High-temperature hydrogen sensor based on MOFs-derived Mn-doped In 2 O 3 hollow nanotubes

Developing high -temperature hydrogen (H 2 ) 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 In 2 O 3 hollow nanotubes (Mn-In 2 O 3 ) 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 In 2 O 3 - based sensors towards H 2 . In particular, the responses of 3 mol% Mn-In 2 O 3 are 2.57 and 2.3 towards 50 ppm H 2 at 360 degrees C and 400 degrees C, respectively, which are much higher than those of bare In 2 O 3 hollow nanotubes. Besides, the sensor based on 3 mol% Mn-In 2 O 3 exhibits a low limit of detection (25 ppb), excellent selectivity, rapid response/recovery speed (-4 and -15 s@20 ppm), and excellent stability at high temperature (360 degrees C). Such enhancement of H 2 -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-In 2 O 3 hollow nanotubes could be regarded as promising materials for selectively detecting H 2 in a wide range of concentrations.