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Two-dimensional (2D) metal−organic frameworks (MOFs) play an essential role in response to external stimuli by changing their physical or chemical properties. This Review mainly aims at the recent progress of stimuliresponse in 2D MOFs. The various external stimuli, such as ions, solvents, gas, light, electron, temperature, and others, to 2D MOFs are systematically introduced and summarized. In addition, future perspectives relate to 2D MOFs for the stimuli-response are also discussed. We hope that this Review could provide a guideline to help researchers to design new stimuli-response 2D MOFs.

Two identical layered metal–organic frameworks (MOFs) (CoFRS and NiFRS) are constructed by using flexible 1,10‐bis(1,2,4‐triazol‐1‐yl)decane as pillars and 1,4‐benzenedicarboxylic acid as rigid linkers. The single‐crystal structure analysis indicates that the as‐synthesized MOFs possess fluctuant 2D networks with large interlayer lattices. Serving as active electrode elements in supercapacitors, both MOFs deliver excellent rate capabilities, high capacities, and longstanding endurances. Moreover, the new intermediates in two electrodes before and after long‐lifespan cycling are also examined, which cannot be identified as metal hydroxides in the peer reports. After assembled into battery‐supercapacitor (BatCap) hybrid devices, the NiFRS//activated carbon (AC) device displays better electrochemical results in terms of gravimetric capacitance and cycling performance than CoFRS//AC devices, and a higher energy‐density value of 28.7 Wh kg−1 compared to other peer references with MOFs‐based electrodes. Furthermore, the possible factors to support the distinct performances are discussed and analyzed.

With the trigonal linker 4,4′,4″-s-triazine-2,4,6-triyltribenzoic acid as a building block, porous cobalt metal–organic frameworks (named as PCN) have been successfully prepared and directly utilized as active materials in alkaline battery-type devices. For comparison, their carbon-supported hybrids (CNFs/PCN) have also been employed as battery-type electrodes. We found that the pristine PCN displayed a better performance than the CNFs/PCN composite electrode in electrochemical cells. To further investigate their electrochemical performances, alkaline battery–supercapacitor hybrid (BSH) devices with these materials as positive electrodes and activated carbon (AC) as the negative electrode were fabricated. The results indicate that the PCN//AC BSH devices delivered a maximum energy density of 16.0 Wh kg–1 at a power density of 749 W kg–1 within the voltage range of 0–1.5 V, which are much higher than those of CNFs/PCN//AC devices (12.4 Wh kg–1 at 753 W kg–1).

Novel nanostructured non-redox-metal potassium metal–organic framework, [C7H3KNO4]n, as an effective organic anode for long-cycle life OPIBs.

One two-dimensional Fe-based metal−organic framework (FeSC1) and one one-dimensional coordination polymer (FeSC2) have been solvothermally prepared through the reaction among FeSO 4 •7H 2 O, the tripodal ligand 4,4′,4″-striazine-2,4,6-triyl-tribenzoate (H 3 TATB), and flexible secondary building blocks p/m-bis((1H-imidazole-1-yl)methyl)benzene (bib). Given that their abundant interlayer spaces and different coordination modes, two compounds have been employed as battery-type electrodes to understand how void space and different coordination modes affect their performances in three-electrode electrochemical systems. Both materials exhibit outstanding but different electrochemical performances (including distinct capacities and charge-transfer abilities) under three-electrode configurations, where the charge storage for each electrode material is mainly dominated by the diffusion-controlled section (i ∝ v 0.5 ) through power-law equations. Additionally, the partial phase transformations to more stable FeOOH are also detected in the longterm cycling loops. After coupling with the capacitive carbon-based electrode to assemble into the semi-solid-state battery− supercapacitor-hybrid (sss-BSH) devices, the sss-FeSC1//AC BSH device delivers excellent capacitance, superior energy and power density, and longstanding endurance as well as the potential practical property.

As a new generation of two-dimensional (2D) materials, 2D metal-organic frameworks (MOFs) can provide uniform active sites and unique open channels as well as excellent catalytic activities, interesting magnetic properties,...

Narrowing the capacitance gap between the positive and negative electrodes for the enhancement of the energy densities of battery–supercapacitor hybrid (BSH) devices is urgent and very important. Herein, a new strategy to synchronously improve the positive–negative system and reduce the capacitance discrepancies between two electrodes through the utilization of the same MOF-based precursors ([Ni­(ATA)2(H2O)2]­(H2O)3) has been proposed. Nickel/nitrogen codoped carbon (Ni@NC) materials, serving as positive electrodes, deliver battery-type behavior with the enhancement of capacities, which are even superior to those of pristine carbon-based materials with large surface areas. Meanwhile, HCl-treated Ni@NC materials (named A-Ni@NC) are employed as negative electrodes within the potential window of −1 to 0 V and exhibit higher capacitances than that of the commercial activated carbon. With Ni@NC and A-Ni@NC as positive and negative electrodes in BSH devices, the as-fabricated cells display higher capacities and energy densities, more excellent cycling stability, and far superior capacity retention in comparison with those of Ni@NC//AC cells. These results clearly confirm that our strategy is successful and effective.