Facile and template-free fabrication of hierarchical coral spheres for acetone gas sensors

In this paper, highly dispersed hierarchical coral spheres of CeO2/ZnO have been constructed through a facile template-free hydrothermal strategy, followed by an annealing treatment. The resulting coral spheres exhibit enhanced activity for acetone sensing compared with CeO2 or ZnO as well as excellent cyclability and long-term stability. At the optimum working temperature of 245 & DEG;C, by controlling the ratio of Ce/Zn, the highest response of the coral spheres towards 100 ppm acetone is up to 145, which is about 5.5 times that of ZnO coral spheres. The significantly improved gas sensing activity may be ascribed to the well-dispersed and assembled CeO2 nanoparticles on the surface of ZnO coral spheres and the heterojunctions between CeO2 and ZnO, which produced abundant oxygen vacancies in the CeO2/ZnO coral spheres.

Automated summary

Hierarchical coral spheres of CeO2/ZnO were prepared using a template-free hydrothermal method followed by annealing treatment. The resulting coral spheres exhibited superior acetone sensing, cycling stability, and long-term stability compared to CeO2 or ZnO. By controlling the Ce/Zn ratio, the coral spheres showed the highest response towards 100 ppm acetone at the optimum working temperature of 245°C, reaching up to 145, which was approximately 5.5 times higher than that of ZnO coral spheres. The enhanced gas sensing performance could be attributed to the well-dispersed and assembled CeO2 nanoparticles on the surface of ZnO coral spheres and the heterojunctions between CeO2 and ZnO, which generated abundant oxygen vacancies in the CeO2/ZnO coral spheres.