Template-free fabrication of hierarchically flower-like tungsten trioxide assemblies with enhanced visible-light-driven photocatalytic activity.
Template-free fabrication of hierarchically flower-like tungsten trioxide assemblies with enhanced visible-light-driven photocatalytic activity.
复制标题
DOI：
10.1016/j.jhazmat.2009.03.082
复制
发表时间：
2009-09
影响因子：
13.6
通讯作者：
Jiaguo Yu;Lifang Qi
中科院分区：
文献类型：
--
作者：
Jiaguo Yu;Lifang Qi
以钨酸钠为原料，采用硝酸水热法制备了具有层次结构的花状三氧化钨组装体。采用X射线衍射、扫描电镜和N2吸附-脱附等手段对样品进行了表征。以罗丹明B水溶液为研究对象，考察了其在可见光照射下的光催化脱色性能。研究发现，三维三氧化钨组装体是由二维层状结构构成的，二维层状结构由大量不同尺寸的板条状纳米片相互连接而成。这种花状组装体由于其特定的分级孔作为光和反应物的传输路径而表现出分级多孔结构和比没有这种分级结构的样品更高的可见光光催化活性。经过5个循环的RhB光降解，催化剂没有表现出任何大的活性损失，证实了层次花状三氧化钨是稳定的，没有光腐蚀。该研究为环境友好型光催化材料的制备和设计以及光催化活性的提高提供了新的思路。
Hierarchically flower-like tungsten trioxide assemblies were fabricated on a large scale by a simple hydrothermal treatment of sodium tungstate in aqueous solution of nitric acid. The as-prepared samples were characterized by X-ray diffraction, scanning electron microscopy and N2adsorption–desorption measurements. The photocatalytic activity was evaluated by photocatalytic decolorization of rhodamine B aqueous solution under visible-light irradiation. It was found that the three-dimensional tungsten trioxide assemblies were constructed from two-dimensional layers, which were further composed of a large number of interconnected lathy nanoplates with different sizes. Such flower-like assemblies exhibited hierarchically porous structure and higher visible-light photocatalytic activity than the samples without such hierarchical structures due to their specific hierarchical pores that served as the transport paths for light and reactants. After five recycles for the photodegradation of RhB, the catalyst did not exhibit any great loss in activity, confirming hierarchically flower-like tungsten trioxide was stability and not photocorroded. This study may provide new insight into environmentally benign preparation and design of novel photocatalytic materials and enhancement of photocatalytic activity.