摘要
为了研究原子级别的贵金属Ag负载TiO2介孔纳米带对光催化氧化活性影响,采用温和的还原条件,将Ag^+沉积在TiO2介孔纳米带上,获得原子级分散的Ag簇,再经适当的热处理建立强金属-基体相互作用(metal-substrate interaction,MSI),制备出Ag clusters-TiO2纳米带(nanobelts,NBs).借助STEM、UV-vis、PL和EXAFS等多种表征手段,对材料的微观形貌结构、光吸收性能、载流子分离和气态污染物光催化氧化性能进行深入分析.结果表明,与负载Ag纳米颗粒的Ag NPs-TiO2 NBs相比较,Ag clusters-TiO2 NBs展现出优异的光催化氧化活性.在极低的Ag负载量(w=0.1%)下,Ag clusters-TiO2 NBs的可见光催化NO降解效率达到56.04%,甲醛降解效率为95.20%,分别是Ag NPs-TiO2 NBs的2.29倍和1.22倍.TiO2介孔纳米带提供了丰富的锚定位置使Ag得以原子级分散,增加了催化活性位点数量.Ag簇与TiO2之间的强相互作用以及Ag簇可逆的氧化态,均有助于分子氧的活化和光生载流子的有效利用.
To investigate the effect of atomically dispersed Ag-loaded TiO2 mesoporous nanobelts on photocatalytic oxidation activity,Ag clusters-TiO2 nanobelts(NBs)were prepared through a facile process,including a mild reduction of Ag+on the surface of TiO2 mesoporous nanobelts and a moderate heat treatment,which formed atomically dispersed Ag with strong metal-substrate interaction(MSI).The microstructure,light absorption,carrier separation and photocatalytic oxidation performance of prepared materials were investigated by XRD,STEM,UV-vis,PL,EXAFS and other techniques.Results show that Ag clusters-TiO2 NBs exhibit an excellent photocatalytic oxidation activity for gaseous pollutants under visible light irradiation.At low Ag loading(w=0.1%),the photodegradation efficiency of NO reaches 56.04%,and the removal rate of formaldehyde is 95.20%,which are 2.29 times and 1.22 times higher than that of Ag NPs-TiO2 NBs counterpart,respectively.TiO2 mesoporous nanobelts provide abundant anchor sites allowing Ag to disperse atomically,resulting in increased number of catalytically active sites.The strong interaction between Ag cluster and TiO2 and the reversible oxidation state of Ag cluster favor the activation of oxygen and the effective utilization of photogenerated carriers.
作者
李永利
张志鹏
王金淑
周文元
徐相峰
罗维
张楠
LI Yongli;ZHANG Zhipeng;WANG Jinshu;ZHOU Wenyuan;XU Xiangfeng;LUO Wei;ZHANG Nan(College of Materials Science and Engineering,Beijing University of Technology,Beijing 100124,China;Key Laboratory of Advanced Functional Materials,Ministry of Education,Beijing 100124,China)
出处
《北京工业大学学报》
CAS
CSCD
北大核心
2020年第10期1139-1148,共10页
Journal of Beijing University of Technology
基金
北京市自然科学基金资助项目(2151001)
国家杰出青年科学基金资助项目(51225402)
北京市教育委员会科技计划资助项目(KM201610005026)。
