201109271 六、發明說明： 【發明所屬之技術領域】 一種z-scheme光催化進行水分解產生氫氣、氧氣之方法 及裝置，係及時分離所產生氫氣和氧氣之方法，尤指以產氫光 觸媒和產氧光觸媒在於Fe3+/Fe2+的水溶液中，並以離子交換膜 將兩觸媒分開至兩個連結的反應器，進行光催化水分解之方法。 【先前技術】 使用光觸媒(photocatalyst)進行光催化水分解，為一種將光 電子能量轉變為化學能的反應’此研究自從1972年Honda* Fujishima (Nature, 238 : 37-38, 1972)首先提出以 Ti〇2 半導體電 極照光將水分解成氫氣與氧氣後，便開始一直發展至今。近年 來，這項研究也有了重大的突破，各式各樣的新型光觸媒一一 被發現可以用於水分解反應’也由於這些觸媒的發現，使此研 究領域更往前一大步。 早期的光觸媒多為紫外光觸媒如TiCb，故所使用的光源為 紫外光，而實際應用上，在最理想的光源太陽光下，紫外光含 量極少只佔不到4%，故如何使光觸媒能利用更多的太陽光能 疋現5的一項珠遞’故近年來的研究’也慢慢從紫外光觸媒往 可見光觸媒的方向發展。不幸地’可見光觸媒的發展卻出現了 瓶頸’由於其能帶間隙的寬度’限制了可使用光觸媒的種類， 故常使用添加助觸媒、摻雜元素等方式來減少能帶隙寬度以增 加可見光範圍的吸收，但上述的方式還是受到本身光觸媒還原 201109271201109271 VI. Description of the invention: [Technical field of invention] A method and device for photocatalytic hydrolysis of hydrogen and oxygen by z-scheme, which is a method for separating hydrogen and oxygen generated in time, especially for producing hydrogen photocatalyst and production The oxygen photocatalyst is in an aqueous solution of Fe3+/Fe2+, and the two catalysts are separated into two connected reactors by an ion exchange membrane to perform photocatalytic water decomposition. [Prior Art] Photocatalytic water splitting using photocatalyst is a reaction to convert photoelectron energy into chemical energy. This study was first proposed by Honda* Fujishima (Nature, 238: 37-38, 1972) in 1972. 〇2 After the semiconductor electrode illuminates water into hydrogen and oxygen, it has been developed ever since. In recent years, this research has also made a major breakthrough. A variety of new photocatalysts have been found to be used in water decomposition reactions. The discovery of these catalysts has made this research field a big step forward. Most of the early photocatalysts were UV photocatalysts such as TiCb, so the light source used was ultraviolet light. In practical applications, under the most ideal source of sunlight, the ultraviolet light content rarely accounted for less than 4%, so how to make photocatalyst can be utilized. More of the sun's light can be seen in the past five years, and the research in recent years has slowly evolved from the ultraviolet photocatalyst to the visible light catalyst. Unfortunately, the development of visible light catalysts has a bottleneck 'because its width with gaps' limits the types of photocatalysts that can be used. Therefore, the use of supplementary catalysts, doping elements, etc. is often used to reduce the bandgap width to increase the visible range. Absorption, but the above method is still subject to its own photocatalyst restoration 201109271
I 電位位置的關，所财會造财些細顧合產 有_適合產生減的情I @ @ 針對以上的狀況，便有人提㈣兩種不_細媒結合在 一起使用’讓適合產氫_媒只產生氫氣，其還原電位高於水 還原成氫的電位，照光只能產生氧氣，另—方面讓適合產氧的 光觸媒/、產生氧氣，其氧化電位低於水氧化成氧的電位，照光 "犯產生氧氣。再湘外加離子作為電子轉移以及還原氧化反 瞻麟％的肖色’由於此健合^種光觸雛來進行光催化水 分解的系統，類似綠色植物光合作用，所以稱其為zsch_ 的反應系統，此㈣的顧是光照射光觸，使兩光觸媒 皆產生電子制對，由相對還原電位的位置，產氫光觸媒的電 子會還原氫軒錢，產氧細媒的㈣會氧化氫氧根形成氧 氣，而外加離子則藉由自身的氧化還原反應，將產氧觸媒的電 子轉移到產氫光觸媒以達到電荷平衡。 > Z-Scheme的發展，早期是以紫外光觸媒為主，之後的研究 也開始朝向可見光觸媒的方向，陸續有人提出不同可見光觸媒 的組合來進行反應，如Abe等人於(Chem phys [机， 344:339·344, 20()1)提出以嬉a〇N作為錢光觸媒、pt/w〇3 作為產氧光觸媒，放置於含有氧化還原對I7I〇3-的水溶液中進 行可見光催化水分解反應，而Say_等人於phys> Lett, 277:387-391，1997)提出以相同的氧化還原對Γ/Ι〇3·作為溶液， 以Pt/SrTi〇3:Cr/Ta作為產氫光觸媒、!>請〇3作為產氧光觸媒來「 201109271 進行可見光催化水分解反應。 然而這些利用可見光觸媒進行 Z-Scheme反應者，都是將兩種光觸媒混合後再進行照光反應 所以產生的氣體是氫氣和氧氣的混合氣體，氫氧混合在—起會 發生逆反應，降低水分解效率。而且氫氧混合氣也有爆炸安全 上的顧慮，對於往後的氫能源應用，尚須經過分離氧的步驟方 可使用。I potential position, the financial accounting will make some careful consideration of the production _ suitable for the reduction of the situation I @ @ In response to the above situation, it is raised (four) two kinds of non-fine media combined use 'to make suitable for hydrogen production _ The medium only produces hydrogen, the reduction potential is higher than the potential of water to reduce to hydrogen, the light can only produce oxygen, and the other is to make the photocatalyst suitable for oxygen production, generate oxygen, and its oxidation potential is lower than the potential of water oxidation to oxygen, illumination " commits oxygen. Further, the addition of ions as an electron transfer and reduction oxidation of the anti-stretching of the color of the "color" of