Ir Nanoparticles Anchored on Metal‐Organic Frameworks for Efficient Overall Water Splitting under pH‐Universal Conditions

Abstract

The construction of high‐activity and low‐cost electrocatalysts is critical for efficient hydrogen production by water electrolysis. Herein, we developed an advanced electrocatalyst by anchoring well‐dispersed Ir nanoparticles on nickel metal‐organic framework (MOF) Ni‐NDC (NDC: 2,6‐naphthalenedicarboxylic) nanosheets. Benefiting from the strong synergy between Ir and MOF through interfacial Ni−O−Ir bonds, the synthesized Ir@Ni‐NDC showed exceptional electrocatalytic performance for hydrogen evolution reaction (HER), oxygen evolution reaction (OER) and overall water splitting in a wide pH range, superior to commercial benchmarks and most reported electrocatalysts. Theoretical calculations revealed that the charge redistribution of Ni−O−Ir bridge induced the optimization of H2O, OH* and H* adsorption, thus leading to the accelerated electrochemical kinetics for HER and OER. This work provides a new clue to exploit bifunctional electrocatalysts for pH‐universal overall water splitting.

Recent advanced strategies for bimetallenes toward electrocatalytic energy conversion reactions

“…Among various technologies for hydrogen generation, overall water splitting can produce carbon-free H 2 without consuming fossil fuels. 33,34 However, the reaction occurring at the anode can raise problems. The oxygen evolution reaction (OER) requires a high overpotential, leading to unsatisfactory overall water splitting.…”

Ultrafine Iridium Nanoparticles Anchored on Co-Based Metal–Organic Framework Nanosheets for Robust Hydrogen Evolution in Alkaline Media

“…43,44 Li and co-workers reported a catalyst with improved HER performance by incorporating Ir NPs into Ni-NDC, and the Ir@Ni-NDC had an optimal Ir content of 9.72 wt %. 45 of noble-metal NPs. 26,46,47 Therefore, it is necessary and of great significance to investigate the HER catalytic behavior of 2D MOFs loaded with a low-mass ratio of noble metal and uncover the underlying electrocatalytic mechanism.…”

“…Iridium (Ir) offers distinct advantages over Ru as a catalyst, particularly in electrocatalytic applications like HER. − Ir stands out for its remarkable efficacy even at lower loadings, offering a more cost-efficient solution by requiring less material to attain high performance. , Furthermore, it demonstrates superior resistance to catalyst poisoning and boasts enhanced stability against oxidation and leaching, effectively addressing common drawbacks associated with platinum (Pt) and Ru. − The synergistic interaction between iridium and the support materials within the catalyst structures significantly enhances its overall performance. This synergy elevates iridium to a position of high value for advanced electrocatalytic applications, leveraging its distinct properties for ground-breaking results. , Li and co-workers reported a catalyst with improved HER performance by incorporating Ir NPs into Ni-NDC, and the Ir@Ni-NDC had an optimal Ir content of 9.72 wt % . All of the above MOFs-based catalysts have demonstrated high catalytic activity due to the formation of M–O–M bonds at the interface and avoiding the aggregation of noble-metal NPs. ,, Therefore, it is necessary and of great significance to investigate the HER catalytic behavior of 2D MOFs loaded with a low-mass ratio of noble metal and uncover the underlying electrocatalytic mechanism.…”

Nitrogen Plasma Activates CoMn-Layered Double Hydroxides for Superior Electrochemical Oxygen Evolution

“…Recently, transition metal-based compounds have become an ideal choice to replace precious metal catalysts because of their abundant reserves and adjustable structural properties. , For example, oxides, , hydroxides, , layered double hydroxides (LDH), − metal organic frameworks (MOFs), − and their derivatives have attracted lots of research interests. Among them, the LDHs are an important kind of two-dimensional layered anionic clay, which consists of positively charged layers (brucite-like M(OH) 6 octahedron) and anions between layers. − LDHs possess many advantages, such as the adjustable chemical composition of layers, easy exchange of anions between layers, structural topological transformation, high specific surface area, etc. ,, As catalysts themselves, catalyst carriers, or catalyst precursors, LDHs exhibit many important applications in photocatalysis and electrocatalysis. , In particular, Co–Mn-based double-layer hydroxide has become one of the most active materials in electrolytic water oxidation because of its low cost and easy control of structure .…”