Scientists from the University of Illinois have just developed a new type of solar cell that converts carbon dioxide gas into fuel. This new photosynthetic cell uses energy from the sun to convert carbon dioxide into a gas that can then be converted into hydrocarbon fuels. The details are in a paper just published in Science.
The research team engineered a unique solar cell that acts more like an artificial leaf than a traditional photovoltaic cell. After capturing light, a co-catalyst system reduces atmospheric carbon dioxide into a mixture of carbon monoxide and hydrogen gas. This mixture, called Syngas, can be burned as fuel on its own or converted into other fuel types, including diesel.
The researchers first needed to solve the problem of finding a good catalyst. A catalyst is required for reducing carbon dioxide into fuel. Previous studies had tried precious metals, such as silver, but these reactions were expensive and inefficient. The team decided to look into a group of compounds called transition metal dichalcogenides. One in particular, nanoflake tungsten diselenide, was found to be much cheaper and more efficient than precious metal catalysts. The problem was that the catalyst couldn’t survive the harsh reduction reactions.
The research team then tried using a combination of water and ethyl-methyl-imidazolium tetraflouroborate to preserve the new catalyst. The ionic fluid was able to protect the active sites of the nanoflake tungsten diselenide catalyst, allowing it to survive the reaction.
This new solar cell technology can be easily scaled up for use in solar farms but is also inexpensive and simple enough for small-scale uses. The authors also believe that this type of technology could be utilized on Mars since the atmosphere contains a lot of carbon dioxide gas. The photosynthetic cells are also unique in that they can convert greenhouse gas pollution into renewable energy, potentially solving two problems at once.
Mohammad Asadi et al. Nanostructured transition metal dichalcogenide electrocatalysts for CO2 reduction in ionic liquid. Science (2016).