摘要
采用溶胶-凝胶法将Keggin型H4Si W12O40负载在Si O2上,并用30%H2O2溶液对其进行敏化,制得H4Si W12O40/Si O2/H2O2光催化剂,分别利用傅里叶变换红外光谱仪（FT-IR）、X射线衍射（XRD）对该光催化剂进行表征分析,结果表明H4Si W12O40高度分散在Si O2上,并且经过H2O2溶液处理的光催化剂在935.2 cm^-1出现了一个较弱的过氧基吸收峰,这与过氧多酸化合物的吸收峰较一致。另外,进行甲基橙模拟废水溶液在黑暗条件下的吸附-脱附平衡实验,结果表明在30 min达到吸附-脱附平衡,故优化组实验选择在黑暗下搅拌30 min以达到吸附-脱附平衡。接着对甲基橙的初始浓度、溶液p H以及催化剂用量进行优化。实验发现,在甲基橙初始浓度为15 mg·L^- 1,溶液p H为1.0,催化剂的用量为6 g·L^- 1的优化情况下,光降解3.0 h,甲基橙的降解率达到99.0%,H4Si W12O40/Si O2/H2O2光催化降解甲基橙溶液的过程符合一级动力学反应规律;且H4Si W12O40/Si O2/H2O2对甲基紫、孔雀石绿、亚甲基蓝、罗丹明B和甲基红均具有较高的光催化活性,降解率达87.5%－100.0%。
The Keggin-type H4 Si W12O40was loaded on the surface of Si O2 with sol-gel method,and sensitized by 30% H2O2 solution,then the photocatalyst was characterized using Fourier transform infrared（ FT-IR） spectrometer,X-ray diffraction（ XRD）. The results showed that H4 Si W12O40was highly dispersed on the Si O2,and the sensitized photocatalyst appeared a weak absorption peak at935. 2 cm^-1,which was in agreement with the absorption peak of peroxy compound. The adsorption-desorption equilibrium experiment of methyl orange waste water in dark condition showed that the process reached an equilibrium at 30 min,so stirring for 30 min in the dark was selected for the optimization experiment. Then,the photocatalytic degradation of methyl orange by H4 Si W12O40/ Si O2/ H2O2 under simulated natural light irradiation was investigated. At the same time,influences of the initial methyl orange concentration,the solution p H and the catalyst dosage on the photocatalytic degradation rate of methyl orange were also examined. The results demonstra-ted that when the initial concentration of methyl orange was 15 mg·L^- 1,catalyst dosage was 6 g·L^- 1and the p H was 1. 0,the degradation ratio of methyl orange was as high as 99. 0% after simulated natural light irradiation for 3. 0 h. The reaction of photocatalysis for methyl orange could be expressed as first-order kinetic model. The photodegradation of methyl violet,malachite green,methylene blue,rhodamine B and methyl red were also tested,and the degradation rate of dyes could reach 87. 5% － 100. 0%.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2014年第6期1073-1079,共7页
Chinese Journal of Rare Metals
基金
国家自然科学基金项目(21273065)
湖北省重点实验室开放基金项目(KL2013M08)
湖北师范学院2012年校级大学生创新创业训练计划项目(2012017)资助
关键词
硅钨酸
甲基橙
SIO2
光催化
降解
H4SiW12O40
methyl orange
SiO2
photocatalytic
degradation
