Dynamic Confinement and High-Entropy Catalytic Synergy Engineering in Hollow Nano-Metal-Organic Frameworks.

The systematic regulation of the pore size and chemical environment of nano-metal-organic skeletons (n-MOFs) has been challenged, making it difficult to study their structure-property relationships in depth. In this study, a universal dynamic template strategy is proposed and successfully achieves the controllable construction of various hollow n-MOFs (including ZIF-67, Co-BTC, etc.).

2D boehmite/mesoporous nanosphere composites with hierarchical ion transport for efficient capacitive deionization.

Mesoporous nanospheres coated with 2D boehmite nanosheets were synthesized. The hierarchical ion-transport networks within this engineered structure facilitate efficient Na transport. The optimized composite exhibits a high salt adsorption capacity (131.

Electrochemical Exfoliation of the Two-Dimensional Conjugated Metal-Organic Framework for High-Performance Urea Electrooxidation.

Two-dimensional (2D) conjugated metal-organic frameworks (c-MOFs) have attracted extensive interest in electrochemical fields due to their inherent electrical conductivity. However, the severe interlayer stacking still poses barriers toward their potential applications. The reliable synthesis of ultrathin c-MOF nanosheets is crucial yet remains challenging.

Nano-Metal-Organic Frameworks Isolated in Mesoporous Structures.

As an alternative to bulk counterparts, metal-organic framework (MOF) nanoparticles isolated within conductive mesoporous carbon matrices are of increasing interest for electrochemical applications. Although promising, a "clean" carbon surface is generally associated with poor compatibility and weak interactions with metal/ligand precursors, which leads to the growth of MOFs with inhomogeneous particle sizes on outer pore walls. Here, a general methodology for in situ synthesis of eight nanoMOF composites within mesochannels with high dispersity and stability are reported.

Self-Reconstruction of High Entropy Alloys for Efficient Alkaline Hydrogen Evolution.

Alkaline water (HO) electrolysis is currently a commercialized green hydrogen (H) production technology, yet the unsatisfactory hydrogen evolution reaction (HER) performance severely limits its energy conversion efficiency and cost reduction. Herein, PtRuFeCoNi high entropy alloys (HEAs) is synthesized and subsequently exploited electrochemically induced structural oxidation processes to construct self-reconfigurable HEAs, as an efficient alkaline HER catalyst. The optimized self-reconstructed PtRuFeCoNi HEAs with the HEAs and cobalt rutheniate interface (HEAs-CoRuO) exhibits excellent alkaline HER performance, requiring just 11.

Grain-Boundary-Rich Pt/CoO Nanosheets for Solar-Driven Overall Water Splitting.

Interfacial engineering is considered an effective strategy to improve the electrochemical water-splitting activity of catalysts by modulating the local electronic structure to expose more active sites. Therefore, we report a platinum-cobaltic oxide nanosheets (Pt/CoO NSs) with plentiful grain boundary as the efficient bifunctional electrocatalyst for water splitting. The Pt/CoO NSs exhibit a low overpotential of 55 and 201 mV at a current density of 10 mA cm for the hydrogen evolution reaction and oxygen evolution reaction in 1.

Immobilization of Metal Nanoparticles to an Ultrathin Two-Dimensional Conjugated Metal-Organic Framework for Synergistic Electrocatalysis.

Metal-organic frameworks (MOFs) have been considered as promising hosts for immobilizing ultrafine metal nanoparticles (MNPs) due to their high surface area and porosity. However, electrochemical applications of such emerging composites are severely limited by the poor electrical conductivity and large size of the MOFs. Herein, we report the general synthesis of incorporating various MNPs into a conjugated MOF ultrathin nanosheet (Cu-TCPP UNS) matrix, which not only prevents agglomeration and restricts the growth of MNPs but also benefits the exposure of active sites and the transport of electrons.

Interfacial engineering of ruthenium-nickel for efficient hydrogen electrocatalysis in alkaline medium.

Developing highly efficient electrocatalyst with heterostructure for hydrogen evolution and oxidation reactions (HER/HOR) in alkaline media is crucial to the fabrication and conversion of hydrogen energy but also remains a great challenge. Herein, the synthesis of ruthenium-nickel nanoparticles (Ru-Ni NPs) with heterostructure for hydrogen electrocatalysis is reported, and studies show that their catalytic activity is improved by electron redistribution caused by the distinctly heterogeneous interface. Impressively, Ru-Ni NPs possess the remarkable exchange current density (2.

