A reducing agent for use in production of a product gas containing carbon monoxide, the reducing agent being brought into contact with a raw material gas containing carbon dioxide to reduce the carbon dioxide to produce the product gas; the reducing agent containing an oxygen carrier having oxygen ionic conductivity, and a basic oxide supported on the oxygen carrier. In addition, the basic oxide preferably contains at least one selected from the group consisting of lithium (Li), sodium (Na), potassium (K), magnesium (Mg), manganese (Mn), cobalt (Co), strontium (Sr), and rubidium (Rb). The reducing agent has a high conversion efficiency of carbon dioxide to carbon monoxide, and can be used, for example, in a chemical looping method, and a method for producing a gas using such a reducing agent.

A selective emitter exhibiting heat resistance up to 1000° C., comprising a metal body, a first dielectric layer provided on one surface of the metal body, a composite layer provided on another surface of the first dielectric layer at an opposite side to the metal body side, and a second dielectric layer provided on another surface of the composite layer at an opposite side to the first dielectric layer, the composite layer being a layer provided with a metal or semiconductor dispersed in an oxide of the metal or the semiconductor.

A selective emitter exhibiting heat resistance up to 1000° C., comprising a metal body, a first dielectric layer provided on one surface of the metal body, a composite layer provided on another surface of the first dielectric layer at an opposite side to the metal body side, and a second dielectric layer provided on another surface of the composite layer at an opposite side to the first dielectric layer, the composite layer being a layer provided with a metal or semiconductor dispersed in an oxide of the metal or the semiconductor.

A CuCrZnO based pigment includes a CuCrO based oxide and Zn derived from a zinc oxide added as a modifying oxide and solid-dissolved in the CuCrO based oxide. The CuCrZnO based pigment has a composition formula of aCuO.Math.bCr.sub.2O.sub.3.Math.cZnO (mol %), in which 0.1c5, 45a+c55, and 45b55 (a+b+c=100).

A selective emitter exhibiting heat resistance up to 1000 C., comprising a metal body, a first dielectric layer provided on one surface of the metal body, a composite layer provided on another surface of the first dielectric layer at an opposite side to the metal body side, and a second dielectric layer provided on another surface of the composite layer at an opposite side to the first dielectric layer, the composite layer being a layer provided with a metal or semiconductor dispersed in an oxide of the metal or the semiconductor.

A selective emitter exhibiting heat resistance up to 1000 C., comprising a metal body, a first dielectric layer provided on one surface of the metal body, a composite layer provided on another surface of the first dielectric layer at an opposite side to the metal body side, and a second dielectric layer provided on another surface of the composite layer at an opposite side to the first dielectric layer, the composite layer being a layer provided with a metal or semiconductor dispersed in an oxide of the metal or the semiconductor.

A process for preparing a mesoporous material, e.g., transition metal oxide, sulfide, selenide or telluride, Lanthanide metal oxide, sulfide, selenide or telluride, a post-transition metal oxide, sulfide, selenide or telluride and metalloid oxide, sulfide, selenide or telluride. The process comprises providing an acidic mixture comprising a metal precursor, an interface modifier, a hydrotropic or lyotropic ion precursor, and a surfactant; and heating the acidic mixture at a temperature and for a period of time sufficient to form the mesoporous material. A mesoporous material prepared by the above process. A method of controlling nano-sized wall crystallinity and mesoporosity in mesoporous materials. The method comprises providing an acidic mixture comprising a metal precursor, an interface modifier, a hydrotropic or lyotropic ion precursor, and a surfactant; and heating the acidic mixture at a temperature and for a period of time sufficient to control nano-sized wall crystallinity and mesoporosity in the mesoporous material. Mesoporous materials and a method of tuning structural properties of mesoporous materials.

A process for preparing a mesoporous material, e.g., transition metal oxide, sulfide, selenide or telluride, Lanthanide metal oxide, sulfide, selenide or telluride, a post-transition metal oxide, sulfide, selenide or telluride and metalloid oxide, sulfide, selenide or telluride. The process comprises providing an acidic mixture comprising a metal precursor, an interface modifier, a hydrotropic or lyotropic ion precursor, and a surfactant; and heating the acidic mixture at a temperature and for a period of time sufficient to form the mesoporous material. A mesoporous material prepared by the above process. A method of controlling nano-sized wall crystallinity and mesoporosity in mesoporous materials. The method comprises providing an acidic mixture comprising a metal precursor, an interface modifier, a hydrotropic or lyotropic ion precursor, and a surfactant; and heating the acidic mixture at a temperature and for a period of time sufficient to control nano-sized wall crystallinity and mesoporosity in the mesoporous material. Mesoporous materials and a method of tuning structural properties of mesoporous materials.

A CuCrZnO based pigment includes a CuCrO based oxide and Zn derived from a zinc oxide added as a modifying oxide and solid-dissolved in the CuCrO based oxide. The CuCrZnO based pigment has a composition formula of aCuO.Math.bCr.sub.2O.sub.3.Math.cZnO (mol %), in which 0.1?c?5, 45?a+c?55, and 45?b?55 (a+b+c=100).

A CuCrZnO based pigment includes a CuCrO based oxide and Zn derived from a zinc oxide added as a modifying oxide and solid-dissolved in the CuCrO based oxide. The CuCrZnO based pigment has a composition formula of aCuO.Math.bCr.sub.2O.sub.3.Math.cZnO (mol %), in which 0.1?c?5, 45?a+c?55, and 45?b?55 (a+b+c=100).