Programme

O.4 -- Oral, VCTP-46

Date: Monday, 4 October 2021

Time: 14:30 - 14:50

First-principles study on the absorption of aceton, ethanol, and propanal on WS2 monolayer

Tran Quang Huy (1), Tran Thi Nhan (2), Luong Thi Theu (3), Van An Dinh (4)

(1) Faculty of Physics, Hanoi Pedagogical University 2, Hanoi, Vietnam (2) Hanoi University of Industry, 298 Cau Dien, Hanoi, Vietnam (3) Institute of Applied Technology, Thu Dau Mot University, Binh Duong Province, Vietnam (4) Department of Precision Engineering, Graduate School of Engineering, Osaka University, Osaka 565-0871, Japan

This presentation reports the adsorption mechanism of the Volatile Organic Compounds (VOCs) on the monolayer WS2 using the density functional theory (DFT). To characterize the adsorption of there VOC molecules (acetone, ethanol, and propanal) and the WS2 substrate, we adopted the non-empirical van der Waals DFT simulations. The global minimum energy configuration, binding energy and adsoption energy of VOC molecules adsorbed on WS2 were determined using the Computational DFT-based Nanoscope tool [1] in order to explore the binding possibilities of VOC molecules on the surface of WS2. The adsorption energy profiles were calculated by employing the five van der Waals functionals, namely revPBE-vdW, optPBE-vdW, vdW-DF2, optB88, and optB86b. The results showed that the adsorption energy increases in the following sequence optPBE < optB88 = optB86b < revPBE < vdW-DF2. Among the above three VOC molecules, acetone is the most sensitive gas to be adsorbed by WS2 with the largest adsorption energy (390meV) and the largest reduction in the bandgap (33meV, i.e 1.71% in comparison with the non-adsorption). Detailed discussions on the interaction between VOC molecules and the WS2 substrate in terms of charge transfer, electronic structure, substrate deformation are also given. [1] Computational DFT-based Nanoscope, developed by Van An Dinh (2017).

Presenter: Tran Quang Huy