Tuned Sensing Properties of Metal-Modified Carbon-Based Nanostructures Layers for Gas Microsensors

摘要

In this work, carbon nanomaterials have been prepared by CVD technology onto alumina substrates, coated by nanosized Co-catalyst at different thickness (2.5 nm and 7.5 nm) and used for a simple gas sensor device. The surface has been functionalized with sputtered Pt-nanocluster at a tuned loading of 8, 15 and 30 nm. The response of the chemiresistors in terms of p-type electrical conductance has been investigated as a function of the thickness of the Pt-nanoclusters towards different gases (NO_2, NH_3, CO, CH_4, CO_2). Furthermore, the effect of the temperature ranging from 20℃ to 250℃ on the sensor response has been addressed as well. Additionally, a short-term stability of the carbon nanomaterials based sensor towards NO_2 gas detection has been investigated for a 2-month period. The gas sensors based on Pt-modified carbon nanomaterials exhibit higher sensitivity compared to unmodified material, fast response, reversibility, repeatability, moderate drift of the baseline signal, sub-ppm range detection limit.