A DFT study of Zr2CO2/MoS2 heterostructures as gas sensors to HCN

The adsorption behavior of HCN molecule on perfect, O-vacancy defected, transition metal (TM) doped Zr2CO2/MoS2 heterostructures was explored using density functional theory (DFT). Various adoption sites and styles were examined, and the results indicated that HCN molecule was weakly adsorbed on the perfect Zr2CO2/MoS2 heterostructures. After the introducing of O-vacancy in Zr2CO2 layer, the activity of Zr2CO2/MoS2 was improved. TM-doping (Ti, Cr, Mn, Fe, Co, and Ni) enriched the magnetic properties of Zr2CO2/MoS2 substrates, which also enhanced the adsorption stability of the HCN molecule. Interestingly, the Cr- and Fe-doped Zr2CO2/MoS2 were conductors, which exhibited half-metal state by adsorbing HCN. Furthermore, the appropriate adsorption energy, charge transfer, and recovery time suggested that O-vacancy defected Zr2CO2/MoS2 and Ni-doped heterostructures could operate as effective sensors to detect HCN gas.