SnO2 core-shell hollow microspheres co-modification with Au and NiO nanoparticles for acetone gas sensing

SnO2 core-shell hollow microspheres co-modified with Au and NiO nanoparticles (Au-NiO@SnO2) were successfully fabricated for use as an acetone gas sensor. The SnO2 core-shell hollow microspheres were prepared by a facile chemical precipitation method using tin tetrachloride pentahydrate (SnCl4 center dot 5H(2)O) and 4-methylimidazole as the primary raw materials. The co-modification with Au and NiO nanoparticles was carried out by a simple chemical reduction approach. Compared with Au@SnO2, NiO@SnO2, and pure SnO2, the AuNiO@SnO2 core-shell hollow microspheres exhibited enhanced gas sensing properties toward acetone including high response, fast response-recovery speed, good selectivity, low detection limit, and work stability. The improved gas sensing performance was attributed to the unique SnO2 core-shell hollow microsphere structure, the p-n heterojunction between NiO and SnO2, and the catalytic action of Au nanoparticles. (C) 2020 Elsevier B.V. All rights reserved.