A new paint produces hydrogen gas from water vapor and sunlight, allowing building walls to act as a fuel source.
Hydrogen gas, generated by splitting water molecules into hydrogen and oxygen atoms, is one of the cleanest sources of energy, and could one day be used as an alternative to fossil fuels. One hurdle preventing hydrogen from becoming more widespread as a fuel source is the difficulty in generating the hydrogen in an eco-friendly manner. Currently, the energy for splitting the water molecules comes from electricity, much of which is generated through the use of fossil fuels. Now, researchers at Australia’s RMIT University have developed a solar paint that can absorb water vapor directly from the air and split it to generate hydrogen.
The paint combines titanium oxide particles with a newly-developed material, synthetic molybdenum-sulphide, to create a compound which absorbs moisture and acts as a semi-conductor to catalyse the splitting of water molecules into hydrogen and oxygen. At the same time, the paint absorbs sunlight, providing the energy to power the reaction. According to RMIT lead researcher Dr Torben Daeneke, “Titanium oxide is the white pigment that is already commonly used in wall paint, meaning that the simple addition of the new material can convert a brick wall into energy harvesting and fuel production real estate”.
When incorporated with commercially available membranes, to harvest and store the hydrogen gas, the paint will allow buildings and other structures to generate their own fuel. Unlike other hydrogen generation systems, there is no need for clean or purified water – the paint is effective in any area with some water vapor in the air, including desert areas near the ocean. The RMIT research team are so convinced of the importance of this new paint that they have released their finding into the public domain rather than apply for patent protection, to allow rapid development and improvement of the idea that could lead to faster commercial use. We have recently seen graphene paint that can conduct electricity and thermoelectric paint that produces electricity. Now, how might hydrogen-generating paint aid in the development of smart cities?