Hai Guojuan, Huang Jianfeng, Cao Liyun, Jie Yanni, Li Jiayin, Wang Xing
School of Materials Science & Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China.
Nanomaterials (Basel). 2016 Dec 14;6(12):240. doi: 10.3390/nano6120240.
Hierarchical tungsten oxide assemblies such as spindle-like structures, flowers with sharp petals, nanowires and regular hexagonal structures are successfully synthesized via a solvothermal reduction method by simply adjusting the reaction conditions. On the basis of the experimental results, it is determined that the reaction time significantly influences the phase transition, microstructure and photocatalytic activity of the prepared samples. The possible mechanisms for the morphology evolution process have been systematically proposed. Moreover, the as-prepared products exhibit significant morphology-dependent photocatalytic activity. The flower-like WO prepared at 6 h possesses a large specific surface area (150.1 m²∙g), improved separation efficiency of electron-hole pairs and decreased electron-transfer resistance according to the photoelectrochemical measurements. As a result, the flower-like WO prepared at 6 h exhibits the highest photocatalytic activity for the degradation of Methyl orange aqueous solution. The radical trap experiments showed that the degradation of MO was driven mainly by the participation of h⁺ and •O₂ radicals.
通过简单地调整反应条件，采用溶剂热还原法成功合成了分级氧化钨组装体，如纺锤状结构、带有尖锐花瓣的花状结构、纳米线和规则的六边形结构。基于实验结果，确定反应时间对所制备样品的相变、微观结构和光催化活性有显著影响。系统地提出了形貌演变过程的可能机制。此外，所制备的产物表现出显著的形貌依赖性光催化活性。根据光电化学测量，在6小时制备的花状WO具有大的比表面积（150.1 m²∙g）、提高的电子-空穴对分离效率和降低的电子转移电阻。因此，在6小时制备的花状WO对甲基橙水溶液的降解表现出最高的光催化活性。自由基捕获实验表明，MO的降解主要由h⁺和•O₂自由基的参与驱动。
