二氧化鈦納米復(fù)合材料的制備及其光催化性能研究
發(fā)布時間：2019-01-29 21:24
【摘要】：隨著現(xiàn)代社會的不斷發(fā)展,環(huán)境污染問題變得越來越嚴重。光催化技術(shù)作為一種新型污染物降解技術(shù),其能耗低、使用范圍廣,成為解決環(huán)境污染問題的有效方法。二氧化鈦是一種廣泛使用的光催化材料,擁有無毒、無污染、價格低廉、催化效率高等優(yōu)點。然而理論研究發(fā)現(xiàn)二氧化鈦自身存在兩個嚴重缺陷,一是光生電子-空穴對復(fù)合速率過快;二是在可見光范圍內(nèi)沒有響應(yīng)(禁帶寬度為3.2 eV)。為了更好的利用二氧化鈦的光催化性能,科研人員設(shè)計了一系列改進方法,包括表面修飾等方法。本論文通過降低二氧化鈦光生電子-空穴復(fù)合速率、提高二氧化鈦比表面積和降低二氧化鈦帶隙能等方法,設(shè)計出三種新型二氧化鈦復(fù)合材料,并通過XRD、Raman、SEM、TEM、Uv-Vis和XPS等測試對材料的晶格結(jié)構(gòu)、微觀形態(tài)、質(zhì)構(gòu)特性、帶隙能、表面化學狀態(tài)等進行表征;通過光催化降解、光電流測試對材料光催化性能進行表征,其主要研究內(nèi)容如下:(1)還原氧化石墨烯-二氧化鈦復(fù)合光催化劑:通過水熱法將氧化石墨烯與二氧化鈦納米顆粒(NP)相復(fù)合,制備得到納米尺寸的石墨烯-二氧化鈦復(fù)合物。石墨烯與二氧化鈦納米顆粒的界面效應(yīng)能降低催化劑帶隙能;同時石墨烯的高導電性能提高催化劑中電子轉(zhuǎn)移速率。在所制備的還原氧化石墨烯-二氧化鈦復(fù)合物中,25%還原氧化石墨烯-二氧化鈦復(fù)合物擁有最佳的光催化性能,其吸附有機物能力和光降解有機物能力都超過其它復(fù)合物催化劑,并且擁有高循環(huán)利用性能,循環(huán)降解甲基橙30次后降解率仍然能達到93%。(2)二氧化鈦納米顆粒-二氧化鈰納米棒復(fù)合光催化劑:采用合成的大比表面積二氧化鈰納米棒,通過簡單的水熱法將二氧化鈦納米顆粒負載在二氧化鈰納米棒上,制備了一種新型二氧化鈦復(fù)合光催化劑。二氧化鈰納米棒的大比表面積提高催化劑對于污染物的吸附能力,同時二氧化鈰納米棒與二氧化鈦納米顆粒之間的界面效應(yīng)能有效降低催化劑帶隙能。在所制備的二氧化鈦納米顆粒-二氧化鈰納米棒復(fù)合材料中,30%二氧化鈦納米顆粒-二氧化鈰納米棒復(fù)合物擁有最佳的光催化性能,其光降解有機物能力超過其它復(fù)合物催化劑。(3)硫化鎘納米顆粒-二氧化鈦納米棒復(fù)合物光催化劑:采用制備的硫化鎘納米顆粒,通過簡單的水熱法將硫化鎘納米顆粒負載到二氧化鈦納米棒表面,制備出了一種新型二氧化鈦復(fù)合催化劑。硫化鎘納米顆粒較低的帶隙能(2.42 eV)能提高催化劑對于可見光的響應(yīng)范圍,同時利用硫化鎘納米顆粒較低的尺寸可提高催化劑吸附污染物能力。在所制備的硫化鎘納米顆粒-二氧化鈦納米棒復(fù)合材料中,40%硫化鎘納米顆粒-二氧化鈦納米棒復(fù)合物擁有最佳的光催化性能,其光降解有機物能力超過其它復(fù)合物催化劑,在太陽光下光催化性能比純品二氧化鈦光催化性能提高了2倍以上。
[Abstract]:With the development of modern society, the problem of environmental pollution becomes more and more serious. Photocatalytic technology, as a new pollutant degradation technology, has low energy consumption and wide range of application, so it has become an effective method to solve the problem of environmental pollution. Titanium dioxide is a widely used photocatalytic material, which has the advantages of non-toxic, pollution-free, low price and high catalytic efficiency. However, the theoretical study found that there are two serious defects in titanium dioxide itself, one is that the photoelectron / hole pair recombination rate is too fast, and the other is that there is no response in the visible light range (bandgap is 3.2 eV). In order to make better use of the photocatalytic properties of titanium dioxide, researchers have designed a series of improved methods, including surface modification. In this paper, three new titanium dioxide composites were designed by reducing the photogenerated electron-hole recombination rate, increasing the specific surface area of titanium dioxide and reducing the band gap energy of titanium dioxide. The lattice structure, microstructure, texture, band gap energy and surface chemical state were characterized by Uv-Vis and XPS. The photocatalytic properties of the