the photocatalytic water decomposition of the system, similar to green plant photosynthesis, so called the reaction system of zsch_ (4) This is the light exposure of the light, so that both photocatalysts are generated by electrons. From the position of the relative reduction potential, the electrons of the hydrogen-producing photocatalyst will reduce the hydrogen, and the oxygen-generating medium will form oxygen. The external ions transfer the electrons of the oxygen generating catalyst to the hydrogen-producing photocatalyst to achieve charge balance by their own redox reaction. > The development of Z-Scheme was mainly based on ultraviolet photocatalyst, and the subsequent research began to move toward the direction of visible light catalyst. Some people have proposed a combination of different visible light catalysts to react, such as Abe et al. (Chem phys [machine, 344:339·344, 20()1) proposed the use of 〇a〇N as a light photocatalyst, pt/w〇3 as an oxygen generating photocatalyst, and placed in an aqueous solution containing redox couple I7I〇3- for visible light catalytic water decomposition reaction. And Say_ et al., phys> Lett, 277:387-391, 1997) proposed the same redox pair Γ/Ι〇3 as a solution, Pt/SrTi〇3:Cr/Ta as a hydrogen-producing photocatalyst, !>Please use 〇3 as an oxygen-producing photocatalyst to perform a visible-light-catalyzed water-decomposition reaction in 201109271. However, in the case of Z-Scheme reaction using a visible light catalyst, the two photocatalysts are mixed and then subjected to an illuminating reaction, so that the gas generated is hydrogen. Mixed with oxygen, hydrogen and oxygen will react in reverse to reduce water decomposition efficiency. Hydrogen-oxygen mixture also has explosion safety concerns. For future hydrogen energy applications, it is still necessary to separate oxygen. Side step may be used.
Fujihara 等人在（J. Chem. Soc.，FaradayTmnSaeti〇ns， 94:3705-3709, 1998)提出以Pt/Ti〇2作為產氫光觸媒置於Br_水 溶液、Ti〇2則作為產氧光觸媒置KFe3+水溶液線，用離子交換 膜區隔進行照光反應，兩個反應器以朽線相連傳遞電子，氫和 氧分別生成於兩個反應器’但此方法須要外電路作為電子通路。 【發明内容】 本發明係針對上述之缺點做改良，因此，本發明之目的係 提供一種Z-scheme光催化進行水分解產生氫氣和氧氣之方法 及裝置，其特徵為將兩種光觸媒以離子交換膜分開至兩個連結 的反應器中，將兩反應器中所產生的氳氣及氧氣分離。並且， 氧化還原對離子仍可透過離子交換膜維持氧化還原循環，而不 需外電路作為電子通路。 本發明之Z-scheme光催化進行水分解產生氫氣、氧氣之方 法係至少包括下列步驟： (A) 將產氫光觸媒分散於具有離子的水溶液，製備產氫端溶液； (B) 將產氧光觸媒分散於具有離子的水溶液，製備產氧端溶液； 201109271 (c)以離子交換膜分隔產氫端及產氧端溶液，並區隔水分解產生 之氫氣及氧氣； (D)分別加入電子傳遞媒介於產氫端及產氧端溶液，個別進行水 分解的還原和氧化反應的循環。 其中產氫端溶液與產氧端溶液係以離子交換膜分隔，該離子交 換膜經由官能基調整加以改質，不僅分隔水分解所產生之氫氣 和氧氣，並可供電子傳遞媒介和氫離子通過，以維持氧化還原 之循環。 本發明另包含Z-scheme光催化進行水分解產生氫氣和氧氣 之裝置，該裝置至少包括： 一種z-scheme光催化進行水分解產生氫氣和氧氣之裝置，其包 含： 一產氫端容器：其包括產氫光觸媒以及離子水溶液； 一產氫端容器：其包含產氧光觸媒以及離子水溶液； 一對電子傳遞媒介進行氧化還原反應的循環； 一離子交換膜； 其中產氫端容器與產氧端容器係以離子交換膜分隔，該離子交 換膜係經由官能基調整之改質處理，可分隔兩容器所產生之氫 氣、氧氣；而該離子交換膜可供電子傳遞媒介和氫離子通過以 維持氧化還原的循環。 201109271 f實施方式】 〃發明之實施與特點，在於設計一種雙反應器系統，製備產 氯光觸媒’以及應用特珠處理過之離子交換膜，分離光催化水 分解產生之氫氣及氧氣，詳細操作情雜在下列各實施方式說 明之，並將本發明與習用之光催化水分解系統做產率上之比 較，以凸顯本發明於該領域之進步性。 清參閱第1圖’為z—sch光催化進行水分解之反應途 徑❶將兩種不同的光_P02、PH2結合在一起使用利用適合f 產氫之產氫光觸媒ΡΗ2光只產生氫氣氏，適合產生氧氣之產氧 ^光觸媒:只產生氧氣Ο?再利用電子傳遞媒介（由金屬離子μ /Μ 所構成)做為電子轉移以及電荷平衡的角色，該結 合兩種光觸雜來進行光條水分解的系統，_綠色植物 進行光&作用戶斤以稱其為Z-scheme的反應系統，此系統的原 理疋利用可見光照射產氫光觸媒pH2、產氧光觸媒酸，使兩光 觸媒皆產生電子電洞對e7h+’由相對氧化電位、還原電位的位# 置，產氫光觸媒PH2的電子會還原氫離子錢，產氧光觸媒p〇2 的電洞會氧化氫氧根形成氧氣，而金屬離子ΜΠ+/Μ u+ih則藉 由自身的氧化還原反應，將產氧光顧的電子轉移到產氣 光觸媒PH2㈣洞以達到電荷平衡，本發明係將上述兩種光觸 媒利用離子交換膜隔開，該離子交換膜可阻擋光催化水解所產 生之H2、〇2混合，但可讓電子傳遞媒介通過以維持氧化還原 反應的循環。 8 201109271 上述之Z-scheme光催化進行水分解產生氫氣、氧氣之方 法及裝置係以Pt/SrTiOyRh作為產氫光觸媒，以|〇3作為產氧 光觸媒’並選擇Fe3+/Fe2+作為氧化還原的電子傳遞媒介，在可 見光下進行催>ib水分解的反應，並利用特殊處理過之離子交換 膜將兩種光觸媒分開至兩個連結的反應器中，使Fe2+/Fe3+可經 由離子交換膜分別擴散移動至氧氣端或氫氣端進行氧化還原的 步驟’形成一個Fe2+/Fe3+氧化還原的循環，以防止光催化水分 解所產生之氫氣與氧氣混合，避免發生逆反應以及氫氧混合爆 炸之危險。 請參閱第2圖’該實施例係兩個相互連結的反應器1〇〇， 該連結之反應器100利用已改質之離子交換膜(Fe3+形式之 Nafion膜)110所分隔為產氫端1〇1及產氧端1〇2，分別配置有 產氫端溶液150及產氧端溶液151，產氫端溶液150包含Fe2+ 離子140、產氫光觸媒(Pt/SrTi〇3:Rh)120，該產氫光觸媒 (Pt/SrTi〇3:Rh)120表面附有助觸媒（Pt)以提高光觸媒活性。 產氧端溶液151包含產氧光觸媒(W〇3)130以及Fe3+離子141。光 線170照射產氩光觸媒(Pt/SrTi(kRh)120以及產氧光觸媒 (W〇3)130，使兩光觸媒開始產生水分解並分別產生氫氣H2與氧 氣〇2，Fe3+離子擴散方向162通往產氫端1(H、Fe2+離子擴散方 向161通往產氧端102顯示，兩端離子Fe3+/Fe2+可通過離子交 換膜(Fe3+形式之Nafion膜)110，以維持氧化還原之循環，以 及氫離子H+160也透過離子交換膜，到達產氫端以持續產生氫 201109271 氣。 