In-situ growing carbon nanotubes reinforced highly heat dissipative three-dimensional aluminum framework composites.

The demand for lightweight heat dissipation design in highly miniaturized and portable electronic devices with high thermal density is becoming increasingly urgent. Herein, highly thermal conductive carbon nanotubes (CNTs) reinforced aluminum foam composites were prepared by catalyst chemical bath and subsequent in-situ growth approach. The dense CNTs show the intertwined structure features and construct high-speed channels near the surface of the skeletons for efficient thermal conduction, promoting the transport efficiency of heat flow.

IrO/MnO metal oxide-support interaction enables robust acidic water oxidation.

The sluggish kinetics, poor stability, and high iridium loading in acidic oxygen evolution reaction (OER) present significant challenges for proton exchange membrane water electrolyzers (PEMWE). While supported catalysts can enhance the utilization and activity of Ir atoms, they often fail to mitigate the detrimental effects of over-oxidation and dissolution of Ir. Here, we leverage the redox properties of the Mn/Mn couple as electronic modulators to develop a low-iridium, durable electrocatalyst for acidic OER.

Confined Synthesis of 2D Molybdenum Diphosphide Nanosheets via Gas-Solid Transformation.

Molybdenum diphosphide (MoP), a topological semimetal, possesses distinctive properties and applications in catalysis, energy storage, and condensed matter physics. However, synthesizing high-purity MoP is complex and often results in undesired stoichiometric by-products. Additionally, the intrinsic orthorhombic crystal structure makes it difficult to synthesize MoP in a 2D morphology, which is desirable for device and energy applications.

A high-speed infrared tellurium photodetector on a silicon nitride platform.

The hybrid integration of two-dimensional (2D) materials on various photonic integration platforms has attracted widespread research interest because of the new functionalities enabled by the 2D materials for applications in photodetection, optical modulation and nonlinear optical signal processing. Tellurium is known to have high mobility, and quasi-2D tellurium is stable in air and has a small bandgap that may make it suitable for platform-independent scalable integration of high-performance photodetectors in the infrared band. In this work, we propose and implement a new structure for integrating tellurium with silicon nitride (SiN) waveguides, adding photodetector capability to an otherwise passive waveguide platform.

Emerging Two-Dimensional Materials for Proton-Based Energy Storage.

The rapid diffusion kinetics and smallest ion radius make protons the ideal cations toward the ultimate energy storage technology combining the ultrafast charging capabilities of supercapacitors and the high energy densities of batteries. Despite the concept existing for centuries, the lack of satisfactory electrode materials hinders its practical development. Recently, the rapid advancement of the emerging two-dimensional (2D) materials, characterized by their ultrathin morphology, interlayer van der Waals gaps, and distinctive electrochemical properties, injects promises into future proton-based energy storage systems.

Rational Construction of Pt Incorporated CoO as High-Performance Electrocatalyst for Hydrogen Evolution Reaction.

Electrocatalysts in alkaline electrocatalytic water splitting are required to efficiently produce hydrogen while posing a challenge to show excellent performances. Herein, we have successfully synthesized platinum nanoparticles incorporated in a CoO nanostructure (denoted as Pt-CoO) that show superior HER activity and stability in alkaline solutions (the overpotentials of 37 mV to reach 10 mA cm). The outstanding electrocatalytic activity originates from synergistic effects between Pt and CoO and increased electron conduction.

Constructing N-Containing Poly(p-Phenylene) (PPP) Films Through A Cathodic-Dehalogenation Polymerization Method.

Developing the films of N-containing unsubstituted poly(p-phenylene) (PPP) films for diverse applications is significant and highly desirable because the replacement of sp C atoms with sp N atoms will bring novel properties to the as-prepared polymers. In this research, an electrochemical-dehalogenation polymerization strategy is employed to construct two N-containing PPP films under constant potentials, where 2,5-diiodopyridine (DIPy) and 2,5-dibromopyrazine (DBPz) are used as starting agents. The corresponding polymers are named CityU-23 (for polypyridine) and CityU-24 (for polypyrazine).

Wet-Chemical Synthesis of Elemental 2D Materials.

