Theoretical study on W-Co3O4 (1 1 1) surface: Acetone adsorption and sensing mechanism

Volatile organic compounds are highly toxic, and need advanced sensing technology for detection. The morphology, composition and surface characteristics are critical parameters to enhance the gas sensing of metal oxide-based sensors. However, the experimental results only reflect macroscopic phenomena, but cannot explain the sensing mechanism in depth. In this study, the acetone sensing performance of pristine and W modified Co3O4 (1 1 1) surface have been studied using DFT methods. Various adsorption sites have been investigated on top of the clean and O adsorped W-Co3O4 (1 1 1) surfaces. Our results show the decorated W atom in direct vicinity of pre-adsorbed oxygen is the best site for acetone adsorption. The modification of W atom makes energy band-gap narrower, alters the electronic properties, and enhances the number of transferred electrons. Our study provides a theoretical basis for finding better modified p-type semiconductor sensors toward acetone.