Electronic Modulation Caused by Interfacial Ni‐O‐M (M=Ru, Ir, Pd) Bonding for Accelerating Hydrogen Evolution Kinetics

Abstract

Designing definite metal‐support interfacial bond is an effective strategy for optimizing the intrinsic activity of noble metals, but rather challenging. Herein, a series of quantum‐sized metal nanoparticles (NPs) anchored on nickel metal–organic framework nanohybrids (M@Ni‐MOF, M=Ru, Ir, Pd) are rationally developed through a spontaneous redox strategy. The metal‐oxygen bonds between the NPs and Ni‐MOF guarantee structural stability and sufficient exposure of the surface active sites. More importantly, such precise interfacial feature can effectively modulate the electronic structure of hybrids through the charge transfer of the formed Ni‐O‐M bridge and then improves the reaction kinetics. As a result, the representative Ru@Ni‐MOF exhibits excellent hydrogen evolution reaction (HER) activity at all pH values, even superior to commercial Pt/C and recent noble‐metal catalysts. Theoretical calculations deepen the mechanism understanding of the superior HER performance of Ru@Ni‐MOF through the optimized adsorption free energies of water and hydrogen due to the interfacial‐bond‐induced electron redistribution.

Interfacial Fe−O−Ni−O−Fe Bonding Regulates the Active Ni Sites of Ni‐MOFs via Iron Doping and Decorating with FeOOH for Super‐Efficient Oxygen Evolution

“…In addition, the strong bands of Fe-doped-(Ni-MOFs)/FeOOH at 1578 and 1377 cm À 1 correspond to the antisymmetric and asymmetric stretching vibration of the coordinated (À COO) group, [28] which shifts to higher frequencies compared with those of Ni-MOFs and Fedoped-(Ni-MOFs), indicating the coordination of carboxylic acid groups with FeOOH. [29] The other two peaks of Fedoped-(Ni-MOFs)/FeOOH at 1500 and 1068 cm À 1 can be attributed to the stretching vibrations of CÀ H and OÀ H bonding, [30] respectively. The Raman spectrum of Fe-doped-(Ni-MOFs)/FeOOH in Figure S9 shows new FeÀ O vibration modes for FeOOH at 314, 675 and 706 cm À 1 .…”

Recent Development of Polyaniline/graphene Composite Electrodes for Flexible Supercapacitor Devices

“…[65] Furthermore, a porous structure effectively improves the performance of a supercapacitor by providing a facile path for ionic diffusions and an expansive surface area for the electrochemical reactions. [32,66] The construction of this structure is considerably tricky as the pore size should be small enough to enlarge the surface area, but wide enough to allow rapid ion transport at the same time. [67] The three-dimensional porous electrode can be built on a flexible substrate or in free-standing forms.…”

“…The interconnected structure offers high mechanical strength to retain structural robustness during deformations [65] . Furthermore, a porous structure effectively improves the performance of a supercapacitor by providing a facile path for ionic diffusions and an expansive surface area for the electrochemical reactions [32,66] . The construction of this structure is considerably tricky as the pore size should be small enough to enlarge the surface area, but wide enough to allow rapid ion transport at the same time [67] …”

Construction of Ru/FeCoP heterointerface to drive dual active site mechanism for efficient overall water splitting

“…31 Therefore, it is crucial to use interfacial engineering strategies to readjust the electron density around Ru and optimize the adsorption of reaction intermediates. 32,33 Mu and coworkers constructed an Ru/RuS 2 heterointerface through in situ phase separation technology, exhibiting splendid acidic HER and OER activities due to the optimization of the electronic structure of Ru. 34 Chen's group and Steven's group both designed Ru/RuO 2 catalysts with high alkaline electrocatalytic activity.…”