Nanoporous Graphene with Encapsulated Multicomponent Carbide as High-Performance Binder-Free Lithium-Ion Battery Anodes.

Metal carbides are considered attractive lithium-ion battery (LIB) anode materials. Their potential practical application, however, still needs nanostructure optimization to further enhance the Li-storage capacity, especially under large current densities. Herein, a nanoporous structured multi-metal carbide is designed, which is encapsulated in a 3D free-standing nanotubular graphene film (MnNiCoFe-MoC@NG).

Thermodynamics and kinetics of lithiation-induced phase transitions in nanoporous antimony.

The impact of nanosizing on the phase transition mechanisms of electrode materials is still not well understood. In this study, we reveal that nanosizing can lower the energy barrier and entropy changes associated with phase transformations, ultimately improving the electrochemical performance of nanoporous antimony electrodes in comparison to microsized antimony.

Enhanced Structure Stability of Au Nanobipyramids by an Customized Silver Armor.

Revealing the structure stability and evolution of gold nanocrystals at the atomic scale is crucial to their versatile applications; however, the fundamental mechanism remains elusive due to the lack of characterizations. In this work, the structural evolution of two types of Au nanobipyramids (Au NBPs) at elevated temperatures is monitored through electron microscopy analysis, and there is a sharp distinction between their structure stability despite that they possess the same crystalline structure. Detailed material characterization reveals that the surface alloying of residual Ag with Au (customized Ag armor) can greatly inhibit the Au atom diffusion and contribute remarkably to the stability and surface-enhanced Raman scattering improvement.

Designing cobalt-nickel dual-atoms on boron, nitrogen-codoped carbon nanotubes for carbon dioxide electroreduction to syngas.

Developing highly efficient electrocatalysts to produce syngas with a stable hydrogen/carbon monoxide (H/CO) ratio in a wide potential window via electrochemical carbon dioxide (CO) reduction is desperately required but still challenging. Herein, a dual-atomic site on boron, nitrogen-codoped carbon nanotubes (BCN) has been designed, containing both cobalt (CoN) and nickel (NiNB) sites. Benefiting from the structure advantage and the bifunctional Co/Ni sites, such designed catalyst (CoNi-BCN) demonstrates remarkable performance for syngas production, achieving a stable H/CO ratio of 1.

N, S-Codoped 3D Carbon Protected Nanoporous MnS With Record High Sodium Ion Storage Performance for Potential Industry Applications.

With a high theoretical capacity, the MnS anode, however, exhibits a rather complex sodium diffusion kinetics and poor mechanical stability that hinder its application in sodium-ion batteries (SIBs). In this work, a simple, economical, and scalable strategy is developed to inherently coat nanoporous MnS with a 3D N, S co-doped thin carbon layer by using commercially available MnCO as precursors. Specifically, the strategy involves a two-step annealing process, which converts the MnCO microparticles into nanoporous MnO and MnS step by step.

Multi-Component and Nanoporous Design toward RuO-Based Electrocatalyst with Enhanced Performance for Acidic Water Splitting.

Developing electrocatalysts with excellent activity and stability for water splitting in acidic media remains a formidable challenge due to the sluggish kinetics and severe dissolution. As a solution, a multi-component doped RuO prepared through a process of dealloying-annealing is presented. The resulting multi-doped RuO possesses a nanoporous structure, ensuring a high utilization efficiency of Ru.

Bubbling resilient 3D free-standing nanoporous graphene with an encapsulated multicomponent nano-alloy for enhanced electrocatalysis.

The design and synthesis of highly durable and active electrocatalysts are crucial for improving the hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). In this work, we present a novel dealloyed nanoporous PtCuNiCoMn multicomponent alloy with ligaments/pores ranging from 2-3 nm, which is encapsulated in a three-dimensional, free-standing nanoporous nanotubular graphene network featuring a pore/tube diameter of ∼200 to 300 nm. This method allows precise control over the noble metal loading and alloy composition while preventing noble metal loss throughout the preparation process.

Cycling Reconstructed Hierarchical Nanoporous High-Entropy Oxides with Continuously Increasing Capacity for Li Storage.

High-entropy oxides (HEOs) have been showing great promise in a wide range of applications. There remains a lack of clarity regarding the influence of nanostructure and composition on their Li storage performance. Herein, a dealloying technique to synthesize hierarchical nanoporous HEOs with tunable compositions is employed.

Confinement Effect and 3D Design Endow Unsaturated Single Ni Atoms with Ultrahigh Stability and Selectivity toward CO Electroreduction.

Developing single-atomic catalysts with superior selectivity and outstanding stability for CO electroreduction is desperately required but still challenging. Herein, confinement strategy and three-dimensional (3D) nanoporous structure design strategy are combined to construct unsaturated single Ni sites (Ni-N) stabilized by pyridinic N-rich interconnected carbon nanosheets. The confinement agent chitosan and its strong interaction with g-CN nanosheet are effective for dispersing Ni and restraining their agglomeration during pyrolysis, resulting in ultrastable Ni single-atom catalyst.

