Programme

P.15 -- Poster, VCTP-47

Date: Tuesday, 2 August 2022

Time: 08:30 - 10:00

A first-principles investigation of methanal gas absorption on WS2 monolayer

Tran Quang Huy (1), Tran Thi Nhan (2), Luong Thi Theu (3), Phung Viet Bac (4), Van An Dinh (5)

(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) VNU Vietnam Japan University, Luu Huu Phuoc, My Dinh I, Hanoi, Vietnam; (5) Department of Precision Engineering, Graduate School of Engineering, Osaka University, Osaka 565-0871, Japan

In this work, we investigate the adsorption mechanism of methanal (the simplest aldehyde) molecule on the monolayer WS2 surface using the density functional theory (DFT). To characterize the adsorption of this gas molecule and the WS2 substrate, we adopt DFT simulations with taking into account the van de Waals (vdW) interactions. The global minimum energy configuration and binding energy of methanal adsorbed WS2 were determined using the Computational DFT-based Nanoscope tool in order to image the binding possibilities of gas molecule adsorbed on the surface of WS2. The adsorption energy profiles were calculated by employing five non-emperical vdW functionals, namely revPBE-vdW, optPBE-vdW, vdW-DF2, optB88, and optB86b. The detailed discussion on the interaction between methanal gas molecule and the WS2 substrate in terms of charge transfer, altered density of states and band structure, substrate deformation, and a series of calculated parameters such as adsorption distance, response length, recovery time, work function, bond length and angle will be given. We found that the adsorption of methanal on the WS2 substrate is physical with an adsorption energy of 224 meV. Upon adsorption, the bandgap is reduced up to 21 meV, and the 0.18 electron transfer from the substrate to gas.

Presenter: Huy Tran Quang