Competitive Coordination‐Oriented Monodispersed Ruthenium Sites in Conductive MOF/LDH Heteronanotree Catalysts for Efficient Overall Water Splitting in Alkaline Media

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 is considered an efficient but complicated strategy. Here, we report the fabrication of a cMOF/LDH heteronanotree catalyst (CoNiRu-NT) coupled with monodispersed ruthenium (Ru) sites via a controllable grafted-growth strategy. Rich-amino hexaiminotriphenylene (HITP) linkers coordinate with the LDH nanotrunk to form the cMOF nanobranch, providing numerous anchoring sites to precisely confine and stabilize Ru-N4 sites into the CoNiRu-NT heteronanotree structure. Moreover, monodispersed and reduced Ru moieties facilitate H2O adsorption and dissociation, and the heterointerface between the cMOF and LDH further modifies the chemical and electronic structures. The optimized heteronanotree array 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, heteronanotree 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 that of mostly reported MOF-based catalysts. This article is protected by copyright. All rights reserved