Self-Floating Nanoporous High-Entropy Oxides with Tunable Bandgap for Efficient Solar Seawater Desalination.

Nanoporous high-entropy oxide (np-HEO) powders with tunable composition are integrated with a poly(vinylidene fluoride) network to create self-floating solar absorber films for seawater desalination. By progressively increasing the element count, we obtain an optimized 9-component AlNiCoFeCrMoVCuTi-O. Density functional theory (DFT) calculations reveal a remarkable reduction in its bandgap, facilitating the light-induced migration of electrons to conduction bands to generate electron-hole pairs, which recombine to produce heat.

All-Solid-State Mg-Air Battery Enhanced with Free-Standing N-Doped 3D Nanoporous Graphene.

Nitrogen (N) doping of graphene with a three-dimensional (3D) porous structure, high flexibility, and low cost exhibits potential for developing metal-air batteries to power electric/electronic devices. The optimization of N-doping into graphene and the design of interconnected and monolithic graphene-based 3D porous structures are crucial for mass/ion diffusion and the final oxygen reduction reaction (ORR)/battery performance. Aqueous-type and all-solid-state primary Mg-air batteries using N-doped nanoporous graphene as air cathodes are assembled.

Revealing Atomic Configuration and Synergistic Interaction of Single-Atom-Based Zn-Co-Fe Trimetallic Sites for Enhancing Oxygen Reduction and Evolution Reactions.

Anchoring single metal atom to carbon supports represents an exceptionally effective strategy to maximize the efficiency of catalysts. Recently, dual-atom catalysts (DACs) emerge as an intriguing candidate for atomic catalysts, which perform better than single-atom catalysts (SACs). However, the clarification of the polynary single-atom structures and their beneficial effects remains a daunting challenge.

Enhanced Photothermal Steam Generation and Gold Using the Efficiency of Ultralight Gold Foam with Hierarchical Porosity.

Controlling the optical properties of metal plasma nanomaterials through structure manipulation has attracted great attention for solar steam generation. However, realizing broadband solar absorption for high-efficiency vapor generation is still challenging. In this work, a free-standing ultralight gold film/foam with a hierarchical porous microstructure and high porosity is obtained through controllably etching a designed cold-rolled (NiCoFeCr)Au high-entropy precursor alloy with a unique grain texture.

Designing strategies and enhancing mechanism for multicomponent high-entropy catalysts.

High-entropy materials (HEMs) are new-fashioned functional materials in the field of catalysis owing to their large designing space, tunable electronic structure, interesting "cocktail effect", and entropy stabilization effect. Many effective strategies have been developed to design advanced catalysts for various important reactions. Herein, we firstly review effective strategies developed so far for optimizing HEM-based catalysts and the underlying mechanism revealed by both theoretical simulations and experimental aspects.

Curvature effects on the bifunctional oxygen catalytic performance of single atom metal-N-C.

Understanding the fundamental relationship between the structural information of electrocatalysts and their catalytic activities plays a key role in controlling many important electrochemical processes. Recently, single-atom catalysts (SACs) with the so-called MN structure, consisting of a central transition metal quadruply bound to four pyridine nitrogen atoms all situated in an extended carbon-based matrix, have attracted intensive scientific attention owing to their exceptional catalytic performance. In this work, we perform the first-principles density functional theory (DFT) calculations to explore the curvature effects of the carbon matrix surfaces on the catalytic activities for two fundamental electrochemical processes, namely, the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER).

Simultaneous Improvement of Oxygen Reduction and Catalyst Anchoring via Multiple Dopants on Mesoporous Carbon Frameworks for Flexible Al-Air Batteries.

Mesoporous carbon supported non-noble metals, as promising catalysts for boosting the oxygen reduction reaction (ORR) in metal-air batteries, usually face challenges of low activity and performance degradation caused by the catalyst detachment from carbon substrates. Herein, a one-stone-two-birds strategy is reported to simultaneously improve the ORR activity and anchor nanosized MnS catalysts on a mesoporous carbon framework via nitrogen (N) and sulfur (S) dopants (MnS/NS-C). Synchrotron-based X-ray absorption spectroscopy (XAS) confirms the existence of Mn-N and Mn-S bonds, which firmly anchor active MnS nanoparticles.

A fourteen-component high-entropy alloy@oxide bifunctional electrocatalyst with a record-low Δ of 0.61 V for highly reversible Zn-air batteries.

Nanostructured high-entropy materials such as alloys, oxides, , are attracting extensive attention because of their widely tunable surface electronic structure/catalytic activity through mixing different elements in one system. To further tune the catalytic performance and multifunctionality, the designed fabrication of multicomponent high-entropy nanocomposites such as high-entropy alloy@high-entropy oxides (HEA@HEO) should be very promising. In this work, we design a two-step alloying-dealloying strategy to synthesize ultra-small HEA nanoclusters (∼2 nm) loaded on nanoporous HEO nanowires, and the compositions of both the HEA and HEO can be adjusted separately.

RuO electronic structure and lattice strain dual engineering for enhanced acidic oxygen evolution reaction performance.

