A weakly coupled enhanced graphene film includes an enhanced graphene structure based on weak coupling, wherein the enhanced graphene structure based on weak coupling comprises a plurality of graphene units stacked vertically; the graphene unit is a single graphene sheet, or consists of two or more graphene sheets stacked in AB form; two vertically adjacent graphene units are weakly coupled, to promote the hot electron transition and increase the joint density of states, thereby increasing the number of hot electrons in high-energy states; the stacking direction of the graphene units in the graphene structure is in the thickness direction of the graphene film; and the graphene film enhances the accumulation of hot electrons in high-energy states by the enhanced graphene structure based on weak coupling.

Systems and methods of synthesizing nanoparticles on substrates using rapid, high temperature thermal shock. A method involves depositing micro-sized particles or salt precursors on a substrate, and applying a rapid, high temperature thermal shock to the micro-sized particles or the salt precursors to become nanoparticles on the substrate. A system may include a rotatable member that receives a roll of a substrate sheet having micro-sized particles or salt precursors; a motor that rotates the rotatable member so as to unroll the substrate; and a thermal energy source that applies a short, high temperature thermal shock to the substrate. The nanoparticles may be metallic, ceramic, inorganic, semiconductor, or compound nanoparticles. The substrate may be a carbon-based substrate, a conducting substrate, or a non-conducting substrate. The high temperature thermal shock process may be enabled by electrical Joule heating, microwave heating, thermal radiative heating, plasma heating, or laser heating.

Production method for metal oxide fine particles includes: a step of mixing a fatty acid represented by C.sub.nH.sub.2nO.sub.2 (n=5 to 14) and a metal source consisting of a metal, metal oxide, or metal hydroxide of at least two metal elements selected from the group consisting of Zn, In, Sn, and Sb to obtain a mixture; a step of heating the mixture at a temperature that is equal to or higher than a melting temperature of the fatty acid and lower than a decomposition temperature of the fatty acid to obtain a metal soap which is a precursor of metal oxide fine particles; and a step of heating the precursor at a temperature that is equal to or higher than a melting temperature of the precursor and lower than a decomposition temperature of the precursor to obtain metal oxide fine particles having an average particle diameter of 80 nm or less.

A method for obtaining metal oxides supported on mesoporous silica particles includes a) providing a solution of at least one metal salt, b) providing a solution of at least one template forming agent of the general formula (I) Y.sub.3Si(CH.sub.2).sub.n—X (I), wherein X is a complexing functional group; Y is —OH or a hydrolysable moiety selected from the group containing halogen, alkoxy, aryloxy, acyloxy, c) mixing the metal salt solution and the complex forming agent solution to obtain a metal precursor; d) adding at least one solution containing at least one pore structure directing agent to the metal precursor to obtain a metal precursor template mixture; e) adding at least one alkali silicate solution to the metal precursor template mixture at room temperature to obtain a silica-supported metal complex; and f) calcination of the silica-supported metal complex under air to obtain the supported metal oxide mesoporous silica particles.

Disclosed are a method for manufacturing an electrode, an electrode manufactured thereby, a membrane-electrode assembly including the electrode, and a fuel cell containing the membrane-electrode assembly. The method includes the steps of: preparing an electrode forming composition by mixing a catalyst with an ionomer; applying a low-frequency acoustic energy to the electrode forming composition to perform resonant vibratory mixing so as to coat the ionomer on the surface of the catalyst; and coating the electrode forming composition to manufacture an electrode.

A nano-thin Bi.sub.xO.sub.ySe.sub.z low-temperature oxygen transporter membrane for oxygen transport, separation, and two-dimensional (2D) material manipulation comprising a material comprising a compound of Bi.sub.xO.sub.ySe.sub.z and R3m bismuth oxide (Bi.sub.2O.sub.3). A method of making a nano-thin Bi.sub.xO.sub.ySe.sub.z low-temperature oxygen transporter membrane for oxygen transport, separation, and two-dimensional (2D) material manipulation comprising providing an oxygen environment, providing Bi.sub.2Se.sub.3, processing the Bi.sub.2Se.sub.3 in the oxygen environment, incorporating oxygen, removing selenium, creating a structural change, and creating a compound of Bi.sub.xO.sub.ySe.sub.z and R3m bismuth oxide (Bi.sub.2O.sub.3), wherein the material transports oxygen at room temperature.

A method for producing aluminum oxide is provided. The method uses an aluminum-oxide-forming agent containing a partially hydrolyzed aluminum alkyl compound containing an aluminum trialkyl or a mixture thereof, and a solvent. It is thus possible to produce an aluminum oxide thin film or aluminum oxide particles on or in a substrate that is not resistant to polar solvents. A method of producing a polyolefin-based polymer nanocomposite containing zinc oxide particles or aluminum oxide particles using a solution containing a partially hydrolyzed zinc alkyl or a solution containing a partially hydrolyzed aluminum alkyl is also provided. The polyolefin-based polymer nanocomposite contains a polyolefin substrate and zinc oxide particles or aluminum oxide particles, and does not contain a dispersant. The zinc oxide particles or aluminum oxide particles have an average particle size of less than 100 nm.

Proposed are a layered Group III-V compound having ferroelectric properties, a Group III-V compound nanosheet that may be prepared using the same, and an electrical device including the materials. Proposed is a layered compound represented by [Formula 1] M.sub.x−mA.sub.yB.sub.z (M is at least one of Group I or Group II elements, A is at least one of Group III elements, B is at least one of Group V 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), and having ferroelectric-like properties.

The present invention relates to a positive electrode active material and a lithium secondary battery including the same, and more particularly, to a positive electrode active material which includes an overlithiated lithium manganese-based oxide including at least lithium, nickel, manganese and a doping metal, and in which the degradation in stability caused by excessive amounts of lithium and manganese in the lithium manganese-based oxide is mitigated and/or prevented by controlling the concentration of a transition metal in the lithium manganese-based oxide for each region, and a lithium secondary battery including the same.

There is provided herein a porous silica particle characterized by having a hierarchical pore structure wherein at least about 20% of the pores of the silica particle are of a size in the range of from about 7.0 to about 13.0 nm, and at least about 10% of the pores of the silica particle are of a size in the range of from about 0.5 to about 5.0 nm, and by having a particle size of from about 0.1 μm to about 10.0 μm. There is also provided compositions comprising such silica particles, process for their preparation, and medical and non-medical uses thereof.