High Performance Acetone Sensor Based on Au Modified ZnO Nanosheets Fabricated via Solvothermal and Ultrasonic Reduction Method

Au modified ZnO nanosheets with excellent acetone sensing were successfully fabricated via solvothermal routine and ultrasonic reduction method. The structure, morphology and composition of the as-synthesized products were characterized by x-ray diffraction, field-emission electron microscopy, transmission electron microscopy and energy dispersive x-ray spectroscopy. Gas sensors based on the as-prepared products with different Au content were tested in detail. The results indicate that ultrasonic reduction can effectively drive in situ nucleation and growth of gold nanoparticles on the surface of ZnO, resulting in a close contact phase boundary between Au nanoparticles and ZnO nanosheets that is very beneficial to the material’s gas sensitivity. Au modification can greatly enhance the gas sensing ability of ZnO sensors. Specifically, the sensor based on 0.5 at.% Au modified ZnO exhibits the highest response, quickest response and satisfactory selectivity towards acetone. The response increases to 164–100 ppm acetone at 275°C, which is more than about 4.5 times the response (37) of pure ZnO. This study demonstrates that Au modified ZnO has great potential for acetone detection in industrial applications.