Electronic modulation by interfacial bridging between Ir nanoparticle and metal–organic framework to enhance hydrogen evolution

Abstract

In the quest for amplifying the inherent capabilities of noble metals, crafting precise metal–support interfacial bonds stands as a challenging yet fruitful endeavor. Here, we introduce an approach to synthesize exceptionally small metal nanoparticles (NPs), which are securely anchored onto cobalt-based metal–organic framework (Co-MOF) nanosheets through a wet chemical method. The creation of metal–oxygen linkages between these Ir NPs and Co-MOF not only guarantees structural robustness but also ensures a generous exposure of active sites. Importantly, the distinct interface fine-tunes the electronic configuration of the composites by facilitating charge transfer along the Ir–O–Co pathway, consequently boosting the reaction dynamics. As a result, the hydrogen evolution reaction (HER) performance of our pioneering product, Ir@Co-MOF, in alkaline media, rivals that of the benchmark Pt/C catalyst and surpasses other recent noble metal catalysts. Theoretical analysis reveals that the exceptional HER efficiency of Ir@Co-MOF originates from the optimal adsorption energies for water and hydrogen, a consequence of electron re-allocation owing to its unique interfacial bond.