The recent advances in chloride‐ion capturing electrodes for capacitive deionization (CDI) are limited by the capacity, rate, and stability of desalination. This work introduces Ti3C2Tx/Ag synthesized via a facile oxidation‐reduction method and then uses it as an anode for chloride‐ion capture in CDI. Silver nanoparticles are formed successfully and uniformly distributed with the layered‐structure of Ti3C2Tx. All Ti3C2Tx/Ag samples are hydrophilic, which is beneficial for water desalination. Ti3C2Tx/Ag samples with a low charge transfer resistance exhibit both pseudocapacitive and battery behaviors. Herein, the Ti3C2Tx/Ag electrode with a reaction time of 3 h exhibits excellent desalination performance with a capacity of 135 mg Cl− g−1 at 20 mA g−1 in a 10 × 10−3 m NaCl solution. Furthermore, low energy consumption of 0.42 kWh kg−1 Cl− and a desalination rate of 1.5 mg Cl− g−1 min−1 at 50 mA g−1 is achieved. The Ti3C2Tx/Ag system exhibits fast rate capability, high desalination capacity, low energy consumption, and excellent cyclability, which can be ascribed to the synergistic effect between the battery and pseudocapacitive behaviors of the Ti3C2Tx/Ag hybrid material. This work provides fundamental insight into the coupling of battery and pseudocapacitive behaviors during Cl− capture for electrochemical desalination.

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Developing high‐performance defect‐rich carbon materials with abundant accessible active sites is exceedingly vital for electrochemical water desalination, but this still remains a significant challenge. Herein, a reverse‐defect‐engineering strategy is reported to synthesize high edge‐nitrogen‐doped nanotube‐like carbon through the annealing process of protonated g‐C3N4 under H2 atmosphere. The hydrogen bonds interaction between the proton and nitrogen atoms performs a crucial role in regulating nitrogen configurations. The nitrogen‐doped carbon obtained from HCl pretreatment (HCl‐NC) reduces the proportion of graphitic N and exhibits a high ratio of pyrrolic N to pyridinic N. Thus, the resulting synergetic structure of high edge‐type N and small graphitic carbon nanodomains ensures more accessible active sites and fast charge‐transfer kinetics simultaneously, contributing to high desalination capacity (100.3 mg g−1 at 1.2 V), fast time‐average specific adsorption rate (1.7 mg g−1 min−1), low energy consumption (82.9 kJ molNaCl−1), and superior cyclic stability (no signs of performance decay after long‐term cycling). The Na+‐intercalation mechanism and structure‐response relationship of HCl‐NC are revealed by the electrochemical quartz crystal microbalance with dissipation monitoring and density functional theory calculations, respectively. This study provides a novel idea to modulate the nanotube‐like, nitrogen‐containing configurations for engineering carbon nanomaterials for advanced electrochemical applications.

The enhanced fluorescence of FGDY is considered to be induced by low phonon energy of fluoride, reducing non-radiative transition sites.

Rational engineering of nanostructured anode materials is important to develop lithium-ion batteries (LIBs). In this study, hierarchical composites of fluoridated carbonaceous GeO 2 (F-GeO 2 @C) with rich oxygen vacancies were prepared by a simple annealing method. It is found that F − ions not only exist in the carbon matrix but also replace O 2− of metallic oxides. The abundant introduced oxygen vacancies can provide more active sites and contribute to better electronic conductivity. Moreover, density functional theory (DFT) calculations confirm that Fdoping greatly changes the electronic structure of the GeO 2 composite, exhibiting interesting metallic behavior. Consequently, the F-GeO 2 @C anode shows an enhanced initial Coulombic efficiency (ICE) value of 71.6% and delivers excellent rate capability, much higher than most reported GeO 2 -based anodes. The enhancement of the electrochemical performance for F-GeO 2 @C is attributed to the hierarchical nanostructure and F-doping by increased reaction kinetics, reversibility, and cycling stability. Thus, such rational fabrication of the composite can motivate other high-performance germanium-based materials in LIBs.

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