High density anchoring of NiMoS4 on ultrathin Ti3C2 MXene assisted by dopamine for supercapacitor electrode materials

MXenes have a broad application in electrochemical energy storage. However, the smooth surface of high-density MXenes makes it difficult to stabilize the anchored active material. In this study, ultrathin Ti 3 C 2 MXenes were doped with a high density of NiMoS 4 nanoparticles with the assistance of dopamine (DA). DA was adsorbed by the Ti 3 C 2 surface (Ti 3 C 2 -DA) to form a negatively charged layer, which was beneficial for the enrichment of metal ions. NiMoS 4 was anchored to Ti 3 C 2 -DA via a hydrothermal reaction . The resultant Ti 3 C 2 -DA-NiMoS 4 heterostructure increased the exposure of NiMoS 4 active sites, and reduced the decrease in specific capacitance caused by volume changes. Consequently, Ti 3 C 2 -DA-NiMoS 4 exhibited excellent electrochemical performance with a high specific capacitance of 1288 F g −1 at 1 A g −1 . In addition, an asymmetric supercapacitor based on a Ti 3 C 2 -DA-NiMoS 4 positive electrode achieved a high energy density of 40.5 Wh kg −1 at 810 W kg −1 , and demonstrated excellent cycling stability (capacitance retention of 89% after 9000 cycles at 10 A g −1 ). These results demonstrate that the Ti 3 C 2 -DA-NiMoS 4 heterostructure is a prospective candidate material for high-performance supercapacitors.