Synthesis of free‐standing flexible g‐C ₃ N ₄ / MXene film as electrode materials for supercapacitors

Abstract

Flexible supercapacitors (SCs) have the advantages of high flexibility, high mechanical strength, easy assembly, and high power density, so SCs can be widely used in portable and wearable electronic devices. It is of great significance to research and develop high-performance electrode materials in order to further improve the performance of SCs and expand their application fields. Here, we prepared a free-standing flexible g-C 3 N 4 /Ti 3 C 2 hybrid film as electrode material for SCs by inserting two-dimensional g-C 3 N 4 nanosheets between Ti 3 C 2 layers-based vacuum suction filtration methods. The addition of g-C 3 N 4 nanosheets effectively prevented the self-stacking of MXene layers, significantly increasing the interlayer spacing of g-C 3 N 4 /Ti 3 C 2 hybrid film. The electrochemical results show that the mass specific capacity of 10 wt% g-C 3 N 4 / Ti 3 C 2 is as high as 552 F g À1 at the scanning rate of 2 mV s À1 , which is 3.29 times higher than 168 F g À1 of Ti 3 C 2 , the capacity retention rate of 10 wt% g-C 3 N 4 /Ti 3 C 2 is 97% after 10 4 cycles at a current density of 3 A g À1 .

Recent Advances of Flexible MXene and its Composites for Supercapacitors

“…Its excellent various properties have made it shine in this field. For the existing related reports, they can be roughly categorized into three different perspectives to construct MXene-based composites: (i) using MXene as the main component, and using other molecules or materials to improve the performance of MXene; (ii) MXene synergizes with composite materials and they exhibit equal importance in composite materials; (iii) Utilizing certain advantages specific to T-Ti 3 C 2 T x 446.9 F g À 1 at 5 mV s À 1 1 M H 2 SO 4 À 0.7 to 0.2 (vs. Ag/AgCl) 95.8 % 10000 [81] MXene@PTA 320 F g À 1 at 20 mV s À 1 3 M H 2 SO 4 À 1 to À 0.2 (vs. Hg/Hg 2 SO 4 ) 96.1 % 10000 [82] MXene/PZS 380 F g À 1 at 2 mV s À 1 1 M H 2 SO 4 À 0.7 to 0.3 (vs. Ag/AgCl) / / [85] MXene/CA 1244.6 F cm À 3 at 1 A g À 1 3 M H 2 SO 4 À 0.7 to 0.3 (vs. Ag/AgCl) 93.5 % 30000 [84] g-C 3 N 4 /Ti 3 C 2 552 F g À 1 at 2 mV s À 1 1 M H 2 SO 4 À 0.8 to 0.2 (vs. Ag/AgCl) 97 % 10000 [94] GDY-NTs 337.4 F g À 1 at 2 A g À 1 1 M H 2 SO 4 À 0.7 to 0.3 (vs. Ag/AgCl) 88.2 % 10000 [83] MXene/PANI 425.7 F g À 1 at 10 mV s À 1 1 M H 2 SO 4 À 0.4 to 0.4 (vs. Ag/AgCl) / / [101] M-PPy3 563.8 F g À 1 at 0.5 A g À 1 1 M H 2 SO 4 À 0.4 to 0.4 (vs. Ag/AgCl) 79.5 % 6000 [102] Ni-BTA/MXene 264.4 F g À 1 at 5 mV s À 1 1 M H 2 SO 4 À 0.6 to 0.3 (vs. Ag/AgCl) 94.6 % 10000 [98] MXene/V 2 O 5 319.1 F g À 1 at 0.5 A g À 1 1 M H 2 SO 4 À 0.8 to 0.4 (vs. Ag/AgCl) 70.4 % 5000 [104] CuMnHS@MX 2089 mF cm À 2 at 2.5 mA cm À 2 1 M H 2 SO 4 À 0.5 to 0.5 (vs. Ag/AgCl) 99.89 % 8000 [99] MXene/CuS 491 F g À 1 at 1 A g À 1 1 M H 2 SO 4 À 0.3 to 0.5 (vs. SCE) 89 % 5000 [106] Ti 3 C 2 T x /SCNF 220 F g À 1 at 1 A g À 1 1 M H 2 SO 4 À 0.4 to 0.3 (vs. Ag/AgCl) 100 % 5000 [108] Mxene-hemi 335 F g À 1 at 10 mV s À 1 1 M H 2 SO 4 À 0.8 to 0 (vs. Ag/AgCl) / / [111] COF/MXene 390 F g À 1 at 0.5 A g À 1 1 M H 2 SO 4 À 0.5 to 0.2 (vs. SCE) 99 % 30000 [112] Co-TCPP/MXene 1591.7 mF cm À 2 at 1 mA cm À 2 1 M H 2 SO 4 À 0.5 to 0.4 (vs. Ag/AgCl) 99.81 % 8000 [114] MXene/Borophene 1328 mF cm À 2 at 0.5 mA cm À 2 1 M LiCl À 0.8 to 0 (vs. Ag/AgCl) 98.5 % 10000 [115] Ti 3 C 2 T x /CNTs/CuS 336.7 F g À 1 at 1 A g À 1 3 M KOH 0 to 0.8 (vs. Hg/HgCl 2 ) 99.6 % 5000 [113] MGC 463.5 F g À 1 at 1 A g À 1 1 M H 2 SO 4 À 0.4 to 0.4 (vs. Ag/AgCl) / / [117] MXene/CNTs@Ni 990.8 F cm À 3 at 1 A g À 1 1 M H 2 SO 4 À 0.6 to 0.4 (vs. Ag/AgCl) / / [119] rGO/MXene-PPy 408.2 F g À 1 at 1.0 A g À 1 .…”

