Portable room-temperature self-powered/active H2 sensor driven by human motion through piezoelectric screening effect

Room-temperature high H-2 sensing has been realized from SnO2/ZnO nanoarray nanogenerator. Without any external electricity power source, the portable device can be self-powered under the driving of human motion, in which the piezoelectric output can actively act as both the power source and H-2 sensing signal. Upon exposure to 800 ppm H-2 at room temperature, the piezoelectric output voltage of the device under the same applied deformation decreases from 0.80 V (in dry air) to 0.14V, and the sensitivity is up to 471.4. The detection limit is similar to 10 ppm H-2, and the selectivity against H-2 at room temperature is very high. The excellent room-temperature H-2 sensing performance can be attributed to the coupling of the piezoelectric screening effect of ZnO nanowires and the conversion of SnO2/ZnO heterojunctions. This study can stimulate a research trend for the development of the next generation of portable room-temperature H-2 sensors. (C) 2014 Elsevier Ltd. All rights reserved.