The conjugation of metal–organic frameworks (MOFs) into different multicomponent materials to precisely construct aligned heterostructures is fascinating but elusive owing to the disparate interfacial energy and nucleation kinetics. Herein, a promising lattice‐matching growth strategy is demonstrated for conductive MOF/layered double hydroxide (cMOF/LDH) heteronanotube arrays with highly ordered hierarchical porous structures enabling an ultraefficient oxygen evolution reaction (OER). CoNiFe‐LDH nanowires are used as interior template to engineer an interface by inlaying cMOF and matching two crystal lattice systems, thus conducting a graft growth of cMOF/LDH heterostructures along the LDH nanowire. A class of hierarchical porous cMOF/LDH heteronanotube arrays is produced through continuously regulating the transformation degree. The synergistic effects of the cMOF and LDH components significantly promote the chemical and electronic structures of the heteronanotube arrays and their electroactive surface area. Optimized heteronanotube arrays exhibit extraordinary OER activity with ultralow overpotentials of 216 and 227 mV to deliver current densities of 50 and 100 mA cm−2 with a small Tafel slope of 34.1 mV dec−1, ranking it among the best MOF and non‐noble‐metal‐based catalysts for OER. The robust performance under high current density and vigorous gas bubble conditions enable such hierarchical MOF/LDH heteronanotube arrays as promising materials for practical water electrolysis.

production of pure H 2 ; this technique can be coupled with other instantaneous energy conversion techniques. [2] However, the sluggish reaction kinetics of both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) limit the application of water splitting. [3] So far, ruthenium-(Ru-), iridium-(Ir-), and platinum-(Pt-) based materials, such as noble metal oxides, [4] noble-metal single-atom catalysts, [5] and hetero-structured noblemetal-based catalysts [6] are still the most efficient HER and OER catalysts. However, their high costs and low stability greatly limit their practical application. Great efforts has been devoted to exploring novel inexpensive bifunctional catalysts for efficient overall water splitting. [7] In particular, the development of non-noble-metal-based catalysts under alkaline conditions, which require several-fold high catalytic activity due to the ultralow proton activity in alkaline solution, was found to be an attractive but challenging approach. [8] Dispersing ultralow-content noble metals on nonprecious material platforms is an effective improvement strategy. This approach not only improves the adsorption capabilities of hydrogen-and oxygencontaining intermediates and accelerates the reaction kinetics of both the HER and OER, [9] but also balances the performance and cost. Multimetal-based layered double hydroxides (LDHs) can be utilized as support materials owing to their low cost, Rational exploration of efficient, inexpensive, and robust electrocatalysts is critical for the efficient water splitting. Conjugated conductive metal-organic frameworks (cMOFs) with multicomponent layered double hydroxides (LDHs) to construct bifunctional heterostructure catalysts are considered as an efficient but complicated strategy. Here, the fabrication of a cMOF/ LDH hetero-nanotree array catalyst (CoNiRu-NT) coupled with monodispersed ruthenium (Ru) sites via a controllable grafted-growth strategy is reported. Rich-amino hexaiminotriphenylene linkers coordinate with the LDH nanotrunk to form cMOF nanobranches, providing numerous anchoring sites to precisely confine and stabilize RuN 4 sites. Moreover, mono dispersed and reduced Ru moieties facilitate H 2 O adsorption and dissociation, and the heterointerface between the cMOF and the LDH further modifies the chemical and electronic structures. Optimized CoNiRu-NT displays a significant increase in electrochemical water-splitting properties in alkaline media, affording low overpotentials of 22 mV at 10 mA cm −2 and 255 mV at 20 mA cm −2 for the hydrogen evolution reaction and oxygen evolution reaction, respectively. In an actual electrochemical system, CoNiRu-NT drives an overall water splitting at a low cell voltage of 1.47 V to reach 10 mA cm −2 . This performance is comparable to that of pure noble-metal-based materials and superior to most reported MOF-based catalysts.

Design an in-situ semi-transformation strategy for the development of Fe-Ni LDH/MOF hierarchical architecture exhibiting large accessible surface, open electron transport channel and multiple active sites to promote the electrocatalytic capacity.

Precise design of low‐cost, efficient and definite electrocatalysts is the key to sustainable renewable energy. Herein, this work develops a targeted‐anchored and subsequent spontaneous‐redox strategy to synthesize nickel‐iron layered double hydroxide (LDH) nanosheets anchored with monodispersed platinum (Pt) sites (Pt@LDH). Intermediate metal‐organic frameworks (MOF)/LDH heterostructure not only provides numerous confine points to guarantee the stability of Pt sites, but also excites the spontaneous reduction for PtII. Electronic structure, charge transfer ability and reaction kinetics of Pt@LDH can be effectively facilitated by the monodispersed Pt moieties. As a result, the optimized Pt@LDH that with the 5% ultra‐low content Pt exhibits the significant increment in electrochemical water splitting performance in alkaline media, which only afford low overpotentials of 58 mV at 10 mA cm−2 for hydrogen evolution reaction (HER) and 239 mV at 10 mA cm−2 for oxygen evolution reaction (OER), respectively. In a real device, Pt@LDH can drive an overall water‐splitting at low cell voltage of 1.49 V at 10 mA cm−2, which can be superior to most reported similar LDH‐based catalysts. Moreover, the versatility of the method is extended to other MOF precursors and noble metals for the design of ultrathin LDH supported monodispersed noble metal electrocatalysts promoting research interest in material design.

It is crucial to design highly selective and cost-effective materials for the efficient CO2 uptake and the desirable transformation of CO2 into fuels or high-value chemical products. Here, we synthesize...