Electrochemical study of hydrothermally synthesised reduced MoS2 layered nanosheets

Abstract

In this work, we report one-step, facile and cost-effective synthesis of 2-dimensional (2D) reduced MoS2 (r-MoS2) nanostructures via hydrothermal method using two reducing agents. The detection of hexagonal phase, estimation of lattice parameters and crystallite size is done using X-ray diffraction and Williamson-Hall plots are drawn to estimate strain produced in the sample. Field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) confirms the formation of nanosheet like structures. MoS2 reduced using hydrazine hydrate is found to have better electrochemical properties with heterogenous rate transfer constant equal to 5.03 × 10−4 cm/s and electroactive surface area calculated as 7.05 × 10−4 cm−2. Raman spectra, TEM images and W–H plots explains the better electrochemical performance of rMoS2 synthesised using hydrazine hydrate. Also, it is observed that out of electrochemical impedance spectroscopy (EIS), cyclic voltammetry and differential pulse voltammetry, EIS turns out to be best technique for studying electrochemical properties of layered materials. This work provides theoretical guidance to use chemically synthesised rMoS2 as a matrix for electrochemical sensing applications where an increase or decrease in current/resistance value gives confirmation of attachment of bio/gas molecules and determination of parameters like heterogenous rate transfer constant can indicate sensitivity towards a particular analyte.