實施步驟一：光觸媒之製備 產氫光觸媒Pt(0.5%)/SrTiO3:Rh(l%)是先以固態熔融法 (solid state method)製備SrTi03:Rh，再利用光催化沈積法 (photocatalytic deposition method)將 Pt金屬於 SrTi03:Rh表面沈 積而得。固態熔融法製備SrTi03:Rh光觸媒，先依化學計量比取 得一定量的SrC03、Ti02和Rh203依序加入研蛛中並充份研磨混 合’過程中加入少量CH30H增加混合效果，最後將研磨過後的 上述混合物置於船型缽中’放入高溫爐以每分鐘10°c的升溫速 率至1200°C，鍛燒1〇小時後形成SrTi03:Rh粉末，待其冷卻拿出 再以研妹充份研磨。 為了得到更高的光觸媒活性，本研究中選用Pt作為助觸 媒’以光催化沈積法將Pt金屬光催化沈積在SrTi〇3:Rh光觸媒表 面上。此法是以HftCl6 · 6H2〇作為前驅物，依照所欲製備的pt 金屬比例定量稱取’配置成HJtCl6的水溶液，接著將藉由固態 熔融法製備而得的SrTKVRh放入溶液中，封住瓶口並在磁石攪 拌器上攪拌，並以紫外光進行照射，讓Pt金屬光催化沈積在 SrTiOvRh光觸媒表面上，同時，藉氏!>〇6水溶液由淡黃色轉變 為無色來決定光催化沈積的完成，而後將溶液置於80°c供箱乾 燥’最後再將其取出研磨而得產氫光觸媒Pt/SrTiOyRh。而本實 驗所使用的產氧光觸媒W03是直接購買現成的(Hayashi Pure 201109271Fujihara et al. (J. Chem. Soc., Faraday Tmn Saeti〇ns, 94: 3705-3709, 1998) proposed placing Pt/Ti〇2 as a hydrogen-producing photocatalyst in Br_aqueous solution and Ti〇2 as an oxygen-generating photocatalyst. The KFe3+ aqueous solution line is irradiated with ion exchange membranes. The two reactors are connected by electrons, and hydrogen and oxygen are generated in the two reactors respectively. However, this method requires an external circuit as an electron path. SUMMARY OF THE INVENTION The present invention is directed to the above disadvantages. Accordingly, it is an object of the present invention to provide a method and apparatus for Z-scheme photocatalytic hydrolysis to produce hydrogen and oxygen, characterized in that two photocatalysts are ion exchanged. The membrane is separated into two connected reactors to separate helium and oxygen produced in the two reactors. Moreover, the redox ion can still maintain the redox cycle through the ion exchange membrane without the need for an external circuit as an electron path. The method for photocatalyzing the water to generate hydrogen and oxygen by the Z-scheme of the present invention comprises at least the following steps: (A) dispersing a hydrogen-producing photocatalyst in an aqueous solution having ions to prepare a hydrogen-producing end solution; (B) producing an oxygen-producing photocatalyst Dispersing in an aqueous solution with ions to prepare an oxygen generating end solution; 201109271 (c) Separating the hydrogen producing end and the oxygen generating end solution by an ion exchange membrane, and partitioning hydrogen and oxygen generated by water decomposition; (D) separately adding an electron transfer medium At the hydrogen-producing end and the oxygen-generating end solution, a cycle of reduction and oxidation reaction of water decomposition is performed individually. The hydrogen-producing solution and the oxygen-generating end solution are separated by an ion exchange membrane, and the ion exchange membrane is modified by functional group adjustment, which not only separates hydrogen and oxygen generated by water decomposition, but also allows passage of electron transport medium and hydrogen ions. To maintain the cycle of redox. The invention further comprises a Z-scheme photocatalytic device for hydrolyzing to produce hydrogen and oxygen, the device comprising at least: a z-scheme photocatalytic device for hydrolyzing to produce hydrogen and oxygen, comprising: a hydrogen producing end container: The invention comprises a hydrogen-producing photocatalyst and an aqueous ion solution; a hydrogen-producing end container comprising: an oxygen generating photocatalyst and an ionic aqueous solution; a pair of electron transfer medium for performing a redox reaction cycle; an ion exchange membrane; wherein the hydrogen producing end container and the oxygen generating end container Separated by an ion exchange membrane, the ion exchange membrane is separated from hydrogen and oxygen generated by the two vessels by a functional group-adjusted modification treatment; and the ion exchange membrane is used for electron transport medium and hydrogen ions to pass through to maintain redox The loop. 201109271 f implementation method 〃 The implementation and characteristics of the invention are designed to design a dual reactor system, prepare chlorine-producing photocatalyst and ion-exchange membrane treated with special beads, and separate hydrogen and oxygen generated by photocatalytic