Tungsten doped FeCoP nanoparticles embedded into carbon for highly efficient oxygen evolution reaction.

Designing active and stable electrocatalysts with economic efficiency for oxygen evolution reaction (OER) is essential for developing water splitting process at an industrial scale. Herein, we rationally designed a tungsten doped iron cobalt phosphide incorporated with carbon (W-FeCoP/C), prepared by a mechanochemical approach. X-ray photoelectron spectroscopy (XPS) revealed that the doping of W led to an increasing of Co/Co and Fe/Fe molar ratios, which contributed to the enhanced OER performance.

Electrolyte Design for Low-Temperature Li-Metal Batteries: Challenges and Prospects.

Electrolyte design holds the greatest opportunity for the development of batteries that are capable of sub-zero temperature operation. To get the most energy storage out of the battery at low temperatures, improvements in electrolyte chemistry need to be coupled with optimized electrode materials and tailored electrolyte/electrode interphases. Herein, this review critically outlines electrolytes' limiting factors, including reduced ionic conductivity, large de-solvation energy, sluggish charge transfer, and slow Li-ion transportation across the electrolyte/electrode interphases, which affect the low-temperature performance of Li-metal batteries.

Cu-Sn Aerogels for Electrochemical CO Reduction with High CO Selectivity.

This work reports the synthesis of CuSn alloy aerogels for electrochemical CO reduction catalysts. An in situ reduction and the subsequent freeze-drying process can successfully give CnxSny aerogels with tuneable Sn contents, and such aerogels are composed of three-dimensional architectures made from inter-connected fine nanoparticles with pores as the channels. Density functional theory (DFT) calculations show that the introduction of Sn in Cu aerogels inhibits H evolution reaction (HER) activity, while the accelerated CO desorption on the catalyst surface is found at the same time.

Bi-Fe chalcogenides anchored carbon matrix and structured core-shell Bi-Fe-P@Ni-P nanoarchitectures with appealing performances for supercapacitors.

Pseudocapacitive materials based on multi-active components are attractive platforms for future portable energy devices due to their excellent redox processes and low cost. In this study, nanostructured bismuth-iron chalcogenide anchored on multiwalled carbon nanotube framework (Bi-Fe chalcogenide/C)-based electrode materials were fabricated via a simple solvothermal protocol with enhanced electrochemical performances. The obtained Bi-Fe chalcogenide/C nanocomposites combining the improved electroconductivity of carbonic frameworks and high pseudocapacitive properties of Bi/Fe reversible redox processes were employed as negative electrodes for asymmetric supercapacitor (ASC) devices.

N plasma-activated NiO nanosheet arrays with enhanced water splitting performance.

NiO is a promising electrocatalyst for electrochemical energy conversion due to its rich redox sites, low cost, and ease of synthesis. However, hindered by low electrical conductivity and limited electrocatalytic active sites, bare NiO usually exhibits poor electrochemical performance towards hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Herein, we develop an N plasma activation approach to simultaneously improve both HER and OER activity of NiO by constructing heterostructured Ni/NiN/NiO nanosheet arrays on Ni foam.

Electrospinning metal Phosphide/Carbon nanofibers from Phytic Acid for hydrogen evolution reaction catalysts.

This paper reports a general electrospinning method to prepare various metal phosphide/carbon nanofibers composite for electrochemical hydrogen evolution reaction (HER) catalysts. An earth-abundant organic acid-phytic acid is successfully incorporated into a conventional electrospinning precursor as the phosphorus source, and continuous nanofibers can be obtained through spinning. After heat treatment, metal phosphide/carbon composite nanofibers can be obtained, with fine phosphide nanoparticles well dispersed on the surface of an interconnected carbon backbone network.

Synthesis of porous AgS-NiCoS hollow architecture as effective electrode material with high capacitive performances.

Fabrication of highly reactive and cost-effective electrode materials is a key to efficient functioning of green energy technologies. Decorating redox-active metal sulfides with conductive dopants is one of the most effective approaches to enhance electric conductivity and consequently boost capacitive properties. Herein, hierarchically hollow AgS-NiCoS architectures are designed with an enhanced conductivity by a simple solvothermal approach.

Progress and Challenges Toward the Rational Design of Oxygen Electrocatalysts Based on a Descriptor Approach.

Oxygen redox catalysis, including the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), is crucial in determining the electrochemical performance of energy conversion and storage devices such as fuel cells, metal-air batteries,and electrolyzers. The rational design of electrochemical catalysts replaces the traditional trial-and-error methods and thus promotes the R&D process. Identifying descriptors that link structure and activity as well as selectivity of catalysts is the key for rational design.

