Porous and hollow nanomaterials have been an exciting research area for numerous next-generation technological applications. However, it is still a challenge to assemble porous and hollow nanostructures of appropriate composition and characteristics in designed architectures. Here, we report a self-templated metal− organic frameworks based strategy for the synthesis and engineering of porous and hollow nanostructures in designed architectures by developing graphitic-carbonintermingled porous Co 3 O 4 nanotentacles, for the first time, on electrospun hollow carbon nanofibers in a designed 3D pattern (3D Co 3 O 4 /C@HCNFs). The asdeveloped nanocomposite sheet, as a free-standing electrode for supercapacitors, shows a high specific capacity of 199 mA h g −1 (1623 F g −1 ) at 1 A g −1 with good cyclic life and outstanding rate capability. Moreover, the assembled asymmetric supercapacitor device supplies an energy density of 36.6 W h kg −1 at the power density of 471 W kg −1 with significant cyclic life and rate capability indicating its potential practical application. This synthetic strategy suggests a simple, cost-effective and convenient route for the synthesis and assembly of porous and hollow structured nanomaterials in designed architectures for diverse applications.

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The development of bifunctional, highly active electrocatalysts for an overall water splitting reaction remains a major challenge. Here, the sacrificial template-assisted transformation of cobalt hydroxide nanowire (Co(OH) 2 NW) into a metal−organic framework network (MOF) is conceived as a porous structure that provides extremely active and durable electrochemical energy conversion characteristics. After this, the 1D MOF modified Co NWs can be further transformed into a hybrid structure (MOF CoSeO 3 NWs) by selenization. The self-template transformation strategy allows the interconnected porous conductive network to be exposed to abundant reactive sites and to improve electronic conductivity/structural integrity. Thus, the obtained catalyst established by electrocatalytic activity in the course of the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER) in 1 M KOH solution requires overpotentials (η) of 290 and 150 mV to achieve a current density of 50 and 10 mA cm −2 for both OER and HER. Interestingly, as a full cell water electrolyzer (MOF CoSeO 3 NWs (+) // MOF CoSeO 3 NWs (−)), the MOF CoSeO 3 NW's modified electrode exhibits an affordable cell voltage of 1.675 V at a current density of 100 mA cm −2 . This work involves a viable and systematic strategy to prepare many other functional integrated MOFs that can be used for energy storage and conversion in multiple applications.

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The fast development of portable water-splitting devices has led to a great deal of work on rechargeable metal–air batteries or solar cells; however, the lack of affordable multifunctional electrocatalysts still hampers their widespread applications. Herein, a well-aligned ternary metal (oxy)­hydroxide nanostructure is a sacrificial pseudomorphic transformation template of an integrated metal–organic network on the carbon cloth (CC) surface, that is, the Fe-doped metal–organic framework (MOF) ZnNiCoSe@CC nanosheet network, exhibiting powerful and efficient multifunctional electrocatalysts such as the oxygen reduction reaction, oxygen evolution reaction, and hydrogen evolution reaction in alkaline media combined with desirable electrode kinetics. As a proof-of-concept observational study, the nanostructured Fe-doped MOF ZnNiCoSe@CC could be used as air-cathode materials in the rechargeable metal–air battery. The fabricated device delivered higher open-circuit voltage, higher capacity, and peak power density, excellent discharge–charge performance, and long cycle life. Thus, our research creates a unique perspective on the development of highly portable air electrodes with a favorable electrocatalytic application of overall water-splitting reaction.

Large reversible biaxial (xy) stretching in energy storage devices is now an urgent requirement for the field of stretchable electronics to enable reliability in practical applications. Here, a fascinating stretching machine is designed and used for xy‐stretching of a high‐performance supercapacitor device without performance degradation. A trimetallic metal organic framework (MOF)‐derived ternary metal oxide on graphitic‐2200 knitted carbon fiber (MOF‐ZNCO@g‐KCF), activated carbon loaded onto drilled knitted carbon fiber (AC@g‐KCF‐d), and a poly‐vinyl alcohol, poly‐ethylene oxide, and potassium hydroxide (PVA/PEO/KOH) based hydrogel polymer film are used as a faradic cathode, a double layer anode, and an electrolyte, respectively, to integrate the biaxially stretchable asymmetric supercapacitor (BSASC) device. The fabricated MOF‐ZNCO@g‐KCF//AC@g‐KCF‐d BSASC maintains an outstanding performance consistency at different xy‐stretched conditions, even after repeated deformations. Notably, after 10 000 galvanostatic charge–discharge cycles, the BSASC in the xy‐biaxial stretched condition is retained at 93.7%, and after 100 successive stretch–relax cycles for the same stretching dimension it still retains a 92.48% capacity, demonstrating excellent mechanical and electrochemical stability. The exceptional performance consistency in the xy‐stretched position, demonstrates that the BSASC is one of the best performers among the stretchable supercapacitors reported to date.

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