Facilitating alkaline hydrogen evolution reaction on the hetero-interfaced Ru/RuO through Pt single atoms doping.

Exploring an active and cost-effective electrocatalyst alternative to carbon-supported platinum nanoparticles for alkaline hydrogen evolution reaction (HER) have remained elusive to date. Here, we report a catalyst based on platinum single atoms (SAs) doped into the hetero-interfaced Ru/RuO support (referred to as Pt-Ru/RuO), which features a low HER overpotential, an excellent stability and a distinctly enhanced cost-based activity compared to commercial Pt/C and Ru/C in 1 M KOH. Advanced physico-chemical characterizations disclose that the sluggish water dissociation is accelerated by RuO while Pt SAs and the metallic Ru facilitate the subsequent H* combination.

Recent Progress in 2D Metal-Organic Framework-Related Materials.

2D metal-organic frameworks-based (2D MOF-related) materials benefit from variable topological structures, plentiful open active sites, and high specific surface areas, demonstrating promising applications in gas storage, adsorption and separation, energy conversion, and other domains. In recent years, researchers have innovatively designed multiple strategies to avoid the adverse effects of conventional methods on the synthesis of high-quality 2D MOFs. This review focuses on the latest advances in creative synthesis techniques for 2D MOF-related materials from both the top-down and bottom-up perspectives.

2D MOF-assisted Pyrolysis-displacement-alloying Synthesis of High-entropy Alloy Nanoparticles Library for Efficient Electrocatalytic Hydrogen Oxidation.

Multimetallic alloy nanoparticles (NPs) have received considerable attention in various applications due to their compositional variability and exceptional properties. However, the complexity of both the general synthesis and structure-activity relationships remain the long-standing challenges in this field. Herein, we report a versatile 2D MOF-assisted pyrolysis-displacement-alloying route to successfully synthesize a series of binary, ternary and even high-entropy NPs that are uniformly dispersed on porous nitrogen-doped carbon nanosheets (PNC NSs).

Stable and Ordered Body-Centered Cubic PdCu Phase for Highly Selective Hydrogenation.

Phase engineering of nanomaterials plays a crucial role for regulating the catalytic performance. Nevertheless, great challenges still remain for elucidating the structure-selectivity correlation. Herein, this study demonstrates that the body-centered cubic phase of PdCu (bcc-PdCu) can serve as a highly active and selective catalyst for 3-nitrostyrene (NS) hydrogenation under mild conditions.

Synergistic Mechanism of Sub-Nanometric Ru Clusters Anchored on Tungsten Oxide Nanowires for High-Efficient Bifunctional Hydrogen Electrocatalysis.

The construction of strong interactions and synergistic effects between small metal clusters and supports offers a great opportunity to achieve high-performance and cost-effective heterogeneous catalysis, however, studies on its applications in electrocatalysis are still insufficient. Herein, it is reported that W O nanowires supported sub-nanometric Ru clusters (denoted as Ru SNC/W O NWs) constitute an efficient bifunctional electrocatalyst for hydrogen evolution/oxidation reactions (HER and HOR) under acidic condition. Microstructural analyses, X-ray absorption spectroscopy, and density functional theory (DFT) calculations reveal that the Ru SNCs with an average RuRu coordination number of 4.

MXene-Copper/Cobalt Hybrids via Lewis Acidic Molten Salts Etching for High Performance Symmetric Supercapacitors.

MXenes have attracted great interests as supercapacitors due to their metallic conductivity, high density, and hydrophilic nature. Herein we report Ti C -Cu/Co hybrids via molten salt etching in which the existence of metal atoms and their interactions with MXene via surficial O atoms were elucidated by XAFS for the first time. The electrochemical investigation of Ti C -Cu electrode demonstrated the pseudocapacitive contribution of Cu and a splendid specific capacitance of 885.

Compressive Strain in N-Doped Palladium/Amorphous-Cobalt (II) Interface Facilitates Alkaline Hydrogen Evolution.

