Development of microstructure CO sensor based on hierarchically porous ZnO nanosheet thin films

A novel microstructure sensor based on hierarchically porous ZnO nanosheet thin films has been successfully applied to detecting CO with high response and fast recovery characteristics. A microstructure sensor based on hierarchically porous ZnO nanosheet (NS) thin films has been achieved by using a facile two-step solution phase method. The transparent ZnO seed-layer covered on both the conducting electrodes and the insulating SiO2 spacer regions acts as lattice-matched template, on which the assembly of ZnO NS thin films has been subsequently completed via a facile solvothermal process. The phase purity, morphology, and structure of the as-prepared NSs are investigated, and the results reveal that ZnO NSs, grown vertically on the substrate, exhibit hierarchically porous nanostructure with subunits of nanoparticles. The gas-sensing properties exhibit not only high response to CO with the response time of 25s, but also low cross response to common interference gases at the operating temperature of 300°C.