Functionalization of 1D In2O3 nanotubes with abundant oxygen vacancies by rare earth dopant for ultra-high sensitive ethanol detection

Herein, pristine indium oxide (In2O3) and rare earth (Ce, Tm, Eu, Er, and Tb)-doped In2O3 nanotubes were synthesized by a facile one-step electrospinning method. Rare-earth (RE) doping increases the number of active sites on the surface, which enhances the electrical response and gas-sensing performance of In2O3, with different RE elements causing different enhancement effects. Transmission electron microscopy elemental mapping shows a homogeneous distribution of RE elements on the whole nanotube. Analysis of the gas-sensing mechanism shows that RE doping modifies the oxygen species adsorbed on the sensor surface. Our findings promote the development of new dopant-based metal oxide semiconductors for high-performance gas sensing.