Abstract
Bismuth molybdate (Bi2MoO6) is a multi-elemental metal oxide of the molybdate series, which could show great potentials for the application of gas sensors with outstanding sensitivity. Oxygen vacancy is a ubiquitous defect in this class of materials, and their introduction may be an effective strategy to regulate gas sensing performance. In this work, coupling investigations of experiment and first-principles calculations were performed to gain insight into the effect of oxygen deficiency on the gas-sensitive properties of Bi2MoO6. The oxygen vacancies existed in surface lattice changes the adsorption reaction pathway of the gas by modifying the coordination state and geometry of lattice oxygens, which is more favorable for the adsorption or dissociation of target gas and oxygen molecule. Further, the oxygen-deficient Bi2MoO6 was synthesized experimentally by a one-step solvothermal method. The gas sensor based on the oxygen -deficient Bi2MoO6 could respond to NH3 gas sensitively and selectively, with a high response value of 53.97 (5 ppm) at the optimal temperature of 75 degrees C. Combining the clarifications by first-principles calculations, the satisfactory sensing performance exhibited experimentally could be understood based on the promotion of adsorption activity and adsorption capability. (C) 2021 Elsevier B.V. All rights reserved.
NSTL
Elsevier