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Ti3C2Tx MXene is regarded as a promising material in energy-related applications; however, the overscreening charge effect of the electric double layer on electrified interfaces, along with "inert" F terminations, limits the electrochemical operation efficiencies. Here, we developed a protocol to harvest a coupled conductor through confining in situ 1-ethyl-3-methylimidazolium ([Emim]+) ions into Ti3C2Tx interlayers. The ionic–electronic coupling does not require any external counterions, but activates terminal F and even sub-surface Ti, and endows the conductor with metal-like and ionophilic characteristics. Different from physically preintercalated or adsorbed ions, the resulting chemically confined [Emim]+ ions offer more accessible electroactive sites, faster electron transport in surface redox, and more efficient channels for ion transfer. Hence, the Ti3C2Tx electrodes present high gravimetric capacitance, rate performance and cycling stability. This work highlights the important roles of the coupling in the design and research of mixed ionic–electronic conductors with high electrochemical activity. [ABSTRACT FROM AUTHOR]

Although significant progress has been made in the synthesis of covalent organic frameworks (COFs) in recent years, the construction of hierarchical pores in such materials remains a great challenge. Herein, we report a facile synthesis of hierarchically porous COFs (HP-COFs) under mild conditions in ionic liquids 1-alkyl-3-methylimidazolium tetrafluoroborates ([Cnmim][BF4], n = 4, 6, 10). It has been found that apart from the inherent micropores, a large mesoporous structure has been produced in the COFs in which the size of pores can be simply tuned by adjusting the alkyl chain length of the ionic liquids. These mesopores have been confirmed by N2 sorption and electron microscopy techniques. Importantly, this approach is applicable for the preparation of various HP-COFs, such as imine and hydrazone based COFs, which are quite difficult to acquire through traditional methods. In addition, these HP-COFs show highly effective catalytic performance for C–C bond formation, especially for large size molecule based C–C coupling reactions in comparison with uni-pore COFs. [ABSTRACT FROM AUTHOR]

The charge transfer and active sites of metal-free imidazolium-based composites were unveiled by an electrochemical method with high sensitivity and selectivity due to the specific donor–acceptor coupling of imidazolium with NO2−. [ABSTRACT FROM AUTHOR]

A two-dimensional (2D) nanoporous Ni(OH) 2 film was successfully developed from triethanolamine (TEA) as the alkali source and soft template using a scalable hydrothermal technique. The nanostructured Ni(OH) 2 film was flexible and translucent, and could be directly compressed on a current collector. Owing to the uniform well-defined morphology and stable structure, the Ni(OH) 2 film binder-free electrode displayed a high specific capacity, exceptional rate capability, and admirable cycle life. The specific capacitance was 453.6 mA h g -1 (1633 F g -1 ) at 0.5 A g -1 . The assembled Ni(OH) 2 //activated carbon (AC) asymmetric supercapacitor (ASC) device had an energy density of 58.7 W h kg -1 at a power density of 400 W kg -1 . These prominent electrochemical properties of Ni(OH) 2 were attributed to the high electrical conductivity, high surface area, and unique porous architecture. Free tailoring, binder-free, and direct pressing were the most significant achievements of the Ni(OH) 2 film in the development of high-performance energy storage devices., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

This study proposes a facile solvothermal synthesis of nickel tungstate (NiWO 4 ) nanowires for application as a novel cathode material for supercapacitors. The structure, morphology, surface area and pore distribution were characterized and their capacitive performances were investigated. The results showed that the NiWO 4 nanowires synthesized in ethylene glycol solvent could offer a high specific capacitance of 1190 F g -1 at a current density of 0.5 A g -1 and a capacitance retaining ratio of 61.5% within 0.5-10 A g -1 . When used as a cathodic electrode of an asymmetric supercapacitor (ASC), the NiWO 4 nanowire based device can be cycled reversibly in a high-voltage region of 0-1.7 V with a high specific capacitance of 160 F g -1 at 0.5 A g -1 , which therefore contributed to an energy density of 64.2 W h kg -1 at a power density of 425 W kg -1 . Moreover, 92.8% of its initial specific capacitance can be maintained after 5000 consecutive cycles (5 A g -1 ). These excellent capacitive properties make NiWO 4 a credible electrode material for high-performance supercapacitors., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Thiol-functionalized dialkylimidazolium bromide was synthesized, and used as a stabilizer to prepare monodisperse silver nanocrystals through a facile one-pot aqueous approach. It is shown that the multipurpose ligands play a vital role in improving the performance of nanocrystals. The mechanisms of dialkylimidazolium-mediated promotion were analyzed on the basis of the physicochemical properties of the specifically designed ligand.