New photoreactor tech provides clean green energy

Clean energy sources

Photoreactors bring together the photons in sunlight and various reactants to produce green chemicals and fuels. This sustainable process reduces carbon emissions and allows for the generation of clean energy sources.

“Solar cells are renowned for efficiently and economically converting sunlight to green electricity, circumventing the use of greenhouse-gas-emitting fossil fuels,” said Geoffrey Ozin, University Professor in U of T's department of chemistry in the Faculty of Arts & Science.

However, thus far, photoreactors have not seen vast applications as they have been burdened by several challenges, one of which is the high cost of construction materials and the devices’ reported inefficiency in converting photons to products. 

One area of improvement that can greatly increase the performance of photoreactors is by upgrading their photocatalysts, a material that absorbs light and converts a reactant into a product and is often responsible for energy loss.

Boosting catalyst performance

Incorporating sun-tracking- a device that adjusts the angle of the photoreactor with respect to the position of the sun for optimal harvesting of light- can result in a major boost of performance for the catalyst. To achieve this, the researchers “developed a panel-like photoreactor that contains hundreds of parallel microscale reaction channels.”

“A key feature of their design is that each reaction channel is connected to a V-shaped light-capture unit that guides the light into the channel where the photocatalyst is located. All surfaces are highly reflective to optimize the transport of photons from the external light source to the photocatalyst housed in the microchannels with minimal light losses,” noted the release.

This design eliminates the need for sun-tracking as the photoreactor is set up to capture photons at high efficiency under varying sun directions. The new model has been found to outperform existing state-of-art photoreactors.

“This technology has inspired the development of a new generation of solar-powered devices that instead make green fuels such as hydrogen from sunlight and water,” Ozin said.

“These solar products will substitute their fossil-based analogues – and will help to reduce our carbon footprint,” added KIT researcher Kant.

“This directly increases chances that we will be able to reach the dream of a sustainably living humanity. Hopefully, we will even make it in time – without drastic temperature overshoot and related disasters.”