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.

Synthesis and Characterization of NaX Zeolite from Coal Gangue and Its Efficacy in Cd and Pb Remediation in Water and Soil.

Alkaline fusion is a pivotal process influencing the cost of synthesizing zeolite from coal gangue. This study examined the effects of alkaline fusion temperature ( ), treatment duration ( ) and the NaOH/coal gangue weight ratio ( ) on the composition and properties of the products, as well as their adsorption capacities for Cd ( ) and Pb ( ). Response surface methodology (RSM) was employed to analyze the interactions among these factors, and the adsorption mechanisms for Cd and Pb were investigated using X-ray diffraction, scanning electron microscopy-EDS, Fourier transform infrared, X-ray photoelectron spectroscopy, and N adsorption-desorption techniques.

A short review of the sustainable utilization of coal gangue in environmental applications.

The production of coal gangue, a by-product of coal mining and washing, is rapidly increasing due to growing energy consumption. As the accumulated coal gangue has not been appropriately utilized, this has resulted in a squander of resources, waste disposal problems, and environmental pollution issues. However, coal gangue, a form of solid waste, exhibits various potential applications in the field of recycling.

Optimization of the Carbonization Process for the Preparation of High-Grade Needle Coke Based on the Response Surface Method and Microstructure Analysis.

Refined coal tar pitch (RCTP) with a quinoline insoluble (QI) content less than 0.01% was obtained from Wuhai coal tar pitch (CTP), which was used as a raw material to prepare needle coke by carbonization and calcination experiments. In this work, the effects of carbonization time, carbonization temperature, and carbonization pressure on the optical structure of green coke and the microstructure of needle coke were investigated.

Relationship between Xylene Solubles and Crystallization Elution Fractionation of Polypropylene.

The Xylene Soluble (XS) is one of the most important parameters closely related to the performance of polypropylene (PP) materials. In order to obtain precise and accurate XS data, ASTM D 5492-17, based on the wet chemistry separation mechanism, strictly specifies each and every step of the procedure, such as a glassware setup, heating and cooling rates, etc. Meanwhile, crystallization elution fractionation (CEF), a newly developed technique, is capable of quantifying polyolefin structural regularity and comonomer distribution in a fast and automated manner.

The Evaluation and Detection of the Chemical Bond Between Silane Coupling Agent and Silver Layer on Alkali Activated Fly Ash.

In this study, wettability was employed to evaluate the effect of alkali activation by NaOH on different fly ash (FA) particle sizes. The results indicated that the surface wettability of FA particles with 13.8 μm increased from 0.

Carbon-Encapsulated Bimetallic Fe-W-Based Selenides with Abundant Heterogeneous Conductive Network for Superior Potassium Ion Storage.

Potassium-ion batteries (KIBs) are one of the most promising alternatives to lithium-ion batteries (LIBs) due to their high ion mobility, abundant resources, and low cost. However, the problems of low capacity and poor cycling stability of KIBs remain unsolved; therefore, it is crucial to explore alternative electrode materials suitable for reversible insertion and extraction of K. Herein, carbon-encapsulated FeSe/WSe microsphere material assembled from nanosheets with abundant heterogeneous interfaces and expanded interlayer spacing (denoted as FWSC) is designed as an anode material for superior potassium ion storage.

Surface Catalytic Repair for the Efficient Regeneration of Spent Layered Oxide Cathodes.

Direct recycling is considered to be the next-generation recycling technology for spent lithium-ion batteries due to its potential economic benefits and environmental friendliness. For the spent layered oxide cathode materials, an irreversible phase transition to a rock-salt structure near the particle surface impedes the reintercalation of lithium ions, thereby hindering the lithium compensation process from fully restoring composition defects and repairing failed structures. We introduced a transition-metal hydroxide precursor, utilizing its surface catalytic activity produced during annealing to convert the rock-salt structure into a layered structure that provides fast migration pathways for lithium ions.

Achieving Superior Cyclability Pouch Cells with Oxygen Vacancy-Moderated P'2/P3 Hybrid Layered Sodium Cathode Materials.

Layered P2-type sodium manganese oxide has emerged as a promising cathode candidate for sodium-ion batteries due to its appealing cost-effectiveness and high discharge voltage. However, its practical capacity within the voltage range of 2.0-4.

Continuous polyamorphic transition in high-entropy metallic glass.

Polyamorphic transition (PT) is a compelling and pivotal physical phenomenon in the field of glass and materials science. Understanding this transition is of scientific and technological significance, as it offers an important pathway for effectively tuning the structure and property of glasses. In contrast to the PT observed in conventional metallic glasses (MGs), which typically exhibit a pronounced first-order nature, herein we report a continuous PT (CPT) without first-order characteristics in high-entropy MGs (HEMGs) upon heating.

Phase Transition Modulated by Grain Size and Lattice Distortion in Layered Transition Metal Oxide for Sodium-Ion Batteries.

