Improvement in efficiency of MoS2 nanoflower based ethylene gas sensor on transition metal doping: An experimental and theoretical investigation

Abstract

There is an immense need for inexpensive, accurate, and repeatable ethylene sensors for post-harvest management. This paper presents resistive-type sensors based on transition metal (Ni, Fe, Co) doped molybdenum disulfide (MoS2) nanoflowers synthesized via simple hydrothermal route. A comparative study of sensing properties of pristine MoS2 and doped (Ni, Fe, Co)-MoS2 was performed in natural ambient conditions. The results reveal that Ni-doped MoS2 shows the optimized result in sensitivity as well as lower detection limit, compared to other three materials. Density functional theory (DFT) studies were carried out to evaluate interaction of ethylene molecules with MoS2 and doped MoS2. The sensing mechanism for all the materials was investigated in terms of adsorption energy, density of states (DOS), and charge transfer. The calculated results indicate large adsorption energy and higher charge transfer in the case of Ni-doped MoS2 supporting the experimental findings.