Ultrathin Ti3C2Tx (MXene) Nanosheet-Wrapped NiSe2 Octahedral Crystal for Enhanced Supercapacitor Performance and Synergetic Electrocatalytic Water Splitting

Abstract

Metal selenides, such as NiSe2, have exhibited great potentials as multifunctional materials for energy storage and conversation. However, the utilization of pure NiSe2 as electrode materials is limited by its poor cycling stability, low electrical conductivity, and insufficient electrochemically active sites. To remedy these defects, herein, a novel NiSe2/Ti3C2Tx hybrid with strong interfacial interaction and electrical properties is fabricated, by wrapping NiSe2 octahedral crystal with ultrathin Ti3C2Tx MXene nanosheet. The NiSe2/Ti3C2Tx hybrid exhibits excellent electrochemical performance, with a high specific capacitance of 531.2 F g−1 at 1 A g−1 for supercapacitor, low overpotential of 200 mV at 10 mA g−1, and small Tafel slope of 37.7 mV dec−1 for hydrogen evolution reaction (HER). Furthermore, greater cycling stabilities for NiSe2/Ti3C2Tx hybrid in both supercapacitor and HER have also been achieved. These significant improvements compared with unmodified NiSe2 should be owing to the strong interfacial interaction between NiSe2 octahedral crystal and Ti3C2Tx MXene, which provides enhanced conductivity, fast charge transfer as well as abundant active sites, and highlight the promising potentials in combinations of MXene with metal selenides for multifunctional applications such as energy storage and conversion.

Enhanced Ionic Accessibility of Flexible MXene Electrodes Produced by Natural Sedimentation

“…However, the electrochemical properties of those materials need further improvement. Transition metal carbides, nitrides and carbonitrides, a large family of two-dimensional (2D) materials known as MXenes, have been gaining a lot of interest in a variety of applications, especially for energy storage and conversion [8][9][10]. The characteristics of MXenes, including their unique 2D morphologies, rich chemistries, ultra-high electronic conductivities, and abundant surface functional groups, make them promising candidates for electrodes of supercapacitors (SCs) and LIBs [11][12][13][14][15].…”

2D MXenes as Co-catalysts in Photocatalysis: Synthetic Methods

“…MXenes, comprising transition metal carbides, nitrides, and carbonitrides, are a new family of two-dimensional (2D) materials that have attracted much attention in recent years [2]. The general formula of MXene is M n+1 X n (n = 1, 2, 3), where M represents a transition metal, such as Sc, Ti, Zr, Hf, V, Nb, Ta, and Mo, while X represents C and/or N. Owing to their unique structure and superior photoelectronic properties, layered structure MXenes show various potential applications in different areas, such as energy storage [3,[33][34][35][36][37][38], electromagnetic interference shielding [39,40], gas sensors [41], wireless communication [42], water treatment [43,44], solar cells [45][46][47], and catalysis [41,[48][49][50][51]. 2D MXenes are being increasingly studied in the past few years, as evidenced by the rapidly increasing number of scientific articles published per year (Fig.…”

MXene‐Based Nanocomposites for Energy Conversion and Storage Applications

“…The areal and volume capacitances of the prepared solid‐state micro‐supercapacitors are measured to be 108.1 mF cm −2 and 720.7 F cm −3 , respectively. NiSe 2 /Ti 3 C 2 T x hybrid with strong interface and electrical properties was prepared by coating NiSe 2 octahedral crystal with ultrathin Ti 3 C 2 T x MXene nanosheets . The hybrid of NiSe 2 /Ti 3 C 2 T x shows good electrochemical performance with a specific capacitance of 531.2 F g −1 at 1 A g −1 .…”