water decomposition. It is described in the following embodiments, and the present invention is compared with a conventional photocatalytic water decomposition system in order to highlight the progress of the present invention in this field. Refer to Figure 1 for the reaction pathway for water decomposition of z-sch photocatalysis. Combine two different kinds of light _P02 and PH2 to produce hydrogen gas using hydrogen photocatalyst 适合2 light suitable for hydrogen production. Oxygen production by oxygen ^ Photocatalyst: only produces oxygen Ο? Reuse the electron transfer medium (consisting of metal ions μ / )) as the role of electron transfer and charge balance, which combines two kinds of light contact to carry out light strip water Decomposed system, _ green plants carry light & as user's reaction to call it Z-scheme's reaction system, the principle of this system 疋 use visible light to irradiate hydrogen photocatalyst pH2, produce oxygen photocatalyst acid, so that both photocatalysts generate electronic electricity The hole to e7h+' is set by the relative oxidation potential and the reduction potential. The electrons of the hydrogen-producing photocatalyst PH2 will reduce the hydrogen ion. The hole of the oxygen-generating photocatalyst p〇2 will form oxygen with oxygen and the metal ion ΜΠ+ /Μ u+ih transfers the oxygen-producing electrons to the gas-generating photocatalyst PH2 (four) hole to achieve charge balance by its own redox reaction. The present invention utilizes the above two photocatalysts by ion exchange. Apart, the ion-exchange membrane photocatalytic H2 produced by the hydrolysis, can be mixed 〇2 barrier, but lets through the electron transfer medium to maintain the repetition of redox reactions. 8 201109271 The above Z-scheme photocatalytic process for the decomposition of water to produce hydrogen and oxygen is based on Pt/SrTiOyRh as a hydrogen-producing photocatalyst, using 〇3 as an oxygen-producing photocatalyst and selecting Fe3+/Fe2+ as the redox electron transport. The medium is subjected to a reaction of catalyzing water decomposition under visible light, and the two photocatalysts are separated into two connected reactors by using a specially treated ion exchange membrane, so that Fe2+/Fe3+ can be separately diffused and moved via the ion exchange membrane. The step of redoxing to the oxygen or hydrogen end 'forms a cycle of Fe2+/Fe3+ redox to prevent the hydrogen produced by photocatalytic water decomposition from mixing with oxygen, avoiding the danger of reverse reaction and mixed explosion of hydrogen and oxygen. Please refer to FIG. 2 'This embodiment is two interconnected reactors 1 . The connected reactor 100 is separated into hydrogen producing ends by a modified ion exchange membrane (Nafion membrane in the form of Fe 3 + ) 110 . 〇1 and the oxygen generating end 1〇2 are respectively provided with a hydrogen producing end solution 150 and an oxygen generating end solution 151, and the hydrogen producing end solution 150 comprises Fe2+ ions 140 and a hydrogen generating photocatalyst (Pt/SrTi〇3: Rh) 120. A photocatalyst (Pt) is attached to the surface of the hydrogen-producing photocatalyst (Pt/SrTi〇3: Rh) 120 to enhance photocatalytic activity. The oxygen generating end solution 151 contains an oxygen generating photocatalyst (W〇3) 130 and Fe3+ ions 141. The light 170 irradiates the argon-producing photocatalyst (Pt/SrTi(kRh)120 and the oxygen generating photocatalyst (W〇3) 130, so that the two photocatalysts start to decompose water and generate hydrogen H2 and oxygen 〇2, respectively, and the Fe3+ ion diffusion direction 162 leads to production. Hydrogen terminal 1 (H, Fe2+ ion diffusion direction 161 leads to oxygen generating end 102, the two ends of the ion Fe3+ / Fe2+ can pass through the ion exchange membrane (Fe3+ form of Nafion membrane) 110 to maintain the redox cycle, and hydrogen ion H +160 also passes through the ion exchange membrane to reach the hydrogen producing end to continuously produce hydrogen 201109271 gas. Step 1: Preparation of photocatalyst Hydrogen photocatalyst Pt(0.5%)/SrTiO3: