Ternary alkali metal chalcogenide engineered reduced graphene oxide (rGO) as a new class of composite (NaFeS2-rGO) and its electrochemical performance

Abstract

By employing a simple hydrothermal process, a new class of ternary alkali metal-based chalcogenide (NaFeS2 (NFS)) has been produced and anchored on to reduced graphene oxide (rGO) sheets for the first time. Transition metal-based chalcogenides (TMC) exhibit limited conductivity because of their semiconducting nature and hence, engineering TMCs with 2D carbonaceous materials yields better catalytic performance. Alkali metal-based chalcogenides and their composites appear to be promising alternatives, whose electrochemical properties haven't been explored much. This work presents a detailed insight into the structure and morphology of the prepared NFS-rGO composite, along with its electrochemical properties. The cyclic voltammetry (CV) response at the NFS-rGO composite electrode for the redox probe K4Fe(CN)6 is better with low peak to peak separation potentials (ΔEp ​= ​99 ​mV) compared to the individual components NFS (ΔEp ​= ​190 ​mV) and GO (∆Ep ​= ​130 ​mV), indicating a better electron transfer kinetics. The NFS-rGO composite electrode displays an enhanced electrocatalytic activity as evidenced by the high electrochemically active surface area (6.09 ​× ​10−2 ​cm2) and the heterogeneous electron transfer rate constant (k0 ​= ​5.4 ​× ​10−2 ​cms−1). In general, the NFS-rGO composite exhibits excellent material as well electrocatalytic properties due to the synergistic effect between NFS and rGO and can further be explored for electrochemical sensing applications as well.