First-Principles Study of Gas Molecules Adsorption on Ti-Doped Sns2

This study examines the geometric properties of intrinsic SnS2 and SnS2 doped with Ti at the atomic site of Sn using first-principles computations. Additionally, it investigates the adsorption behaviour of three gases, namely CO, NO2 and NO, on the surfaces of these two materials. Three different adsorption sites were tested for each individual gas molecule and the most favourable adsorption site was identified. To gain insights into the adsorption mechanism many parameters were computed, including adsorption energy, energy band structure, transmitted charge, recovery time and density of states. Previous studies have indicated that the adsorption capacity of CO gas molecules on the intrinsic form of tin disulphide SnS2 is rather low. Conversely, the adsorption capacity of NO and NO2 on intrinsic SnS2 is considerably high. The stability of SnS2 doped with Ti in place of Sn atoms is rather high, concurrently leading to varied degrees of increased adsorption energy for these three gas molecules on its surface. The findings indicate that the substitution of Sn atomic sites with Ti and the introduction of SnS2 doping lead to enhanced adsorption capabilities of the SnS2 material. Simultaneously, the practicality of its preparation procedure renders it a viable candidate for utilisation as a constituent material in gas sensor applications.