A Simple Method for Production of High Aspect Ratio ZnO Nanowires with Uniform Structure for NO2 Gas Sensors

摘要

Semiconducting thin films consist of high aspect ratio ZnO nanowires with a uniform structure were prepared through thermal evaporation and vapor transportation of a mixture of highly pure ZnO and graphite powders in 1:1 weight ratio. The mixture was heated at 1100 degrees C under various flow rates of N-2 and air mixture. The surface morphology and structural characteristics of synthesized ZnO nanowires revealed a highly crystalline structure with an average diameter of about 30 nm and length of several micrometers. For sensing properties, ZnO nanowires were coated on the Pt interdigitated microelectrodes arrays and examined at operating temperatures of 150 and 350 degrees C for the detection capacity of NO2 gas. The changes in response resistance revealed that the sensor exhibited a high sensing performance for low concentrations of NO2 gas (0.5 ppm).