Coming dean

摘要

Specialists in thin-film chemistry are honing the technology for better self-cleaning surfaces and oth-er applications.A team from University College London (UCL) has devised a method in order to find the best combination of dopants for certain desired properties.Thin films of titanium dioxide (TiO_2) are already used in self-cleaning windows. As wide-band semiconductors, these films are excited by sunlight, leading to charge separation and the generation of radicals, which kill bacteria and degrade organic molecules. Furthermore, this photocat-alytic process also makes the glass hydroxylated and therefore super-hydrophilic-so water spreads evenly on the surfaces to wash away dirt.