论文总字数：26566字

摘 要

光催化剂是一种新型水处理技术，通常用半导体作光触媒材料。Cu₂O作为可见光的光催化剂被广泛应用。但是Cu₂O光催化剂存在光催化活性低、稳定性低等缺点，制约了其在水污染治理中的应用。针对Cu₂O光催化剂的缺点，本文将半导体负载至载体上，增大光催化剂的比表面积，再将贵金属与光催化剂复合，提升光催化剂的稳定性和光催化活性。

本文以沸石为载体，采用化学还原法制备氧化亚铜-沸石光催化剂（Cu₂O-沸石），再负载银纳米颗粒得到银-氧化亚铜-沸石光催化剂（Ag-Cu₂O-沸石）。采用X射线衍射（XRD）、扫描电子显微镜（SEM）和物理吸附分析（BET）等分析手段研究了Ag-Cu₂O-沸石的微观结构。

XRD表明制备的Ag-Cu₂O-沸石光催化剂出现Ag和Cu₂O和沸石的特征衍射峰，同时出现氧化铜（CuO）的特征衍射峰，说明制备的光催化剂有少部分被氧化，存在少量CuO杂质。SEM表明Ag-Cu₂O-沸石光催化剂具有多孔结构，并有Cu₂O粒子沉积在沸石表面，且Ag占据Cu₂O表面，可以证明Ag确实负载到Cu₂O-沸石上。BET表明虽然Ag-Cu₂O-沸石复合材料的比表面积和孔体积比Cu₂O和Cu₂O-沸石低，但是Ag-Cu₂O-沸石复合材料的平均吸附孔径比沸石、Cu₂O和Cu₂O-沸石复合材料都要高，这说明Ag-Cu₂O-沸石复合材料的吸附力比其他几种材料都要高。

本文以甲基橙配制模拟废水为对象，由于甲基橙为偶氮类染料，不会受到光分解、稳定性强，所以作为实验研究对象具有一定的代表性。为了了解Ag-Cu₂O-沸石的光催化性能，在可见光条件下降解甲基橙以进行研究，考察了光催化条件对光催化剂性能的影响。

结果表明：在AgNO₃负载量为0.005 mmol时，光催化剂的光催化活性达到最佳。在光催化剂用量为0.5 g/L时为最适光催化剂用量。在甲基橙溶液浓度不超过30 mg/L时，光催化效果较好。在pH = 7和pH = 9时，光催化剂表现出良好的降解性能。随着反应时间的增加，光催化剂对甲基橙的降解率逐渐增大，在45 min后增长趋势减缓，在90 min时达到最高。随着光催化剂利用次数的增加，对甲基橙的降解率逐渐降低，但降幅不大，经过5次反应降解后，对甲基橙的降解效率降低约15 %。

关键词：氧化亚铜 银纳米粒子 光催化 偶氮染料

Preparation of Ag-Cu₂O-zeolite composite and its photo catalytic treatment of Methyl Orange Wastewater

Abstract

Photo catalyst is a new type of water treatment technology, which usually uses semi-conductor as photo catalyst material. Cu₂O is widely used as visible light photo catalyst. However, Cu₂O photo- catalyst has the disadvantages of low photo catalytic activity and low stability, which restrict its application in water pollution control. In view of the disadvantages of Cu₂O photo catalyst, the semiconductor is loaded on the support, the specific surface area of photo catalyst is increased, and then the noble metal and photo catalyst are compounded to improve the stability and photo catalytic activity of the photo catalyst.

In this paper, cuprous oxide zeolite Photo catalyst (Cu₂O-zeolite) was prepared by chemical reduction method with zeolite as the carrier, and then argentum cuprous oxide zeolite Photo-catalyst (Ag-Cu₂O-zeolite) was prepared by loading argentum nanoparticles. The microstructure of Ag-Cu₂O-zeolite was studied by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and physical adsorption analysis (BET).

XRD showed that the characteristic diffraction peaks of Ag, Cu₂O and zeolite appeared in the prepared Ag-Cu₂O-zeolite photo catalyst, and the characteristic diffraction peaks of copper oxide (CuO) appeared at the same time. The results show that a small part of the photo catalyst is oxidized and a small amount of CuO impurity exists. SEM shows that Ag-Cu₂O-zeolite photo catalyst has a porous structure, and Cu₂O particles are deposited on the surface of zeolite, and Ag occupies the surface of Cu₂O, which proves that Argentum is indeed loaded on the Cu₂O-zeolite. BET shows that the specific surface area and pore volume of Ag-Cu₂O-zeolite photo catalyst are lower than that of Cu₂O and Cu₂O-zeolite. However, the average adsorption pore size of Ag-Cu₂O-zeolite photo catalyst is higher than that of zeolite, Cu₂O and Cu₂O-zeolite composite. This shows that the adsorption capacity of Ag-Cu₂O-zeolite composite is higher than other materials.

In this article, methyl orange is used to prepare simulated wastewater. Because methyl orange is an azo dye, it will not be decomposed by light and has strong stability, so it has certain representativeness as an experimental research object. In order to understand the photo catalytic performance of Ag-Cu₂O-zeolite, methyl orange was degraded under visible light conditions for study, and the influence of photo catalytic conditions on the photo catalytic performance was investigated.

The results show that: The photo catalytic activity of the photo catalyst the best when the AgNO₃ loading is 0.005 mmol. When the amount of photo catalyst is 0.5 g/L, it is the optimal amount of photo catalyst. And the photo catalytic effect is better when the concentration of methyl orange solution is not more than 30 mg/L. At pH = 7 and pH = 9, the photo catalyst showed good degradation performance. With the increase of reaction time, the degradation rate of methyl orange by photo catalyst gradually increased, and the growth trend slowed down after 45 minutes, and reached the highest at 90 minutes. With the increase of the utilization times of photo catalyst, the degradation rate of methyl orange gradually decreased, but the decrease was not large. After 5 times of degradation, the degradation efficiency of methyl orange decreased about 15%.

Key Words: Cuprous oxide; Silver nanoparticle; Photo-catalytic; azo dye

目 录

摘要 I

Abstract III

第一章 前言 1

1.1 印染废水及其偶氮染料概述 1

1.2 印染废水的危害 1

1.3 印染废水的处理方法 2

1.3.1 物理法 2

1.3.2 化学法 3

1.3.3 物化法 3

1.3.4 生物法 5

1.4 光催化剂在印染废水中的应用 6

1.5 论文研究意义及内容 7

第二章 光催化剂的制备 9

2.1 实验仪器及试剂 9

2.1.1 实验仪器 9

2.1.2 实验试剂 10

2.1.3 实验水样 10

2.2 光催化剂的制备 10

2.2.1 沸石的预处理 10

2.2.2 Cu₂O-沸石复合材料的制备 11

2.2.3 Ag-Cu₂O-沸石复合材料的制备 11

2.3 Ag-Cu₂O-沸石复合材料的表征分析 11

2.3.1 XRD（X射线衍射）图谱分析 11

2.3.2 SEM（扫描电子显微镜）分析 12

2.3.3 BET（物理吸附分析） 13

第三章 光催化性能分析 15

3.1 甲基橙的紫外-可见光谱图及标准曲线 15

3.1.1 全波长分析 15

3.1.2 标准曲线 15

3.1.3 实验分析 16

3.2 光催化性能分析 17

3.2.1 AgNO₃的负载量对降解效果的影响 17

3.2.2 催化剂用量对降解效果的影响 18

3.2.3 甲基橙初始浓度对降解效果的影响 19

3.2.4 pH值对降解效果的影响 19

3.2.5 反应时间对降解效果的影响 20

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