First-principles study on sensing properties of Ni-decorated MoS2 with synergetic intrinsic defects towards dopamine molecule

Abstract

The two-dimensional (2D) transition-metal sulfide and single-atom catalysts are attractive materials and their excellent performance play an important role in various fields. In this study, we investigate the sensing properties of Ni-decorated MoS2 towards dopamine (DA) molecule by using first-principles method. Ni is identified as the primary anchoring point for the DA molecule. We further examine the synergistic effect of intrinsic defects on the system and find that they significantly influence the adsorption behavior. The presence of a Mo defect leads to a 7 % increase in the adsorption energy compared to the scenario without any defects. By applying an in-plane voltage to these models, the I–V curve and conductivity are calculated to simulate the experimental detectability. The detection sensitivity can be significantly improved by suitable in-plane voltage. By applying a back-gate electric field, the influence of interface charge transfer on the adsorption characteristics of DA is investigated, and the back-gate electric field brings a significant enhancement of the adsorption energy, with an impressive increase up to 34 %. This study provides valuable insights into the sensing properties of DA by assessing the adsorption energy and suggests possible avenues for improving the detection sensitivity.