本文選題：熔鹽法 + 光催化　； 參考：《中國地質(zhì)大學(xué)(北京)》2017年碩士論文

【摘要】：鈦基光催化劑擁有無毒無污染、穩(wěn)定的物化性質(zhì)和低成本等優(yōu)點(diǎn),作為高效的半導(dǎo)體光催化劑在光催化方面獲得廣泛的應(yīng)用。但鈦基光催化劑的寬帶隙和較高的電子空穴復(fù)合率阻礙了它的發(fā)展,近年來對(duì)其光催化能力的提高成為人們研究的熱點(diǎn)。所以,本論文主要集中于對(duì)鈦基光催化劑材料性能和制備方法的改進(jìn)。本論文以鈦基光催化劑為主要研究對(duì)象,采用熔鹽法在煅燒過程中引入硝酸鹽制備鈦酸鹽及氮摻雜、氮氟共摻雜的TiO_2,通過熔鹽體系降低制備樣品的煅燒溫度,提高樣品的光催化活性,研究其對(duì)樣品結(jié)構(gòu)組成、能帶寬度、光催化機(jī)制的影響。通過對(duì)樣品的組成分析、形貌結(jié)構(gòu)及光學(xué)性能進(jìn)行分析,結(jié)果表明:(1)采用熔鹽法制備的N摻雜單晶TiO_2催化劑在可見光照射下對(duì)亞甲基藍(lán)(MB)具有很高的光催化降解效果。氮摻雜使TiO_2的能帶寬度降低,促進(jìn)催化劑對(duì)光的吸收向可見光范圍的拓展;熔鹽體系促進(jìn)TiO_2單晶結(jié)構(gòu)的形成、比表面積的增大以及表面NO物種的增多,有利于提高樣品的光催化能力。(2)采用熔鹽法制備的氮氟共摻雜的納米立方形單晶TiO_2催化劑具有較高的(001)面暴露率,有利于光催化性能的提高。氮氟共摻雜TiO_2的禁帶寬度較小,使TiO_2對(duì)光的吸收向可見光方向遷移,并且其表面吸附了NO和氟離子,有利于提高樣品的光催化能力。(3)采用熔鹽法制備的鈦酸鹽催化劑隨著煅燒溫度的升高,其比表面積呈減小的趨勢,而禁帶寬度呈先增大后減小的趨勢,于600℃下制得樣品的禁帶寬度最小,700℃的禁帶寬度最大。于650℃下制備出具有層狀結(jié)構(gòu)的鈦酸鹽納米帶,其具有較好的光催化效果。
[Abstract]:Titanium based photocatalyst has many advantages, such as non-toxic and pollution-free, stable physicochemical properties and low cost. As a highly effective semiconductor photocatalyst, it has been widely used in photocatalysis. However, the wide band gap and high electron hole recombination rate of titanium-based photocatalyst hinder its development. In recent years, the improvement of its photocatalytic ability has become a hot research topic. Therefore, this paper mainly focuses on the improvement of the properties and preparation methods of titanium based photocatalyst materials. In this thesis, titanium based photocatalyst was used as the main research object. Titanate and nitrogen-doped TiO2 were prepared by introducing nitrate into the calcination process by molten salt method. The calcination temperature of the prepared samples was reduced by melting salt system. The influence of the photocatalytic activity on the structure, band width and photocatalytic mechanism of the samples was studied. The composition, morphology and optical properties of the samples were analyzed. The results show that the N-doped single crystal TiO_2 catalyst prepared by molten salt method has a high photocatalytic degradation effect on methylene blue MBs under visible light irradiation. Nitrogen doping reduced the band width of TiO_2, promoted the light absorption of catalyst to visible light, and promoted the formation of TiO_2 single crystal structure, the increase of specific surface area and the increase of no species on the surface. It is advantageous to improve the photocatalytic ability of the sample. (2) the nitrofluorine-co-doped nano-square single crystal TiO_2 catalyst prepared by molten salt method has a high surface exposure rate, and is beneficial to the improvement of photocatalytic performance. The band gap of nitrofluorine co-doped TiO_2 is small, which makes the absorption of TiO_2 light migrate to visible light, and no and fluoride ions are adsorbed on the surface of TiO_2. The specific surface area of titanate catalyst prepared by molten salt method decreased with the increase of calcination temperature, while the width of forbidden band increased first and then decreased. The band-gap of the sample prepared at 600 鈩，

本文編號(hào)：1916368