發(fā)布時(shí)間：2018-05-22 11:18

  本文選題：WO_x(W_(18)O_(49)) + MoO_x(Mo_4O_(11))　； 參考：《北京交通大學(xué)》2017年碩士論文

【摘要】：現(xiàn)代社會(huì)人類面臨著環(huán)境污染和能源短缺的兩大挑戰(zhàn)。半導(dǎo)體光催化技術(shù)和染料敏化太陽(yáng)能電池(Dye-sensitized solar cell,DSSC)是解決環(huán)境和能源危機(jī)的有效途徑。傳統(tǒng)的Ti02光催化劑帶隙較寬、光催化活性低;DSSC對(duì)電極使用貴金屬Pt難以產(chǎn)業(yè)化,上述問(wèn)題使得光催化技術(shù)和DSSC發(fā)展受到了阻礙。非化學(xué)計(jì)量比的W_(18)O_(49)是單斜結(jié)構(gòu),電子能級(jí)帶隙較窄,對(duì)太陽(yáng)光有較好的響應(yīng),且具有優(yōu)良的導(dǎo)電性能,適用于半導(dǎo)體光催化等領(lǐng)域。非化學(xué)計(jì)量比的鉬氧化物具有多價(jià)態(tài),在應(yīng)用過(guò)程中多個(gè)價(jià)態(tài)變換,表現(xiàn)出較強(qiáng)的化學(xué)活性和較好的電子傳輸性能,尤其是Mo_4O_(11),電阻率較小(10-4Ω·cm),具有更好的傳輸性能,是理想的光催化媒介和光陰極材料。因此,本論文首次對(duì)三維有序大孔(Three-dimentional ordered macroporous,3 DOM)結(jié)構(gòu)的WO_x材料進(jìn)行了表面性能表征,并制備出高M(jìn)o_4O_(11)含量、可見(jiàn)光吸收性能優(yōu)異的MoO_x材料,詳細(xì)開(kāi)展了以下研究工作:(1)采用無(wú)乳液聚合法合成出不同粒徑的單分散PMMA微球;利用離心法和恒溫水浴成膜法組裝PMMA微球得到有序排列的膠體晶體模板。使用三氧化鎢的氫氟酸溶液浸泡PMMA膠體晶體模板,經(jīng)過(guò)干燥、煅燒后得到WO_x 3DOM材料。利用SEM、XRD、XPS、Raman和UV-vis吸收光譜等手段對(duì)材料進(jìn)行表征。(2)采用溶劑熱法,改變?nèi)軇┖蚖C16溶液的濃度,制備出納米線、梭形、海膽狀的W18049納米材料,利用SEM和XRD對(duì)材料進(jìn)行表征。使用制備的W_(18)O_(49)納米材料作光催化劑,在紫外-可見(jiàn)光照射下降解甲基橙,結(jié)果表明:納米線和梭形W_(18)O_(49)對(duì)甲基橙的降解效果較好,最高降解效率分別達(dá)到94%和100%。(3)采用不同工藝制備MoO_x材料,研究了工藝條件對(duì)MoO_x的相組成及相含量的影響。①將鉬酸銨直接在5vol%H_2/Ar氣氛下熱解還原,在600℃下保溫2h得到的MO_4O_(11)含量最高(84.8%)。②使用水熱法合成帶狀三氧化鉬,然后三氧化鉬在5vol%H_2/Ar氣氛下還原,在 600℃下保溫2h得到的Mo_4O_(11)含量最高(92%)。③將鉬酸銨在空氣中煅燒,在650℃下保溫5h得到三氧化鉬,然后三氧化鉬在5 vol%H_2/Ar氣氛下還原,在625℃下保溫2h得到Mo_4O_(11)含量高達(dá)98.5%。利用SEM、XRD、XPS、Raman和UV-vis吸收光譜等方法對(duì)MoO_x材料進(jìn)行表征。使用制備的MoO_x材料作光催化劑,在紫外-可見(jiàn)光照射下降解羅丹明B,結(jié)果表明:98.5%Mo_4O_(11)含量的MoO_x材料的降解效率最高(97%)。使用Mo_4O_(11)作DSSC對(duì)電極得到了初步電池性能結(jié)果。
[Abstract]:In modern society, human beings are faced with two major challenges of environmental pollution and energy shortage. Semiconductor photocatalytic technology and Dye-sensitized solar cell DSSC are effective ways to solve the environmental and energy crisis. The traditional Ti02 photocatalyst has wide band gap and low photocatalytic activity. It is difficult to industrialize using noble metal Pt for photocatalytic activity. These problems hinder the development of photocatalytic technology and DSSC. The non-stoichiometric WSCL _ (18) O / O _ (49) has a monoclinic structure, narrow band gap of electronic energy levels, good response to solar light, excellent conductivity, and is suitable for semiconductor photocatalysis and so on. Molybdenum oxides with non-stoichiometric ratio have multivalent states, and in the process of application, they exhibit stronger chemical activity and better electron transport performance, especially for Mo _ 4O _ S _ (11), resistivity is 10 ~ (-4) 惟 cm ~ (-1), and it has better transport performance. It is an ideal photocatalytic medium and photocathode material. Therefore, for the first time, the surface properties of three-dimentional ordered macroporous3DOM-based WO_x materials with three dimensional ordered macroporous structure have been characterized, and MoO_x materials with high Mo4O structure and excellent visible light absorption have been prepared. The following research work was carried out in detail: (1) Mono-dispersed PMMA microspheres with different particle sizes were synthesized by non-emulsion polymerization, and PMMA microspheres were assembled by centrifugal method and isothermal water bath film forming method to obtain ordered colloidal crystal templates. The PMMA colloidal crystal template was soaked in the hydrofluoric acid solution of tungsten trioxide, and the WO_x 3DOM material was obtained after drying and calcining. The nanocrystalline, fusiform and sea urchin W18049 nanomaterials were prepared by means of solvothermal method, changing the concentration of solvent and WC16 solution, and characterized by SEM and XRD. The photocatalytic degradation of methyl orange by using the prepared WSP _ 18O _ S _ (49) nanomaterials under ultraviolet and visible light irradiation showed that nanowires and fusiform Washi-18o _ s _ (49) had better degradation effect on methyl orange, and the results showed that the degradation of methyl orange by nanowires and fusiform Wsn _ (18) O _ (O) was better. The highest degradation efficiency reached 94% and 100% respectively) MoO_x materials were prepared by different processes. The effects of process conditions on the phase composition and phase content of MoO_x were studied. 1 ammonium molybdate was pyrolyzed and reduced directly in 5vol%H_2/Ar atmosphere. Molybdenum trioxide was synthesized by hydrothermal method, then reduced in 5vol%H_2/Ar atmosphere, and Mo4OOT11 obtained by heat preservation at 600 鈩，

本文編號(hào)：1921847