本文選題：水熱法　切入點(diǎn)：介孔TiO_2　出處：《吉首大學(xué)》2016年碩士論文　論文類(lèi)型：學(xué)位論文

【摘要】：基于空氣質(zhì)量的日益惡化,光催化技術(shù)在空氣凈化方面得到了廣泛的發(fā)展。其中,TiO_2由于具有氧化性強(qiáng)、價(jià)格低廉、性能穩(wěn)定和易于改性等優(yōu)勢(shì),在空氣治理方面具有很大的研究潛能。因此,本文對(duì)TiO_2光電極的制備、改性及機(jī)制進(jìn)行了探討,主要內(nèi)容如下:以十六烷基三甲基溴化銨為液晶模板,四氯化鈦為鈦源,導(dǎo)電碳?xì)譃檩d體,通過(guò)超聲波輔助水熱法(Ultrasound-assisted hydrothermal method,UH)制備介孔二氧化鈦/導(dǎo)電碳?xì)?Mesoporous titania/conductive carbon felt,MPT/CCF)復(fù)合光電極材料(UH-MPT/CCF),利用X-射線衍射(XRD)、掃描電鏡(SEM)、透射電鏡(TEM)、傅里葉紅外(FT-IR)、N_2吸附-脫附、熱重-差熱(TG-DTA)等方法對(duì)樣品結(jié)構(gòu)進(jìn)行表征。結(jié)果表明,介孔化處理提高了UH-MPT/CCF光電極的比表面積,增加了活性中心(·OH和Ti3+),TiO_2固載化提高了對(duì)目標(biāo)降解物的吸附和表面電子轉(zhuǎn)移,協(xié)同偏電壓促進(jìn)光生電子-空穴對(duì)的分離。在多方的協(xié)同作用下UH-MPT/CCF對(duì)苯甲醛在100 min內(nèi)降解率為83.9%,分別是水熱法制備介孔二氧化鈦/導(dǎo)電碳?xì)?H-MPT/CCF)、無(wú)孔二氧化鈦/導(dǎo)電碳?xì)?No porous titania/conductive carbon felt,NPT/CCF)和P25/CCF的1.38、1.75和2.38倍。此外,采用相同的制備工藝,分別制備了導(dǎo)電碳?xì)重?fù)載鉑摻雜介孔TiO_2光電極(MPT-Pt/CCF)、導(dǎo)電碳?xì)重?fù)載錳摻雜介孔TiO_2光電極(MPT-Mn/CCF)、導(dǎo)電碳?xì)重?fù)載鐵摻雜介孔TiO_2光電極(MPT-Fe/CCF)和導(dǎo)電碳?xì)重?fù)載鋅摻雜介孔TiO_2光電極(MPT-Zn/CCF)。結(jié)果表明,金屬Pt離子的摻雜能引入了雜質(zhì)能級(jí),減小TiO_2的能帶隙,同時(shí),Pt充當(dāng)光生電子-空穴捕獲阱,阻止電子-空穴對(duì)的復(fù)合,使得MPT-Pt/CCF具有更高的光電催化效率。最后,以氣相苯甲醛為目標(biāo)降解物,探討了MPT/CCF系列光電極的光電催化性能及其對(duì)氣相苯甲醛的降解機(jī)理。根據(jù)GC/MS結(jié)果分析,提出了氣相苯甲醛的降解機(jī)制。同時(shí),得出光電極材料的最佳制備工藝條件是2次負(fù)載500℃煅燒,最佳的降解條件為溫度35℃、相對(duì)濕度55%、偏電壓10 V、初始濃度40 mg/m3、電極間距20 cm。
[Abstract]:Due to the deterioration of air quality, photocatalytic technology has been widely developed in air purification, among which TiO-2 has the advantages of strong oxidation, low price, stable performance and easy modification. Therefore, the preparation, modification and mechanism of TiO_2 photoelectrode are discussed in this paper. The main contents are as follows: cetyltrimethylammonium bromide as liquid crystal template, titanium tetrachloride as titanium source, hexadecyltrimethylammonium bromide as liquid crystal template, titanium tetrachloride as titanium source, Conductive carbon felt was prepared by ultrasonic assisted hydrothermal method (UH). The composite photoelectrode material, UH-MPT / CCF, was prepared by ultrasonic assisted hydrothermal method (UH). The composite photoelectrode material, UH-MPT / CCF, was adsorbed and desorbed by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FTIR), FT-IRT / N2. The results showed that mesoporous treatment increased the specific surface area of UH-MPT/CCF photoelectrode, and increased the active center (路OH and Ti3) tio _ 2 immobilization, which increased the adsorption and surface electron transfer of the target degradation, and the structure of the sample was characterized by thermogravimetry and differential thermogravimetric TG-DTA.The results showed that the mesoporous treatment increased the specific surface area of the photoelectrode, and increased the active center (路OH and Ti3 / TiO2). The synergistic bias voltage promotes the separation of photogenerated electron-hole pairs. The degradation rate of benzaldehyde by UH-MPT/CCF in 100 min is 83.9%. The mesoporous TIO _ 2 / conductive carbon felts prepared by hydrothermal method is H-MPT / CCF _ (2), no porous titanium dioxide / conductance. Carbon felt No porous titania/conductive carbon feltr NPT / CCF and P25 / CCF 1.38% and 2.38 times. Using the same preparation process, Conductive carbon felts supported on platinum-doped mesoporous TiO_2 photoelectrodes, conductive carbon felts supported on manganese doped mesoporous TiO_2 photoelectrodes, conductive carbon felts supported iron doped mesoporous TiO_2 photoelectrodes (MPT-Fe / CCFF) and conducting carbon felts supported zinc doped mesoporous TiO_2 photoelectrodes were prepared. The results show that, The doping energy of metal Pt ion introduces impurity energy level, reduces the energy band gap of TiO_2, while Pt acts as photogenerated electron-hole trapping trap, which prevents the recombination of electron-hole pair, which makes MPT-Pt/CCF have higher photocatalytic efficiency. The photocatalytic performance of MPT/CCF series photoelectrode and its degradation mechanism of gaseous benzaldehyde were discussed. Based on the analysis of GC/MS results, the degradation mechanism of gaseous benzaldehyde was proposed. The optimum preparation conditions of photoelectrode materials were obtained as follows: twice calcined at 500 鈩，

本文編號(hào)：1628806