Vanadium disulfide monolayers for efficient sensing of target volatile organic compounds

The presence of volatile organic compounds (VOCs) in the atmosphere seriously threatens the environment and human health. Therefore, designing efficient nanosensors to detect the targeted VOCs is inevitable. In the present study, using density functional theory (DFT), the adsorption of two prominent VOCs, namely propylene oxide (PO) and crotonaldehyde (CRA), was studied on pristine and titanium/chromium (Ti/Cr)-doped vanadium di-sulfide (Ti/Cr-VS₂) monolayers in both trigonal prismatic (H) and octahedral (T) phases. Van der Waals-corrected DFT calculations revealed that the doping of the Ti atom in VS₂ is favorable in comparison with Cr doping for both phases. It was observed that the pristine VS₂ systems exhibited weak adsorption towards the above-mentioned VOCs. However, doping of Ti in VS₂ systems significantly enhanced the adsorption of PO and CRA molecules. The calculated adsorption energy of PO on the T phase of Ti-VS₂ systems was 1.66 eV, and for CRA on the H phase of Ti-VS₂ systems was 1.71 eV, respectively. Bader charge analysis showed that PO and CRA behave as charge donors to the Ti-VS₂. Upon PO/CRA adsorptions, significant changes were observed in the work function of Ti-VS₂. Based on our DFT analysis for adsorption parameters, we believe Ti-VS₂ could be a promising material for detecting PO and CRA.