Can you provide a reference? Did I link to the wrong paper? That's an important detail and it's not in the article. I'm not sure if you can get past the paywal

Can you provide a reference? Did I link to the wrong paper? That's an important detail and it's not in the article. I'm not sure if you can get past the paywall but: Section 2, paragraph 4, last sentence. "Carbon doped TiO2 from Kronos International was used." How much more effective? It varies from 2x-10x depending on the reaction conditions. Here is a paper that shows 2x-4x based on a relatively primitive doping technique. http://dx.doi.org/10.1016/j.apcatb.2007.09.046 http://dx.doi.org/10.1016/j.apcatb.2007.09.046 Italcementi Their TX Active may or may not be carbon doped, I couldn't find a straight answer on their website. Self-cleaning TiO2 is almost certainly doped (Ag or SiO2).