Enhancement of Visible-Light-Induced Photocurrent and Photocatalytic Activity of V and N Codoped TiO2 Nanotube Array Films

Highly ordered TiO2 nanotube arrays (TNAs) codoped with V and N were synthesized by electrochemical anodization in association with hydrothermal treatment. The samples were characterized by field emission scanning electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The photocurrent and photocatalytic activity of codoped TiO2 nanotube arrays were investigated under visible light irradiation. Moreover, the production of hydroxyl radicals on the surface of visible light-irradiated samples is detected by a photoluminescence technique using terephthalic acid (TA) as a probe molecule. It was found that the V+N co-doped TiO2 nanotube arrays showed remarkably enhanced photocurrent and photocatalytic activity than undoped sample due to the V and N codoping.Comment: 15 Pages, 6 figure

On the Context Vein of “Competence” and Its Generating Mechanism-Based on the Perspective of Situational Learning Theory

“Key competence” has become a hot vocabulary in educational reform in recent years. However, the essential connotation and specific generation mechanism of “competence” as its basic concept are still far from clear, and often controversial due to vague expressions. The rise of the concept of “key competence undoubtedly originated in the West, but in the context of Chinese, its meaning has changed significantly.By analyzing the origin and evolution of the concept of “competence” in the Western social context and the concept from “quality to“competence”in the Chinese social context, we can deeply understand the essence of the concept of “competence”and further clarify the specific generation mechanism of “competence” and its relationship with education. Analyzing the formation of competence based on situational learning theory emphasizes the occurrence of competence through participation in situational activities, the development of learning courses and identity consultation, which can provide some inspiration for the formation of competence

Facile synthesis and enhanced visible light photocatalytic activity of N and Zr co-doped TiO2 nanostructures from nanotubular titanic acid precursors

Zr/N co-doped TiO2 nanostructures were successfully synthesized using nanotubular titanic acid (NTA) as precursors by a facile wet chemical route and subsequent calcination. These Zr/N-doped TiO2 nanostructures made by NTA precursors show significantly enhanced visible light absorption and much higher photocatalytic performance than the Zr/N-doped P25 TiO2 nanoparticles. Impacts of Zr/N co-doping on the morphologies, optical properties, and photocatalytic activities of the NTA precursor-based TiO2 were thoroughly investigated. The origin of the enhanced visible light photocatalytic activity is discussed in detail.Comment: 8 pages, 7 figure