In Situ Growth of Ni-MOF Nanorods Array on TiCT Nanosheets for Supercapacitive Electrodes.

For the energy supply of smart and portable equipment, high performance supercapacitor electrode materials are drawing more and more concerns. Conductive Ni-MOF is a class of materials with higher conductivity compared with traditional MOFs, but it continues to lack stability. Specifically, MXene (TiCT) has been employed as an electrochemical substrate for its high mechanical stability and abundant active sites, which can be combined with MOFs to improve its electrochemical performance. In this paper, a novel Ni-MOF nanorods array/TiCT nanocomposite was prepared via a facile hydrothermal reaction, which makes good use of the advantages of conductive Ni-MOF and high strength TiCT. The high density forest-like Ni-MOF array in situ grown on the surface of TiCT can provide abundant active electrochemical sites and construct a pathway for effective ion transport. The formation of a "Ti-O···Ni" bond accomplished during an in situ growth reaction endows the strong interfacial interaction between Ni-MOF and TiCT. As a result, the Ni-MOF/TiCT nanocomposite can achieve a high specific capacitance of 497.6 F·g at 0.5 A·g and remain over 66% of the initial capacitance when the current density increases five times. In addition, the influence of the TiCT concentration and reaction time on the morphology and performance of the resultant products were also investigated, leading to a good understanding of the formation process of the nanocomposite and the electrochemical mechanism for a supercapacitive reaction.