Abstract: An electrode composed of a substrate including a graphene layer coated on a first metal; and a complex including a second metal deposited on the substrate and a hydroxide of the first metal, where the complex is in the form of core-shell in which the second metal is a core and the hydroxide of the first metal is a shell, and the second metal has a higher standard reduction potential than the first metal. The graphene-coated metal foam of the present invention is the first case that proves not only theoretically but also by experiment that the remarkable catalytic ability reducing other metals (Au, Pt, Ag, and Cu, etc.) with a higher reduction potential than the metal by graphene coated on the metal surface it electroless deposition without additional reductant or electrical reduction conditions is due to the electrical double layer or interfacial dipole induced between the graphene and the metal.

Abstract: The present invention relates to a polymer, an organic solar cell comprising the polymer, and a perovskite solar cell comprising the polymer. The polymer according to the present invention has excellent absorption ability for visible light and an energy level suitable for the use as an electron donor compound in a photo-active layer of the organic solar cell, thereby increasing the light conversion efficiency of the organic solar cell. In addition, the polymer according to the present invention has high hole mobility, and is used as a compound for a hole transport layer, and thus can improve efficiency and service life of the perovskite solar cell without an additive.

Abstract: Disclosed are a perovskite compound, a method for producing the perovskite compound, a catalyst for a fuel cell including the perovskite compound, and a method for producing the catalyst. The perovskite compound overcomes the low stability of palladium due to its perovskite structural properties. Therefore, the perovskite compound can be used as a catalyst material for a fuel cell. In addition, the use of palladium in the catalyst instead of expensive platinum leads to an improvement in the price competitiveness of fuel cells. The catalyst is highly durable and catalytically active due to its perovskite structure.

Abstract: Disclosed are a metal single-atom catalyst and a method for preparing the same. The method uses a minimal amount of chemicals and is thus environmentally friendly compared to conventional chemical and/or physical methods. In addition, the method enables the preparation of a single-atom catalyst in a simple and economical manner without the need for further treatment such as acid treatment or heat treatment. Furthermore, the method is universally applicable to the preparation of single-atom catalysts irrespective of the kinds of metals and supports, unlike conventional methods that suffer from very limited choices of metal materials and supports. Therefore, the method can be widely utilized to prepare various types of metal single-atom catalysts. All metal atoms in the metal single-atom catalyst can participate in catalytic reactions. This optimal atom utilization achieves maximum reactivity per unit mass and can minimize the amount of the metal used, which is very economical.

Abstract: The present disclosure relates to a method of synthesizing composites for removing heavy metals, including: preparing hollow hydroxyapatite particles including a functional group; preparing a composite in which magnetic oxide nanoparticles are combined on the hollow hydroxyapatite; and preparing a composite of hollow hydroxyapatite and metal particles by performing reduction annealing to the composite.

Abstract: The present disclosure relates to a resistive random access memory device and a preparing method thereof.

Abstract: Disclosed is a method for preparing a carbon-supported platinum-transition metal alloy nanoparticle catalyst using a stabilizer. According to the method, the transition metal on the nanoparticle surface and the stabilizer are simultaneously removed by treatment with acetic acid. Therefore, the method enables the preparation of a carbon-supported platinum-transition metal alloy nanoparticle catalyst in a simple and environmentally friendly manner compared to conventional methods. The carbon-supported platinum-transition metal alloy nanoparticle catalyst can be applied as a high-performance, highly durable fuel cell catalyst.

Abstract: The present disclosure relates to a method for preparing a metal single-atom catalyst for a fuel cell. The method for preparing a metal single-atom catalyst uses a relatively lower amount of chemical substances as compared to the conventional methods and thus is eco-friendly, uses no liquid through the whole process and avoids a need for additional steps for separating and/or washing the catalyst after its synthesis, thereby allowing simplification of the process, and can produce a single-atom catalyst at low cost. In addition, unlike the conventional methods having a limitation in metallic materials, the method can be applied in common regardless of types of metals, and thus is significantly advantageous in that it can be applied widely to obtain various types of metal single-atom catalysts. Further, in the method for preparing a metal single-atom catalyst, metal atoms totally participate in the reaction. Thus, the method can minimize the usage of metal to provide high cost-efficiency.

Abstract: An electronic device, such as, without limitation, a perovskite solar cell or a light emitting diode, includes an assembly including at least one electronic portion or component, and a composite coating layer covering at least part of the assembly including the at least one electronic portion or component. The composite coating layer includes a polymer material, such as, without limitation, PMMA or PMMA-PU, having nanoparticles, such as, without limitation, reduced graphene oxide or SiO2, embedded therein. The electronic device may further include a second coating layer including a second polymer material (such as, without limitation, PMMA or PMMA-PU without nanoparticles) positioned between the coating layer and the assembly.

Abstract: The present disclosure discloses a method of manufacturing a multilayer perovskite structure, and a multilayer perovskite structure and solar cell manufactured using the same. The method of manufacturing a multilayer perovskite structure according to an embodiment of the present disclosure includes a step of forming a first perovskite layer using a compound including a first perovskite precursor on a base substrate; a step of forming a second perovskite layer using a compound including a second perovskite precursor on a donor substrate; and a step of laminating the first and second perovskite layers so that the first and second perovskite layers contact each other and then applying heat or pressure to form a multilayer perovskite structure.

