摘要
采用溶胶-凝胶法制备了一种核壳材料星状Au@TiO_(2),对其进行了水热晶化处理,并运用多种技术手段进行了表征,考察了星状Au@TiO_(2)对溶液中刃天青的光催化降解性能,探讨了降解机理。表征结果显示:晶化处理后,核心星状Au的形貌未发生改变,壳层TiO_(2)由无定形转化为锐钛矿型。实验结果表明:晶化处理后,星状Au@TiO_(2)的光催化性能增强,在初始刃天青质量浓度6 mg/L、催化剂加入量1 g/L、暗反应30 min、氙灯(500 W)照射60 min的条件下,星状Au@TiO_(2)经4次循环实验后,刃天青去除率由99.2%逐渐降低至91.0%,表现出良好的重复使用性能;经4次循环使用后,星状Au@TiO_(2)的结构未发生明显变化,稳定性良好。星状Au@TiO_(2)光催化降解刃天青的机理为:在可见光照射下,星状Au会产生局域表面等离子共振(LSPR)效应,当热电子能量积累超过Au的功函数时,热电子就会迅速迁移到星状Au外层的TiO_(2)表面并参与还原反应,产生·O_(2)^(-);同时,TiO_(2)表面光生空穴会氧化吸附的水分子,产生·OH;刃天青在·O_(2)^(-)和·OH的作用下,被氧化降解。
Stellate Au@TiO_(2)coated with core-shell structure was prepared using the sol-gel method and subjected to hydrothermal crystallization treatment.The morphology and structure of stellate Au@TiO_(2)were characterized using various techniques,and the photocatalytic degradation performance of stellate Au@TiO_(2)on resazurin from the solution was investigated.The degradation mechanism was discussed.Characterization results show that after the crystallization treatment,the morphology of the core stellate Au remains unchanged,while the TiO_(2)shell transforms from amorphous to anatase phase.The experimental results indicate that the photocatalytic performance of stellate Au@TiO_(2)is enhanced after the crystallization treatment.Under the conditions of an initial resazurin concentration of 6 mg/L,catalyst dosage of 1 g/L,dark reaction for 30 min,and xenon lamp(500 W)irradiation for 60 min,the removal efficiency of resazurin by stellate Au@TiO_(2)decreases gradually from 99.2%to 91.0%after four cycles of experiments,demonstrating good reusability.The structure of stellate Au@TiO_(2)remains unchanged after 4 cycles of use,indicating good stability.The mechanism of photocatalytic degradation of resazurin by stellate Au@TiO_(2)involves the generation of localized surface plasmon resonance(LSPR)effect by the stellate Au under visible light irradiation.When the accumulated hot electron energy exceeds the work function of Au,the hot electrons rapidly migrate to the TiO_(2)surface of the stellate Au and participate in the reduction reaction,producing·O_(2)^(-).Simultaneously,the photo-generated holes on the TiO_(2)surface oxidize the adsorbed H2O,generating·OH radicals.Resazurin is oxidatively degraded under the action of·O_(2)^(-)and·OH radicals.
作者
刘兵
刘智强
张黄
韩洪亮
胡长文
张英磊
LIU Bing;LIU Zhiqiang;ZHANG Huang;HAN Hongliang;HU Changwen;ZHANG Yinglei(Beijing Capital Beike Environmental Technology Research Institute Co.,Ltd.,Beijing 100044,China;China Railway Beijing Group Co.,Ltd.,Beijing 100860,China;College of Environment and Energy Engineering,Beijing University of Technology,Beijing 100124,China;Department of Chemistry,Capital Normal University,Beijing 100089,China;College of Chemistry and Chemical Engineering,Beijing Institute of Technology,Beijing 102401,China)
出处
《化工环保》
CAS
CSCD
北大核心
2024年第3期432-440,共9页
Environmental Protection of Chemical Industry
基金
国家自然科学基金项目(21173021,21231002,21276026,21471016,21271023)
国家重点基础研究发展计划项目(2014CB932103)
高等学校学科创新引智计划项目(B07012)。
关键词
光催化
二氧化钛
星状金
可见光
photocatalysis
TiO_(2)
stellate Au
visible light