Rational Design of Porous Structured Nickel Manganese Sulfides Hexagonal Sheets-in-Cage Structures as an Advanced Electrode Material for High-Performance Electrochemical Capacitors.

The design of hierarchical electrodes comprising multiple components with a high electrical conductivity and a large specific surface area has been recognized as a feasible strategy to remarkably boost pseudocapacitors. Herein, we delineate hexagonal sheets-in-cage shaped nickel-manganese sulfides (Ni-Mn-S) with nanosized open spaces for supercapacitor applications to realize faster redox reactions and a lower charge-transfer resistance with a markedly enhanced specific capacitance. The hybrid was facilely prepared through a two-step hydrothermal method.

Fe ions modulated formation of hollow NiFe oxyphosphide spheres with enhanced oxygen evolution performance.

A facile template-engaged strategy is developed to synthesize hollow NiFe mixed metal oxyphosphide spheres using different Fe ions (Fe2+ and Fe3+) as modulators. Benefiting from the optimized compositional and structural features, the as-obtained hollow spheres show excellent performance for the oxygen evolution reaction.

Recent Trends in Synthesis and Investigation of Nickel Phosphide Compound/Hybrid-Based Electrocatalysts Towards Hydrogen Generation from Water Electrocatalysis.

Sustainable and high performance energy devices such as solar cells, fuel cells, metal-air batteries, as well as alternative energy conversion and storage systems have been considered as promising technologies to meet the ever-growing demands for clean energy. Hydrogen evolution reaction (HER) is a crucial process for cost-effective hydrogen production; however, functional electrocatalysts are potentially desirable to expedite reaction kinetics and supply high energy density. Thus, the development of inexpensive and catalytically active electrocatalysts is one of the most significant and challenging issues in the field of electrochemical energy storage and conversion.

Sponge Effect Boosting Oxygen Reduction Reaction at the Interfaces between Mullite SmMnO and Nitrogen-Doped Reduced Graphene Oxide.

Exploring the effect of interfacial structural properties on catalytic performance of hybrid materials is essential in rationally designing novel electrocatalysts with high stability and activity. Here, in situ growth of mullite SmMnO on nitrogen-doped reduced graphene oxide (SMO@NrGO) is achieved for highly efficient oxygen reduction reaction (ORR). Combining X-ray photoelectron spectroscopy and density functional theory calculations, interfacial chemical interactions between Mn and substrates are verified.

Synthesis of coaxial carbon@NiMoO composite nanofibers for supercapacitor electrodes.

This work reports the synthesis of coaxial carbon@NiMoO nanofibers for supercapacitor electrode applications. Thin NiMoO nanosheets are uniformly coated on the conductive electrospun carbon nanofibers by a microwave assisted hydrothermal method to form a hierarchical structure, which increases the porosity as well as the conductivity of the electrode. The thickness of the NiMoO can be easily adjusted by varying the precursor concentrations.

CoS nanoparticle-decorated carbon nanofibers as high-performance supercapacitor electrodes.

This work reported CoS nanoparticle-decorated carbon nanofibers (CNF) as a supercapacitor electrode. By using a mild ion-exchange method, the cobalt oxide-based precursor nanoparticles were transformed to CoS nanoparticles in a microwave hydrothermal process, and these nanoparticles were decorated onto a carbon nanofiber backbone. The composition of the nanofibers can be readily tuned by varying the Co acetate content in the precursor.

Cobalt sulfide aerogel prepared by anion exchange method with enhanced pseudocapacitive and water oxidation performances.

This work introduces the anion exchange method into the sol-gel process for the first time to prepare a metal sulfide aerogel. A porous CoS aerogel with a high surface area (274.2 m g) and large pore volume (0.

The investigation of an organic acid assisted sol-gel method for preparing monolithic zirconia aerogels.

In our previous work, a citric acid assisted sol-gel method was developed for preparing monolithic metal oxide aerogels. Such method adopted citric acid as the gelator, which replaced the well-studied proton scavenger propylene oxide. In this work, we have further extended this "organic acid assisted" sol-gel method and investigated the gelation mechanism.

Nano Titanium Monoxide Crystals and Unusual Superconductivity at 11 K.

