The effect of MoS2 modified with Transition Metal (Fe, Co, Ni, Cu) on H2O adsorption: A first principle study

Abstract

MoS2 has great potential as a humidity sensor, and doping is considered the most promising method to enhance the adsorption of H2O molecule by MoS2. Unfortunately, vacancy doping sacrifices the stability of the material while enhancing adsorption efficiency. Here, we use Fe, Co, Ni, Cu to modify the surface of MoS2 and study the adsorption characteristics of H2O molecule on MoS2 before and after modification. The first principles calculations further indicate that partial transition metal (TM) doping can induce spin polarization in MoS2. Spin polarization further enhances orbital hybridization between atoms, thereby improving adsorption performance. On the basis of qualitative analysis of thermodynamic stability and electrical properties, quantitative analysis was conducted on adsorption energy and charge transfer. The results indicate that the adsorption energy, in descending order, is Fe-MoS2 > Co-MoS2 > Ni-MoS2 > Cu-MoS2 > MoS2. Compared with MoS2, Fe-MoS2 has the best adsorption effect among the four doping systems, with an adsorption energy increase of 22.1 times. Importantly, simulations of desorption time have demonstrated that Fe-MoS2 and Co-MoS2 exhibit a significant reduction in desorption time with increasing temperature and can be rapidly recycled.