Wet-chemical synthesis refers to the bottom-up chemical synthesis in solution, which is among the most popular synthetic approaches towards functional two-dimensional (2D) materials. It offers several advantages, including cost-effectiveness, high yields,, precious control over the production process. As an emerging family of 2D materials, elemental 2D materials (Xenes) have shown great potential in various applications such as electronics, catalysts, biochemistry,, sensing technologies due to their exceptional/exotic properties such as large surface area, tunable band gap,, high carrier mobility.

S-induced Phase Change Forming In O /In S Heterostructure for Photoelectrochemical Glucose Sensor.

In the past several decades, Photoelectrochemical (PEC) sensing still remains a great challenge to design highly-efficient semiconductor photocatalysts via a facile method. It is of much importance to design and synthesize various novel nanostructured sensing materials for further improving the response performance. Herein, we present an In O /In S heterostructure obtained by combining microwave assisted hydrothermal method with S-induced phase change, whose energy band and electronic structure could be adjusted by changing the S content.

Ag/microcrystalline-CuO composite film as an interfacial regulator for highly reversible lithium metal anode.

Lithium (Li) metal is a promising anode material for high-energy-density batteries, yet its low average Coulombic efficiency (CE) results in poor cycling stability. Although significant progress has been made in addressing these issues, the stability of Li metal anode at high rates and large capacities falls short of meeting the practical application requirements. Herein, we develop a microcrystalline (MC)-CuO/Ag composite film on Cu current collector to regulate the interfacial properties for achieving even and dense Li deposition.

Tensile Strain-Mediated Spinel Ferrites Enable Superior Oxygen Evolution Activity.

Exploring efficient strategies to overcome the performance constraints of oxygen evolution reaction (OER) electrocatalysts is vital for electrocatalytic applications such as HO splitting, CO reduction, N reduction, . Herein, tunable, wide-range strain engineering of spinel oxides, such as NiFeO, is proposed to enhance the OER activity. The lattice strain is regulated by interfacial thermal mismatch during the bonding process between thermally expanding NiFeO nanoparticles and the nonexpanding carbon fiber substrate.

Surfactant-Free Ultrasonication-Assisted Synthesis of 2d Tellurium Based on Metastable 1T'-MoTe.

Elemental 2D materials (E2DMs) have been attracting considerable attention owing to their chemical simplicity and excellent/exotic properties. However, the lack of robust chemical synthetic methods seriously limits their potential. Here, a surfactant-free liquid-phase synthesis of high-quality 2D tellurium is reported based on ultrasonication-assisted exfoliation of metastable 1T'-MoTe.

On-chip electrocatalytic microdevices.

On-chip electrocatalytic microdevices (OCEMs) are an emerging electrochemical platform specialized for investigating nanocatalysts at the microscopic level. The OCEM platform allows high-precision electrochemical measurements at the individual nanomaterial level and, more importantly, offers unique perspectives inaccessible with conventional electrochemical methods. This protocol describes the critical concepts, experimental standardization, operational principles and data analysis of OCEMs.

Reversible Semimetal-Semiconductor Transition of Unconventional-Phase WS Nanosheets.

Phase transition with band gap modulation of materials has gained intensive research attention due to its various applications, including memories, neuromorphic computing, and transistors. As a powerful strategy to tune the crystal phase of transition-metal dichalcogenides (TMDs), the phase transition of TMDs provides opportunities to prepare new phases of TMDs for exploring their phase-dependent property, function, and application. However, the previously reported phase transition of TMDs is mainly irreversible.

Filling the Gap between Heteroatom Doping and Edge Enrichment of 2D Electrocatalysts for Enhanced Hydrogen Evolution.

Composition modulation and edge enrichment are established protocols to steer the electronic structures and catalytic activities of two-dimensional (2D) materials. It is believed that a heteroatom enhances the catalytic performance by activating the chemically inert basal plane of 2D crystals. However, the edge and basal plane have inherently different electronic states, and how the dopants affect the edge activity remains ambiguous.

On-Chip Investigation of Electrocatalytic Oxygen Reduction Reaction of 2D Materials.

