Zhang Gong, Sun Meng, Liu Yang, Lang Xiufeng, Liu Limin, Liu Huijuan, Qu Jiuhui, Li Jinghong
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China.
ACS Appl Mater Interfaces. 2015 Jan 14;7(1):511-8. doi: 10.1021/am506640k. Epub 2014 Dec 17.
In practical implementation of TiO2 semiconductors, utilization of their outstanding properties is mainly hindered by poor material quality and high operational costs. In this contribution, the electrospinning method was employed to fabricate N-doped mixed-crystalline TiO2 with exposed high-energy facets. The Ti oxide transformation process was thoroughly studied. During the mixed crystal structure formation process, the high-energy facets could be preserved due to the lower calcination temperature and the protective role of polyvinylpyrrolidone (PVP) in the electrospinning process. In addition, after calcination, the N doping, generated by the decomposition of PVP, extended the absorption spectrum of TiO2 to the visible region. These TiO2 fibers exhibited superior photooxidation of arsenite (III) to arsenate (V)in both the UV and visible light regions, mainly attributed to the exposure of high-energy facets, robust separation of photoexcited charge carriers between the anatase/rutile phases, and narrow band gap induced by the in situ N doping. Combining both robustness and scalability, the TiO2 fibers produced via this electrospinning process have the potential for a broad range of applications.
在二氧化钛半导体的实际应用中，其优异性能的发挥主要受到材料质量差和运行成本高的阻碍。在本研究中，采用静电纺丝法制备了具有暴露高能面的氮掺杂混合晶型二氧化钛。对氧化钛的转变过程进行了深入研究。在混合晶体结构形成过程中，由于较低的煅烧温度以及聚乙烯吡咯烷酮（PVP）在静电纺丝过程中的保护作用，高能面得以保留。此外，煅烧后，由PVP分解产生的氮掺杂将二氧化钛的吸收光谱扩展到了可见光区域。这些二氧化钛纤维在紫外光和可见光区域均表现出对亚砷酸盐（III）向砷酸盐（V）的优异光氧化性能，这主要归因于高能面的暴露、锐钛矿/金红石相之间光生电荷载流子的有效分离以及原位氮掺杂诱导的窄带隙。兼具稳健性和可扩展性，通过这种静电纺丝工艺制备的二氧化钛纤维具有广泛的应用潜力。
