Bridged Ti₃C₂T_X MXene Film with Superior Oxidation Resistance and Structural Stability for High-Performance Flexible Supercapacitors

Abstract

Two-dimensional (2D) Ti3C2T X MXene has been a promising nanomaterial in energy storage, electromagnetic shielding, and sensors. However, MXene suffers from major drawbacks of unstable structure and vulnerable oxidation in ambient moisture. Herein, a facile strategy is proposed to address the challenging problems via oxygen-rich molecular bridging. The tannic acid bridging agent with abundant O-containing ligands can self-polymerize and bind at the terminal groups and exposed Ti atom of Ti3C2T X by a synergistic hydrogen bond and coordination bond. The enhanced interlaminar interaction endows the MXene film with resistance to oxidation, swelling, and mechanical fragility. Density functional theory calculations prove that the charge transfer from MXene to oxygen-rich molecules improves the interface electronic structure, thus enlarging the work function of pristine Ti3C2T X , which means increased resistance toward losing electrons and being oxidized. The resultant bridged MXene film achieves 7 times toughness enhancement compared with pristine MXene, stable conductivity during the long-term storage in a humid environment, excellent structural and electrochemical stability during 10 000 cycles in aqueous electrolytes, and a remarkable energy density of 53.3 mW h cm–3 used for flexible symmetric micro-supercapacitors. This work opens opportunities for the rational design and fabrication of robust 2D MXene assemblies for aqueous energy storage.

One-Pot Fabrication of an MXene-ZrP@PDA Heterojunction for Enhanced Corrosion/Wear Resistance of Waterborne Epoxy Coatings

“…Figure a shows that the MXene dispersion changed from black to gray and finally to white over time, indicating that MXene was gradually oxidized. The XRD pattern also shows the appearance of the TiO 2 diffraction peak in the MXene nanosheets on the 4th day . The TiO 2 diffraction peaks became stronger on the 8th day, which demonstrates that MXene was further oxidized.…”

“…The XRD pattern also shows the appearance of the TiO 2 diffraction peak in the MXene nanosheets on the 4th day. 47 The TiO 2 diffraction peaks became stronger on the 8th day, which demonstrates that MXene was further oxidized. Fortunately, the color of the MXene-ZrP@PDA dispersion did not become white, and the TiO 2 diffraction peak did not appear in the XRD pattern.…”

Hemin-Functionalized Microfluidic Chip with Dual-Electric Signal Outputs for Accurate Determination of Uric Acid

“…To overcome the above-mentioned drawbacks, one desirable strategy is to anchor the reference molecule to another substrate such as multi-walled carbon nanotube (CNT), metal–organic framework, and titanium carbide (Ti 3 C 2 T x ) MXene . Among them, Ti 3 C 2 T x MXene is considered as a desirable substrate owing to its inherent properties: (i) Ti 3 C 2 T x with abundant surface groups (e.g., −O–, −OH, and −F) enables it to bond with other functional parts to develop functionalized hybrid; , (ii) accordion-like architecture of MXene with a large surface area can provide sufficient attachment sites for biorecognition elements to enhance signal response; , (iii) Ti 3 C 2 T x and its derivatives also possess unique photoelectrochemical property . Benefiting from these peculiarities, Ti 3 C 2 T x MXene is considered as a versatile substrate for advanced sensors …”

Delamination of Ti3C2Tx Nanosheets with NaCl and KCl for Improved Environmental Stability of MXene Films

“…Here, by environmental stability of MXene films we imply decreased conductivity when placed in a humid environment or even disassembly of the films when placed in water, which is different from colloidal stability (aggregation of MXene flakes) or chemical stability (chemical degradation due to oxidation or hydrolysis) of MXene flakes dispersed in water . Different strategies of bridging MXene layers using multivalent ions, polymers, , or high-temperature annealing , have been employed to prevent MXene swelling and degradation of MXene membranes.…”

“…Here, by environmental stability of MXene films we imply decreased conductivity when placed in a humid environment or even disassembly of the films when placed in water, 12 different from colloidal stability (aggregation of MXene flakes) or chemical stability (chemical degradation due to oxidation or hydrolysis) of MXene flakes dispersed in water. 14 Different strategies of bridging MXene layers using multivalent ions, 15 polymers, 16,17 or high-temperature annealing 18,19 have been employed to prevent MXene swelling and degradation of MXene membranes. Chen et al demonstrated that removing Li + from MXene decreases the interlayer spacing and improves the environmental stability of MXene films but requires additional acid treatment, 12 which, in turn, compromises the colloidal stability of MXene flakes in water.…”