Enhanced n-butanol sensing performance of SnO2/ZnO nanoflowers fabricated via a facile solvothermal method

Abstract

High-performance gas sensors have important application prospects in the detection and monitoring of toxic and harmful gases that exist in the environment and workshop. Herein, SnO2/ZnO nanoflowers with core-shell like structure were successfully fabricated by a two-step solvothermal method. Morphology and mineral phase characterizations demonstrate that the nanoflowers, composed of a SnO2 flower core in a diameter of about 50 nm and ZnO nanoparticles embedded in the interstice of SnO2 petals, has a novel mesoporous hierarchical structure with pore size distributed in about 3 nm and 30 nm and a specific surface area of 36.474 m2/g, benefitting to gas-sensing. The results reveal that, compared to pure SnO2 nanoflowers, the optimal SnO2/ZnO (Zn/Sn is 5%) based gas sensor shows 2.7-fold sensing enhancement, fast response (3 s), long-term stability toward n-butanol. It has an outstanding selectivity to n-butanol rather than other gas, its response toward 100 ppm n-butanol at 200 °C is up to 13, 34, 15 and 32 times of that to acetone, xylene, ammonia and carbon monoxide respectively. Hence, SnO2/ZnO nanoflowers can be considered as a practical sensing material for n-butanol detection.