Element-dependent effects of alkali cations on nitrate reduction to ammonia.

Catalytic conversion of nitrate (NO) pollutants into ammonia (NH) offers a sustainable and promising route for both wastewater treatment and NH synthesis. Alkali cations are prevalent in nitrate solutions, but their roles beyond charge balance in catalytic NO conversion have been generally ignored. Herein, we report the promotion effect of K cations in KNO solution for NO reduction over a TiO-supported Ni single-atom catalyst (Ni/TiO).

Engineering Dual CO- and Photothermal-Responsive Membranes for Switchable Double Emulsion Separation.

Stimulus-responsive membranes demonstrate promising applications in switchable oil/water emulsion separations. However, they are unsuitable for the treatment of double emulsions like oil-in-water-in-oil (O/W/O) and water-in-oil-in-water (W/O/W) emulsions. For efficient separation of these complicated emulsions, fine control over the wettability, response time, and aperture structure of the membrane is required.

Simultaneously Geometrical and Electronic Modulation of L-PtZn by Trace Ge Boosts High-performance Oxygen Reduction Reaction.

Developing a highly active, durable, and low-platinum-based electrocatalyst for the cathodic oxygen reduction reaction (ORR) is for breaking the bottleneck of large-scale applications of proton exchange membrane fuel cells (PEMFCs). Herein, ultrafine PtZn intermetallic nanoparticles with low Pt-loading and trace germanium (Ge) involvement confined in the nitrogen-doped porous carbon (Ge-L-PtZn@N-C) are reported. The Ge-L-PtZn@N-C exhibit superior ORR activity with a mass activity of 3.

Microstructure optimization of bioderived polyester nanofilms for antibiotic desalination via nanofiltration.

The successful implementation of thin-film composite membranes (TFCM) for challenging solute-solute separations in the pharmaceutical industry requires a fine control over the microstructure (size, distribution, and connectivity of the free-volume elements) and thickness of the selective layer. For example, desalinating antibiotic streams requires highly interconnected free-volume elements of the right size to block antibiotics but allow the passage of salt ions and water. Here, we introduce stevioside, a plant-derived contorted glycoside, as a promising aqueous phase monomer for optimizing the microstructure of TFCM made via interfacial polymerization.

Promoting CO Dynamic Activation via Micro-Engineering Technology for Enhancing Electrochemical CO Reduction.

Optimizing the coordination structure and microscopic reaction environment of isolated metal sites is promising for boosting catalytic activity for electrocatalytic CO reduction reaction (CO RR) but is still challenging to achieve. Herein, a newly electrostatic induced self-assembly strategy for encapsulating isolated Ni-C N moiety into hollow nano-reactor as I-Ni SA/NHCRs is developed, which achieves FE  of 94.91% at -0.

Scalable and switchable CO-responsive membranes with high wettability for separation of various oil/water systems.

Smart membranes with responsive wettability show promise for controllably separating oil/water mixtures, including immiscible oil-water mixtures and surfactant-stabilized oil/water emulsions. However, the membranes are challenged by unsatisfactory external stimuli, inadequate wettability responsiveness, difficulty in scalability and poor self-cleaning performance. Here, we develop a capillary force-driven confinement self-assembling strategy to construct a scalable and stable CO-responsive membrane for the smart separation of various oil/water systems.

Monitoring Electron Flow in Nickel Single-Atom Catalysts during Nitrogen Photofixation.

An efficient catalytic system for nitrogen (N) photofixation generally consists of light-harvesting units, active sites, and an electron-transfer bridge. In order to track photogenerated electron flow between different functional units, it is highly desired to develop characterization techniques with element-specific capability, surface sensitivity, and detection of unoccupied states. In this work, we developed synchrotron radiation soft X-ray absorption spectroscopy ( sXAS) to probe the variation of electronic structure for a reaction system during N photoreduction.

In situ Observation of Structural Evolution and Phase Engineering of Amorphous Materials during Crystal Nucleation.

The nucleation pathway determines the structures and thus properties of formed nanomaterials, which is governed by the free energy of the intermediate phase during nucleation. The amorphous structure, as one of the intermediate phases during nucleation, plays an important role in modulating the nucleation pathway. However, the process and mechanism of crystal nucleation from amorphous structures still need to be fully investigated.

Zn V O ⋅1.8 H O Cathode Stabilized by In Situ Phase Transformation for Aqueous Zinc-Ion Batteries with Ultra-Long Cyclability.

Developing cathode materials integrating good rate performance and sufficient cycle life is the key to commercialization of aqueous zinc-ion batteries. The hyperstable Zn V O ⋅1.8 H O (ZVOH) cathode with excellent rate performance has been successfully developed via an in situ self-transformation from zinc-rich Zn V O (ZVO) in this study.

Reversing the Nucleophilicity of Active Sites in CoP Enables Exceptional Hydrogen Evolution Catalysis.

