Programme

O.11 -- Oral, VCTP-46

Date: Tuesday, 5 October 2021

Time: 11:20 - 11:40

Aldehyde Gas Absorption on Monolayer WSe_{2}

Tran Thi Nhan (1), Tran Quang Huy (2), Luong Thi Theu (2), Dinh Van An (3)

(1) Hanoi University of Industry, 298 Cau Dien street, Bac Tu Liem, Hanoi; (2) Hanoi Pedagogical University of Number 2, Xuan Hoa, Vinh Phuc; (3) Department of Precision Engineering, Graduate School of Engineering, Osaka University, Osaka, Japan

We present a systematically non-empirical van der Waals density functional study on the adsorption of the aldehyde gas molecules, including methanal, propanal, and methacrolein, on the monolayer (ML) WSe_{2}. The most stable configuration of the gas-WSe_{2} adsorption systems was explored by carefully optimizing the geometry structure and calculating the interaction energy as a function of spatial coordinates based on the Computational DFT-based Nanoscope tool. Simultaneously, the diffusion paths of the gas molecules on the ML WSe_{2} were predicted. The adsorption mechanism and charge transfer inside the adsorption systems are discussed in great details. It was found that these aldehyde gases are physisorbed on WSe_{2} with a relatively high adsorption energies and their dipole polarization is enhanced due to the great amount of charge transfer from Carbon to Hydrogen atoms. The adsorption causes a slightly lattice deformation, the changes in the electronic structure and consequently the electronic properties of ML WSe_{2}. The gas molecules receive charges due to the fact that the charge donation of the Se atoms is larger than the charge backdonation of the oxygen atom. ML WSe_{2} is predicted to interact with the three gases by van der Waals interaction and may be used as a physic-resistance aldehyde gas sensing devices with high performance.

Presenter: Trần Thị Nhàn