Composites of NiS₂ Microblocks, MoS₂ Nanosheets, and Reduced Graphene Oxide for Energy Storage and Electrochemical Detection of Bisphenol A

Electrode material plays a critical role in both electrochemical energy storage and sensors, and there is an urgent need to develop novel electrode materials with high reactivity and catalytic activity. Herein, a multicomponent NiS2/MoS2/rGO electrode nanomaterial consisting of self-stacking NiS2 microblocks, hydrangea-like MoS2 nanosheets, and ultrathin reduced graphene oxide (rGO) nanolayers is synthesized via a facile two-step hydrothermal process. The ingenious combination of NiS2, MoS2, and rGO provides the nanocomposite good capacitance and sensitivity in electrochemical applications. As a result, the NiS2/MoS2/rGO nanocomposite exhibits a good specific capacitance of 645.3 F g–1 at 0.5 A g–1 and rate performance of 126.7 F g–1 at 10 A g–1. The assembled asymmetric supercapacitor of NiS2/MoS2/rGO//activated carbon delivers a high energy density of 19.4 Wh kg–1 at a power density of 156.1 W kg–1 for electrochemical energy storage. In addition, the electrochemical sensor based on a NiS2/MoS2/rGO nanocomposite modified onto glassy carbon electrode (GCE) shows superior activity toward detection of bisphenol A (BPA) compared with other reported electrochemical sensors. A wide linear range of 0.02–200 μM and a low detection limit of 2.1 nM can be obtained under the optimal conditions. This work provides insights into the development of multicomponent NiS2/MoS2/rGO electrode nanomaterial, including its facile synthesis method, good specific capacitance, and ultrasensitive detection of BPA, that exhibits bifunctional electrochemical applications.