Supercapacitors based on Ti3C2Tx MXene extracted from supernatant and current collectors passivated by CVD-graphene

Abstract

An ultrahigh capacity supercapacitor is fabricated using a nano-layered MXene as an active electrode material, and Ni-foil is used as a current collector. The high-quality Ti3C2Tx obtained from supernatant during etching and washing processes improves the specific capacitance significantly. As another strategy, the surface of Ni-foil is engineered by coating chemical vapor deposition-grown graphene. The graphene grown directly on the Ni-foil is used as a current collector, forming the electrode structure of Ti3C2Tx/graphene/Ni. The surface passivation of the current collectors has a high impact on charge-transfer, which in turn increases the capacitance of the supercapacitors. It is found that the capacitance of the graphene-based supercapacitors is more than 1.5 times of the capacitance without graphene. A high specific capacitance, ~ 542 F/g, is achieved at 5 mV/s scan rate based on cyclic voltammetry analysis. Also, the graphene-based supercapacitor exhibits a quasi-rectangular form in cyclic voltammetry curves and a symmetric behavior in charge/discharge curves. Furthermore, cyclic stability up to 5000 cycles is confirmed with high capacitance retention at high scan rate 1000 mV/s. A reduced series resistance with a high limit capacitance is revealed by equivalent circuit analysis with the Nyquist plot.

Ti3C2Tx MXene embedded metal–organic framework-based porous electrospun carbon nanofibers as a freestanding electrode for supercapacitors

“…For MXenes, the additional peak at approximately 401 cm −1 is due to oxygen atom vibrations. 50 Furthermore, the peak at approximately 613 cm −1 corresponds to the E g vibrational mode of carbon in Ti 3 C 2 T x MXenes with the –OH functional group. 50,51 The additional peak at approximately 645 cm −1 in MX-5@PCNF is due to the E g vibrational mode of carbon in Ti 3 C 2 T(OH) x , which is evidence for proper compositing of MXenes in the resulting material.…”

A bio-inspired MXene/quaternary chitosan membrane with a “brick-and-mortar” structure towards high-performance photothermal conversion

“…S4, ESI†). This is due to chemical etching, and the MXene surface forms many active terminal groups (–OH, –O, –F), 44 which facilitate the intercalation of QCS into MXene flakes. We prepared an MXene/QCS membrane by casting-assisted self-assembly.…”

Metal–Organic-Framework- and MXene-Based Taste Sensors and Glucose Detection

“…In addition, they display an array of outstanding features, such as tunable surface characteristics, good mechanical properties, and high electrical conductivity [40,41]. Therefore, the past decade has witnessed the rapid development of MXenes in many different areas, including the catalysis [42][43][44], sensors [45][46][47], and supercapacitors field [48][49][50]. The collective results demonstrate the potential of MOFs and MXenes as excellent templates for taste sensors in particular and sensing applications in general.…”