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.

Oxygen reduction reaction (ORR) activity can be effectively tuned by modulating the electron configuration and optimizing the chemical bonds. Herein, a general strategy to optimize the activity of metal single‐atoms is achieved by the decoration of metal clusters via a coating–pyrolysis–etching route. In this unique structure, the metal clusters are able to induce electron redistribution and modulate M−N species bond lengths. As a result, M‐ACSA@NC exhibits superior ORR activity compared with the nanoparticle‐decorated counterparts. The performance enhancement is attributed to the optimized intermediates desorption benefiting from the unique electronic configuration. Theoretical analysis reinforces the significant roles of metal clusters by correlating the ORR activity with cluster‐induced charge transfer. As a proof‐of‐concept, various metal–air batteries assembled with Fe‐ACSA@NC deliver remarkable power densities and capacities. This strategy is an effective and universal technique for electron modulation of M−N−C, which shows great potential in application of energy storage devices.

Engineering of structure and composition is essential but still challenging for electrocatalytic activity modulation. Herein, hybrid nanostructured arrays (HNA) with branched and aligned structures constructed by cobalt selenide (CoSe2) nanotube arrays vertically oriented on carbon cloth with CoNi layered double hydroxide (CoSe2@CoNi LDH HNA) are synthesized by a hydrothermal‐selenization‐hybridization strategy. The branched and hollow structure, as well as the heterointerface between CoSe2 and CoNi LDH guarantee structural stability and sufficient exposure of the surface active sites. More importantly, the strong interaction at the interface can effectively modulate the electronic structure of hybrids through the charge transfer and then improves the reaction kinetics. The resulting branched CoSe2@CoNi LDH HNA as trifunctional catalyst exhibits enhanced electrocatalytic performance toward oxygen evolution/reduction and hydrogen evolution reaction. Consequently, the branched CoSe2@CoNi LDH HNA exhibits low overpotential of 1.58 V at 10 mA cm−2 for water splitting and superior cycling stability (70 h) for rechargeable flexible Zn‐air battery. Theoretical calculations reveal that the construction of heterostructure can effectively lower the reaction barrier as well as improve electrical conductivity, consequently favoring the enhanced electrochemical performance. This work concerning engineering heterostructure and topography‐performance relationship can provide new guidance for the development of multifunctional electrocatalysts.

This work provides various methods for understanding the mechanism of a novel spinel high-entropy oxide (Ni0.2Co0.2Mn0.2Fe0.2Ti0.2)3O4 in energy storage applications.

To examine the quenching of a triplet exciton by low triplet energy (E(T)) polymer hosts with different chain configurations for high E(T) phosphor guests, the quenching rate constant measurements were carried out and analyzed by the standard Stern-Volmer equation. We found that an effective shielding of triplet energy transfer from a high E(T) phosphor guest to a low E(T) polymer host is possible upon introducing dense side chains to the polymer to block direct contact from the guest such that the possibility of Dexter energy transfer between them is reduced to a minimum. Together with energy level matching to allow charge trapping on the guest, high device efficiency can be achieved. The extent of shielding for the systems of phenylene-based conjugated structures from iridium complexes follows the sequence di-substituted (octoxyl chain) in the para position (dC8OPPP) is greater than monosubstituted (mC8OPPP) and the PPPs with longer side chains are much higher than a phenylene tetramer (P4) with two short methyl groups. Further, capping the dialkoxyl-susbstituents with a carbazole (Cz) moiety (CzPPP) provides enhanced extent of shielding. Excellent device efficiency of 30 cd/A (8.25%) for a green electrophosphorescent device can be achieved with CzPPP as a host, which is higher than that of dC8OPPP as host (15 cd/A). The efficiency is higher than those of high E(T) conjugated polymers, poly(3,6-carbazole) derivatives, as hosts (23 cd/A). This observation suggests a new route for molecular design of electroluminescent polymers as a host for a phosphorescent dopant.