空氣中二氧化碳 (Carbon dioxide, CO2) 直接轉換成再生資源，是解決溫室效應與資源再生最佳的方法，本研究以複合膜進行空氣中CO2濃縮並直接轉化為再生資源，此複合膜由選擇層與反應層構成。選擇層以聚醯亞胺 (Polyimide, PI) 藉由乾式法製得，利用其緻密結構對CO2有高度的選擇性，可有效的將空氣中的CO2提濃，使高濃度CO2的空氣進到反應層。反應層以PI與光觸媒共混，藉由濕式法製膜，並調控凝聚槽水與N-甲基吡咯烷酮 (1-Methyl-2-pyrrolidon, NMP ) 比例製得，反應層為多孔連續結構，可提供較多的比表面積與催化反應點，同時促使CO2在孔道中環繞，增長滯留時間，提高CO2與觸媒的接觸機率與時間，同時導入水氣，使CO2、水氣及觸媒三者於薄膜中反應，並以光為驅動力，使觸媒生成電子-電洞，進而把CO2還原為再生資源。
觸媒為四氯化鈦 (Titanium tetrachloride, TiCl4) 及二水合氯化銅 (Copper chloride dehydrate, CuCl2·2H2O) 利用水熱法合成，可形成以二氧化鈦 (TiO2) 為主體並摻雜氧化亞銅 (Cu2O) 之觸媒，銅離子取代鈦離子中心位置，促使電子組態重組生成氧空缺與Ti3+，可改善TiO2在可見光區的吸收度，使得能隙下降至3.057 eV，並使能帶落於有利於CO2還原位置。銅摻雜亦提升光電子傳輸並抑制電子–電洞重合，可提升光催化效率，摻雜氧化亞銅觸媒之一氧化碳 (Carbon monoxide, CO)產量為TiO2的157%，因此銅摻雜有效提升CO2還原反應的效率。
利用薄膜與觸媒結合的複合膜，選擇層可有效地提升進料空氣中CO2濃度，並避免非反應氣體於觸媒表面的活性點發生競爭吸附關係，可提高反應催化點的有效利用，薄膜的多孔結構增加CO2與觸媒表面接觸，可有效地利用活性點並提高氣體於薄膜內部的滯留時間，藉此提升光催化效能，CT-0.1混摻20%的複合膜產量可達1.262 μmole g-1 hr-1，調控選擇層厚度，可使CO2滲透量提升，為觸媒提供更多反應物與富含CO2的有利環境，進而提升還原反應的效率，由選擇層的製膜厚度為200 μm調降至140 μm時，一氧化碳產量可高達2.211 μmole g-1 hr-1，由此可知觸媒與薄膜的分離效能與選擇性具有相依關係，可藉由薄膜調控來提升分離效能並提升光催化效能，因此利用薄膜與觸媒的結合，對於解決CO2與石化資源耗盡的問題具有相當大的潛力。

Carbon dioxide (CO2) in the air is converted into regeneration resources, which is the best solution for the greenhouse effect and regeneration. In this work, CO2 is concentrated and converted into regeneration resources by composite membranes, which is composed of a selective layer and reactive layer. The selective layer is made of polyimide by the dry method, which contains the dense structure that is high selectivity for CO2, which can efficiently concentrate CO2 of the air, which permeates into the reactive layer. The reactive layer is made of polyimide and photocatalyst by the wet method, which needs to control the ratio for water and 1-methyl-2-pyrrolidone (NMP) in the coagulation tank. The reactive layer is the continuous porous structure that can offer more surface and active sites, which also increases the residence time for CO2 in the composite membranes, which can enhance the contact probability and time for CO2 and catalyst. Simultaneously, water vapor is induced into the composite membranes to make CO2, water vapor, and photocatalyst react in the composite membranes. The catalyst produces photoelectron-hole by UV-light as the driving force. CO2 is reduced to the resource of regeneration.
The photocatalyst is made of titanium tetrachloride (TiCl4) and copper chloride dihydrate (CuCl2·2H2O) by the hydrothermal method. Titanium dioxide (TiO2) is the main body, which is doped with copper(I) oxide (Cu2O). Copper ions replace the positions of titanium ions to form oxygen vacancies and Ti3+ improving the absorbance under the visible region, which also reduces bandgap to 3.057 eV, it represents that the position of energy band has changed, that makes favorably CO2 reduction. Cu dopant also enhances photoelectron transport and inhibits the recombination of photoelectron-hole, it can enhance photocatalytic efficiency. Compared with TiO2. Copper-doped TiO2 can enhance the reaction of the photocatalytic and yield 157% more CO.
For the composite membranes, the selective layer can concentrate CO2 in the air, which avoids the competitive adsorption of non-reactive gases on the active points of the catalyst surface, which enhances the active sites. The reactive layer forms the continuous porous structure increasing the residence time. The composite membranes with 20 wt% of CT-0.1 can reach 1.262 μmole g-1 hr-1, the thickness of the selective layer adjusted to 140 μm, which can enhance CO2 permeance to offer more reactant to the catalyst, CO yield enhance to 2.211 μmole g-1 hr-1. It can see that the catalyst depends on the permeance and selectivity of the membrane. Therefore, the combination of membrane and catalyst contains the considerable potential for solving the problem of CO2 and petrochemical resource exhaustion.

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