Effect of {010} crystal facets of Bi2MoO6 and 1D/2D heterostructures for conductometric room temperature NH3 gas sensors

High working temperature and the insufficient limits of detection limit the broad applications of semiconductor chemiresistive gas sensors. Herein, pure Bi 2 MoO 6 nanosheets and a series of one-dimensional/two-dimensional (1D/2D) multi-walled CNTs/Bi 2 MoO 6 nanocomposites were developed via a facile hydrothermal route for room-temperature ammonia monitoring. The as-synthesized samples were characterized by various analytical techniques. 0.5 wt% MWCNTs/Bi 2 MoO 6 nanocomposites showed the best sensing properties to 10–50 ppm NH 3 , including low limit of detection (157 ppb), high response (R a /R g = 44.2 @ 50 ppm), good selectivity, reproductivity, and anti-humidity sensing ability. The enhanced gas sensing mechanism was proposed based on the synergetic effect of high-energy crystal facets, modified surface characteristics and p-n heterojunction . Density functional theory (DFT) studies were also carried out to further clarify the gas sensing mechanisms. This work provides a practical approach to design and fabricate high-precision gas sensors working at room temperature .