Gas sensing and photoluminescence of flower-like ZnO hollow microspheres synthesised using facile solvothermal method

Abstract

Flower-like ZnO microspheres have been solvothermally synthesised using zinc acetate and glycerol as starting materials. Scanning electron microscopy and X-ray powder diffraction results show that the 5 μm diameter as synthesised ZnO microspheres were orderly assembled by numerous nanorods at a radiate posture with a diameter of 70 nm. The gas sensing measurement indicates that the microsphere based sensor has a good linear relationship between gas content and sensitivity, and the maximum sensitivity of 103·24 and 26·70–500 ppm ethanol and acetone at a relatively low temperature respectively. Moreover, its response and recovery time to ethanol and acetone were 1 s and 2, 7 and 9 s respectively. In addition, the photoluminescence measurement shows that the microspheres have an obvious UV (370–400 nm) and visible emission (∼480 nm).