The present application relates to copper-doped double perovskites, for example, copper-doped double perovskites of the formula (I) and to uses thereof, for example as low-bandgap materials such as a semiconducting material in a device. The present application also relates to methods of tuning the bandgap of a Cs.sub.2SbAgZ.sub.6 double perovskite (for example, wherein Z is Cl) comprising doping the double perovskite with copper.
Cs.sub.2Sb.sub.1-aAg.sub.1-bCu.sub.2xZ.sub.6  (I)

The invention relates to improved particulate lithium nickel oxide materials which are useful as cathode materials in lithium secondary batteries. The invention also provides processes for preparing such lithium nickel oxide materials, and electrodes and cells comprising the materials.

According to one embodiment, provided is an active material including a crystal particle that includes a niobium-titanium composite oxide. A ratio A.sub.Nb/A.sub.Ti of a Nb abundance A.sub.Nb to a Ti abundance A.sub.Ti in the crystal particle satisfies 2.3≤A.sub.Nb/A.sub.Ti≤4.0. According to a powder X-ray diffraction spectrum using a Cu-Kα ray for the crystal particle, an intensity ratio I.sub.β/I.sub.α of a peak intensity I.sub.β of a peak β appearing at 12.5°≤2θ≤13.0° to a peak intensity I.sub.α of a peak α appearing at 8.5°≤2θ≤9.0° is within a range of 0.1<I.sub.β/I.sub.α≤2.0.

A positive electrode active material with high charge and discharge capacity is provided. A positive electrode active material with high charge and discharge voltage is provided. A power storage device that hardly deteriorates is provided. A highly safe power storage device is provided. A novel power storage device is provided. A positive electrode active material containing lithium, a plurality of transition metals, oxygen, and an impurity element. The positive electrode active material includes a first region including a surface portion and a second region provided inward from the first region, and the concentration of a transition metal is higher in the first region than in the second region. An impurity region is included between the first region and the second region.

A coated particle having excellent thermal expansion control and electrical insulation properties includes a core of a first inorganic compound containing a metal or semimetal element P; and a shell of a second inorganic compound containing a metal or semimetal element Q. The first inorganic compound satisfies 1, and the coated particles satisfy 2 and 3. 1: |dA(T)/dT| is ≥10 ppm/°C at T1 of -200° C. to 1,200° C. A is (an a-axis lattice constant of a crystal in the first inorganic compound)/(a c-axis lattice constant of a crystal in the first inorganic compound). 2: in XPS of a surface of each of the coated particles, a ratio of a number of atoms of Q contained in the shell to a number of atoms of P contained in the core t is 45 to 300. 3: an average particle diameter of each coated particle is 0.1 to 100 .Math.m.

A method for producing mesoporous magnesium hydroxide nanoplates involving solvothermal treatment of a solution of a magnesium salt, a base, a glycol, and water is disclosed. The method does not use a surfactant or template in the solvothermal treatment. The method yields mesoporous nanoparticles of magnesium hydroxide having a plate-like morphology with a diameter of 20 nm to 100 nm, a mean pore diameter of 2 to 10 nm, a surface area of 50 to 70 m.sup.2/g, and a type-III nitrogen adsorption-desorption BET isotherm with a H3 hysteresis loop. An antibacterial composition containing the mesoporous magnesium hydroxide nanoplates is also disclosed. A method for reducing nitroaromatic compounds with a reducing agent and the mesoporous magnesium hydroxide nanoplates as a catalyst is also disclosed.

The present disclosure belongs to the technical filed of new carbon materials and relates to a novel sp.sup.2-sp.sup.3 hybrid crystalline carbon named Gradia and its preparation process. A novel sp.sup.2-sp.sup.3 hybrid carbon named Gradia is synthesized using sp.sup.2 hybrid carbon as raw materials under high temperature and high pressure. The basic structural units of Gradia are composed of sp.sup.2 hybrid graphite-like structural units and sp.sup.3 hybrid diamond-like structural units. Gradia disclosed in the present disclosure is a class of new sp.sup.2-sp.sup.3 hybrid carbon allotrope, whose crystal structure can vary with the widths and/or crystallographic orientation relationships of internal sp.sup.2 and/or sp.sup.3 structural units.

Proposed are a layered Group III-V arsenic compound, a Group III-V nanosheet that may be prepared using the same, and an electrical device including the materials. There is proposed a layered compound having a composition represented by [Formula 1] Mx-mAyAsz (Where M is at least one of Group I elements, A is at least one of Group III elements, x, y, and z are positive numbers which are determined according to stoichiometric ratios to ensure charge balance when m is 0, and 0<m<x).

Disclosed herein are ceramic materials, such as bismuth substituted garnets, which can have high curie temperatures and high dielectric constants. In certain implementations, indium can be incorporated into the ceramic to improve certain properties and to avoid calcium compensation. The ceramic materials disclosed herein can be particular advantageous for below resonance applications.

A gas-sensitive material, a preparation method therefore and an application thereof, and a gas sensor using the gas-sensitive material are provided. The gas-sensitive material is a carbon material-metal oxide composite nanomaterial formed by compounding a carbon material and metal oxides. The content of the carbon material is 0.5˜20 wt. % and the content of the metal oxides is 80˜99.5 wt. %; the metal oxides contain tungsten oxide and one or more selected from tin oxide, iron oxide, titanium oxide, copper oxide, molybdenum oxide, and zinc oxide; the metal oxides are formed on the carbon material in the form of nanowires, and the nanowires are tungsten oxide-doped nanowires. The gas-sensitive material has reduced resistance, is capable of responding to various gases at a reduced working temperature.