Coating from graphite: solar-powered hydrogen fuel a step closer
A more sustainable way of making hydrogen fuel from water using sunlight is a step closer according to new research from the University of Bath’s Centre for Sustainable Chemical Technologies.
With the pressure on global leaders to reduce carbon emissions significantly to solve a climate change emergency, there is an urgent need to develop cleaner energy alternatives to burning fossil fuels. Hydrogen is a zero carbon emission fuel alternative that can be used to power cars, producing only water as a waste product.
It can be made by splitting water into hydrogen and oxygen, however the process requires large amounts of electricity. Most electricity is made by burning methane so researchers at the University of Bath are developing new solar cells that use light energy directly to split water.
Perovskite solar cell are cheaper to make
Most solar cells currently on the market are made of silicon, however they are expensive to make and require a lot of very pure silicon to manufacture. They are also quite thick and heavy, which limits their applications. Perovskite solar cells, using materials with the same 3D structure as calcium titanium oxide, are cheaper to make, thinner and can be easily printed onto surfaces. They also work in low light conditions and can produce a higher voltage than silicon cells, meaning they could be used indoors to power devices without the need to plug into the mains.
The downside is they are unstable in water which presents a huge obstacle in their development and also limits their use for the direct generation of clean hydrogen fuels. The team of scientists and chemical engineers, from the University of Bath’s Centre for Sustainable Chemical Technologies, has solved this problem by using a waterproof coating from graphite.
Coated cells worked underwater for 30 hours
They tested the waterproofing by submerging the coated perovskite cells in water and using the harvested solar energy to split water into hydrogen and oxygen. The coated cells worked underwater for 30 hours – ten hours longer than the previous record. After this period, the glue sandwiching the coat to the cells failed; the scientists anticipate that using a stronger glue could stabilise the cells for even longer.
The complete study can be found here.
