Exploring the sensitivity of Hf2CO2 towards H2S: a DFT study

The adsorption sensitivity of perfect, vacancy-defected and transition-metal (TM) doped Hf2CO2 towards H2S molecule was investigated using density functional theory (DFT). The H2S molecule was weakly adsorbed on the perfect Hf2CO2 substrate, and the appearance of O-vacancy improved the activity of Hf2CO2. The introducing of TM-dopant (Ti, Cr and Ni) enhanced the adsorption stability of the H2S molecule, which also enriched the magnetic properties of Hf2CO2. In addition, the density of states diagrams indicated that the improvement of adsorption was attributed to the hybridisation between TM-d orbital and H2S molecule. The findings can provide novel insights to develop MXene-based H2S gas detection devices.