Doped titanium niobate is provided, which has a chemical structure of Ti.sub.(1-x)M1.sub.xNb.sub.(2-y)M2.sub.yO.sub.(7-z)Q.sub.z or Ti.sub.(2-x)M1.sub.xNb.sub.(10-y)M2.sub.yO.sub.(29-z)Q.sub.z, wherein M1 is Li, Mg, or a combination thereof; M2 is Fe, Mn, V, Ni, Cr, or a combination thereof; Q is F, Cl, Br, I, S, or a combination thereof; 0x0.15; 0y0.15; 0.01z2; 0x0.3; 0y0.9; and 0.01z8.

A mixed conductor represented by Formula 1:

A.sub.4+xM.sub.5-yM.sub.yO.sub.12-,Formula 1

wherein, in Formula 1, A is a monovalent cation, M is at least one of a divalent cation, a trivalent cation, or a tetravalent cation, M is at least one of a monovalent cation, a divalent cation, a trivalent cation, a tetravalent cation, a pentavalent cation, or a hexavalent cation, M and M are different from each other, and 0.3x<3, 0.01<y<2, and 01 are satisfied.

A perovskite material represented by Formula 1:

Li.sub.xA.sub.yM.sub.zO.sub.3-Formula 1 wherein in Formula 1, 0<x1, 0<y1, 0<x+y<1, 0<z1.5, 01, A is H, Na, K, Rb, Cs, Ca, Sr, Ba, Y, La, Ce, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, or a combination thereof, and M is Ni, Pd, Pb, Fe, Ir, Co, Rh, Mn, Cr, Ru, Re, Sn, V, Ge, W, Zr, Mo, Hf, U, Nb, Th, Ta, Bi, Li, H, Na, K, Rb, Cs, Ca, Sr, Ba, Y, La, Ce, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Mg, Al, Si, Sc, Zn, Ga, Ag, Cd, In, Sb, Pt, Au, or a combination thereof.

A layered double hydroxide (LDH) material, methods for using the LDH material to catalyse the oxygen evolution reaction (OER) in a water-splitting process and methods for preparing the LDH material. The LDH material includes nickel, iron and chromium species and possesses a sheet-like morphology including at least one hole.

Methods of forming spinel ferrite nanoparticles containing a chromium-substituted copper ferrite as well as properties (e.g. particle size, crystallite size, pore size, surface area) of these spinel ferrite nanoparticles are described. Methods of preventing or reducing microbe growth on a surface by applying these spinel ferrite nanoparticles onto the surface in the form of a suspension or an antimicrobial product are also described.

A method for positive electrode active material for a secondary battery includes preparing a precursor by reacting a nickel raw material, a cobalt raw material and an M1 raw material; forming a first surface-treated layer including an oxide of Formula 2 below, on a surface of a core including a lithium composite metal oxide of Formula 1 below, by mixing the precursor with a lithium raw material and an M3 raw material, firing the resultant mixture; and forming a second surface-treated layer including a lithium compound of Formula 3 below, on the core with the first surface-treated layer formed thereon,

Li.sub.aNi.sub.1xyCo.sub.xM1.sub.yM3.sub.zM2.sub.wO.sub.2 [Formula 1]

Li.sub.mM4O.sub.(m+n)/2 [Formula 2]

Li.sub.pM5.sub.qA.sub.r [Formula 3]

wherein, in Formulae 1 to 3, A, M1 to M5, a, x, y, z, w, m, n, p, and q are the same as those defined in the specification.

The present invention provides a positive electrode active material for secondary battery and a secondary battery including the same. The positive electrode active material includes a core including a lithium composite metal oxide of Formula 1 below, a first surface-treated layer positioned on the surface of the core and including a lithium oxide of Formula 2 below, and a second surface treated layer positioned on the core or the first surface-treated layer and including a lithium compound of Formula 3. Thus, the present invention can improve capacity characteristics and output characteristics of a battery and also reduce the generation of gas,
Li.sub.aNi.sub.1-x-yCo.sub.xM1.sub.yM3.sub.zM2.sub.wO.sub.2 [Formula 1]
Li.sub.mM4O.sub.(m+n)/2 [Formula 2]
Li.sub.pM5.sub.qA.sub.r [Formula 3] (in formulae 1 to 3, A, M1 to M5, a, x, y, z, w, m, n, p, and q are the same as those defined in the specification).

The present invention relates to Mn-activated luminescent materials, to a process for preparation thereof and to the use thereof as luminophores or conversion luminophores in light sources. The present invention further relates to a radiation-converting mixture comprising the luminescent material of the invention and a light source comprising the luminescent material of the invention or the radiation-converting mixture. The present invention further provides light sources, especially LEDs, and lighting units comprising a primary light source and the luminescent material of the invention or the radiation-converting mixture. The Mn-activated luminescent materials of the invention are especially suitable for creation of warm white light in LEDs.

A perovskite material represented by Formula 1:
Li.sub.xA.sub.yM.sub.zO.sub.3-?Formula 1 wherein in Formula 1, 0<x?1, 0<y?1, 0<x+y<1, 0<z?1.5, 0???1, A is H, Na, K, Rb, Cs, Ca, Sr, Ba, Y, La, Ce, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, or a combination thereof, and M is Ni, Pd, Pb, Fe, Ir, Co, Rh, Mn, Cr, Ru, Re, Sn, V, Ge, W, Zr, Mo, Hf, U, Nb, Th, Ta, Bi, Li, H, Na, K, Rb, Cs, Ca, Sr, Ba, Y, La, Ce, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Mg, Al, Si, Sc, Zn, Ga, Ag, Cd, In, Sb, Pt, Au, or a combination thereof.

Methods of forming spinel ferrite nanoparticles containing a chromium-substituted copper ferrite as well as properties (e.g. particle size, crystallite size, pore size, surface area) of these spinel ferrite nanoparticles are described. Methods of preventing or reducing microbe growth on a surface by applying these spinel ferrite nanoparticles onto the surface in the form of a suspension or an antimicrobial product are also described.