“…Xu et al. inserted two‐dimensional g‐C 3 N 4 nanosheets between Ti 3 C 2 layers and prepared a freestanding flexible 10 wt% g‐C 3 N 4 /Ti 3 C 2 films with a specific capacitance of 552 F g −1 at 2 mV s −1 [94] . Yuan et al.…”

“…[93] Xu et al inserted two-dimensional g-C 3 N 4 nanosheets between Ti 3 C 2 layers and prepared a freestanding flexible 10 wt % g-C 3 N 4 /Ti 3 C 2 films with a specific capacitance of 552 F g À 1 at 2 mV s À 1 . [94] Yuan et al reported an in-situ strategy for the photochemical synthesis of MXene quantum dots (MQDs), which are uniformly attached to laser-reduced graphene oxide (LRGO) with excellent electrochemical capacitance and ultrahigh transparency using time-and space-forming femtosecond lasers, as shown in Figure 4a. The study simultaneously analyzes and observes both the mechanism of the synthesis process and plasma dynamics.…”

Interfacial Engineering of Ti3C2Tx MXene Electrode Using g-C3N4 Nanosheets for High-Performance Supercapacitor in Neutral Electrolyte

“…This composite indicated a high specific capacitance of about 170.7 F g –1 and as high an energy density as 7.47 Wh kg –1 in an acidic electrolyte . Recently, the supercapacitor made of g-C 3 N 4 /Ti 3 C 2 T x composite was reported by Xu et al with specific capacitance as high as 552 F g –1 in H 2 SO 4 , which was about 3 times higher than that of the pristine Ti 3 C 2 T x . Furthermore, Zhang and colleagues developed a flexible solid-state g-C 3 N 4 /Ti 3 C 2 T x supercapacitor, achieving an energy density of 23.98 Wh kg –1 with a power density of 139.66 W kg –1 .…”

Nickel–Cobalt Metal–Organic Framework CPO-27 and g-C3N4 for Oxygen Reduction Reaction in Alkaline-Exchange-Membrane Fuel Cell

“…Graphitic carbon nitride, also known as g-C 3 N 4 , is a two-dimensional, layered compound made up of tris-triazine units connected by planar amino groups at each layer and a weak van der Waals interaction between layers. 36 Several applications for catalysts, 37 photocatalysts, 38 and supercapacitors 39 have been developed using g-C 3 N 4 due to the proper strip gap, low cost, simplicity in manufacture, high stability, and ecologically advantageous properties. 36 Liu et al 40 prepared g-C 3 N 4 -derived bamboo-like carbon nanotubes/Co as an ORR catalyst in alkaline media.…”