Abstract: An electronic device, such as, without limitation, a perovskite solar cell or a light emitting diode, includes an assembly including at least one electronic portion or component, and a composite coating layer covering at least part of the assembly including the at least one electronic portion or component. The composite coating layer includes a polymer material, such as, without limitation, PMMA or PMMA-PU, having nanoparticles, such as, without limitation, reduced graphene oxide or SiO2, embedded therein. The electronic device may further include a second coating layer including a second polymer material (such as, without limitation, PMMA or PMMA-PU without nanoparticles) positioned between the coating layer and the assembly.

Abstract: Disclosed is a method for preparing a carbon-supported metal oxide and/or alloy nanoparticle catalyst. According to the method, a carbon-supported metal oxide and/or alloy nanoparticle catalyst is prepared by depositing metal oxide and/or alloy nanoparticles on a water-soluble support and dissolving the metal oxide and/or alloy nanoparticles deposited on the water-soluble support in an anhydrous polar solvent containing carbon dispersed therein to support the metal oxide and/or alloy nanoparticles on the carbon. The anhydrous polar solvent has much lower solubility for the water-soluble support than water and is used to dissolve the water-soluble support.

Abstract: A composite polymer electrolyte membrane for a fuel cell may be manufactured by the following method: partially or totally filling the inside of a pore of a porous support with a hydrogen ion conductive polymer electrolyte solution by performing a solution impregnation process; and drying the hydrogen ion conductive polymer electrolyte solution while completely filling the inside of the pore with the hydrogen ion conductive polymer electrolyte solution by performing a spin dry process on the porous support of which the inside of the pore is partially or totally filled with the hydrogen ion conductive polymer electrolyte solution.

Abstract: Disclosed are a perovskite compound, a method for producing the perovskite compound, a catalyst for a fuel cell including the perovskite compound, and a method for producing the catalyst. The perovskite compound overcomes the low stability of palladium due to its perovskite structural properties. Therefore, the perovskite compound can be used as a catalyst material for a fuel cell. In addition, the use of palladium in the catalyst instead of expensive platinum leads to an improvement in the price competitiveness of fuel cells. The catalyst is highly durable and catalytically active due to its perovskite structure.

Abstract: Disclosed are a metal single-atom catalyst and a method for preparing the same. The method uses a minimal amount of chemicals and is thus environmentally friendly compared to conventional chemical and/or physical methods. In addition, the method enables the preparation of a single-atom catalyst in a simple and economical manner without the need for further treatment such as acid treatment or heat treatment. Furthermore, the method is universally applicable to the preparation of single-atom catalysts irrespective of the kinds of metals and supports, unlike conventional methods that suffer from very limited choices of metal materials and supports. Therefore, the method can be widely utilized to prepare various types of metal single-atom catalysts. All metal atoms in the metal single-atom catalyst can participate in catalytic reactions. This optimal atom utilization achieves maximum reactivity per unit mass and can minimize the amount of the metal used, which is very economical.

Abstract: Various perovskite solar cell embodiments include a flexible metal substrate (e.g., including a metal doped TiO2 layer), a perovskite layer, and a transparent electrode layer (e.g., including a dielectric/metal/dielectric structure), wherein the perovskite layer is provided between the flexible metal substrate and the transparent electrode layer. Also, various tandem solar cell embodiments including a perovskite solar cell and either a quantum dot solar cell, and organic solar cell or a thin film solar cell.

Abstract: The present disclosure relates to a resistive random access memory device and a preparing method of the resistive random access memory device, including: a first resistance change layer formed on a first electrode and comprising an organic metal halide having a three-dimensional perovskite crystal structure; a second resistance change layer formed on the first resistance change layer and comprising an organic metal halide having a two-dimensional perovskite crystal structure; and a second electrode formed on the second resistance change layer.

Abstract: Disclosed is a method for preparing a carbon-supported platinum-transition metal alloy nanoparticle catalyst using a stabilizer. According to the method, the transition metal on the nanoparticle surface and the stabilizer are simultaneously removed by treatment with acetic acid. Therefore, the method enables the preparation of a carbon-supported platinum-transition metal alloy nanoparticle catalyst in a simple and environmentally friendly manner compared to conventional methods. The carbon-supported platinum-transition metal alloy nanoparticle catalyst can be applied as a high-performance, highly durable fuel cell catalyst.

Abstract: The present disclosure relates to a preparing method of a large-area perovskite thin film, comprising: forming an organic metal halide-alkylamine compound by exposing an organic metal halide compound having a perovskite structure to an alkylamine gas; preparing a coating solution by adding a solvent on the organic metal halide-alkylamine compound; and preparing a perovskite thin film by coating the coating solution on a substrate.

Abstract: The present invention provides a water-soluble fluorescent compound of resveratrone 6-O-?-glucoside [(E)-4-(8-hydroxy-6-(((2S,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-2-yl)oxy)naphthalen-2-yl)but-3-en-2-one] and its derivatives of Formula I which have at least one water-soluble substituent, and a method for preparing the same by a photochemical reaction of resveratrol 3-O-?-glucoside and its derivatives of having Formula 3 which are not fluorescent. Said new water-soluble fluorescent compounds has single-photon absorptive characteristics and/or two-photon absorptive characteristics as well as no or little toxicity, and can be usefully utilized in fields that requires water-soluble fluorescent characteristics (diagnosis, fluorescent probe, in vivo imaging, display, etc.).