Nitrogen-Containing Tubular Hollow Carbon Frameworks: A Nongraphitic Carbon for a Robust Room Temperature Hydrogen Gas Sensing Application

We report, for the first time, polypyrrole-derived nitrogen-containing tubular hollow carbon (NTHC) frameworks for hydrogen (H2) gas sensing application. NTHC was synthesized simply by pyrolysis of tubular polypyrrole nanostructure, which developed carbon nanostructure of high surface area with numerous micromesopores. The surface of the carbon nanostructure was uniformly decorated with platinum nanoparticles (Pt NPs). The Pt/NTHC sensor, fabricated using a facile drop-casting method, shows good repeatability and complete recovery at room temperature and achieves twofold higher sensitivity compared to Pt NPs dispersed multiwalled carbon nanotubes. The sensor shows interesting gas sensing behavior (conversion of p-type to n-type) during exposure to H2. The possible role of N-doping type in the sensing behavior is discussed.