The on-chip electrocatalytic microdevice (OCEM) is an emerging platform specialized in the electrochemical investigation of single-entity nanomaterials, which is ideal for probing the intrinsic catalytic properties, optimizing performance, and exploring exotic mechanisms. However, the current catalytic applications of OCEMs are almost exclusively in electrocatalytic hydrogen/oxygen evolution reactions with minimized influence from the mass transfer. Here, an OCEM platform specially tailored to investigate the electrocatalytic oxygen reduction reaction (ORR) at a microscopic level by introducing electrolyte convection through a microfluidic flow cell is reported.

Interfacial Microstructure and Mechanical Properties of 1Cr18Ni9Ti/1Cr21Ni5Ti Stainless Steel Joints Brazed with Mn-Based Brazing Filler.

The problem of stainless steel brazing is still the focus of scientific research. In this work, the Mn-based brazing filler was used to braze 1Cr18Ni9Ti and 1Cr21Ni5Ti stainless steel. The typical microstructure of the 1Cr18Ni9Ti/1Cr21Ni5Ti joint was analyzed in detail, and the interface structure of the joint was determined to be 1Cr18Ni9Ti/Mn(s, s)/1Cr21Ni5Ti.

Preparation of 2D Molybdenum Phosphide via Surface-Confined Atomic Substitution.

The emerging nonlayered 2D materials (NL2DMs) are sparking immense interest due to their fascinating physicochemical properties and enhanced performance in many applications. NL2DMs are particularly favored in catalytic applications owing to the extremely large surface area and low-coordinated surface atoms. However, the synthesis of NL2DMs is complex because their crystals are held together by strong isotropic covalent bonds.

Atomic-scale imaging of CHNHPbI structure and its decomposition pathway.

Understanding the atomic structure and structural instability of organic-inorganic hybrid perovskites is the key to appreciate their remarkable photoelectric properties and understand failure mechanism. Here, using low-dose imaging technique by direct-detection electron-counting camera in a transmission electron microscope, we investigate the atomic structure and decomposition pathway of CHNHPbI (MAPbI) at the atomic scale. We successfully image the atomic structure of perovskite in real space under ultra-low electron dose condition, and observe a two-step decomposition process, i.

All-in-One Sulfur Host: Smart Controls of Architecture and Composition for Accelerated Liquid-Solid Redox Conversion in Lithium-Sulfur Batteries.

The development of Li-S batteries (LSBs) is largely impeded by sluggish redox kinetics and notorious polysulfide shuttling. Herein, hierarchical MoC@Ni-NCNT arrays are reported as a multifunctional sulfur host in Li-S batteries, which comprised a flexible carbon fiber cloth substrate decorated with vertical MoC porous nanorods rooted by interconnected nitrogen-doped carbon nanotubes (NCNTs). In the designed host, the inner MoC porous backbone (composed of nanoparticles) along with the in situ-grafted interwoven NCNT shell can greatly maximize the host-guest interactive surface for homogeneous sulfur dispersion, thus realizing decent high-sulfur-loading performance.

Bioinspired Metal-Intermetallic Laminated Composites for the Fabrication of Superhydrophobic Surfaces with Responsive Wettability.

Hundreds of copper and titanium foils were applied to prepare biomimetic metal-intermetallic laminated composites by diffusion bonding. The cross sections of the obtained diffusion bonded bulks were etched selectively with FeCl solution to get regular microarray structures. This kind of microstructure was controlled accurately and promptly by simple parameter adjustment.

Surface activation towards manganese dioxide nanosheet arrays via plasma engineering as cathode and anode for efficient water splitting.

Developing high-efficiency, low-cost electrocatalysts for water splitting is important but challenging. Two-dimensional nanosheet manganese dioxide (MnO) arrays are promising candidates for the design and development of advanced catalysts because of their large surface area. Here, a feasible solution to improve the catalytic activity of MnO materials via decorating the active sites on the surface is proposed.

Transmission electron microscopy of organic-inorganic hybrid perovskites: myths and truths.

Organic-inorganic hybrid perovskites (OIHPs) have attracted extensive research interest as a promising candidate for efficient and inexpensive solar cells. Transmission electron microscopy (TEM) characterizations that can benefit the fundamental understanding and the degradation mechanism are widely used for these materials. However, their sensitivity to the electron beam illumination and hence structural instabilities usually prevent us from obtaining the intrinsic information or even lead to significant artifacts.