Reductive photocatalysis and smart inks.
Reductive photocatalysis and smart inks.
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DOI：
10.1039/c4cs00279b
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发表时间：
2015-05
影响因子：
46.2
通讯作者：
A. Mills;N. Wells
中科院分区：
文献类型：
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作者：
A. Mills;N. Wells
半导体敏化的纳米TiO 2是一个成熟且不断发展的研究、创新和商业化领域;后者主要限于使用TiO 2作为半导体。大多数关于半导体光催化系统的工作都使用氧作为电子受体，并探索了广泛的电子供体;这些系统可以被认为是氧化物的例子，OP。OP支撑了大多数商业自清洁材料的最新例子，例如：玻璃，瓷砖，混凝土，油漆和织物。OP及其无数的应用，多年来在本杂志和其他地方都得到了广泛的评论。然而，二氧化钛和其他半导体敏化剂，促进还原性染料，RP，特别是染料的能力，是显着的，虽然不太为人所知，是越来越重要。在这样的系统中，电子的来源是一些容易氧化的物质，如甘油。RP工艺的一个最近的重要实例是关于光催化剂活性指示剂油墨。paiis，其通过油墨涂层中染料由于不可逆RP的颜色变化速率提供了测试下光催化膜活性的量度。相比之下，通过将半导体敏化剂结合在油墨中，而不是在油墨外部，可以创建基于RP的有效UV剂量计，其可以用作晒伤警告指示剂。在上述实施例中，染料被不可逆地还原，但是当油墨中的光催化剂用于可逆地光还原染料时，可以产生新型的比色氧敏感指示剂油墨，其在食品包装工业中具有商业潜力。最后，如果油墨中不存在染料，并且装载有半导体光催化剂的油墨膜涂覆在容易还原的基底上，例如金属氧化物膜，则它可以用于还原后者，例如，清理失去光泽的钢。以上是智能油墨的示例，即具有活性并提供动态信息（如UV剂量或O2水平）或有用功能（如去除失泽）的油墨，并且所有工作都通过RP过程进行，并在此进行审查。
Semiconductor-sensitised photocatalysis is a well-established and growing area of research, innovation and commercialisation; the latter being mostly limited to the use of TiO2 as the semiconductor. Most of the work on semiconductor photocatalytic systems uses oxygen as the electron acceptor and explores a wide range of electron donors; such systems can be considered to be examples of oxidative photocatalysis, OP. OP underpins most current examples of commercial self-cleaning materials, such as: glass, tiles, concrete, paint and fabrics. OP, and its myriad of applications, have been reviewed extensively over the years both in this journal and elsewhere. However, the ability of TiO2, and other semiconductor sensitisers, to promote reductive photocatalysis, RP, especially of dyes, is significant and, although less well-known, is of growing importance. In such systems, the source of the electrons is some easily oxidised species, such as glycerol. One recent, significant example of a RP process is with respect to photocatalyst activity indicator inks. paiis, which provide a measure of the activity of a photocatalytic film under test via the rate of change of colour of the dye in the ink coating due to irreversible RP. In contrast, by incorporating the semiconductor sensitiser in the ink, rather than outside it, it is possible to create an effective UV dosimeter, based on RP, which can be used as a sun-burn warning indicator. In the above examples the dye is reduced irreversibly, but when the photocatalyst in an ink is used to reversibly photoreduce a dye, a novel, colourimetric oxygen-sensitive indicator ink can be created, which has commercial potential in the food packaging industry. Finally, if no dye is present in the ink, and the semiconductor photocatalyst-loaded ink film coats an easily reduced substrate, such as a metal oxide film, then it can be used to reduce the latter and so, for example, clean up tarnished steel. The above are examples of smart inks, i.e. inks that are active and provide either dynamic information (such as UV dose or O2 level) or a useful function (such as tarnish removal), and all work via a RP process and are reviewed here.