A Gradient Composite Structure Enables a Stable Microsized Silicon Suboxide-Based Anode for a High-Performance Lithium-Ion Battery.

The practical application of microsized anodes is hindered by severe volume changes and fast capacity fading. Herein, we propose a gradient composite strategy and fabricate a silicon suboxide-based composite anode (d-SiO@SiO/C@C) consisting of a disproportionated microsized SiO inner core, a homogeneous composite SiO/C interlayer ( ≈ 1.5), and a highly graphitized carbon outer layer.

The transaction behavior of cryptocurrency and electricity consumption.

Rapidly increasing cryptocurrency prices have encouraged cryptocurrency miners to participate in cryptocurrency production, increasing network hashrates and electricity consumption. Growth in network hashrates has further crowded out small cryptocurrency investors owing to the heightened costs of mining hardware and electricity. These changes prompt cryptocurrency miners to become new investors, leading to cryptocurrency price increases.

Preparation of hierarchical hollow CoFe Prussian blue analogues and its heat-treatment derivatives for the electrocatalyst of oxygen evolution reaction.

The microstructure of materials importantly affects their performance. As electrocatalyst materials, the performance of hollow-structure materials is usually better than that of solid materials because of the larger specific surface area, lower density, and more exposed active sites of hollow structure. Bimetallic catalysts usually exhibit better catalytic activity than monometallic catalysts because of the synergistic effects between different metal elements.

Preparation of Hollow Core-Shell FeO/Nitrogen-Doped Carbon Nanocomposites for Lithium-Ion Batteries.

Iron oxides are potential electrode materials for lithium-ion batteries because of their high theoretical capacities, low cost, rich resources, and their non-polluting properties. However, iron oxides demonstrate large volume expansion during the lithium intercalation process, resulting in the electrode material being crushed, which always results in poor cycle performance. In this paper, to solve the above problem, iron oxide/carbon nanocomposites with a hollow core-shell structure were designed.

Oxygen-Deficient Ferric Oxide as an Electrochemical Cathode Catalyst for High-Energy Lithium-Sulfur Batteries.

Lithium-sulfur batteries, as one of promising next-generation energy storage devices, hold great potential to meet the demands of electric vehicles and grids due to their high specific energy. However, the sluggish kinetics and the inevitable "shuttle effect" severely limit the practical application of this technology. Recently, design of composite cathode with effective catalysts has been reported as an essential way to overcome these issues.

Amorphous Intermediate Derivative from ZIF-67 and Its Outstanding Electrocatalytic Activity.

Increasing active sites is an effective method to enhance the catalytic activity of catalysts. Amorphous materials have attracted considerable attention in catalysis because of their abundant catalytic active sites. Herein, a series of derivatives is prepared via the low-temperature heat treatment of ZIF-67 hollow sphere at different temperatures.

Boosting the performance of broccoli-like Ni-triazole frameworks through a CNTs conductive-matrix.

Different approaches for the fabrication of CNT-supported Ni-triazole composites, such as room-temperature stirring and hydrothermal treatment for a distinct reaction time has been presented. As a result, various morphologies, MMOF wrapped CNTs, CNTs entangled with an MMOF and CNTs attached on an MMOF, were synthesized and investigated through electrochemical measurements. The as-synthesized CNTs/MMOF-based hybrids, especially for the CNTs/MMOF-8H structure, show a good rate capability after 20 times increase, a superior coulombic efficiency and an excellent long-term cycling stability (more than 98% retained after 2000 cycles).

Applications of MSe (M = Fe, Co, Ni) and Their Composites in Electrochemical Energy Storage and Conversion.

Transition-metal selenides (MSe, M = Fe, Co, Ni) and their composites exhibit good storage capacities for sodium and lithium ions and occupy a unique position in research on sodium-ion and lithium-ion batteries. MSe and their composites are used as active materials to improve catalytic activity. However, low electrical conductivity, poor cycle stability, and low rate performance severely limit their applications.

Iron oxide-based nanomaterials for supercapacitors.

As highly efficient and clean electrochemical energy storage devices, supercapacitors (SCs) have drawn widespread attention as promising alternatives to batteries in recent years. Among various electrode materials, iron oxide materials have been widely studied as negative SC electrode materials due to their broad working window in negative potential, ideal theoretical specific capacitance, good redox activity, abundant availability, and eco-friendliness. However, iron oxides still suffer from the problems of low stability and poor conductivity.

Stable Voltage Cutoff Cycle Cathode with Tunable and Ordered Porous Structure for Li-O Batteries.

Ordered porous RuO materials with various pore structure parameters are prepared via a hard-template method and are used as the carbon-free cathodes for Li-O batteries under the voltage cutoff cycle mode. The influences of pore structure parameters of porous RuO on electrochemical performance are systematically studied. Results indicate that specific surface area and pore size determine the specific capacity and round-trip efficiency of Li-O batteries.

Hierarchically Nanostructured Transition Metal Oxides for Lithium-Ion Batteries.

Lithium-ion batteries (LIBs) have been widely used in the field of portable electric devices because of their high energy density and long cycling life. To further improve the performance of LIBs, it is of great importance to develop new electrode materials. Various transition metal oxides (TMOs) have been extensively investigated as electrode materials for LIBs.

An electrochemical microRNA sensing platform based on tungsten diselenide nanosheets and competitive RNA-RNA hybridization.

