Ultimate Localization

Abstract

We report approaches to grow directly noble-metal-(NM)-decorated nanotubes by self-organized anodization. Key to obtain highly defined tubes is an optimized and controlled anodization of Ti-Pt (or other NM) alloys in fluoride containing solutions. In general, the morphology of porous TiO2 and of the tubular layers is affected strongly by the electrochemical growth parameters. NM-decorated titanium-dioxide is a highly functional material that has numerous interesting properties, for example, in solar energy conversion, catalysis of the decomposition of organic compounds (self-cleaning). Therefore this simple approach to produce this highly defined nanoscopic form of NM-TiO2 bears a high potential for technological exploitation. Over the years numerous efforts have been devoted to the shrinkage of the NM-particles to enhance the usage of the noble metal. Evidently the most extreme case of shrinkage is the use of an isolated single atoms of Pt. The use of single atoms as a co-catalyst in photocatalysis has in recent years attracted strong interest, not only because the single atom state represents a maximized surface to volume efficiency, but also because single atom reactivity allows for unprecedented reaction pathways.In the presentation we discuss the formation of Pt dispersed and anchored as single atoms on TiO2 nanotubes and the use of such tubes in highly effective photocatalysis.