發(fā)布時間：2018-03-14 02:23

  本文選題：多孔結(jié)構(gòu)　切入點：TiO_x基材料　出處：《北京交通大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：當(dāng)今全球經(jīng)濟(jì)的快速發(fā)展,帶來了環(huán)境污染和能源短缺問題。隨著光電化學(xué)技術(shù)的迅速發(fā)展,光催化技術(shù)和染料敏化太陽能電池(Dye-sensitized solar cell,DSSC)以其綠色環(huán)保和節(jié)能等特點引起了廣泛關(guān)注。Ti02是光電領(lǐng)域重要的氧化物半導(dǎo)體,其中金紅石相(Eg:3.2eV)和銳鈦礦相(Eg:3.0eV)具有較高的光活性,在光催化劑和新型太陽能電池領(lǐng)域得到了重要應(yīng)用。然而Ti02具有較寬的帶隙以及較高的電子空穴復(fù)合率,使其對太陽能的利用率不足。3DOM(Three-DimensionallyOrdered Macroporous)結(jié)構(gòu)(又稱opal結(jié)構(gòu))具有開放和相互連接的大孔網(wǎng)絡(luò),比表面積大、表面空位多,因而廣泛應(yīng)用于光電(化學(xué))領(lǐng)域。TiOx是具有氧空位的一系列亞氧化態(tài)化合物,電導(dǎo)率高且在腐蝕性介質(zhì)中顯示化學(xué)惰性,其中Ti4O7表現(xiàn)出最高的電導(dǎo)率(1000S/cm),與石墨相當(dāng),Ti4O7以其優(yōu)良的電化學(xué)穩(wěn)定性在光電化學(xué)等領(lǐng)域中被廣泛關(guān)注。SnOx由于具有天然的缺陷,帶隙較窄,可以實現(xiàn)對太陽能的轉(zhuǎn)換利用,可應(yīng)用于光催化、多結(jié)光伏電池等領(lǐng)域。本論文首次將多孔的TiOx材料應(yīng)用于DSSC光陽極和光催化氧化NOx,并首次制備出優(yōu)異近紅外光吸收性能的Ti407/Sn506復(fù)合材料,并應(yīng)用于光催化降解亞甲基藍(lán)溶液。詳細(xì)開展了以下研究工作:1、通過無乳液聚合法合成出不同粒徑的單分散PMMA(聚甲基丙烯酸甲酯)微球,分別使用離心法和恒溫水浴法組裝出不同粒徑的膠晶模板,然后采用溶膠-凝膠法對膠晶模板進(jìn)行Ti02凝膠前驅(qū)物的填充。通過改變前驅(qū)物的浸泡次數(shù)和煅燒的保溫時間制備出TiOx三維有序大孔結(jié)構(gòu),并使用SEM,XRD進(jìn)行材料表征。將3DOM-TiOx材料用于DSSC光陽極,使用300nm粒徑的膠晶模板、前驅(qū)物浸泡次數(shù)為2次,保溫時間為4h的TiOx-3DOM材料的最高光電轉(zhuǎn)化效率為2.5%。2、通過氫氣還原3DOM-TiOx(Ti02相含量接近100%),分別在700、800℃、900℃和1000℃下制備出多孔TiOx,并使用SEM、XRD、N2氣吸脫附儀、紫外-可見吸收光譜對材料進(jìn)行表征。將不同還原溫度下的多孔TiOx應(yīng)用于光催化降解亞甲基藍(lán)(MB)溶液和光催化氧化NOx氣體,結(jié)果表明,還原溫度為700℃的多孔TiOx降解MB 2h和氧化NOx氣體15min后分別達(dá)到98%的降解效率和55%的氧化效率。3、通過一步水熱法制備出Ti4O7/Sn506復(fù)合物,通過調(diào)整Ti4O7和Sn5O6的摩爾比例制備出系列Ti4O7/Sn506復(fù)合物。使用SEM、XRD、TEM、XPS以及紫外-可見吸收光譜對材料進(jìn)行表征。將該復(fù)合材料用于光催化降解MB溶液,當(dāng)Ti407與Sn506之比為1:0.8時光催化效果最佳,在紫外-可見光照4h后達(dá)到97.5%。
[Abstract]:The rapid development of the global economy has brought about environmental pollution and energy shortage. With the rapid development of photochemical technology, Photocatalytic technology and Dye-sensitized solar cell DSSCs have attracted wide attention for their green environmental protection and energy saving. Ti02 is an important oxide semiconductor in the field of optoelectronics, in which rutile phase Eg3.2eV) and anatase phase Eg3.0eV) have high photoactivity. It has been widely used in photocatalyst and new solar cells. However, Ti02 has wide band gap and high electron hole recombination rate. The three-dimensional ordered Macroporous) structure (also known as opal structure) has an open and interconnected macroporous network with large specific surface area and plenty of surface vacancies. Therefore, it is widely used in optoelectronic (chemical) field. TiOx is a series of suboxide compounds with oxygen vacancies, which have high conductivity and show chemical inertia in corrosive media. Among them, Ti4O7 has the highest conductivity of 1000S / cm ~ (-1), and Ti _ 4O _ (7) has been widely concerned in photochemistry because of its excellent electrochemical stability. Because of its natural defects and narrow band gap, Ti4O7 can realize the conversion of solar energy. In this paper, porous TiOx materials were first used in DSSC photoanode and photocatalytic oxidation of no _ x, and Ti407/Sn506 composites with excellent near-infrared absorption properties were prepared for the first time. It was applied to photocatalytic degradation of methylene blue solution. The following research work was carried out in detail. The monodisperse PMMA (polymethyl methacrylate) microspheres with different particle sizes were synthesized by non-emulsion polymerization. The colloidal templates with different particle sizes were assembled by centrifugal method and isothermal water bath method respectively. Then the colloidal template was filled with the precursor of Ti02 gel by sol-gel method. The three-dimensional ordered macroporous structure of TiOx was prepared by changing the immersion times of the precursor and the heat preservation time of calcination. The 3DOM-TiOx material was used as DSSC photoanode, and the precursor was soaked twice with the gel crystal template of 300nm diameter. The highest photoelectric conversion efficiency of TiOx-3DOM materials with holding time of 4 h is 2.5.2. The content of 3DOM-TiOxTi02 phase is close to 100m by hydrogen reduction. Porous TiOxs are prepared at 700,800 鈩，

本文編號：1609181