Nano TiO is investigated intensely due to extraordinary photoelectric performances in photocatalysis, new-type solar cells, etc., but only very few synthesis and physical properties have been reported on nanostructured TiO or other low valent titanium-containing oxides. Here, a core-shell nanoparticle made of TiO core covered with a ≈5 nm shell of amorphous TiO is newly constructed via a controllable reduction method to synthesize nano TiO core and subsequent soft oxidation to form the shell (TiO ).

Conductive Carbon Nitride for Excellent Energy Storage.

Conductive carbon nitride, as a hypothetical carbon material demonstrating high nitrogen doping, high electrical conductivity, and high surface area, has not been fabricated. A major challenge towards its fabrication is that high conductivity requires high temperature synthesis, but the high temperature eliminates nitrogen from carbon. Different from conventional methods, a facile preparation of conductive carbon nitride from novel thermal decomposition of nickel hydrogencyanamide in a confined space is reported.

Mesoporous Piezoelectric Polymer Composite Films with Tunable Mechanical Modulus for Harvesting Energy from Liquid Pressure Fluctuation.

Harvesting mechanical energy from biological systems possesses great potential for in vivo powering implantable electronic devices. In this paper, a development of flexible piezoelectric nanogenerator (NG) is reported based on mesoporous poly(vinylidene fluoride) (PVDF) films. Monolithic mesoporous PVDF is fabricated by a template-free sol-gel-based approach at room temperature.

Hierarchical NiCo2 O4 Hollow Microcuboids as Bifunctional Electrocatalysts for Overall Water-Splitting.

Bifunctional electrocatalysts for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in alkaline electrolyte may improve the efficiency of overall water splitting. Nickel cobaltite (NiCo2 O4 ) has been considered a promising electrode material for the OER. However, NiCo2 O4 that can be used as an electrocatalyst in HER has not been studied yet.

TiO2 Microboxes with Controlled Internal Porosity for High-Performance Lithium Storage.

Titanium dioxide (TiO2) is considered a promising anode material for high-power lithium ion batteries (LIBs) because of its low cost, high thermal/chemical stability, and good safety performance without solid electrolyte interface formation. However, the poor electronic conductivity and low lithium ion diffusivity of TiO2 result in poor cyclability and lithium ion depletion at high current rates, which hinder them from practical applications. Herein we demonstrate that hierarchically structured TiO2 microboxes with controlled internal porosity can address the aforementioned problems for high-power, long-life LIB anodes.

Synthesis of lanthanide-doped NaYF₄@TiO₂ core-shell composites with highly crystalline and tunable TiO₂ shells under mild conditions and their upconversion-based photocatalysis.

NaYF4:Yb,Tm@TiO₂ core-shell composites were synthesized via a facile hydrothermal method. The highly crystalline TiO₂ shell can be uniformly coated onto lanthanide-doped NaYF₄ microrods and nanorods under mild conditions without calcination. The thickness of the TiO₂ shell can be tuned by varying the ratio of fluoride rods and Ti precursors.

Enhanced broadband near-infrared luminescence of Bi-doped oxyfluoride glasses.

Broadband near-infrared luminescence covering 900 to 1600 nm has been observed in Bi-doped oxyfluoride silicate glasses. The partial substitution of fluoride for oxide in Bi-doped silicate glasses leads to an increase of the intensity and lifetime of the near-infrared luminescence and blue-shift of the near-infrared emission peaks. Both Bi-doped silicate and oxyfluoride silicate glasses show visible luminescence with blue, green, orange and red emission bands when excited by ultra-violet light.

Localized control of light-matter interactions by using nanoscale asymmetric TiO2.

This paper reports an asymmetry structure-mediated route for highly localized control of light-matter interactions by using tapered TiO(2). We demonstrate for the first time that the growth habit of Ag nanostructures on tapered TiO(2) can be tuned by controllable photolysis. Site-selective anchoring of Ag nanoparticles or nanowires on tapered TiO(2) can be achieved by simply changing the external light.

Unusual luminescence quenching and reviving behavior of Bi-doped germanate glasses.

Here for the first time, we report an unusual annealing temperature dependent near-infrared (NIR) luminescence quenching and reviving behavior in Bi-doped MgO-Al₂O₃-GeO₂ glasses. Systematic characterizations of the samples by using differential thermal analysis (DTA), photoluminescence and absorption spectra, X-ray diffraction (XRD) and transmission electron microscopy (TEM) indicate that this phenomenon is associated with the reversible reaction of Bi⁺ and Bi⁰ initiated by the change of local glass structure. Excitingly, wavelength tunable luminescence is also observed and it can be ascribed to selective excitation of active Bi⁺ center in different sites.