In this work, we report an ultrasensitive electrochemical biosensor for microRNA-21 (miRNA-21) detection by using a competitive RNA-RNA hybridization configuration. A biotinylated miRNA of the self-same sequence with the target miRNA is mixed with the samples, and allowed competition with the target miRNA for a thiolated RNA probe immobilized onto a tungsten diselenide (WSe) nanosheet modified electrode. Thereafter the current response is obtained by forming the hybridized biotinylated miRNA with streptavidin-horseradish peroxidase (HRP) conjugates to catalyze the HO + hydroquinone (HQ) system.

Subcellular-Scale Drug Transport via Ultrasound-Degradable Mesoporous Nanosilicon to Bypass Cancer Drug Resistance.

Delivering and releasing anticancer agents directly to their subcellular targets of action in a controlled manner are almost the ultimate goal of pharmacology, but it is challenging. In recent decades, plenty of efforts have been made to send drugs to tumor tissue or even specifically to cancer cells; however, at the subcellular scale, cancer cells have multiple cunning ways to hinder drugs from reaching their final action targets. Here, we demonstrate a strategy to bypass the last defense of cancer drug resistance by contolling the drug transportation and release at subcellular scale.

A multi-layered Fe2O3/graphene composite with mesopores as a catalyst for rechargeable aprotic lithium-oxygen batteries.

Aprotic Li-O2 batteries have attracted a huge amount of interest in the past decade owing to their extremely high energy density. However, identifying a desirable cathodic catalyst for this promising battery system is one of the biggest challenges at present. In this work, a multi-layered Fe2O3/graphene nanosheets (Fe2O3/GNS) composite with sandwich structure was synthesized using an easy thermal casting method, and served as a cathodic catalyst for aprotic Li-O2 batteries.

Highly cross-linked Cu/a-Si core-shell nanowires for ultra-long cycle life and high rate lithium batteries.

Seeking long cycle lifetime and high rate performance are still challenging aspects to promote the application of silicon-loaded lithium ion batteries (LIBs), where optimal structural and compositional design are critical to maximize a synergistic effect in composite core-shell nanowire anode structures. We here propose and demonstrate a high quality conformal coating of an amorphous Si (a-Si) thin film over a matrix of highly cross-linked CuO nanowires (NWs). The conformal a-Si coating can serve as both a high capacity storage medium and a high quality binder that joins crossing CuO NWs into a continuous network.

Binder-free carbonized bacterial cellulose-supported ruthenium nanoparticles for Li-O2 batteries.

Network structured carbonized bacterial cellulose-supported Ru nanoparticles (CBC/Ru), which provide sufficient space for Li2O2 deposition without a significant volume effect and improve the transport of oxygen and electrons, were used as the binder-free oxygen electrode in a Li-O2 battery. The CBC/Ru exhibited high activities and good stability during discharge-recharge processes.

Li3VO4 anchored graphene nanosheets for long-life and high-rate lithium-ion batteries.

Li3VO4 nanoparticles embedded in graphene nanosheets (Li3VO4@GNS) were obtained using a sol-gel method. The composite presents excellent high-rate performance with a stable capacity of 133 mA h g(-1) at 50 C and long-life performance with a capacity retention rate of 63.1% after 5000 cycles at 5 C.

Fe2O3 nanocrystals anchored onto graphene nanosheets as the anode material for low-cost sodium-ion batteries.

Fe2O3 nanocrystals were uniformly anchored onto graphene nanosheets (Fe2O3@GNS) by a nanocasting technique, and the resulting composites were applied as anodes of sodium-ion batteries. Fe2O3@GNS exhibits excellent cycling performance and rate capability.

Indirect transformation of coordination-polymer particles into magnetic carbon-coated MN3O4 (MN3O4@C) nanowires for supercapacitor electrodes with good cycling performance.

Carbon-coated Mn3O4 nanowires (Mn3O4@C NWs) have been synthesized by the reduction of well-shaped carbon-coated bixbyite networks and characterized by TEM, X-ray diffraction, X-ray photoelectron spectroscopy, and electrochemical experiments. To assess the properties of 1D carbon-coated nanowires for their use in supercapacitors, cyclic voltammetry and galvanostatic charging-discharging measurements were performed. Mn3O4 @C NWs could be charged and discharged faster and had higher capacitance than bare Mn3O4 nanostructures and other commercial materials.

Template synthesis of carbon nanofibers containing linear mesocage arrays.

Carbon nanofibers containing linear mesocage arrays were prepared via evaporation induced self-assembly method within AAO template with an average channel diameter of about 25 nm. The TEM results show that the mesocages have an elongated shape in the transversal direction. The results of N2 adsorption-desorption analysis indicate that the sample possesses a cage-like mesoporous structure and the average mesopore size of the sample is about 18 nm.

Microwave-assisted synthesis of Sb2Se3 submicron tetragonal tubular and spherical crystals.

Sb(2)Se(3) submicron tetragonal tubes have been prepared by a microwave-assisted polyol method using antimony trichloride and sodium selenite as the Sb and Se precursors. Scanning electron microscopy (SEM) results showed a novel transformation of Sb(2)Se(3) microstructures from submicron tubes to submicron spheres during the microwave heating process. The potential growth mechanism has been investigated by analyzing the samples at different growth stages.

A new restriction effect of hard templates for the shrinkage of mesoporous polymer during carbonization.

A new restriction effect of hard templates for the shrinkage of mesoporous polymer results in anomalous increase of the mesopore size during carbonization.