【作者】 董娜；

【导师】 苏碧桃；

【作者基本信息】 西北师范大学 ， 物理化学， 2008， 硕士

【摘要】 本论文通过对复合型光催化剂的研究,成功合成了四种可见光型复合催化剂。以亚甲基蓝溶液的脱色研究了复合催化剂的催化性能,探讨了掺杂量、热处理条件以及光源对催化性能的影响,并运用TEM、XRD、UV-Vis等测试技术对复合催化剂的结构进行了表征。本论文主要由以下三个方面组成:1.用沉淀法制备了一系列不同Sn4+掺杂量的纳米ZnO光催化剂。结果表明:采用沉淀法制备的Sn4+/ZnO纳米材料为无定型结构,平均粒径在30 nm左右;当Sn4+∶ZnO的摩尔比为1∶200,煅烧温度为600℃时,Sn4+/ZnO的光催化活性最强,在3 h内,太阳光条件下,亚甲基蓝(MB)溶液的降解率达96.37 %。2.以氯化镉和硫化钠为原料,采用固体研磨法制备了尺寸为70 nm的CdS,进而用溶胶-凝胶法制备了一系列不同配比的Fe3+-CdS/TiO2光催化材料。结果表明:当Fe3+∶CdS∶TiO2的摩尔比为0.005∶1∶1、煅烧温度为300℃、煅烧时间为30 min、光源为太阳光时,Fe3+-CdS/TiO2的光催化活性最高,在60 min内可以使亚甲基蓝(MB)溶液的降解率达98.62 %。3.采用尿素络合燃烧法(凝胶-燃烧合成法)合成尖晶石型铁酸锌以及铁酸镉。结果表明:(1)尿素络合燃烧法制备的纳米ZnFe2O4近似呈球形,平均粒径为30 nm左右,煅烧温度为600℃、煅烧时间为1 h、尿素与金属离子的摩尔比为4∶1时铁酸锌的光催化活性最高,在太阳光的条件下4 h可以使亚甲基蓝(MB)溶液的降解率达67 %。(2)尿素络合燃烧法制备的铁酸镉纳米材料呈棒状,直径为80 nm,长度为1400 nm,在太阳光条件下3 h可以使亚甲基蓝(MB)溶液的降解率达54 %。更多还原

【Abstract】 In this thesis, four novel composites of sunlight photocatalyst were successfully designed and prepared. Their catalytic activities were evaluated by measuring the decolorization efficiency of MB in aqueous solution. In addition, the effects of the content of the nanocomposite photocatalysts and calcination temperature and light source on photocatalytic activity were investigated. These composites were also characterized using TEM、XRD and UV-Vis techniques.This thesis mainly consists of three major aspects.1. A series of Sn4+/ZnO nano-photocatalysts were successfully synthesized by a co-precipitation production method. The results indicated while the molar ratio of Sn4+ and ZnO was about 1∶200 and calcinations temperature was 600℃, the nanocomposite semiconductor showed the highest photocatalytic activity and the decolorization efficiency of MB (10 mg.L-1) reached 94.70 % when the reaction time was 3 h under the sunlight illumination.2. The size of 70 nm cadmium sulfide was prepared from cadmium chloride and sodium sulfide as raw materials by solid grinding method and a series of Fe3+-CdS/TiO2 photocatalysts were successfully synthesized by a sol-gel method. The results indicated that while the molar ratio of CdS∶Fe3+∶TiO2 was 0.005∶1∶1, calcination temperature and time were respectively 300℃and 30 min, the coupled semiconductor had the highest photocatalytic activity, and the degradation rate of MB (10 mg.L-1) irradiated for 60 minutes was 98.62 % under the sunlight illumination.3. Two spinel-type ZnFe2O4 and CdFe2O4 nanosized photocatalysts were synthesized by the combustion of urea. The results were shown in the following.(1) The size of the sphere-like ZnFe2O4 particles was about 30 nm. when the calcination temperature and time were respectively 600℃and 1 h and the molar ratio of urea∶metal iron was 4∶1, the catalyst reached the highest activity, the degradation efficiency of MB reached 67 % under the sunlight illumination and the reaction time 4 h. (2) CdFe2O4 nanorods with average diameters 80 nm and length of up to 1.4μm were synthesized via the combustion of urea. The degradation efficiency of MB reached 54 % under the sunlight illumination and the reaction time 3 h.更多还原