Researchers from Southern California Viterbi School of Engineering are working to create a technology that can break apart carbon dioxide (CO2) and convert it into useful materials using energy from the sun. The team says this is the first computational study of its kind to look at how sun energy can be used in CO2 conversion.

The team's goal is to turn harmful CO2 into fuels and consumer products. Typically this process requires a lot of energy, the team set out to use solar energy as a green energy replacement.

Source: Southern California Viterbi School of EngineeringSource: Southern California Viterbi School of Engineering

Researchers demonstrated how UV light could be used to excite oligophenylene, an organic molecule. When exposed to UV, oligophenylene turns into a negatively charged anon and transfers electrons to the nearest molecule, like CO2. This makes CO2 reactive which can then be reduced and converted into plastics, drugs, furniture and more.

In traditional CO2 conversion, heat or electricity is used with a catalyst to speed up CO2 conversion into products. This is an energy-intensive process. But using sunlight to excite the catalyst molecule is an energy efficient and sustainable alternative. Another alternative is to use carbon-based organic catalysts for carrying out the light-assisted conversion.

The team used quantum chemistry solutions to understand how electrons move between catalyst and CO2 to identify viable catalysts. The team found that systematic modifications can be done to an oligophenylene catalyst. This adds groups of atoms that impart specific properties when bonded to molecules to speed up reactions.

The team has to address some challenges to this technology before it can be used commercially. The technology can harness radiation, but little of the radiation is in the visible region of the catalyst where light is shone in order to spark a reaction. The team is exploring catalyst design strategies that create high reaction rates and allow molecules to be excited by visible light. This method uses quantum chemistry and genetic algorithms.

A paper on this technology was published in the Journal of Physical Chemistry A.