Highly Tension-Strained Copper Concentrates Diluted Cations for Selective Proton-Exchange Membrane CO2 Electrolysis.

Electrolysis of carbon dioxide (CO2) in acid offers a promising route to overcome CO2 loss in alkaline and neutral electrolytes, but requires concentrated alkali cations (typical ≥3 M) to mitigate the trade-off between low pH and high hydrogen evolution reaction (HER) rate, causing salt precipitation. Here we report a strategy to resolve this problem by introducing tensile strain in a copper (Cu) catalyst, which can selectively reduce CO2 to valuable multicarbon products, particularly ethylene, in a pH 1 electrolyte with 1 M potassium ions. We find that the tension-strained Cu creates an electron-rich surface that concentrates diluted potassium ions, contributing to CO2 activation and HER suppression.

Self-assembly of 1T/1H superlattices in transition metal dichalcogenides.

Heterostructures and superlattices composed of layered transition metal dichalcogenides (TMDs), celebrated for their superior emergent properties over individual components, offer significant promise for the development of multifunctional electronic devices. However, conventional fabrication techniques for these structures depend on layer-by-layer artificial construction and are hindered by their complexity and inefficiency. Herein, we introduce a universal strategy for the automated synthesis of TMD superlattice single crystals through self-assembly, exemplified by the NbSeTe 1T/1H superlattice.

Hetero-Nucleation Induced [111]-Oriented Mixed Halide Perovskite for Stable Pure Red Light-Emitting Diodes.

Mixed halide 3D perovskites are promising for bright, efficient, and wide-color gamut light-emitting diodes (LEDs) due to their excellent carrier transport, high luminescence, and easily tunable bandgaps. However, serious halide ion migration inside mixed halide 3D perovskite results in poor operational and spectral stability of the as-fabricated LEDs. Here, a hetero-nucleation crystallization strategy is reported to grow [111]-orientation preferred mixed halide 3D perovskite CsPbIBr thin films for stable pure red LEDs.

In-situ atomic tracking of intermetallic compound formation during thermal annealing.

Intermetallic compounds (IMCs) with ordered atomic structure have gained great attention as nanocatalysts for its enhanced activity and stability. Although the reliance of IMC preparation on high-temperature annealing is well known, a comprehensive understanding of the formation mechanisms of IMCs in this process is currently lacking. Here, we employ aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (AC-HAADF-STEM) to track the formation process of IMCs on carbon supports during in-situ annealing, by taking PtFe as a case study within an industry-relevant impregnation synthesis framework.

Interfacial Charge-Transfer Excitonic Insulator in a Two-Dimensional Organic-Inorganic Superlattice.

Excitonic insulators are long-sought-after quantum materials predicted to spontaneously open a gap by the Bose condensation of bound electron-hole pairs, namely, excitons, in their ground state. Since the theoretical conjecture, extensive efforts have been devoted to pursuing excitonic insulator platforms for exploring macroscopic quantum phenomena in real materials. Reliable evidence of excitonic character has been obtained in layered chalcogenides as promising candidates.

Highly Crystalline Iridium-Nickel Nanocages with Subnanopores for Acidic Bifunctional Water Splitting Electrolysis.

Developing efficient bifunctional materials is highly desirable for overall proton membrane water splitting. However, the design of iridium materials with high overall acidic water splitting activity and durability, as well as an in-depth understanding of the catalytic mechanism, is challenging. Herein, we successfully developed subnanoporous IrNi ultrathin nanocages with high crystallinity as bifunctional materials for acidic water splitting.

Precise arrangement of metal atoms at the interface by a thermal printing strategy.

The kinetics and pathway of most catalyzed reactions depend on the existence of interface, which makes the precise construction of highly active single-atom sites at the reaction interface a desirable goal. Herein, we propose a thermal printing strategy that not only arranges metal atoms at the silica and carbon layer interface but also stabilizes them by strong coordination. Just like the typesetting of Chinese characters on paper, this method relies on the controlled migration of movable nanoparticles between two contact substrates and the simultaneous emission of atoms from the nanoparticle surface at high temperatures.

Symmetry-Induced Regulation of Pt Strain Derived from Pt Ga Intermetallic for Boosting Oxygen Reduction Reaction.

Pt-based fuel cell catalysts with excellent activity and stability for proton-exchange membrane fuel cells (PEMFCs) have been developed through strain regulation in recent years. Herein, this work demonstrates that symmetry-induced strain regulation of Pt surface of PtGa intermetallic compounds can greatly enhance the catalytic performance of the oxygen reduction reaction (ORR). With the strain environment varies derived from the lattice mismatch of analogous PtGa core but different symmetry, the Pt surface of the PtGa alloy and the Pt Ga (Pm m) precisely realize 0.

Layered Inorganic Silicate Aerogel Pillared by Nanoclusters for High Temperature Thermal Insulation.

Layered inorganic material, with large-area interlayer surface and interface, provides an essential material platform for constructing new configuration of functional materials. Herein, a layered material pillared with nanoclusters realizing high temperature thermal insulation performance is demonstrated for the first time. Specifically, systematic synchrotron radiation spectroscopy and finite element calculation analysis show that ZrO nanoclusters served as "pillars" to effectively produce porous structures with enough boundary defect while maintaining the layered structure, thereby significantly reducing solid state thermal conductivity (≈0.

Co-activation for enhanced K-ion storage in battery anodes.

The relative natural abundance of potassium and potentially high energy density has established potassium-ion batteries as a promising technology for future large-scale global energy storage. However, the anodes' low capacity and high discharge platform lead to low energy density, which impedes their rapid development. Herein, we present a possible co-activation mechanism between bismuth (Bi) and tin (Sn) that enhances K-ion storage in battery anodes.

Planar defect-free pure red perovskite light-emitting diodes via metastable phase crystallization.

Solution-processable all-inorganic CsPbIBr perovskite holds great potential for pure red light-emitting diodes. However, the widely existing defects in this mixed halide perovskite markedly limit the efficiency and stability of present light-emitting diode devices. We here identify that intragrain Ruddlesden-Popper planar defects are primary forms of such defects in the CsPbIBr thin film owing to the lattice strain caused by inhomogeneous halogen ion distribution.

Recent advances in MXenes and their composites for wearable sensors.

Flexible wearable sensors have attracted significant interests and created high technological impact on human health monitoring, environmental pollutant detection and bimolecular identification. For sensors, the choice of sensing materials is a crucial priority. As a rising star in the family of two-dimensional materials, MXenes has metal-like electrical properties, adjustable surface chemical property, hydrophilicity and excellent mechanical properties, making them attractive for building different high-performance sensors.

Epitaxial Growth of Ultrathin Highly Crystalline Pt-Ni Nanostructure on a Metal Carbide Template for Efficient Oxygen Reduction Reaction.

Structure engineering strategies such as core-shell and hollow nanostructures are effective pathways to improve the utilization of noble metals for catalysis. However, nowadays materials design based on these strategies still largely rely on precious metal templates. Herein, the epitaxial growth of highly crystalline Pt Ni overlayer on earth-abundant nickel carbide is reported, forming Ni C@Pt Ni core-shell nanoparticles with a well-defined interface through a new lattice-match-directed synthetic strategy.