Room Temperature Hydrogen Sensor of Mace-Like In₂O₃@ZnO Microtubules

In this paper, mace-like In2O3@ZnO microtubes were obtained from MIL-68/ZIF-8 as a precursor via a simple hydrothermal and template method. The resulting microtubules were characterized and analyzed by a series of methods (XPS, SEM, TEM, and XRD). Compared to pure In2O3 microtubes, the In-2Zn (In2O3:ZnO of 2:1) sensor was found to have a higher response (6.67) to 10,000 ppm of H2 at room temperature (25 °C) and faster response/recovery time (178/338 s). The improvement of hydrogen sensing performance was mainly attributed to the porous structure of the composite and large specific surface area due to the mace-like structure of abundant nanowires grown on the microbars. Besides, the formation of an n-n heterojunction at the interface of In2O3 and ZnO was also an important factor for performance improvement. The sensing property indicated that the mace-like In2O3@ZnO nanocomposite was promising for the detection of H2 at room temperature.