Precisely constructing the local configurations of active sites to achieve on-demand catalytic functions is highly critical yet challenging. Herein, an anion-deficient strategy to precisely capture Ru single atoms on the anion vacancies of CoP (Ru-SA/Pv-CoP ) is developed. Refined structural characterizations reveal that the Ru single atoms preferably bind to the anion vacancy sites and consequently build a superior catalytic surface with neighboring CoP and CoRu coordination states for the hydrogen evolution reaction (HER) catalysis.

High-Polarity Fluoroalkyl Ether Electrolyte Enables Solvation-Free Li Transfer for High-Rate Lithium Metal Batteries.

Lithium metal batteries (LMBs) have aroused extensive interest in the field of energy storage owing to the ultrahigh anode capacity. However, strong solvation of Li and slow interfacial ion transfer associated with conventional electrolytes limit their long-cycle and high-rate capabilities. Herein an electrolyte system based on fluoroalkyl ether 2,2,2-trifluoroethyl-1,1,2,3,3,3-hexafluoropropyl ether (THE) and ether electrolytes is designed to effectively upgrade the long-cycle and high-rate performances of LMBs.

Amorphization-induced surface electronic states modulation of cobaltous oxide nanosheets for lithium-sulfur batteries.

Lithium-sulfur batteries show great potential to achieve high-energy-density storage, but their long-term stability is still limited due to the shuttle effect caused by the dissolution of polysulfides into electrolyte. Herein, we report a strategy of significantly improving the polysulfides adsorption capability of cobaltous oxide by amorphization-induced surface electronic states modulation. The amorphous cobaltous oxide nanosheets as the cathode additives for lithium-sulfur batteries demonstrates the rate capability and cycling stability with an initial capacity of 1248.

Prototypical Study of Double-Layered Cathodes for Aqueous Rechargeable Static Zn-I Batteries.

Aqueous rechargeable zinc-iodine batteries (ZIBs) are promising candidates for grid energy storage because they are safe and low-cost and have high energy density. However, the shuttling of highly soluble triiodide ions severely limits the device's Coulombic efficiency. Herein, we demonstrate for the first time a double-layered cathode configuration with a conductive layer (CL) coupled with an adsorptive layer (AL) for ZIBs.

Spatially Confined Formation of Single Atoms in Highly Porous Carbon Nitride Nanoreactors.

Reducing the size of a catalyst to a single atom (SA) level can dramatically change its physicochemical properties and significantly boost its catalytic activity. However, the massive synthesis of SA catalysts still remains a grand challenge mainly because of the aggregation and nucleation of the generated atoms during the reaction. Here, we design and implement a spatially confined synthetic strategy based on a porous-hollow carbon nitride (-CN) coordinated with 1-butyl-3-methylimidazole hexafluorophosphate, which can act as a nanoreactor and allow us to obtain metal SA catalysts (-CN@M SAs).

Ultrafine MoP Nanoparticle Splotched Nitrogen-Doped Carbon Nanosheets Enabling High-Performance 3D-Printed Potassium-Ion Hybrid Capacitors.

Size engineering is deemed to be an adoptable method to boost the electrochemical properties of potassium-ion storage; however, it remains a critical challenge to significantly reduce the nanoparticle size without compromising the uniformity. In this work, a series of MoP nanoparticle splotched nitrogen-doped carbon nanosheets (MoP@NC) is synthesized. Due to the coordinate and hydrogen bonds in the water-soluble polyacrylamide hydrogel, MoP is uniformly confined in a 3D porous NC to form ultrafine nanoparticles which facilitate the extreme exposure of abundant three-phase boundaries (MoP, NC, and electrolyte) for ionic binding and storage.

Tailoring the d-Band Center of Double-Perovskite LaCoNiO Nanorods for High Activity in Artificial N Fixation.

The d-band center of a catalyst can be applied for the prediction of its catalytic activity, but the application of d-band theory for the electrocatalytic nitrogen reduction reaction (eNRR) has rarely been studied in perovskite materials. In this work, a series of double-perovskite LaCoNiO (LCNO) nanorods (NRs) were synthesized as models, where the d-band centers can be modulated by changing the stoichiometric ratios between Co and Ni elements. Experimentally, the LCNO-III NRs ( = 0.

Synergistic Interface-Assisted Electrode-Electrolyte Coupling Toward Advanced Charge Storage.

Owing to the limited charge storage capability of transitional metal oxides in aqueous electrolytes, the use of redox electrolytes (RE) represents a promising strategy to further increase the energy density of aqueous batteries or pseudocapacitors. The usual coupling of an electrode and an RE possesses weak electrode/RE interaction and weak adsorption of redox moieties on the electrode, resulting in a low capacity contribution and fast self-discharge. In this work, Fe(CN) groups are grafted on the surface of Co O electrode via formation of CoN bonds, creating a synergistic interface between the electrode and the RE.

