Two-dimensional layered reduced graphene oxide-tungsten disulphide nanocomposite for highly sensitive and selective determination of para nitrophenol

Abstract

In this study, a facile and scalable synthetic strategy has been developed to prepare 2D layered reduced graphene oxide-tungsten disulfide (rGO@WS2) nanocomposite for the electrochemical detection of para nitrophenol (p-NP). The rGO@WS2 nanocomposite was synthesized by using tungsten hexachloride (WCl6), thioacetamide (CH3CSNH2) and graphite oxide as starting material through a microwave-assisted route. The formation of the nanocomposite was confirmed by powder X-ray diffraction whereas the 2D structural morphology was established by using field emission scanning electron microscopy. The electrochemical measurement of the as-synthesized nanocomposite was done through cyclic voltammetry. The cyclic voltammetric study was carried out by using a modified glassy carbon electrode (GCE), which indicates the enhancement in the peak current (22.0 μA to 33.9 μA) in the case of rGO-WS2 as compared to WS2. To have a better understanding of the interaction mechanism, detection limit and sensitivity, differential pulse voltammetry was utilized. This reveals that the as-synthesized rGO-WS2 nanocomposite sensor exhibited good detection limit (2.88 μM), excellent sensitivity (0.589 µA µM-1 cm-2) and broad linear range (0.50–12.0 µM). Therefore, it is demonstrated that the rGO@WS2 nanocomposite modified GCE provides superior electrochemical sensing application due to the synergistic effect of WS2 (high catalytic activity) and rGO nanosheets (high conductivity).