In2O3 nanoplates with different crystallinity and porosity: Controllable synthesis and gas-sensing properties investigation

Porous In2O3 nanoplates with polycrystalline structure (pp-In2O3 NPs) and single-crystalline structure (ps-In2O3 NPs) were synthesized through a facile solvothermal combined with a post calcination process. The gas sensing performance of the In2O3 nanoplates with different crystallinity and porosity was investigated. Compared with the pp-In2O3 nanoplates, the ps-In2O3 nanoplates exhibited significantly enhanced gas sensitivity and selectivity towards triethylamine (TEA). The enhancement of the gas response of the ps-In2O3 NPs can be attributed to the larger pore size and single-crystalline structure. Larger pore size can facilitate the target gas to diffuse into the inner surface of the sensing materials and increase the contacting chances of target gas and surface adsorbed oxygen species, while single-crystalline structure can decrease a part of grain boundary junction barrier and enhance the conductivity of the sensing film. This work would be important for further understanding the gas sensing mechanism and developing high promising In2O3 gas-sensing materials. (C) 2019 Elsevier B.V. All rights reserved.