materials were characterized by photocatalytic degradation and photocurrent test. The main research contents are as follows: (1) reduced graphene oxide / TIO _ 2 composite photocatalyst: graphene oxide and TIO _ 2 nanoparticles (NP) phase were synthesized by hydrothermal method. Nano-sized graphene-titanium dioxide composites were prepared. The interfacial effect between graphene and TIO _ 2 nanoparticles can reduce the band gap energy of the catalyst, and the high conductivity of graphene can improve the electron transfer rate in the catalyst. The 25% reductive graphene oxide titania composite has the best photocatalytic activity among the reduced graphene oxide titanium dioxide complexes. The ability of adsorption and photodegradation of organic compounds is higher than that of other complex catalysts, and has high recycling performance. The degradation rate of methyl orange can still reach 933 after 30 cycles. (2) Titanium dioxide nanoparticles and cerium dioxide nanorods composite photocatalyst: the synthesized cerium oxide nanorods with large specific surface area, A new type of TIO _ 2 composite photocatalyst was prepared by a simple hydrothermal method with TIO _ 2 nanoparticles loaded on cerium oxide nanorods. The large specific surface area of cerium oxide nanorods improves the adsorption ability of the catalyst to pollutants, and the interfacial effect between cerium oxide nanorods and titanium dioxide nanoparticles can effectively reduce the band gap energy of the catalyst. Among the prepared TIO _ 2 nanoparticles and cerium dioxide nanorods composites, 30% TIO _ 2 nanoparticles and cerium dioxide nanorods composites have the best photocatalytic properties. The photodegradation of organic compounds is superior to that of other complex catalysts. (3) cadmium sulphide nanoparticles-titanium dioxide nanorods composite photocatalysts: the preparation of cadmium sulfide nanoparticles, A new titanium dioxide composite catalyst was prepared by simply loading cadmium sulfide nanoparticles onto the surface of titanium dioxide nanorods. The low band gap energy (2.42 eV) of cadmium sulfide nanoparticles can increase the response range of the catalyst to visible light, and the adsorption ability of the catalyst can be improved by using the lower size of cadmium sulfide nanoparticles. Among the prepared cadmium sulfide nanoparticles and titanium dioxide nanorods composites, 40% cadmium sulfide nanocrystalline titania nanorods composite has the best photocatalytic performance, and its photodegradation ability is superior to that of other composite catalysts. The photocatalytic performance of pure titanium dioxide is more than 2 times higher than that of pure titanium dioxide under sunlight.
