High Performance Micro CO Sensors Based on ZnO-SnO2 Composite Nanofibers with Anti-Humidity Characteristics
YUE Xue-Jun1,2, HONG Tian-Sheng1, XIANG Wei2**, CAI Kun1, XU Xing1
1Key Laboratory of Key Technology on Agricultural Machine and Equipment (Ministry of Education), Engineering College, South China Agricultural University, Guangzhou 510642 2Faculty of Engineering and Surveying, University of Southern Queensland, Toowoomba QLD 4350, Australia
Abstract：ZnO-SnO2 composite nanofibers are synthesized via an electrospinning method and characterized by x-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Micro sensors are fabricated by spinning the nanofibers on Si substrates with Pt signal and heater electrodes. The sensors with small areas (600 μm×200 μm) can detect CO down to 1 ppm at 360°C. The corresponding sensitivity, response time, and recovery time are 3.2, 6 s, and 11 s, respectively. Importantly, the sensors can operate at high humidity conditions. The sensitivity only decreases to 2.3 when the sensors are exposed to 1 ppm CO at 95% relative humidity. These excellent sensing properties are due to combining the benefits of one-dimensional nanomaterials and the ZnO-SnO2 grain boundary in the nanofibers.
2012, Vol. 29 
