Porous carbon material composites and their production process, adsorbents, cosmetics, purification agents, and composite photocatalyst materials

Abstract

Provided is a porous carbon material composite formed of a porous carbon material and a functional material and equipped with high functionality. A porous carbon material composite is formed of (A) a porous carbon material obtainable from a plant-derived material having a silicon (Si) content of 5 wt % or higher as a raw material, said porous carbon material having a silicon (Si) content of 1 wt % or lower, and (B) a functional material adhered on the porous carbon material, and has a specific surface area of 10 m2 / g or greater as determined by the nitrogen BET method and a pore volume of 0.1 cm3 / g or greater as determined by the BJH method and MP method.

Description

TECHNICAL FIELD[0001]This invention relates to porous carbon material composites making use of plant-derived materials as raw materials and their production process, and also to adsorbents, cosmetics, purification agents and composite photocatalyst materials, all of which are composed of the porous carbon material composites.BACKGROUND ART[0002]Functional materials which are each obtainable by imparting a physical or physicochemical property such as, for example, a magnetic property, a light absorption property, a light emission property, or adsorption ability for a specific substance to porous materials are materials of high interest, because they each have both a large specific surface area and the physical property imparted to the functional material. These porous materials can include alumina, carbon, silica, and the like. Functional materials, each of which has a magnetic property, a property that shows a unique behavior to light (such a property will hereinafter be called “an ...

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Benefits of technology

[0016][C] the treatment system is economical and is easy to handle, can be recovered as needed, and does not disturb the environmental ecosystem.

[0037](B) a metal-based material adhered on the porous carbon material and having a reactive oxygen removing effect,

[0043]Concerning the porous carbon material composite according to the present invention or the porous carbon material composite obtainable by the production process according to the present invention, or the adsorbent, cosmetics, purification agent or composite photocatalyst material according to the present invention, silicon is contained at 5 wt % or more in the plant-derived material. However, by carbonizing the plant-derived material at from 800° C. to 1,400° C. upon its conversion into a porous carbon material precursor [1] or carbonaceous material [1] to be described subsequently herein, the silicon contained in the plant-derived material is not converted into silicon carbide (SiC) but is converted into silicon components (oxidized silicon compounds) such as silicon dioxide (SiOx), silicon oxide and silicon oxide salts. By conducting treatment with an acid or alkali (base) in the subsequent step, the silicon components (oxidized silicon compounds) such as silicon dioxide, silicon oxide and silicon oxide salts are thus eliminated. As a result, it is possible to obtain a large value of specific surface area as determined by the nitrogen BET method. Described specifically, it is possible to obtain a porous carbon material having a specific surface area value of 10 m2 / g or greater as determined by the nitrogen BET method, a silicon content of 1 wt % or lower, and a pore volume of 0.1 cm3 / g or greater as determined by the BJH method and MP method. By causing a functional material to adhere on such a porous carbon material, the functional material can be caused to adhere in an increased amount per unit gram of porous carbon material, thereby making it possible to obtain a porous carbon material composite having high properties and high functionality.

[0045]As mentioned above, the porous carbon material in the present invention is an environment compatible material derived from a natural product, and its microstructure can be obtained by treating and removing silicon components (oxidized silicon compounds), which are inherently contained in a plant-derived material as a raw material, with an acid or alkali. Therefore, its pores have sizes unrealizable with conventional activated carbon or sizes in a meso range (2 to 50 nm), and the array of pores still retains the bioregularity of the plant. In the composite photocatalyst material according to the present invention, the photocatalyst material is caused to adhere on the porous carbon material extremely effectively owing to such a pore size and array, thereby making it possible to effectively induce decomposition by a photocatalytic effect. In the cosmetic according to the present invention, the metal-based material having a reactive-oxygen removing effect is carried extremely effectively on the porous carbon material owing to such a pore size and array. It is, therefore, no longer essential to use a protective colloid agent, for example, for forming fine platinum particles of nanosize into a colloid, thereby making it possible to exhibit a high antioxidation effect against reactive oxygen species such as superoxides, hydroxy radicals, hydrogen peroxide and singlet oxygen which are considered to be causes of acute inflammatory, tissue damage and aging. In the purification agent according to the present invention, that is, an environment purification material, such a pore size and array is also considered to effectively act for the adsorption of a toxic substance, and at the same time, can cause the photocatalyst material to adhere on the porous carbon material extremely effectively, thereby effectively inducing the decomposition and detoxification of a toxic substance by a photocatalytic effect. Moreover, the spreading of the toxic substance inside the purification agent can be promoted, thereby making it possible to more effectively induce the decomposition by the photocatalytic effect and to conduct the purification of water or the purification of air extremely effectively.

Problems solved by technology

An introduction of microcystin LR into the body inflicts significant damage on the liver, and its toxicity has also been reported based on experiments on mice.

However, L-ascorbic acid salts, L-ascorbic acid derivatives and the like have a problem with stability so that they themselves are oxidized as a result of single reducing action.

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