Development of MoS2 doping strategy for enhanced SO2 detection at room temperature

Abstract

Despite significant efforts to limit the use of fossil fuels, SO2 remains a major air pollutant that adversely affects human health and the environment, especially in heavily industrialized regions of developing countries. Consequently, effective and sustainable methods of SO2 monitoring remain vital issues for detector development. However, despite decades of progress, current solutions based on resistive sensors remain limited by poor sensing performance of semiconducting materials when operated at room temperature and thus suffer from high power consumption due to heating. One solution could be to employ novel 2D semiconductor nanomaterials like MoS2, which have shown good room-temperature performance for gases such as NO2 and NH3. However, they have also shown limited response to other gases, which, on the other hand, can be improved by substitutional doping. Consequently, this work investigates, employing density functional theory, the doping of MoS2 with Si, P, Cl, Ge, and Se to improve its SO2 sensing capability. The results show that P, Cl, and P+Cl doping facilitates all desired effects with molecule-sheet charge transfers enhanced by over 300%, and moderate binding energies that enable effective surface diffusion of SO2 at 300 K.