MOF-derived Co3O4 nanoparticles over direct grown ZnO nanoflower on ceramic for CO sensor with high selectivity

ZnO nanoflower was directly fabricated on ceramic and then Co3O4 was grown in-situ on ZnO nanoflower by a MOF-derived method. Co3O4 nanoparticles were successfully coated on the surface of ZnO nanoflower to develop a sensor for the detection of carbon monoxide. Notably, the Co3O4/ZnO sensor exhibits an outstanding response of 38 % to 100 ppm CO at 210 celcius 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 NH3). In the meantime, the sensor's response remained a stable value when the 100 ppm CO is mixed with 100 ppm H2, CH4 and HN3, 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 Co3O4 nanoparticles directly on ZnO nano-flower have promising application for constructing high performance CO sensor in the detection domain.