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Asked by alamin to Suze on 13 Jun 2011.
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Suze Kundu answered on 13 Jun 2011:
Good morning!
The answer is, pretty much, yes. Obviously, the cleaner the better as all the water molecules are ready to rock. The technology that I’m using to do this is really flexible, and uses a material called titanium dioxide, and a whole load of lovely sunlight. You might not have heard of titanium dioxide, but you’ve definitely touched it. It’s all around you! It is a really white material that is used in suncream, wall paints, and even on self-cleaning glass – but more about that in a bit!
The water that you’re using to make fuel like hydrogen would ideally not be too murky, but if it was, you can chuck a load of powdered titanium dioxide in there. This stuff is able to break down any dirt or earthy matter into smaller molecules like carbon dioxide and release these, which makes the water less murky. The less dirty the water, the further light can reach into the depths of the water. This technology is actually used to create clean water in developing countries where people may not have access to fresh water nearby, and so have to rely on dirty water. Using powders like this, they can break down all the horrible dirt in the water.
This technology is also used to make windows that are able to clean themselves! This is important if, like me, you are scared of heights. Imagine being a window cleaner, cleaning the windows of the 80th floor of a building?! I don’t think I’d like that very much! The self-cleaning glass has a thin layer of this same magical material, titanium dioxide, all over it. When dirt lands on the layer of titanium dioxide, light activates the layer of titanium dioxide, and this breaks down the dirt molecules. When it rains, the water washes away any remaining broken down dirt.
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Comments
David commented on :
One small problem with splitting water into hydrogen and oxygen and then burning them for fuel is that it takes a lot of energy to generate split the water in the first place. You need lots of electricity from somewhere. One possibility is to use wind turbines, wave or tidal power to generate the electricity and then make hydrogen instead of sending it to the grid. You can move the hydrogen more easily than the electrons and it can go to lots more destinations.
If we make the hydrogen with coal, oil or gas as the source of electricity our “green car” will be less green than a gas powered one we burned the fuel to make electricity to make fuel! — a bad idea.
Suze commented on :
David, my research is concerned with the photocatalytic splitting of water. This means that we use a catalyst that is capable of harnessing the energy in the sun to then kick-start the water splitting reaction, so actually it’s an entirely clean process. There is enough energy falling to Earth from the Sun in one hour to meet the world’s energy demands for a whole year, so it’s just a case of catching it in a sensible way, and using it to split the water. Plants do it all the time, and have done so for 2.1 billion years in photosynthesis, where they use sunlight energy to drive the reaction to make sugars. They also use up carbon dioxide in the process, which is good for us! Anyway, this is why this procses is also known as artificual photosynthesis, because we’re trying to mimic plants.
I’d like to curtsey here, because I feel like a real scientist. If only there was an emoticon for it! 😛 Imagine me doing a little science dance instead… On second thoughts, maybe not!
James commented on :
One other way proposed is to use the high temperatures of nuclear fission plant (Gen IV). These “fast reactor systems” are intended to consume waste fuel to prevent (or most likely reduce the amount of) highly active waste. The high temperatures (over 900C) can be used to drive the reaction to split water into hydrogen and oxygen.
Why the debate about nuclear/solar? It depends on when we need the energy, and also how good we are at distributing it. The solar solution is a no-brainer – of course we should use it, but the technology isn’t here yet. The nuclear one is viewed as a “least-worst” solution by many people. The technology is here now, and it has a high energy density (I mean, a lot of energy can be produced in a small space) and it fits with the world’s networks of energy distribution. So – if we need a lot of “cleaner” energy in the next few decades, we should seriously look at this technology while continuing to work on alternatives.