Repealing the Responsivity to Selectivity-Compromise of Carbon Nanotube-Based Hydrogen Sensors by Polymer/Noble-Metal Functionalization

We report on heterogeneous sensor functionalization of carbon nanotube-based hydrogen sensors by Poly(4-vinylpyridin) (P4VP) polymeric encapsulation combined with (bi-)metallic catalysts. Parametrical studies unfold the influence of different functionalization architectures on the sensor's responsivities and time constants. Moreover, these studies provide fundamental insights on the underlying doping- and charge transport phenomena for repealing the responsivity/selectivity trade-off. In an optimized sensor configuration, we report on highly linear behavior from 2500 ppm down to 10 ppm and a response time below 15 s enabling safety-relevant leak detection within the whole hydrogen value chain.