Developing high-temperature hydrogen (H2) sensors with fast response speed is urgently demanded in harsh application environments, especially for chemical industries and the aerospace field. Herein, we have reported a facile strategy to synthesize Mn-doped In2O3 hollow nanotubes (Mn-In2O3) by solvothermal and annealing route using In-MOFs as precursors. The experimental results indicate that the obtained products possess hollow nanotube structures with plenty of holes and Mn doping greatly boosts the gas-sensing performance of In2O3-based sensors towards H2. In particular, the responses of 3 mol% Mn-In2O3 are 2.57 and 2.3 towards 50 ppm H2 at 360 oC and 400 oC, respectively, which are much higher than those of bare In2O3 hollow nanotubes. Besides, the sensor based on 3 mol% Mn-In2O3 exhibits a low limit of detection (25 ppb), excellent selectivity, rapid response/recovery speed (~4 and ~15s@20 ppm), and excellent stability at high temperature (360 oC). Such enhancement of H2-sensing properties can be put down to the hollow structure derived from In-MOFs and abundant oxygen vacancy defects produced by Mn doping. The Mn-In2O3 hollow nanotubes could be regarded as promising materials for selectively detecting H2 in a wide range of concentrations.
