# Photocatalytic Titanium Dioxide - is it for real? **URL:** \ **Category:** Factual Questions\ **Created:** [December 12, 2008, 4:51am UTC](https://boards.straightdope.com/t/photocatalytic-titanium-dioxide-is-it-for-real/476842 "2008-12-12T04:51:57Z")\ **Posts on this page:** 8\ **Page:** 2
**Author:** ![Raygun99](https://avatars.discourse-cdn.com/v4/letter/r/6f9a4e/32.png) [@Raygun99](https://boards.straightdope.com/u/Raygun99)\ **Post date:** [December 12, 2008, 11:12pm UTC](https://boards.straightdope.com/t/photocatalytic-titanium-dioxide-is-it-for-real/476842/21 "2008-12-12T23:12:53Z")
> [@Shamozzle](#): > > Isn’t titanium dioxide also used as a food ingredient? I recall seeing it listed in some sour gumballs I used to eat when I was a kid. It’s a common ingredient in coffee whitener. ---
**Author:** ![Necros](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/necros/32/11086_2.png) [@Necros](https://boards.straightdope.com/u/Necros)\ **Post date:** [December 12, 2008, 11:14pm UTC](https://boards.straightdope.com/t/photocatalytic-titanium-dioxide-is-it-for-real/476842/22 "2008-12-12T23:14:30Z")
This would be an example of what I am talking about: > **[SteriPEN Adventurer Water Purifier | REI Co-op](https://www.rei.com/product/750366/steripen-adventurer-water-purifier)** > > The SteriPEN Adventurer water purifier provides the same great water treatment as the original SteriPEN, but with a smaller size and even lower weight. It does not appear to be substantially different that what **beowulff** is talking about. I have no idea how it would work on surfaces, but it definitely works in water. Sorry, we appeared to have hijacked. :o ---
**Author:** ![Raygun99](https://avatars.discourse-cdn.com/v4/letter/r/6f9a4e/32.png) [@Raygun99](https://boards.straightdope.com/u/Raygun99)\ **Post date:** [December 12, 2008, 11:15pm UTC](https://boards.straightdope.com/t/photocatalytic-titanium-dioxide-is-it-for-real/476842/23 "2008-12-12T23:15:26Z")
> [@beowulff](#): > > No, I’m not sure. > Here’s what I’m skeptical about: [EarthTech Products — Solar Generators, Backup Power & Solar Lighting Since 2006](http://www.earthtechproducts.com/mini-uv-light-wand.html) > (Actually, I’m skeptical about any UV sanitizer wand, LED or not) I might question its necessity for a kitchen counter, but there’s no reason to wonder whether it would work. A number of water treatment plants are moving to UV treatment of water as an alternative to or addition to chlorine. ---
**Author:** ![Illuminatiprimus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/illuminatiprimus/32/11520_2.png) [@Illuminatiprimus](https://boards.straightdope.com/u/Illuminatiprimus)\ **Post date:** [December 12, 2008, 11:15pm UTC](https://boards.straightdope.com/t/photocatalytic-titanium-dioxide-is-it-for-real/476842/24 "2008-12-12T23:15:47Z")
> [@beowulff](#): > > No, I’m not sure. > Here’s what I’m skeptical about: [EarthTech Products — Solar Generators, Backup Power & Solar Lighting Since 2006](http://www.earthtechproducts.com/mini-uv-light-wand.html) > (Actually, I’m skeptical about any UV sanitizer wand, LED or not) I see - yes that product description is a tad confusing. I don’t know if it works, to be honest (although like you I’m pretty sceptical). ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [December 12, 2008, 11:38pm UTC](https://boards.straightdope.com/t/photocatalytic-titanium-dioxide-is-it-for-real/476842/25 "2008-12-12T23:38:01Z")
> [@Raygun99](#): > > I might question its necessity for a kitchen counter, but there’s no reason to wonder whether it would work. A number of water treatment plants are moving to UV treatment of water as an alternative to or addition to chlorine. Once again, I know that UV treatment CAN work (in an industrial setting). I just doubt that the units sold for home use actually do anything. You can read some information here: [http://www.iuva.org/iuva/faqs](http://www.iuva.org/iuva/faqs) You are welcome to calculate whether a small UV “sterilizer” actually puts out enough energy to work. ---
