Computational screening for enhanced hydrogen sensing by doped-2H and pristine-1T MoS₂

Hydrogen is a kind of high-efficiency and clean energy, but easy to leak out. The detecting of hydrogen is important during storage and transport. Since the large surface area, two-dimensional layered materials have an advantage of sensing gas molecules. And monolayer MoS₂ is a typical kind that has been widely studied recently. Here, the comparison between doped-2H MoS₂ and pristine-1T MoS₂ on sensing hydrogen (H₂) molecules is performed using first principles for the first time. The results show that the four kinds of doped-2H and pristine-1T MoS₂ all have stronger effects of orbital hybridization with hydrogen molecule than pristine-2H MoS₂. The Si-doped one shows the best adsorption properties in multiple hydrogen situations, signifying a better sensing accuracy. Interestingly, pristine-1T MoS₂ has much higher hydrogen adsorption energy than any kind of doped-2H MoS₂, indicating a higher sensibility. Thus, trade-offs between doping processes and phase engineering should be considered for promoting the gas sensing performance of MoS₂-based materials. With researches in this paper, a reference for further research on the application of highly integrated hydrogen sensing was provided.