorated SnO2 (SnO2 3Ni) sensor reached its highest response (153 at 100 ppm) at an operating temperature of 260 degC. Moreover, the SnO2 3Ni sensor had substantially improved moisture resistance. The excellent properties of the sensors can be attributed to the uniform dispersion of the NiO nanoparticles on the surface of the SnO2 nanosheets and the formation of NiO SnO2 p n heterojunctions. Considering the long term stability and reproducibility of these sensors, our study suggests that the NiO nanoparticle decorated SnO2 nanosheets are a promising material for highly efficient detection of ethanol.Nanomaterials: Novel material offers improved ethanol sensingResearchers in China have developed a new material which is a more sensitive and selective ethanol sensor than existing technologies and which maintains its performance at high humidity. Fei Wang and colleagues at the Southern University of Science and Technology improved the sensing activity of tin oxide nanosheets by decorating them with nickel oxide nanoparticles. This altered the change in resistance in response to ethanol gas, increasing the material's sensitivity to ethanol. The sensor was also selective, responding more strongly to ethanol than to methanol, acetone, or other gases. These decorated nanosheets maintained their performance over four weeks of testing and retained 71% of their response at humidity levels that reduced the performance of tin oxide alone to 32% These findings demonstrated that nickel oxide decorated tin oxide nanosheets are a promising material for improved ethanol sensors.
Microsystems nanoengineering