Low-dimensional HfS as SO adsorbent and gas sensor: effect of water and sulfur vacancies.

First-principles based on density functional theory (DFT) calculations were performed to investigate the interaction of two-dimensional (2D) HfS with SO, a harmful gas with implications for climate change. In particular, we describe the effect of water and sulfur vacancies on such interaction. The former promotes the physisorption of SO, whereas the latter promotes its chemisorption with structural changes on the absorbing surface.