The development of palladium-based catalysts for alkaline hydrogen evolution reaction (HER) is highly desired for renewable hydrogen energy systems, yet still challenging due to the strong palladium-hydrogen bond. Herein, the bottleneck is largely overcome by constructing a nitridation-induced compressively strained-interface N-doped palladium/amorphous cobalt (II) interface (N-Pd/A-Co(II)), which dramatically boosts HER performance in alkaline condition. The optimized catalyst with the compressive strain of 2.

Partially hydroxylated ultrathin iridium nanosheets as efficient electrocatalysts for water splitting.

Ultrathin two-dimensional (2D) materials have attracted considerable attention for their unique physicochemical properties and promising applications; however, preparation of freestanding ultrathin 2D noble metal remains a significant challenge. Here, for the first time, we report use of a wet-chemical method to synthesize partially hydroxylated ultrathin Ir nanosheets (Ir-NSs) of only five to six atomic layers' thickness. Detailed analysis indicates that the growth confinement effect of carbon monoxide and the partially hydroxylated surface play a critical role in formation of the ultrathin structure.

Spin Regulation on 2D Pd-Fe-Pt Nanomeshes Promotes Fuel Electrooxidations.

Spin engineering provides a powerful strategy for manipulating the interaction between electrons in the d orbital and oxygen-containing adsorbates, while a little endeavor was performed to understand whether such a strategy can make a prosperous enhancement for fuel electrooxidations. Herein, we demonstrate that spin engineering of trimetallic Pd-Fe-Pt nanomeshes (NMs) can achieve superior enhancement for fuel electrooxidations. Magnetization characterizations reveal that PdFePt NMs own the highest number of polarized spins (μ = 0.

Double Perovskite LaFe Ni O Nanorods Enable Efficient Oxygen Evolution Electrocatalysis.

Perovskite-based electrocatalysts are one of the most promising materials for oxygen evolution reaction (OER), but their activity and durability are still far from desirable. Herein, we demonstrate that the double perovskite LaFe Ni O (LFNO) nanorods (NRs) can be adopted as highly active and stable OER electrocatalysts. The optimized LFNO-II NRs with Ni/Fe ratio of 8:2 achieve a low overpotential of 302 mV at 10 mA cm and a small Tafel slope of 50 mV dec , outperforming those of the commercial Ir/C.

Phase and structure engineering of copper tin heterostructures for efficient electrochemical carbon dioxide reduction.

While engineering the phase and structure of electrocatalysts could regulate the performance of many typical electrochemical processes, its importance to the carbon dioxide electroreduction has been largely unexplored. Herein, a series of phase and structure engineered copper-tin dioxide catalysts have been created and thoroughly exploited for the carbon dioxide electroreduction to correlate performance with their unique structures and phases. The copper oxide/hollow tin dioxide heterostructure catalyst exhibits promising performance, which can tune the products from carbon monoxide to formic acid at high faradaic efficiency by simply changing the electrolysis potentials from -0.

Dynamic Structure Evolution of Composition Segregated Iridium-Nickel Rhombic Dodecahedra toward Efficient Oxygen Evolution Electrocatalysis.

The anodic oxygen evolution reaction (OER) is central to various energy conversion devices, but the investigation of the dynamic evolution of catalysts in different OER conditions remains quite limited, which is unfavorable for the understanding of the actual structure-activity relationship and catalyst optimization. Herein, we constructed monodispersed IrNi nanoparticles (NPs) with distinct composition-segregated features and captured their structural evolution in various OER environments. We decoded the interesting self-reconstruction of IrNi NPs during the OER, in which an Ir-skin framework is generated in an acidic electrolyte, while a Ni-rich surface layer is observed in an alkaline electrolyte owing to Ni migration.

Enhancing Oxygen Evolution Electrocatalysis via the Intimate Hydroxide-Oxide Interface.

The development of electrocatalysts with high activity and stability for oxygen evolution reaction (OER) is critically important, the one being regarded as the bottleneck process of overall water splitting. Herein, we fulfill significant OER improvement in both activity and stability by constructing a class of Ni(OH)-CeO supported on carbon paper (Ni Ce @CP) with an intimate hydroxide (Ni(OH))-oxide (CeO) interface. Such interface largely promotes the OER activity with a low overpotential of 220 mV at 10 mA cm and a small Tafel slope of 81.