**Author:** ![Necros](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/necros/32/11086_2.png) [@Necros](https://boards.straightdope.com/u/Necros)\ **Post date:** [December 12, 2008, 11:53pm UTC](https://boards.straightdope.com/t/photocatalytic-titanium-dioxide-is-it-for-real/476842/26 "2008-12-12T23:53:04Z")
Here are some tests results, at least for water purification, for the pen I linked to: [http://www.steripen.com/testing.html](http://www.steripen.com/testing.html) Here is one such relevant test performed by the University of Maine regarding sterilization of a 32 ounce Nalgene bottle, and the resulting 99.9%+ kill percentage (PDF-O-Rama!): [http://www.steripen.com/PDF/Report\_Nalgene\_UMaine.pdf](http://www.steripen.com/PDF/Report_Nalgene_UMaine.pdf) ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [December 13, 2008, 1:02am UTC](https://boards.straightdope.com/t/photocatalytic-titanium-dioxide-is-it-for-real/476842/27 "2008-12-13T01:02:08Z")
> [@Necros](#): > > Here are some tests results, at least for water purification, for the pen I linked to: > [http://www.steripen.com/testing.html](http://www.steripen.com/testing.html) > > Here is one such relevant test performed by the University of Maine regarding sterilization of a 32 ounce Nalgene bottle, and the resulting 99.9%+ kill percentage (PDF-O-Rama!): > [http://www.steripen.com/PDF/Report\_Nalgene\_UMaine.pdf](http://www.steripen.com/PDF/Report_Nalgene_UMaine.pdf) Not bad. But, it’s a 254 nm light source. I wouldn’t expect UV LEDs to do as well. ---
**Author:** ![AllWalker](https://avatars.discourse-cdn.com/v4/letter/a/db5fbb/32.png) [@AllWalker](https://boards.straightdope.com/u/AllWalker)\ **Post date:** [December 13, 2008, 2:49am UTC](https://boards.straightdope.com/t/photocatalytic-titanium-dioxide-is-it-for-real/476842/28 "2008-12-13T02:49:36Z")
Back to the original topic, > [@Shark](#): > > But if they aren’t talking about nanoparticles, which I doubt they are, since they are talking about using it as an industrial coating, it’s just white paint. Most paints use TiO2 as the white pigment. A lot of paints use TiO2 nanoparticles now. The particles are in suspension. And since the thread title mentions _photocatalytic_ TiO2, I would assume nanoparticles. > [@](#): > > My take on this is that someone has found a way to play up the characteristics of TiO2 in a completely different environment, and claim that it conferrs magical properties to standard old white paint. In other words, snake oil. You do have to be skeptical. There is a lot of nano-snake oil out there. Still, there is a lot of cool stuff it can do. > [@](#): > > I do agree with **AllWalker** that nanoparticles can be cool in the right applications. I also think they might present a host of biological dangers due to the small size of the particles. It’s fascinating to me, that the properties of a solid can be changed so significantly by a reduction in size And that’s why I study it. 🙂 > [@mindfield](#): > > Is this the stuff I’d read and seen a video about a year or two ago that, when coating buildings and the like, can filter and neutralize CO2 emissions? One of the big promises of the immediate future is photovoltaic stuff. They have developed photovoltaic glass, but I don’t think it’s commercially available (or even viable) IIRC. One of the original ideas was paint that was photosynthetic in the traditional sense, taking light and CO2 to make electricity and oxygen. Last I heard, it didn’t work very well, though it did work. TiO2 would have been _one of_ the components, probably. [Previous page](https://boards.straightdope.com/t/photocatalytic-titanium-dioxide-is-it-for-real/476842.md?page=1)