Related Experiment Video
Updated: Jun 3, 2026
05:51
Isotopic Effect in Double Proton Transfer Process of Porphycene Investigated by Enhanced QM/MM Method
Published on: July 19, 2019
Electronic Delocalization-Confinement Coupling in Edge-Coordinated CQDs@MXene Enables Hydrogen-Bond Modulation for
Che Liu1, Kaiyang Guo1, Yan Liu1
1Henan Institute of Advanced Technology, Zhengzhou, Henan, P. R. China.
Advanced Materials (Deerfield Beach, Fla.)
|June 2, 2026
Summary
We enhanced proton transport in 2D electrodes by using carbon quantum dots (CQDs) to weaken hydrogen bonds in MXenes. This strategy improves charge storage kinetics and enables ultrafast ion transport for energy devices.
Area of Science:
- Materials Science
- Electrochemistry
- Nanotechnology
Background:
- Efficient proton transport in 2D confined electrodes is vital for energy storage.
- Strong hydrogen bonds between water and MXene surfaces hinder proton mobility and charge storage.
- Interfacial issues are exacerbated in 2D confined spaces.
Purpose of the Study:
- To develop a strategy for modulating electronic delocalization in Ti3C2Tx MXene.
- To weaken rigid hydrogen bonds and enhance interfacial charge transfer.
- To improve proton transport kinetics and electrochemical performance.
Main Methods:
- Edge-coordination strategy using carboxyl-functionalized carbon quantum dots (CQDs).
- Anchoring CQDs onto positively charged MXene edges for electronic delocalization.
- In situ vibrational spectroscopy and density functional theory (DFT) analysis.
Main Results:
- CQDs induced electron delocalization, weakening hydrogen bonds and facilitating charge transfer.
- A dynamic hydrogen-bond network supported Grotthuss-type proton migration.
- Optimized CQDs@MXene electrode achieved 2507.2 F cm⁻³ capacitance, 65.8% retention at 1000 mV s⁻¹, and 100% stability over 10,000 cycles.
Conclusions:
- Electronic delocalization is an effective method to control hydrogen-bond dynamics.
- Weakened hydrogen bonds and enhanced charge transfer enable ultrafast ion transport.
- This approach offers a new paradigm for designing advanced electrochemical systems.
Related Concept Videos
01:27¹H NMR: Long-Range Coupling
The coupling interactions of nuclei across four or more bonds are usually weak, with J values less than 1 Hz. While these are usually not observed in spectra, the presence of multiple bonds along the coupling pathway can result in observable long-range coupling.
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene π orbitals.
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene π orbitals.
01:20¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)
When proton-coupled carbon-13 spectra are simplified by a broadband proton decoupling technique, structural information about the coupled protons is lost. Distortionless enhancement by polarization transfer (DEPT) is a technique that provides information on the number of hydrogens attached to each carbon in a molecule. While the DEPT experiment utilizes complex pulse sequences, the pulse delay and flip angle are specifically manipulated. The resulting signals have different phases depending on...
01:182D NMR: Overview of Heteronuclear Correlation Techniques
Heteronuclear correlation spectroscopy is an analytical technique that investigates the coupling between different types of nuclei, often a proton and an X-nucleus, such as carbon-13 or nitrogen-15. This method is commonly used in nuclear magnetic resonance (NMR) spectroscopy to gain insights into complex chemical compounds' structural and compositional aspects. A typical heteronuclear correlation spectrum displays X-nucleus chemical shifts on one axis and a proton spectrum on the other axis.
01:12Double Resonance Techniques: Overview
Double resonance techniques in Nuclear Magnetic Resonance (NMR) spectroscopy involve the simultaneous application of two different frequencies or radiofrequency pulses to manipulate and observe two distinct nuclear spins. One important application of double resonance is spin decoupling, which selectively suppresses coupling with one type of nucleus while observing the NMR signal from another nucleus, simplifying the spectrum and enhancing resolution.
Spin decoupling is usually achieved by...
Spin decoupling is usually achieved by...
01:22Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)
Vicinal or three-bond coupling is commonly observed between protons attached to adjacent carbons. Here, nuclear spin information is primarily transferred via electron spin interactions between adjacent C‑H bond orbitals. This generally favors the antiparallel arrangement of spins, so 3J values are usually positive.
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the involved orbitals. The...
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the involved orbitals. The...
01:192D NMR: Heteronuclear Single-Quantum Correlation Spectroscopy (HSQC)
Heteronuclear single-quantum correlation spectroscopy (HSQC) is a 2D NMR technique that reveals one-bond correlations between hydrogen and a heteronucleus. The HSQC experiment is similar to the heteronuclear correlation experiment (HETCOR) but is more sensitive. In the HSQC spectrum, the proton chemical shift is plotted on the horizontal F2 axis, while the 13C chemical shift is plotted on the vertical F1 axis. The corresponding proton and 13C spectra are also shown. The HSQC contour plot does...