Rh (l%) is firstly solid melted (solid) State method) Preparation of SrTi03:Rh, and then depositing Pt metal on the surface of SrTi03:Rh by photocatalytic deposition method. SrTi03:Rh photocatalyst is prepared by solid state melting method, and a certain amount of SrC03 is obtained by stoichiometric ratio. Ti02 and Rh203 were added to the spiders in sequence and thoroughly ground and mixed. The process added a small amount of CH30H to increase the mixing effect. Finally, the ground mixture was placed in a ship's crucible and placed in a high temperature furnace at 10 ° C per minute. The heating rate is up to 1200 ° C, and SrTi03:Rh powder is formed after calcination for 1 hour, and it is cooled and taken out by the researcher. In order to obtain higher photocatalytic activity, Pt is used as the auxiliary catalyst in this study. Pt metal was photocatalyzed by photocatalytic deposition on the surface of SrTi〇3:Rh photocatalyst. This method uses HftCl6 · 6H2 〇 as the precursor, and quantitatively weighs the aqueous solution of HJtCl6 according to the proportion of pt metal to be prepared. Then, the SrTKVRh prepared by the solid state melting method is placed in a solution, the bottle mouth is sealed and stirred on a magnet stirrer, and irradiated with ultraviolet light to photo-catalyze the Pt metal deposition on the surface of the SrTiOvRh photocatalyst. , the borrower's! 〇 6 aqueous solution changed from light yellow to colorless to determine the completion of photocatalytic deposition, and then the solution was placed at 80 ° C for box drying 'final and then removed and ground to obtain hydrogen-producing photocatalyst Pt / SrTiOyRh. The oxygen-producing photocatalyst W03 used in this experiment was purchased directly (Hayashi Pure 201109271)
Chemica〗；99.9%)，反應前再取出研磨使用。 請參閱第3圖，為SrTi〇3:Rh的伽圓譜。本發明之產氨光觸 媒Pt/SrTiCVRh是使關態熔融法來進行製備，利用光繞射儀 (XRD ’ X_rayDiffraetiGn)來蚊錢之㉟酿況。可發現由固 態熔融法製備的光觸媒完全呈現SrTi〇3的晶相，且以角度20 =30。為區分財期衫含有狀麟狀邮加⑽相Ti〇2， 因為SrTi〇3的最強吸收峰位於2(9=324〇1。，硫％和加此相 Ti〇2的最強吸收峰則位於2 0 =27.538。和27.455。，所以可以判別 製備出的產氫光觸媒為純SrTi〇3的晶相，而金屬忾和拙則由於 含量非常微量，故無法在圖中看到。 請參閱第4圖，為SrTiOyRh、SrTi〇3與W03的紫外可見光光 譜’ SrTi〇3:Rh和SrTi〇3皆是利用固態熔融法製備而得，只差別 在加入金屬Rh與否。由圖中可看出單純只有SrTi〇3存在時， SrTi〇3只能吸收到400nm波段’如同Ti〇2為一紫外光觸媒；然而 當Rh2〇3加入到反應物中進行鍛燒後，其紫外可見光光譜就有 明顯地變化，不但增加了紫外光的吸收範圍，更增加了 450〜650nm的可見光吸收鋒，這也反應在顏色的變化，讓本來 白色的SrTi〇3變成深灰色的粉末，故可藉由加入金屬汕，縮小 SrTi〇3的能帶間隙的寬度，使srTi〇3具有可見光觸媒的性質， 而圖中也可發現光觸媒WO3的吸收可從紫外光區到可見光區約 波長480nm的範圍’故WO3亦可作為可見光觸媒，為本實驗的 201109271 產氧光觸媒。 實施步驟二：離子交換膜之前處理 本實施步驟係為離子交換膜應用於分隔產氫端、產氧端溶 液以進行光催化水分解之反應，並於兩端溶液進行光催化水分 解後使氫氣、氧氣分離之方法，做詳盡說明：使用前須先把 Naflon膜上的官能基改成所須的狀態(Fe3+形式），讓鐵離子能 在兩溶液間進行交換。所使用的離子交換膜為Naf1〇n_117離子 交換膜(Aldrich，Lot No. 08304cz)，厚度為 178μηι。Nafion膜須 先經過前處理去除雜質，剪取2*2cm2面積大小的膜，將膜先以 1:1的HNO3煮沸3〜4小時去除在製造過程所殘留在膜上的有機 雜質；接著以大量的去離子水沖洗，並依序將膜浸泡在 NaOH和1M HC1溶液中各4小時以調整膜上官能基的狀態，上述 步驟須重覆2次’再以大量的去離子水沖洗。最後把經過調整官 能基狀態的膜浸泡在0.5M的FeCl3溶液中18小時，以調整膜上官 能基成為所須的狀態(Fe3+形式）。 實施方式一：混合式光催化水分解（習用比較例） 5月參閱第5圖’本實施方式為產氫光觸媒和產氧光觸媒混 合在同一反應裔中，以確δ忍光觸媒具有光催化水分解的活性。 使用可見光觸媒Pt/SrTi〇3:Rh與W03兩者混合’在5〇〇W鹵素燈 (光強度：1.68W/cm2)照射下，照光時間與產物之關係圖。由實 驗結果可以發現氫氣和氧氣皆隨著照光時間增加而增加，兩氣 12 201109271Chemica〗; 99.9%), and then used for removal before grinding. Please refer to Fig. 3, which is the gamma spectrum of SrTi〇3:Rh. The ammonia-generating photocatalyst Pt/SrTiCVRh of the present invention is prepared by an off-state melting method using a light diffractometer (XRD 'X_rayDiffraetiGn) for mosquitoes. It was found that the photocatalyst prepared by the solid state melting method completely exhibited the crystal phase of SrTi〇3 with an angle of 20 = 30. In order to distinguish the financial period, the shirt contains the (10) phase Ti〇2, because the strongest absorption peak of SrTi〇3 is located at 2 (9=324〇1), and the sulfur and the strongest absorption peak of Ti〇2 are located. 2 0 = 27.538 and 27.455. Therefore, it can be discriminated that the hydrogen-producing photocatalyst is pure SrTi〇3 crystal phase, and the metal lanthanum and cerium are not visible in the figure because of the very small content. The UV-visible spectrum of SrTiOyRh, SrTi〇3 and W03 'SrTi〇3:Rh and SrTi〇3 are all prepared by solid state melting method, only the difference is the addition of metal Rh or not. Only SrTi〇3 can only be absorbed into the 400nm band when SrTi〇3 is present. 