Preparation and Enhanced Acetone-Sensing Properties of ZIF-8-Derived Co3O4@ZnO Microspheres

In this work, ZIF-8-derived Co3O4@ZnO microspheres were prepared by a liquid-phase concentration-controlled nucleation strategy. The results of the material characterization showed that Co3O4@ZnO microspheres were obtained, and the surface structure could be controlled with the concentration of the ligand. Compared with pure Co3O4microspheres, the operating temperature of optimized Co3O4@ZnO microspheres increased by 90 °C after the gas-sensing test. The response to 50 ppm acetone of Co3O4@ZnO microspheres was 4.5 times higher than that of pure Co3O4, and the detection limit reached 0.5 ppm. Meanwhile, Co3O4@ZnO microspheres showed a shorter response-recovery time and better selectivity. The enhanced-sensing mechanism of the ZIF-8-derived Co3O4@ZnO microspheres was also analyzed.Keywords:gas sensor;microspheres;MOF;ZIF-8