A first-principles investigation on the adsorption of octanal and nonanal molecules with decorated monolayer WS2 as promising gas sensing platform

Abstract

With the broad applications of two-dimensional transition, metal dichalcogenides in gas sensing prompt us to investigate the adsorption and gas sensing properties of the bare and metal-decorated tungsten disulfide (WS2) interaction with nonanal and octanal gas molecules by using first-principles methods. In this regard, first-principles calculations based on density functional theory (DFT) have been employed to study the detection of nonanal and octanal as well-known breast cancer biomarkers. The results showed that the pristine WS2 monolayer is not appropriate to develop gas sensors for the target. Based on the detailed DFT calculations, decoration of the WS2 surface with Ni and Pt could enhance gas detection and sensitivity and tune the energy bandgap. The present results suggested that the adsorption energy of nonanal and octanal has been increased to −2.59 and −2.34 eV after interaction with Ni-decorated WS2. In addition, sensitivity has been enhanced significantly, and the recovery time of 7.76 s for Ni-decorated WS2 was achieved after interaction with octanal gas. As a result, the decorated WS2-based nanosensor might be an auspicious platform for gas detection. Undoubtedly, this work can open up a prospect for the use of excellent Ni-/Pt-decorated WS2 materials to achieve high-efficiency detection of nonanal and octanal gas molecules.