'As Ti〇2 is an ultraviolet photocatalyst; however, when Rh2〇3 is added to the reactants for calcination, the UV-Vis spectrum changes significantly. Not only increases the absorption range of ultraviolet light, but also increases the visible light absorption front of 450~650nm, which also reflects the change of color, so that the original white SrTi〇3 becomes a dark gray powder, so by adding metal crucible, Reduce the width of the band gap of SrTi〇3, so that srT I〇3 has the property of visible light catalyst, and it can be found that the absorption of photocatalyst WO3 can range from about 480 nm in the ultraviolet region to the visible region. Therefore, WO3 can also be used as a visible light catalyst, which is the 201109271 oxygen generating photocatalyst for this experiment. Step 2: Pre-treatment of the ion exchange membrane This embodiment is an ion exchange membrane applied to separate the hydrogen-producing end and the oxygen-generating end solution for photocatalytic water decomposition, and the photocatalytic water decomposition of the solution at both ends is followed by hydrogen gas. The method of oxygen separation is described in detail. Before use, the functional groups on the Naflon membrane must be changed to the desired state (Fe3+ form), so that the iron ions can be exchanged between the two solutions. The ion exchange membrane used is Naf1. 〇n_117 ion exchange membrane (Aldrich, Lot No. 08304cz), thickness 178μηι. Nafion membrane must be pretreated to remove impurities, cut 2 * 2cm2 area of the membrane, the membrane first boiled 1:1 HNO3 3~ The organic impurities remaining on the film during the manufacturing process were removed for 4 hours; then rinsed with a large amount of deionized water, and the membrane was sequentially immersed in NaOH and 1 M HCl solution for 4 hours each. The state of the functional group on the whole film, the above steps must be repeated twice, and then rinsed with a large amount of deionized water. Finally, the membrane with the adjusted functional state is immersed in a 0.5 M FeCl3 solution for 18 hours to adjust the function on the membrane. The base is in a required state (Fe3+ form). Embodiment 1: Mixed photocatalytic water splitting (comparative example) May 5th drawing 'This embodiment is a hydrogen-producing photocatalyst and an oxygen-producing photocatalyst mixed in the same reactionary In order to confirm the activity of photocatalytic water decomposition of δ photocatalyst. The visible light catalyst Pt/SrTi〇3: mixed with both Rh and W03' is a relationship between the illumination time and the product under irradiation of a 5 〇〇W halogen lamp (light intensity: 1.68 W/cm 2 ). From the experimental results, it can be found that both hydrogen and oxygen increase with the increase of illumination time, two gases 12 201109271
k > I 體皆於照光時間i小時後開始生成，之後呈現線性方式增加，但 其產量有逐漸趨於平緩的情況，顯示逆反應的發生，限制產氫 和氧的持續生成。產生的氫氣和氧氣的含量相比，大致上都符 合化學當量比(stoichiometric ratio)為2:1的比例，證實是由水分 解而來，將反應第七小時的氫氣產量除以反應時間，定義為氫 氣平均產率（averagerate)，由結果計算可得兩光觸媒混合的系 統其虱氣平均產率為0.71 Arnol/g·!!!·。 鲁 實振方式二：光催化水分解產氩/氧系统 先分別配置產氫端和產氧端溶液，取〇 3g的產氫光觸媒 Pt/SrTi〇3:Rh放入已配好濃度為21^的？6€12燒杯溶液中，將混 合溶液置於加熱磁石搜拌器上充份檀拌，並以h2S〇4調整?1^值 為2.4 ’此為產氫端溶液。另取〇 3g的產氧光觸媒w〇3放入已配 好濃度為2mM的FeCl3燒杯溶液中，同樣將混合溶液置於加熱磁 參 石授拌器上充份攪拌’調整pH值到2.4，此稱為產氧端溶液。反 應系統如前圖2所示，離子交換膜將兩光觸媒分開至兩個連結的 反應器中，將已調整成所須狀態(Fe3+形式)的離子交換膜，以 大量的去離子水沖洗膜後，再將膜夾於兩個反應器的中間。再 將前面配置好的產氫端和產氧溶液分別放入兩邊的反應器中， 並鎖好的反應器放於加熱磁石攪拌器上攪拌，並以△1_氣吹除反 應器内的殘留空氣。最後照射可見光進行光催化水分解反應， 生成並分開產物氫氣與氧氣。