A system and method for synthesizing a nanoparticle material includes dissolving a metal nitrate in deionized water, adding a hydrogel precursor in the deionized water containing the dissolved metal nitrate to create an aqueous solution, heating the aqueous solution, cooling the aqueous solution to create a solid gel, and calcinating the solid gel to create a metal oxide nanoparticle material. The metal oxide nanoparticle material may include a zinc oxide-based nanoparticle material. The hydrogel precursor may include an agarose gel. The solid gel may be calcinated at approximately 600 C. The solid gel may be calcinated for approximately five hours in the presence of air. The aqueous solution may be heated to a boil. The aqueous solution may be heated at a temperature of 100 C.

A system and method for synthesizing a nanoparticle material includes dissolving a metal nitrate in deionized water, adding a hydrogel precursor in the deionized water containing the dissolved metal nitrate to create an aqueous solution, heating the aqueous solution, cooling the aqueous solution to create a solid gel, and calcinating the solid gel to create a metal oxide nanoparticle material. The metal oxide nanoparticle material may include a zinc oxide-based nanoparticle material. The hydrogel precursor may include an agarose gel. The solid gel may be calcinated at approximately 600 C. The solid gel may be calcinated for approximately five hours in the presence of air. The aqueous solution may be heated to a boil. The aqueous solution may be heated at a temperature of 100 C.

The method for recycling carbon dioxide according to the present invention includes: injecting a reaction gas containing carbon dioxide and a carbon raw material into a rotary heating furnace; reacting the reaction gas and the carbon raw material with each other in the rotary heating furnace to generate a hydrocarbon precursor containing carbon monoxide; and converting the hydrocarbon precursor into a hydrocarbon compound, thereby exhibiting excellent conversion rate of carbon dioxide.

The method for recycling carbon dioxide according to the present invention includes: injecting a reaction gas containing carbon dioxide and a carbon raw material into a rotary heating furnace; reacting the reaction gas and the carbon raw material with each other in the rotary heating furnace to generate a hydrocarbon precursor containing carbon monoxide; and converting the hydrocarbon precursor into a hydrocarbon compound, thereby exhibiting excellent conversion rate of carbon dioxide.

A method can prepare a metal/metal oxide material from a nanostructure. The nanostructure can contain a first metal to form the metal oxide, and a reaction surface with a reducing agent on the reaction surface. A second metal is deposited onto the reaction surface to form a bimetallic product. The bimetallic product is calcined to form the metal/metal oxide material.

A method can prepare a metal/metal oxide material from a nanostructure. The nanostructure can contain a first metal to form the metal oxide, and a reaction surface with a reducing agent on the reaction surface. A second metal is deposited onto the reaction surface to form a bimetallic product. The bimetallic product is calcined to form the metal/metal oxide material.

A system and method for synthesizing a nanoparticle material includes dissolving a metal nitrate in deionized water, adding a hydrogel precursor in the deionized water containing the dissolved metal nitrate to create an aqueous solution, heating the aqueous solution, cooling the aqueous solution to create a solid gel, and calcinating the solid gel to create a metal oxide nanoparticle material. The metal oxide nanoparticle material may include a zinc oxide-based nanoparticle material. The hydrogel precursor may include an agarose gel. The solid gel may be calcinated at approximately 600 C. The solid gel may be calcinated for approximately five hours in the presence of air. The aqueous solution may be heated to a boil. The aqueous solution may be heated at a temperature of 100 C.

A method for producing metal oxide nanocrystals, according to the embodiment of the present invention, includes: continuously flowing, into a continuous flow path, one or a plurality of nanocrystal precursor solutions each comprising one or more nanocrystal precursors dissolved in a non-polar solvent; directing a segmenting gas into the continuous flow path to create a segmented reaction flow; flowing the segmented reaction flow into a thermal processor; heating the segmented reaction flow in the thermal processor to create a product flow; and collecting metal oxide nanocrystals from the product flow.

A method for producing metal oxide nanocrystals, according to the embodiment of the present invention, includes: continuously flowing, into a continuous flow path, one or a plurality of nanocrystal precursor solutions each comprising one or more nanocrystal precursors dissolved in a non-polar solvent; directing a segmenting gas into the continuous flow path to create a segmented reaction flow; flowing the segmented reaction flow into a thermal processor; heating the segmented reaction flow in the thermal processor to create a product flow; and collecting metal oxide nanocrystals from the product flow.

Provided is a metal oxide production apparatus that implements a flux evaporation method. The production apparatus includes a firing furnace configured to subject a metal compound to firing in the presence of flux, a cooling pipe connected to the firing furnace and configured to convert vaporized flux resulting from the firing into powder, and a recovery means configured to recover powdered flux converted in the cooling pipe. Furthermore, provided is a metal oxide production method comprising a step (1) of subjecting a metal compound to firing in the presence of flux and obtaining a metal oxide and vaporized flux, a step (2) of converting the vaporized flux into powder by cooling the vaporized flux, and a step (3) of recovering powdered flux resulting from the converting.