【學位授予單位】：南昌航空大學
【學位級別】：碩士
【學位授予年份】：2018
【分類號】：TB33;O643.36
本文編號：2417876
[Abstract]:With the development of modern society, the problem of environmental pollution becomes more and more serious. Photocatalytic technology, as a new pollutant degradation technology, has low energy consumption and wide range of application, so it has become an effective method to solve the problem of environmental pollution. Titanium dioxide is a widely used photocatalytic material, which has the advantages of non-toxic, pollution-free, low price and high catalytic efficiency. However, the theoretical study found that there are two serious defects in titanium dioxide itself, one is that the photoelectron / hole pair recombination rate is too fast, and the other is that there is no response in the visible light range (bandgap is 3.2 eV). In order to make better use of the photocatalytic properties of titanium dioxide, researchers have designed a series of improved methods, including surface modification. In this paper, three new titanium dioxide composites were designed by reducing the photogenerated electron-hole recombination rate, increasing the specific surface area of titanium dioxide and reducing the band gap energy of titanium dioxide. The lattice structure, microstructure, texture, band gap energy and surface chemical state were characterized by Uv-Vis and XPS. The photocatalytic properties of the materials were characterized by photocatalytic degradation and photocurrent test. The main research contents are as follows: (1) reduced graphene oxide / TIO _ 2 composite photocatalyst: graphene oxide and TIO _ 2 nanoparticles (NP) phase were synthesized by hydrothermal method. Nano-sized graphene-titanium dioxide composites were prepared. The interfacial effect between graphene and TIO _ 2 nanoparticles can reduce the band gap energy of the catalyst, and the high conductivity of graphene can improve the electron transfer rate in the catalyst. The 25% reductive graphene oxide titania composite has the best photocatalytic activity among the reduced graphene oxide titanium dioxide complexes. The ability of adsorption and photodegradation of organic compounds is higher than that of other complex catalysts, and has high recycling performance. The degradation rate of methyl orange can still reach 933 after 30 cycles. (2) Titanium dioxide nanoparticles and cerium dioxide nanorods composite photocatalyst: the synthesized cerium oxide nanorods with large specific surface area, A new type of TIO _ 2 composite photocatalyst was prepared by a simple hydrothermal method with TIO _ 2 nanoparticles loaded on cerium oxide nanorods. The large specific surface area of cerium oxide nanorods improves the adsorption ability of the catalyst to pollutants, and the interfacial effect between cerium oxide nanorods and titanium dioxide nanoparticles can effectively reduce the band gap energy of the catalyst. Among the prepared TIO _ 2 nanoparticles and cerium dioxide nanorods composites, 30% TIO _ 2 nanoparticles and cerium dioxide nanorods composites have the best photocatalytic properties. The photodegradation of organic compounds is superior to that of other complex catalysts. (3) cadmium sulphide nanoparticles-titanium dioxide nanorods composite photocatalysts: the preparation of cadmium sulfide nanoparticles, A new titanium dioxide composite catalyst was prepared by simply loading cadmium sulfide nanoparticles onto the surface of titanium dioxide nanorods. The low band gap energy (2.42 eV) of cadmium sulfide nanoparticles can increase the response range of the catalyst to visible light, and the adsorption ability of the catalyst can be improved by using the lower size of cadmium sulfide nanoparticles. Among the prepared cadmium sulfide nanoparticles and titanium dioxide nanorods composites, 40% cadmium sulfide nanocrystalline titania nanorods composite has the best photocatalytic performance, and its photodegradation ability is superior to that of other composite catalysts. The photocatalytic performance of pure titanium dioxide is more than 2 times higher than that of pure titanium dioxide under sunlight.
【學位授予單位】：南昌航空大學
【學位級別】：碩士
【學位授予年份】：2018
【分類號】：TB33;O643.36
【參考文獻】
相關(guān)期刊論文 前1條
1 王建強,辛柏福,于海濤,謝玉濤,趙冰,付宏剛;二氧化鈦系列光催化劑的拉曼光譜[J];高等學�；瘜W學報;2003年07期
，本文編號：2417876
本文鏈接：http://sikaile.net/kejilunwen/cailiaohuaxuelunwen/2417876.html
最近更新
教材專著