k > I body starts to generate after i hours of illumination time, then increases linearly, but its yield gradually gradual, showing the occurrence of reverse reaction, limiting the continuous production of hydrogen and oxygen. Compared with the content of hydrogen and oxygen produced, the ratio of stoichiometric ratio is generally 2:1, which is confirmed by water decomposition, and the hydrogen production of the seventh hour of the reaction is divided by the reaction time. For the average yield of hydrogen, the system obtained by the two photocatalysts was calculated to have an average helium gas yield of 0.71 Arnol/g·!!!. Lu Shizhen mode 2: Photocatalytic water decomposition argon/oxygen system is first configured with hydrogen production end and oxygen production end solution, and 3 g of hydrogen-producing photocatalyst Pt/SrTi〇3:Rh is placed in a concentration of 21^. of? In a 6 € 12 beaker solution, the mixed solution was placed on a heated magnet stirrer and filled with sandalwood and adjusted with h2S〇4. The value of 1^ was 2.4 ′. This is the hydrogen producing end solution. Another 3 g of oxygen-producing photocatalyst w〇3 was placed in a FeCl3 beaker solution with a concentration of 2 mM, and the mixed solution was placed on a heated magnetic stone stirrer to fully stir and adjust the pH to 2.4. It is called the oxygen generating end solution. The reaction system is as shown in Figure 2 above. The ion exchange membrane separates the two photocatalysts into two connected reactors, and the ion exchange membrane that has been adjusted to the desired state (Fe3+ form) is rinsed with a large amount of deionized water. Then, the membrane was sandwiched between the two reactors. Then, the hydrogen-producing end and the oxygen-producing solution disposed in the front are respectively placed in the reactors on both sides, and the locked reactor is placed on a heating magnet stirrer to be stirred, and the residue in the reactor is blown off by Δ1_gas. air. Finally, the visible light is irradiated for photocatalytic water decomposition reaction to form and separate the product hydrogen and oxygen.
13 201109271 請參閱第6圖’為利用Nafion膜將兩光觸媒分開至兩個連 結的反應器進行照光的照光時間與產物之關係圖。光催化水解 過程中，皆以GC進行氣體分析，發現在氫氣端沒有氧氣的生 成’而氧氣端也沒有氫氣生成，由此可推測利用改質後的 Nafion膜可以分離兩光觸媒使其能分別產生氫氣和氧氣，促使 兩端的Fe3+/Fe2+能在膜中進行交換。可以發現由兩端產生的氫 氣和氧氣’於照光時間2小時後開始生成，之後皆隨著照光時間 增加而增加’與混合系統不同(見實施方式一），其兩氣體的生 修 成並無趨於平緩的情況，反而有繼續增加的趨勢，比較氫氣和 氧氣的產量，雖然氧氣的產量些微大於理想值’但大致上還是 符合2:1的化學當量比’再經由結果計算可得兩光觸媒分開的系 統其氫氣平均產率為l_59#mol/g·!!!·。比較兩光觸媒分開式反應 與混合式反應(見實施方式一)的實驗結果，可以發現分開式反 應產生氧體的時間較混合式反應早1小時才生成，請參閱第表 1’兩光觸媒混合式反應與分開式反應的氫氣初始產率與平均產鲁 率比較表中，分開式反應的初始產生氫氣速率222^m〇1/gehr 大約有说合式反應初始速率的2倍多，對於1氣平均產率，分開 式反應的產率也有混合式反應式的2倍多，此現象尚未考慮來自 在Nafl〇n膜進行擴散交換時的質傳阻力，氫氣端的 Fe 一旦氧化成Fe3+，須要經由Nafion膜進行交換至氧氣端進行 還原的步驟’同樣地還原後的!^2+也須經由Nafi〇n膜擴散交換到 氫氣端進行氧化，形成一個Fe3+/Fe2+之間變化的循環，此過程 14 201109271 中最大的阻力便是來自於交換Fe3+/Fe2+離子時產生的阻力，此 阻力會造成整個系統的產率降低，但就反應結果而言，以 Nafion膜進行分開式的反應’確實是可以做到氫氧直接分離的 效果’且平均氫氣產量也達到混合式的2倍。 本發明利用Nafion離子交換膜將兩光觸媒分開至兩個連 結的反應器令，再利用可見光進行光催化水分解反應，發現確 實可以做到氫氣和氧氣分開生成的效果，且跟混合性反應相 _ 比，也具有較咼的氫氣的產量。此外，本實驗也證明利用固態 熔融法製備出的產氫光觸媒Pt/SrTi〇3:Rh於含有產氧光觸媒 WO;的Fe3+/Fe2+光催化水分解系統中，在可見光照射下發現其 確實具有水分解產氫的能力。 201109271 【圖式簡單說明】 第1圖係Z-scheme光催化進行水分解產氫反應系統示意圖。 第2圖係本發明之Z-scherae光槪進行水分解產氮反應系統 示意圖。 第3圖係本發明之固態溶融法製備SrTi〇3:Rh之xRD(x_Ray Diffraction))圖譜。 第4圖係本發明之srTi〇3 :Rh、SrTi〇3與W03之紫外可見光光 譜。 弟5圖係習知(以光觸媒pt/SrTi〇3:Rh和W03混合，在2mM FeCl3 溶液中，並以HJO4調整pH值到2.4)照光時間與產物之關係圖。 第6圖係本發明(以Nafion膜分開兩光觸媒Pt/SrTi03:Rh於 2mMFeCl2溶液中、1W03於2mMFeCl3溶液中，並以h2S〇4調整 pH值到2.4)之照光時間與產物關係圖。 表1係習知混合式與本發明分開式反應的氫氣初始產率與平均 產率比較表。 201109271 【主要元件符號說明】 產氫光觸媒PH2 產氧光觸媒P02 金屬離子]\^+、M(n+U + 電子電洞對e7h+ 反應器100 產氫端101 產氧端102 離子交換膜110 產氫光觸媒120 產氧光觸媒130 產氫端溶液150 產氧端溶液151 產氫光觸媒ΠΙ2 產氧光觸媒P02 H+離子擴散方向160 Fe2+離子擴散方向161 Fe3+離子擴散方向162 光線170 氫氣H2 氧氣〇213 201109271 Please refer to Fig. 6' for the relationship between illumination time and product for illuminating the two photocatalysts by using a Nafion membrane to separate the two connected reactors. In the photocatalytic hydrolysis process, GC gas analysis was carried out, and it was found that there was no oxygen generation at the hydrogen end and no hydrogen gas was generated at the oxygen end. It is speculated that the modified Nafion membrane can separate the two photocatalysts to produce them separately. Hydrogen and oxygen promote the exchange of Fe3+/Fe2+ at both ends in the membrane. It can be found that the hydrogen and oxygen produced by both ends start to form after 2 hours of illumination time, and then increase with the increase of illumination time' different from the hybrid system (see Embodiment 1), and the two gases are not repaired. In the mild situation, there is a tendency to continue to increase, comparing the production of hydrogen and oxygen, although the oxygen production is slightly larger than the ideal value 'but generally meets the chemical equivalent ratio of 2:1' and then the two photocatalysts are separated by the results. The average hydrogen yield of the system is l_59#mol/g·!!!