Lychee-like ZnO/ZnFe2O4 core-shell hollow microsphere for improving acetone gas sensing performance

Uniformly lychee-like ZnO/ZnFe2O4 core-shell hollow microspheres with average size of 2.5 mu m were successfully synthesized via one-step solvothermal self-assembly route. The core-shell hollow microspheres possessed mesoporous structure with a pore size of about 8.8 nm and the large specific surface area of approximately 54.0 m(2)/g. The effect of the Zn2+ concentration on the structure, morphology and gas-sensing property of the asprepared samples were investigated by a series of testing techniques. The gas-sensing results demonstrated that the sensors based on core-shell ZnO/ZnFe2O4 hollow microspheres showed superior gas-sensing response, rapid response-recovery to low-ppm acetone. These excellent properties might be mainly owing to the unique coreshell structure, the large specific surface area, high concentration of oxygen vacancies and the synergetic effect between ZnO and ZnFe2O4. Hence, this material can be utilized as promising gas-sensing materials in the acetone detection.