本文選題：鈷 + 鉬��； 參考：《南昌大學(xué)》2017年碩士論文

【摘要】：光催化作為一種有效的太陽能轉(zhuǎn)化技術(shù)引起了研究者的廣泛關(guān)注,多種新型的光催化材料被廣泛研究并應(yīng)用于光催化分解水制氫和有機(jī)污染物降解等領(lǐng)域。其中,ZnO和ZnS光催化材料在受到光激發(fā)后能快速產(chǎn)生光生電子和空穴,且它們導(dǎo)帶的位置都比H+/H2的還原電勢(shì)更負(fù),當(dāng)受到光輻射后可分解水制氫,但是,它們均屬于寬禁帶半導(dǎo)體材料,只能吸收太陽光中小于5%的紫外光,難以利用占主要光譜能量的可見光,極大地限制了其在光催化中的應(yīng)用。因此,對(duì)ZnO和ZnS的表面結(jié)構(gòu)、晶體結(jié)構(gòu)和電子結(jié)構(gòu)進(jìn)行改性,使其具有可見光響應(yīng)就顯得尤為重要。本論文主要通過金屬離子摻雜、形貌調(diào)控、構(gòu)建異質(zhì)結(jié)構(gòu)等方法對(duì)其進(jìn)行修飾改性,獲得具有可見光響應(yīng)的光催化材料。首先我們?cè)谒芤褐惺覝貤l件下,以鋅粉為原料,氧化石墨烯(GO)為載體,利用Zn的強(qiáng)還原性和GO的強(qiáng)氧化性,通過氧化還原反應(yīng)將鋅粉負(fù)載在GO上,防止鋅粉的團(tuán)聚。通過鈷(Co)離子的負(fù)載構(gòu)建原電池,通過微電化學(xué)方法制備Co摻雜ZnO/rGO納米顆粒。相對(duì)于ZnO/rGO,Co摻雜ZnO/rGO對(duì)400nm到700 nm的可見光區(qū)域有較好的吸收。在可見光(?≥420 nm)照射下,展現(xiàn)出了增強(qiáng)的光降解亞甲基藍(lán)(MB)效率及光電流強(qiáng)度。其次,為了縮短光生載流子的遷移距離,減少光生電子空穴復(fù)合,以及改善ZnS的可見光催化活性,通過金屬離子的引入調(diào)控ZnS的形貌結(jié)構(gòu)并原位進(jìn)行金屬離子摻雜來提升光催化效率。本研究選用高價(jià)態(tài)的Mo離子對(duì)寬禁帶半導(dǎo)體ZnS進(jìn)行摻雜改性,采用一步水熱法合成了鉬(Mo)摻雜ZnS片。在生長(zhǎng)過程中,Mo離子吸附在ZnS{111}晶面抑制該晶面方向的生長(zhǎng),得到{111}晶面占優(yōu)的ZnS片狀p型半導(dǎo)體材料。Mo摻雜ZnS片在整個(gè)可見光區(qū)域的吸收能力得到明顯提升,并在可見光下具有更高的光電轉(zhuǎn)化效率。最后,為了解決ZnO和ZnS只能吸收紫外光和光生電子空穴易復(fù)合的問題,并實(shí)現(xiàn)可見光催化制氫,發(fā)展了片狀的ZnO并通過離子交換和光負(fù)載CdS納米顆粒,合成了具有可見光吸收能力的ZnO/ZnS/CdS三元片狀異質(zhì)結(jié)構(gòu)材料。在該異質(zhì)結(jié)構(gòu)中,CdS和ZnS以納米顆粒形式嵌入ZnO片中并形成穩(wěn)定的界面,有利于光生載流子的遷移。ZnO/ZnS/CdS三元片狀異質(zhì)結(jié)構(gòu)在可見光下展現(xiàn)出更高的光催化產(chǎn)氫速率,進(jìn)一步通過助催化劑Pt納米顆粒的負(fù)載,使光催化制氫速率獲得大幅提升。
[Abstract]:As an effective solar energy conversion technology, photocatalysis has attracted extensive attention of researchers. Many new photocatalytic materials have been widely studied and applied in the fields of photocatalytic decomposition of water for hydrogen production and degradation of organic pollutants. ZnO and ZnS photocatalytic materials can produce photogenerated electrons and holes quickly after photoexcitation, and their conduction band positions are more negative than the reduction potential of H / H _ 2. They can decompose water to produce hydrogen when exposed to light radiation, but, They all belong to wide band gap semiconductor materials. They can only absorb less than 5% ultraviolet light in the solar light. It is difficult to use the visible light which accounts for the main spectral energy, which greatly limits their application in photocatalysis. Therefore, it is very important to modify the surface structure, crystal structure and electronic structure of ZnO and ZnS to make them have visible light response. In this paper, metal ions doping, morphology control, and heterostructure construction were mainly used to modify the materials to obtain photocatalytic materials with visible light response. Firstly, zinc powder was loaded on go by redox reaction with zinc powder as raw material and graphene oxide (go) as carrier, and zinc powder was loaded on go by redox reaction to prevent the agglomeration of zinc powder. Co-doped ZnO / rGO nanoparticles were prepared by micro-electrochemical method. Compared with ZnO / rGOCO-doped ZnO / rgo, the visible region of 400nm to 700nm is well absorbed. Under visible light (? 鈮，

本文編號(hào)：2080870