High-entropy alloy (HEA)-based materials are expected to be promising oxygen electrocatalysts due to their exceptional properties. The electronic structure regulation of HEAs plays a pivotal role in enhancing their elctrocatalytic ability. Herein, PtFeCoNiMn nanoparticles (NPs) with subtle lattice distortions are constructed on metal-organic framework-derived nitrogen-doped carbon by an ultra-rapid Joule heating process. Thanks to the modulated electronic structure and the inherent cocktail effect of HEAs, the as-synthesized PtFeCoNiMn/NC exhibits superior bifunctional electrocatalytic performance with a positive half-wave potential of 0.863 V vs. reversible hydrogen electrode (RHE) for oxygen reduction reaction and a low overpotential of 357 mV at 10 mA·cm^–2 for oxygen evolution reaction. The assembled quasi-solid-state zinc-air battery using PtFeCoNiMn/NC as air electrode shows a high peak power density of 192.16 mW·cm^–2, low charge−discharge voltage gap, and excellent durability over 500 cycles at 5 mA·cm^–2. This work demonstrates an effective route for rational design of bifunctional nanostructured HEA electrocatalysts with favorable electronic structures, and opens up a fascinating directions for energy storage and conversion, and beyond.

Two-dimensional metal–organic frameworks (2D MOFs), as a new type of 2D materials, have been widely applied in various applications because of their unique structures and exposed active sites. Herein, we reported two low-cost 2D MOFs constructed by a raw chemical succinic acid (SA), M-SA (M = Ni or Co), which served as efficient photocatalysts for the reduction of CO₂ to CO. Taking advantage of the thinness and open metal sites, the ultrathin Ni-SA nanosheets (ca. 3.6 nm) exhibited excellent CO production of 6.96(7) mmol·g⁻¹·h⁻¹ and CO selectivity of 96.6%. Photoelectrochemical tests and theoretical calculations further confirmed the higher charge transfer efficiency and unsaturated metal sites for promoting photocatalytic performances. More importantly, Ni-SA can also be synthesized in large-scale by an energy-saving method under room temperature, strongly suggesting its promising future and potential for practical applications.

Cu-based materials are seldom reported as oxygen evolution reaction (OER) electrocatalysts due to their inherent electron orbital configuration, which makes them difficult to adsorb oxygen-intermediates during OER. Reasonably engineering the hierarchical architectures and the electronic structures can improve the performance of Cu-based OER catalysts, such as constructing multilevel morphology, inducing the porous materials, improving the Cu valence, building heterostructures, doping heteroatoms, etc. In this work, copper-1,3,5-benzenetricarboxylate (HKUST-1) octahedra in-situ grow on the Cu nanorod (NR)-supported N-doped carbon microplates, meanwhile an active layer of Cu(OH)₂ forms on the surface of the original conductive Cu NRs. The octahedral HKUST-1, serving as a spacer between the microplates, greatly improves the porosity and increases the available active sites, facilitating the mass transport and electron transfer, thus resulting in greatly enhanced OER performance.

The practical application of Li-S batteries is largely impeded by the “shuttle effect” generated at the cathode which results in a short life cycle of the battery. To address this issue, this work discloses a bimetallic metal-organic framework (MOF) as a sulfur host material based on Al-MOF, commonly called (Al)MIL-53. To obtain a high-adsorption capacity to lithium polysulfides (Li₂S_x, 4 ≤ x ≤ 8), we present an effective strategy to incorporate sulfiphilic metal ion (Cu²⁺) with high-binding energy to Li₂S_x into the framework. Through a one-step hydrothermal method, Cu²⁺ is homogeneously dispersed in Al-MOF, producing a bimetallic Al/Cu-MOF as advanced cathode material. The macroscopic Li₂S₄ solution permeation test indicates that the Al/Cu-MOF has better adsorption capacity to lithium polysulfides than monometallic Al-MOF. The sulfur-transfusing process is executed via a melt-diffusion method to obtain the sulfur-containing Al/Cu-MOF (Al/Cu-MOF-S). The assembled Li-S batteries with Al/Cu-MOF-S yield improved cyclic performance, much better than that of monometallic Al-MOF as sulfur host. It is shown that chemical immobilization is an effective method for polysulfide adsorption than physical confinement and the bimetallic Al/Cu-MOF, formed by incorporation of sulfiphilic Cu²⁺ into porous MOF, will provide a novel and powerful approach for efficient sulfur host materials.