Low-cost sodium-ion batteries have demonstrated great prospects in energy storage, among which layered transition metal oxides hold great potential as a cathode material. However, the notorious phase transition in layered cathode materials has greatly hampered their cycle life due to large volume changes upon desodiation/sodiation. In this study, by adopting an O3-type NaNiFeMnO (NFM) with controlled synthesis temperatures, we have revealed that the grain size is closely related to its phase transition behaviors.

Two-Step Hydrothermal Synthesis of Submicrometric and Hierarchical Hollow SAPO-34 with Superior Catalytic Performance in Methanol to Olefin (MTO) Reaction.

A submicrometric and hierarchical hollow SAPO-34 molecular sieve was synthesized by an easy and low-cost two-step hydrothermal method. First, the crystallized mixture was obtained by direct drying after a first-step hydrothermal reaction. Then, the SAPO-34 product was obtained by adding the crystallized mixture to silicon-free gel and using cheap and common template agents.

Fluoride removal from coal mining water using novel polymeric aluminum modified activated carbon prepared through mechanochemical process.

Defluoridation of coal mining water is of great significance for sustainable development of coal industry in western China. A novel one-step mechanochemical method was developed to prepare polymeric aluminum modified powder activated carbon (PAC) for effective fluoride removal from coal mining water. Aluminum was stably loaded on the PAC through facile solid-phase reaction between polymeric aluminum (polyaluminum chloride (PACl) or polyaluminum ferric chloride (PAFC)) and PAC (1:15 W/W).

Spectroscopic characterizations of silicate fertilizers prepared by chemical deashing of coals.

Quality silicate fertilizers should be in great demand, and yet the production has been limited due to strict regulations on heavy metals, despite many raw materials and activation methods being used. In the chemical deashing of coals for the production of ultraclean coals, the silica gels of high purity were precipitated with little heavy metals from the acid deashing solutions, which could be used to produce quality silicate fertilizers by pulping with CaO or MgO under mild conditions. By varying the Ca/Si molar ratios, silicate fertilizers with different chemical compositions were prepared, and the active silica contents were measured and validated by ICP and colorimetric methods.

Damage-Tolerant and Self-Repairing Web-Like Borate Type Binder Enable Stable Operation of Efficient Si-Based Anodes.

Novel binder designs are shown to be fruitful in improving the electrochemical performance of silicon (Si)-based anodes. However, issues with mechanical damage from dramatic volume change and poor lithium-ion (Li) diffusion kinetics in Si-based materials still need to be addressed. Herein, an aqueous self-repairing borate-type binder (SBG) with a web-like architecture and high ionic conductivity is designed for Si and SiO electrodes.

Optimizing the Preparation Process of Refined Asphalt Based on the Response Surface and Preparation of Needle Coke.

Refined asphalt was prepared by solvent extraction sedimentation based on the response surface design, using washing oil and kerosene as solvents and the coal tar pitch as raw materials. The mathematical models of the refined asphalt yield, quinoline insoluble (QI) content, ash content, solvent-to-oil ratio, aromatic-to-aliphatic hydrocarbon ratio, extraction temperature, and sedimentation time were proposed, analyzing the influence of each factor and their interactions on the response values. Therefore, the optimal combination of preparation process parameters and better operation window was obtained by optimizing the experiment.

Electronic structures and quantum capacitance of twisted bilayer graphene with defects based on three-band tight-binding model.

Twisted bilayer graphene (tBLG) with C vacancies would greatly improve the density of states (DOS) around the Fermi level () and quantum capacitance; however, the single-band tight-binding model only considering p orbitals cannot accurately capture the low-energy physics of tBLG with C vacancies. In this work, a three-band tight-binding model containing three p orbitals of C atoms is proposed to explore the modulation mechanism of C vacancies on the DOS and quantum capacitance of tBLG. We first obtain the hopping integral parameters of the three-band tight-binding model, and then explore the electronic structures and the quantum capacitance of tBLG at a twisting angle of = 1.

Experimental Study of Non-Darcian Flow Characteristics in Low-Permeability Coal Pillar Dams.

The safe operation of underground reservoirs and environmental protection heavily rely on the water flow through coal pillar dams in coal mines. Meanwhile, research on the flow characteristics in coal pillar dams has been limited due to their low hydraulic conductivity. To address this gap, this study assembled a novel seepage experimental device and conducted a series of carefully designed seepage experiments to examine the characteristics of low-permeability in coal pillar dams.

In Situ Growth Strategy to Construct "Four-In-One" Separators with Functionalized Polyphosphazene Coatings for Safe and Stable Lithium-Sulfur Batteries.

Lithium-sulfur batteries (LSBs) are facing many challenges, such as the inadequate conductivity of sulfur, the shuttle effect caused by lithium polysulfide (LiPSs), lithium dendrites, and the flammability, which have hindered their commercial applications. Herein, a "four-in-one" functionalized coating is fabricated on the surface of polypropylene (PP) separator by using a novel flame-retardant namely InC-HCTB to meet these challenges. InC-HCTB is obtained by cultivating polyphosphazene on the surface of carbon nanotubes with an in situ growth strategy.