發(fā)布時間：2018-04-14 01:35

  本文選題：固相反應(yīng) + 納米材料��； 參考：《新疆大學(xué)》2015年碩士論文

【摘要】：半導(dǎo)體光催化技術(shù)可將有機(jī)污染物直接降解為CO2、H2O以及其它一些無機(jī)小分子物質(zhì),具有高效和無二次污染等優(yōu)點,從而受到化學(xué)、物理和材料學(xué)家的廣泛關(guān)注。目前,對于半導(dǎo)體光催化劑的研究主要集中在對TiO2等傳統(tǒng)光催化劑的改性和新型半導(dǎo)體光催化劑的開發(fā)。鉍氧基光催化劑具有優(yōu)異的可見光光催化活性和特殊的片狀結(jié)構(gòu),近年來成為新型半導(dǎo)體光催化劑的研究熱點。本論文采用操作簡單的固相化學(xué)反應(yīng)合成了幾種鹵氧化鉍納米光催化劑,系統(tǒng)研究了鹵氧化鉍納米光催化劑在紫外光和可見光照射條件下對于目標(biāo)污染物的降解性能,探討了材料的形貌、比表面積以及帶隙對光催化性能的影響。主要研究內(nèi)容如下:(1)通過室溫固相反應(yīng)快速、簡便地合成了BiOX(X=Cl、Br、I)二維納米片,并通過改變反應(yīng)微環(huán)境合成了納米片構(gòu)筑的具有三維分級結(jié)構(gòu)的微米球,利用XRD、SEM、HRTEM、BET和固體UV~Vis等表征手段對樣品的物相、形貌、比表面積和光學(xué)性質(zhì)進(jìn)行表征,并對其光催化性能進(jìn)行了測試。無論在紫外光還是可見光下,BiOX二維納米片和三維分級微米球都具有較好的光催化性能。Bi OCl微米球表現(xiàn)出比BiOCl納米片更高的光催化活性,紫外光催化反應(yīng)進(jìn)行到13 min時對RhB降解完全,可見光催化反應(yīng)進(jìn)行到240 min時對RhB的降解效率達(dá)到90%。這主要歸因于BiOCl微米球具有較大的比表面積,有利于對染料分子的吸附和傳輸,為光催化提供了更好的條件。在可見光下,BiOX微球?qū)hB的降解效率依次為Bi OClBiOBrBiOI。(2)通過室溫固相反應(yīng)合成了BiOClxI1-x(x=0.75,0.5,0.25)固溶體,該固溶體為二維納米片組裝而成的三維分級微米球。BiOCl0.75I0.25固溶體的比表面積為51.17 m2/g,禁帶寬度為2.96 eV,在可見光條件下降解RhB的實驗中表現(xiàn)出比單相催化劑更強(qiáng)的光催化降解能力,光催化反應(yīng)進(jìn)行120 min時對RhB的降解率達(dá)到96%。(3)通過兩步固相反應(yīng)合成了Bi24O31X10(X=Cl,Br)材料和BiOX/Bi24O31X10異質(zhì)結(jié)材料。BiOX/Bi24O31X10異質(zhì)結(jié)材料的顆粒尺寸小于單相Bi24O31X10(X=Cl,Br)材料,具有比單相Bi24O31X10(X=Cl,Br)更優(yōu)異的光催化活性,這主要是由于Bi OX和Bi24O31X10之間形成的異質(zhì)結(jié)界面處光生電子轉(zhuǎn)移速率加快,進(jìn)而光生電子-空穴的分離效率大大提高,致使異質(zhì)結(jié)材料的光催化性能顯著增強(qiáng)。
[Abstract]:Semiconductor photocatalysis technology can directly degrade organic pollutants to CO2H 2O and some other inorganic small molecules, which has the advantages of high efficiency and no secondary pollution, so it has been widely concerned by chemical, physical and material scientists.At present, the research of semiconductor photocatalyst mainly focuses on the modification of traditional photocatalyst such as TiO2 and the development of new semiconductor photocatalyst.Bismuth oxide based photocatalyst has excellent visible photocatalytic activity and special flake structure, so it has become a research hotspot of new semiconductor photocatalyst in recent years.In this paper, several kinds of bismuth halide nanocrystalline photocatalysts were synthesized by simple solid-state chemical reaction. The degradation performance of bismuth halide nano-photocatalysts to target pollutants under ultraviolet and visible light irradiation was systematically studied.The effects of morphology, specific surface area and band gap on photocatalytic performance were discussed.The main contents of this study are as follows: (1) BiOXX XClClCBI) two dimensional nanowires were synthesized by rapid solid state reaction at room temperature, and microspheres with three dimensional hierarchical structure were synthesized by changing the reaction microenvironment.The phase, morphology, specific surface area and optical properties of the samples were characterized by XRDD-SEM-HRTEMT-BET and solid UV~Vis, and their photocatalytic properties were tested.BiOX two dimensional and three dimensional graded microspheres have better photocatalytic properties. Bi OCl microspheres exhibit higher photocatalytic activity than BiOCl nanoparticles in both ultraviolet and visible light.The degradation of RhB was completely achieved by UV photocatalytic reaction for 13 min and 90% by visible light reaction for 240 min.This is mainly due to the large specific surface area of BiOCl microspheres, which is conducive to the adsorption and transport of dye molecules and provides a better condition for photocatalysis.The degradation efficiency of BiOX microspheres was BiOClBiOBrBiOI.2.The solid solution was synthesized by solid state reaction at room temperature.The solid solution was composed of two dimensional nanowires. The specific surface area of the solid solution was 51.17 m2 / g, and the band gap was 2.96 EV. The photocatalytic degradation of RhB was stronger than that of single-phase catalyst in the experiment of degradation of RhB under visible light, and the specific surface area of the solid solution was 51.17 m2 / g and the band gap was 2.96 EV.The degradation rate of RhB by photocatalytic reaction for 120 min was 96%. 3) Bi24O31X10XC1XC1Brand BiOX/Bi24O31X10 heterojunction material were synthesized by two-step solid state reaction. The particle size of BiOX / Bi24O31X10 heterojunction material was smaller than that of single-phase Bi24O31X10XClBr-based material, and the photocatalytic activity was better than that of single-phase Bi24O31X10XCClBr.This is mainly due to the acceleration of photoelectron transfer rate at the heterojunction between BiOX and Bi24O31X10, and the higher efficiency of photoelectron hole separation, resulting in a remarkable enhancement of photocatalytic performance of heterojunction materials.
【學(xué)位授予單位】：新疆大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TQ135.32;TB383.1

【共引文獻(xiàn)】

相關(guān)博士學(xué)位論文 前2條

1 陳路呀;基于石墨烯或類石墨氮化碳復(fù)合光催化劑的制備、表征及其光催化性能的研究[D];華南理工大學(xué);2014年

2 程麗君;基于Bi_2O_3異質(zhì)結(jié)光催化劑制備、表征及催化活性研究[D];天津大學(xué);2014年

相關(guān)碩士學(xué)位論文 前1條

1 張延濤;納米BaTiO_3和BaTiO_3-Bi_2O_3復(fù)合光催化劑的制備及表征[D];陜西師范大學(xué);2014年

，

本文編號：1747154