MOF-derived Co 3 O 4 nanoparticles over direct grown ZnO nanoflower on ceramic for CO sensor with high selectivity

ZnO nanoflower was directly fabricated on ceramic and then Co 3 O 4 was grown in-situ on ZnO nanoflower by a MOF-derived method. Co 3 O 4 nanoparticles were successfully coated on the surface of ZnO nanoflower to develop a sensor for the detection of carbon monoxide. Notably, the Co 3 O 4 /ZnO sensor exhibits an outstanding response of 38 % to 100 ppm CO at 210 ℃ with a fast response/recovery time (38 s/50 s). In addition, the sensor showed excellent selectivity for CO, which is 14 times better than for the second gas (500 ppm CO and NH 3 ). In the meantime, the sensor's response remained a stable value when the 100 ppm CO is mixed with 100 ppm H 2, CH 4 and HN 3, respectively. The prominent CO sensing performance of the sensor is attributed to its unique structure charaterastics of nanoflower and the constructed heterostructure, which provides a large surface area and abundant active sites. Therefore, the sensor based on MOF-derived Co 3 O 4 nanoparticles directly on ZnO nanoflower have promising application for constructing high performance CO sensor in the detection domain.