改性铁酸铋的制备及光催化性能的研究
发布时间：2019-02-13 08:31
【摘要】：铁酸铋是一种禁带宽度较窄(2.5～2.8eV),对可见光有一定程度响应的新型光催化剂。但铁酸铋也存在一定的缺陷:1、铁酸铋催化剂产生的光生电子和空穴的复合几率大;2、光降解速率较慢;3、铁酸铋催化剂对可见光的利用率比较低。针对上述问题,本文进行了如下研究:(1)以无水乙酸作溶剂,采用溶胶-凝胶法成功制备出纯BiFeO_3催化剂和钛掺杂的Ti-BiFeO_3催化剂。纯BiFeO_3催化剂最佳煅烧温度为550℃。Ti-BiFeO_3催化剂最佳制备条件:煅烧温度为700℃ ,钛掺杂量为10% ,铋钛比为12:1。以硝酸作溶剂成功制备出纯BiFeO_3催化剂和钛掺杂的Ti-BiFeO_3催化剂。以硝酸作溶剂,纯BiFeO_3催化剂的最佳制备条件:煅烧温度为550℃ ,溶剂为硝酸/水的体积比为1:1。以硝酸作溶剂,Ti-BiFeO_3催化剂最佳制备条件:煅烧温度为700℃ ,溶剂为硝酸/水体积比为1:1 ,钛掺杂量为10% ,铋钛比为12:1。(2)利用XRD、SEM和紫外可见漫反射等方法对催化剂结构等进行表征,并利用卤钨灯模拟太阳光,对催化剂的光催化活性进行测试。测试结果表明:钛掺杂能有效地提高铁酸铋的光催化活性,使铁酸铋对太阳光的吸收边带发生红移,也使得铁酸铋的禁带宽度变窄。以无水乙酸作溶剂,在最佳制备条件下制备的Ti-BiFeO_3催化剂的禁带宽度约为1.85eV。以硝酸作溶剂,在最佳制备条件下制备的Ti-BiFeO_3催化剂的禁带宽度约为1.88eV。(3)以亚甲基蓝溶液为目标降解物进行光催化降解实验探讨Ti-BiFeO_3催化剂处理亚甲基蓝溶液的主要影响因素和最佳反应条件。主要影响因素为亚甲基蓝溶液初始pH值、催化剂的投加量和亚甲基蓝溶液的初始浓度。最佳反应条件:亚甲基蓝溶液初始pH值为11 ,催化剂的投加量为2.5 g/L ,亚甲基蓝溶液的初始浓度10 mg/L。在最佳反应条件下,光催化210分钟,利用乙酸作溶剂,在最佳制备条件下制备的Ti-BiFeO_3催化剂处理亚甲基蓝溶液,亚甲基蓝溶液的色度去除率为98.99% , COD去除率为76.96%。利用硝酸作溶剂,在最佳制备条件下制备的Ti-BiFeO_3催化剂处理亚甲基蓝溶液,亚甲基蓝溶液的色度去除率为94.04%。(4)对Ti-BiFeO_3催化剂处理亚甲基蓝模拟染料废水进行动力学研究。由光催化反应动力学研究表明Ti-BiFeO_3催化剂光催化降解亚甲基蓝的反应符合一级反应动力学模型,其模型为:C=C_0exp(0.006257C_0~(-0.05209)Q~(1.1911)t)。
[Abstract]:Bismuth ferrate is a novel photocatalyst with narrow band gap (2.5~2.8eV) and a certain degree of response to visible light. However, bismuth ferrate also has some defects: 1, the photoelectron and hole recombination probability of bismuth ferrate catalyst is high; 2, the photodegradation rate is slow; 3, the utilization ratio of visible light of bismuth ferrate catalyst is low. To solve the above problems, the following studies were carried out: (1) the pure BiFeO_3 catalyst and titanium doped Ti-BiFeO_3 catalyst were successfully prepared by sol-gel method using anhydrous acetic acid as solvent. The optimum calcination temperature of pure BiFeO_3 catalyst is 550 鈩，
本文编号：2421363
[Abstract]:Bismuth ferrate is a novel photocatalyst with narrow band gap (2.5~2.8eV) and a certain degree of response to visible light. However, bismuth ferrate also has some defects: 1, the photoelectron and hole recombination probability of bismuth ferrate catalyst is high; 2, the photodegradation rate is slow; 3, the utilization ratio of visible light of bismuth ferrate catalyst is low. To solve the above problems, the following studies were carried out: (1) the pure BiFeO_3 catalyst and titanium doped Ti-BiFeO_3 catalyst were successfully prepared by sol-gel method using anhydrous acetic acid as solvent. The optimum calcination temperature of pure BiFeO_3 catalyst is 550 鈩，
本文编号：2421363
本文链接：https://www.wllwen.com/kejilunwen/huaxuehuagong/2421363.html