·. Comparing the experimental results of the two photocatalyst split reaction and the mixed reaction (see Embodiment 1), it can be found that the time for generating the oxygen in the split reaction is 1 hour earlier than the mixed reaction. Please refer to Table 1 'Two photocatalyst hybrids. In the comparison between the initial hydrogen yield and the average yield of the reaction and the separate reaction, the initial hydrogen production rate of the separate reaction is 222^m〇1/gehr, which is about twice the initial rate of the combined reaction. The yield of the split reaction is also more than twice that of the mixed reaction. This phenomenon has not been considered from the mass transfer resistance when the Nafl〇n film is subjected to diffusion exchange. Once the hydrogen end of the Fe is oxidized to Fe3+, it needs to pass through the Nafion film. The step of performing the exchange to the oxygen end for reduction 'the same reduction ^^2+ must also be oxidized by diffusion of the Nafi〇n film to the hydrogen end to form a cycle of change between Fe3+/Fe2+, this process 14 201109271 The biggest resistance comes from the resistance generated when exchanging Fe3+/Fe2+ ions, which causes a decrease in the yield of the entire system, but in terms of the reaction results, Nafion Separately type reaction 'can indeed be done directly isolated hydroxide effect' and an average hydrogen production reached a hybrid twice. The invention utilizes a Nafion ion exchange membrane to separate two photocatalysts into two connected reactors, and then uses visible light to carry out photocatalytic water decomposition reaction, and finds that the effect of separately generating hydrogen and oxygen can be achieved, and the mixed reaction phase _ It also has a relatively low production of hydrogen. In addition, this experiment also proves that the hydrogen-producing photocatalyst Pt/SrTi〇3:Rh prepared by solid-state melting method is found in the Fe3+/Fe2+ photocatalytic water-decomposition system containing oxygen-producing photocatalyst WO; Decomposes the ability to produce hydrogen. 201109271 [Simple description of the diagram] Figure 1 is a schematic diagram of the Z-scheme photocatalytic hydrogenation reaction system. Fig. 2 is a schematic view showing a water-splitting nitrogen-producing reaction system of the Z-scherae diaphragm of the present invention. Figure 3 is a plot of the xRD (x_Ray Diffraction) of SrTi〇3:Rh prepared by the solid state melting method of the present invention. Figure 4 is an ultraviolet-visible spectrum of the srTi〇3:Rh, SrTi〇3 and W03 of the present invention. Figure 5 is a diagram showing the relationship between light time and product by photocatalyst pt/SrTi〇3: mixing of Rh and W03 in 2 mM FeCl3 solution and adjusting pH to 2.4 with HJO4. Fig. 6 is a graph showing the relationship between the illuminating time and the product of the present invention (using a Nafion membrane to separate two photocatalysts Pt/SrTi03: Rh in a 2 mM FeCl2 solution, 1W03 in a 2 mM FeCl3 solution, and adjusting the pH to 2.4 with h2S〇4). Table 1 is a comparison table of initial and average hydrogen yields of a conventional mixed reaction with the present invention. 201109271 [Explanation of main component symbols] Hydrogen photocatalyst PH2 Oxygen photocatalyst P02 Metal ion]\^+, M(n+U + electron hole pair e7h+ Reactor 100 Hydrogen production end 101 Oxygen production end 102 Ion exchange membrane 110 Hydrogen production Photocatalyst 120 Oxygen photocatalyst 130 Hydrogen-producing solution 150 Oxygen-producing solution 151 Hydrogen-producing photocatalyst 2 Oxygen-producing photocatalyst P02 H+ ion diffusion direction 160 Fe2+ ion diffusion direction 161 Fe3+ ion diffusion direction 162 Light 170 Hydrogen H2 Oxygen 〇 2