Developing highly active and durable electrocatalysts for acidic oxygen evolution reaction remains a great challenge due to the sluggish kinetics of the four-electron transfer reaction and severe catalyst dissolution. Here we report an electrochemical lithium intercalation method to improve both the activity and stability of RuO for acidic oxygen evolution reaction. The lithium intercalates into the lattice interstices of RuO, donates electrons and distorts the local structure.

Exploiting the Synergistic Electronic Interaction between Pt-Skin Wrapped Intermetallic PtCo Nanoparticles and Co-N-C Support for Efficient ORR/EOR Electrocatalysis in a Direct Ethanol Fuel Cell.

The development of low-Pt catalysts with high activity and durability is critical for fuel cells. Here, Pt-skin wrapped sub-5 nm PtCo intermetallic nanoparticles are successfully mounted on single atom Co-N-C support by exploiting the barrier effect of Co-anchor. According to a collaborative experimental and computational investigation, the increased oxygen reduction reaction activity of PtCo/Co-N-C arises from the direct electron transfer from PtCo to Co-N-C, and the resulting optimal d-band center of Pt.

Theoretically Revealed and Experimentally Demonstrated Synergistic Electronic Interaction of CoFe Dual-Metal Sites on N-doped Carbon for Boosting Both Oxygen Reduction and Evolution Reactions.

Heteronuclear double-atom catalysts, unlike single atom catalysts, may change the charge density of active metal sites by introducing another metal single atom, thereby modifying the adsorption energies of reaction intermediates and increasing the catalytic activities. First, density functional theory calculations are used to figure out the best combination by modeling two transition-metal atoms from Fe, Co, and Ni onto N-doped graphene. Generally, Fe and Co sites are highly active for the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER), respectively.

Highly Strengthened and Toughened Zn-Li-Mn Alloys as Long-Cycling Life and Dendrite-Free Zn Anode for Aqueous Zinc-Ion Batteries.

Zn-ion batteries (ZIBs) using aqueous electrolyte, recently, have been a hot topic owing to the high safety, low cost, and high specific energy capacity. However, the formation of dendrite and side reactions on the Zn anode during cycling inhibit the application of ZIBs. An advanced Zn anode by alloying a small amount of Li and Mn with Zn is hereby reported.

Eight-Component Nanoporous High-Entropy Oxides with Low Ru Contents as High-Performance Bifunctional Catalysts in Zn-Air Batteries.

One major challenge in heterogeneous catalysis is to reduce the usage of noble metals while maintaining the overall catalytic stability and efficiency in various chemical environments. In this work, a series of high-entropy catalysts are synthesized by a chemical dealloying method and find the increased entropy effect and non-noble metal contents would facilitate the formation of complete oxides with low crystallinity. Importantly, an optimal eight-component high-entropy oxide (HEO, Al-Ni-Co-Ru-Mo-Cr-Fe-Ti) is identified, which exhibits further enhanced catalytic activity for the oxygen evolution reaction (OER) as compared to the previously reported quinary AlNiCoRuMo and the widely-used commercial RuO catalysts, and at the same time similar catalytic activity for the oxygen reduction reaction (ORR) as the commercial Pt/C with a half-wave potential of 0.

Electronic Interaction between In Situ Formed RuO Clusters and a Nanoporous ZnVO Support and Its Use in the Oxygen Evolution Reaction.

The catalytic activity and durability of RuO clusters toward the oxygen evolution reaction (OER) are strongly associated with their support; however, how the electronic interaction would enhance the catalytic performance is still not quite clear. Herein, hierarchical nanoporous and single-crystal ZnVO nanosheets are adopted to anchor in situ formed RuO clusters. X-ray photoelectron analysis reveals significant binding energy changes of both Ru and V due to the creation of strong Ru-O-V bonding interaction, which would lead to the reconstruction of the electronic structure of the ZnVO matrix and RuO clusters.

MOF Structure Engineering to Synthesize CoNC Catalyst with Richer Accessible Active Sites for Enhanced Oxygen Reduction.

Single-atom cobalt-based CoNC are promising low-cost electrocatalysts for oxygen reduction reaction (ORR). However, further increasing the single cobalt-based active sites and the ORR activity remain a major challenge. Herein, an acetate (OAc) assisted metal-organic framework (MOF) structure-engineering strategy is developed to synthesize hierarchical accordion-like MOF with higher loading amount and better spatial isolation of Co and much higher yield when compared with widely reported polyhedron MOF.

Designing Ru-doped ZnVO bifunctional OER and HER catalysts through a unified computational and experimental approach.

Developing stable and cost-effective catalysts is the key to the next-generation renewable energy conversion technology. Here we unify computational and experimental approaches to use the ZnVO (001) surface supporting noble metal Ru as a bifunctional catalyst for the OER and HER in alkaline media. In particular, different reaction sites have been studied at four surface terminations along the [001] orientation: the A-layer with V atoms at octahedral sites, the C-layer with V and Zn atoms at octahedral sites, and with additional Zn atoms at tetrahedral sites (B-layer and D-layer, respectively).