Three-Phase Boundary in Cross-Coupled Micro-Mesoporous Networks Enabling 3D-Printed and Ionogel-Based Quasi-Solid-State Micro-Supercapacitors.

The construction of advanced micro-supercapacitors (MSCs) with both wide working-voltage and high energy density is promising but still challenging. In this work, a series of nitrogen-doped, cross-coupled micro-mesoporous carbon-metal networks (N-STC/M O ) is developed as robust additives to 3D printing inks for MSCs fabrication. Taking the N-STC/Fe O nanocomposite as an example, both experimental results and theoretical simulations reveal that the well-developed hierarchical networks with abundantly decorated ultrafine Fe O nanoparticles not only significantly facilitate the ion adsorption at its three-phase boundaries (Fe O , N-STC, and electrolyte), but also greatly favor ionic diffusion/transport with shortened pathways.

Lattice-Strain Engineering of Homogeneous NiS Se Core-Shell Nanostructure as a Highly Efficient and Robust Electrocatalyst for Overall Water Splitting.

Developing highly-efficient non-noble-metal electrocatalysts for water splitting is crucial for the development of clean and reversible hydrogen energy. Introducing lattice strain is an effective strategy to develop efficient electrocatalysts. However, lattice strain is typically co-created with heterostructure, vacancy, or substrate effects, which complicate the identification of the strain-activity correlation.

Lattice oxygen activation enabled by high-valence metal sites for enhanced water oxidation.

Anodic oxygen evolution reaction (OER) is recognized as kinetic bottleneck in water electrolysis. Transition metal sites with high valence states can accelerate the reaction kinetics to offer highly intrinsic activity, but suffer from thermodynamic formation barrier. Here, we show subtle engineering of highly oxidized Ni species in surface reconstructed (oxy)hydroxides on multicomponent FeCoCrNi alloy film through interatomically electronic interplay.

N Electroreduction to NH by Selenium Vacancy-Rich ReSe Catalysis at an Abrupt Interface.

Vacancy engineering has been proved repeatedly as an adoptable strategy to boost electrocatalysis, while its poor selectivity restricts the usage in nitrogen reduction reaction (NRR) as overwhelming competition from hydrogen evolution reaction (HER). Revealed by density functional theory calculations, the selenium vacancy in ReSe crystal can enhance its electroactivity for both NRR and HER by shifting the d-band from -4.42 to -4.

Gradient phosphorus-doping engineering and superficial amorphous reconstruction in NiFeO nanoarrays to enhance the oxygen evolution electrocatalysis.

A better solid-liquid-gas three-phase boundary is vital for low energy cost oxygen evolution reaction (OER), making the designed regulation of interfacial atmosphere necessary. Herein, we find that the OER electrocatalysis can be dramatically improved by synergistically forming disordered electronic structures and superficial amorphous layers, as superficial oxyhydroxide, phosphorus-doped NiFe2O4 nanoarrays on nitrogen-doped carbon nanofibers (OP-NiFe2O4/NCNFs). Unveiled by the depth-profiling analysis from the X-ray photoelectron spectroscopy, the contents of phosphorous doping in the OP-NiFe2O4 nanoarrays change dynamically from outside to inside due to its in situ superficial reconstruction into the oxyhydroxide layer, thereby accelerating electron transfer between heterogeneous phases.

Squeezed metallic droplet with tunable Kubo gap and charge injection in transition metal dichalcogenides.

Shrinking the size of a bulk metal into nanoscale leads to the discreteness of electronic energy levels, the so-called Kubo gap δ. Renormalization of the electronic properties with a tunable and size-dependent δ renders fascinating photon emission and electron tunneling. In contrast with usual three-dimensional (3D) metal clusters, here we demonstrate that Kubo gap δ can be achieved with a two-dimensional (2D) metallic transition metal dichalcogenide (i.

Valence Engineering Dual-Cation and Boron Doping in Pyrite Selenide for Highly Efficient Oxygen Evolution.

Valence engineering has been proved an effective approach to modify the electronic property of a catalyst and boost its oxygen evolution reaction (OER) activity, while the limited number of elements restricts the structural diversity and the active sites. Also, the catalyst performance and stability are greatly limited by cationic dissolution, ripening, or crystal migration in a catalytic system. Here we employed a widely used technique to fabricate heteroepitaxial pyrite selenide through dual-cation substitution and a boron dopant to achieve better activity and stability.

Electronic structures and transport properties of SnS-SnSe nanoribbon lateral heterostructures.

The electronic structures of phosphorene-like SnS/SnSe nanoribbons and the transport properties of a SnS-SnSe nanoribbon lateral heterostructure are investigated by using first-principles calculations combined with nonequilibrium Green's function (NEGF) theory. It is demonstrated that SnS and SnSe nanoribbons with armchair edges (A-SnSNRs and A-SnSeNRs) are semiconductors, independent of the width of the ribbon. Their bandgaps have an indirect-to-direct transition, which varies with the ribbon width.