Metal–organic frameworks (MOFs), which consist of central metal nodes and organic linkers, constitute a fast growing class of crystalline porous materials with excellent application potential. Herein, a series of Mn‐based multimetallic MOF (bimetallic and trimetallic MIL‐100) nano‐octahedra are prepared by a facile one‐pot synthetic strategy. The types and proportions of the incorporated elements can be tuned while retaining the original topological structure. The introduction of other metal ions is verified at the atomic level by combining X‐ray absorption fine structure experiments and theoretical calculations. Furthermore, these multimetallic Mn‐based MIL‐100 nano‐octahedra are utilized as sulfur hosts to prepare cathodes for Li–S batteries. The MnNi‐MIL‐100@S cathode exhibits the best Li–S battery performance among all reported MIL‐100@S composite cathode materials, with a reversible capacity of ≈708.8 mAh g−1 after 200 cycles. The synthetic strategy described herein is utilized to incorporate metal ions into the MOF architecture, of which the parent monometallic MOF nano‐octahedra cannot be prepared directly, thus rationally generating novel multimetallic MOFs. Importantly, the strategy also allows for the general synthesis and study of various micro‐/nanoscale MOFs in the energy storage field.
While stretchable micro‐supercapacitors (MSCs) have been realized, they have suffered from limited areal electrochemical performance, thus greatly restricting their practical electronic application. Herein, a facile strategy of 3D printing and unidirectional freezing of a pseudoplastic nanocomposite gel composed of Ti3C2Tx MXene nanosheets, manganese dioxide nanowire, silver nanowires, and fullerene to construct intrinsically stretchable MSCs with thick and honeycomb‐like porous interdigitated electrodes is introduced. The unique architecture utilizes thick electrodes and a 3D porous conductive scaffold in conjunction with interacting material properties to achieve higher loading of active materials, larger interfacial area, and faster ion transport for significantly improved areal energy and power density. Moreover, the oriented cellular scaffold with fullerene‐induced slippage cell wall structure prompts the printed electrode to withstand large deformations without breaking or exhibiting obvious performance degradation. When imbued with a polymer gel electrolyte, the 3D‐printed MSC achieves an unprecedented areal capacitance of 216.2 mF cm−2 at a scan rate of 10 mV s−1, and remains stable when stretched up to 50% and after 1000 stretch/release cycles. This intrinsically stretchable MSC also exhibits high rate capability and outstanding areal energy density of 19.2 µWh cm−2 and power density of 58.3 mW cm−2, outperforming all reported stretchable MSCs.
The fabrication of fully printable, flexible micro‐supercapacitors (MSCs) with high energy and power density remains a significant technological hurdle. To overcome this grand challenge, the 2D material MXene has garnered significant attention for its application, among others, as a printable electrode material for high performing electrochemical energy storage devices. Herein, a facile and in situ process is proposed to homogeneously anchor hydrous ruthenium oxide (RuO2) nanoparticles on Ti3C2Tx MXene nanosheets. The resulting RuO2@MXene nanosheets can associate with silver nanowires (AgNWs) to serve as a printable electrode with micrometer‐scale resolution for high performing, fully printed MSCs. In this printed nanocomposite electrode, the RuO2 nanoparticles contribute high pseudocapacitance while preventing the MXene nanosheets from restacking, ensuring an effective ion highway for electrolyte ions. The AgNWs coordinate with the RuO2@MXene to guarantee the rheological property of the electrode ink, and provide a highly conductive network architecture for rapid charge transport. As a result, MSCs printed from the nanocomposite inks demonstrate volumetric capacitances of 864.2 F cm−3 at 1 mV s−1, long‐term cycling performance (90% retention after 10 000 cycles), good rate capability (304.0 F cm−3 at 2000 mV s−1), outstanding flexibility, remarkable energy (13.5 mWh cm−3) and power density (48.5 W cm−3).
A solar-thermal water evaporation structure that can continuously generate clean water with high efficiency and good salt rejection ability under sunlight is highly desirable for water desalination, but its realization remains challenging. Here, a hierarchical solar-absorbing architecture is designed and fabricated, which comprises a 3D MXene microporous skeleton with vertically aligned MXene nanosheets, decorated with vertical arrays of metalorganic framework-derived 2D carbon nanoplates embedded with cobalt nano particles. The rational integration of three categories of photothermal materials enables broadband light absorption, efficient light to heat conversion, low heat loss, rapid water transportation behavior, and much-improved corrosion and oxidation resistance. Moreover, when assembling with a hydrophobic insulating layer with hydrophilic channel, the MXene-based solar absorber can exhibit effective inhibition of salt crystallization due to the ability to advect and diffuse concentrated salt back into the water. As a result, when irradiating under one sun, the solar-vapor conversion efficiency of the MXene-based hierarchical design can achieve up to ≈93.4%, and can remain over 91% over 100 h to generate clean vapor for stable and continuous water desalination. This strategy opens an avenue for the development of MXenebased solar absorbers for sustainable solar-driven desalination.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.