Key Laboratory for Green Chemical Technology of the Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
ACS Appl Mater Interfaces. 2012 Mar;4(3):1650-5. doi: 10.1021/am201800j. Epub 2012 Feb 23.
Modulation of anatase toward highly active facets has been attracting much attention, but the mechanism and photoactivity are still ambiguous. Here we demonstrate the inherent mechanisms for facets nucleation and morphology evolution, and clarify some vital influences of facets and surface nature on the photoactivity. Simply tuning the Ti/F ratio in the synthetic mixture leads to single anatase crystal exposed with different facets like {001}, {010}, or {110}. And complex sphere structure exposed with {001} facets can be formed by secondary nucleation and growth. Prolonging the hydrothermal treatment time causes selective etching on {001} facets, whereas defluorination via thermal calcination produces many pores on the surface. The photodegradation of positively and negatively charged, and zwitterionic dyes indicates that the type of reactant, adsorption mode and surface area play significant roles in photocatalysis. This work makes a step toward understanding the formation of facet-mediated structure and designing highly active materials for environmental remediation, hydrogen production, and dye-sensitized solar cells.
锐钛矿的各向异性调变受到了广泛关注，但其形成机制和光催化活性仍不明确。在此，我们揭示了锐钛矿晶面成核和形貌演化的内在机制，并阐明了晶面和表面性质对光催化活性的一些重要影响。通过简单地调节合成混合物中的 Ti/F 比，可以得到不同晶面（如{001}、{010}或{110}）暴露的单一锐钛矿晶体。通过二次成核和生长，可以形成具有{001}晶面的复杂球体结构。延长水热反应时间会导致对{001}晶面的选择性刻蚀，而热煅烧脱氟则会在表面产生许多孔。对正电荷、负电荷和两性离子染料的光降解表明，反应物的类型、吸附模式和比表面积在光催化中起着重要作用。这项工作为理解晶面调控结构的形成以及设计用于环境修复、制氢和染料敏化太阳能电池的高效材料迈出了一步。
