Semi-artificial leaf transforms pollution and sunlight into useful chemicals.

Environment

Technological Innovation Website Editorial Team - 06/11/2025

It doesn't look like a natural leaf, but the biohybrid artificial leaf has proven to be more durable than previous ones. [Image: University of Cambridge]

Biohybrid leaf

An artificial leaf , a type of bioreactor powered by solar energy, mimics photosynthesis to sustainably produce valuable chemicals.

The big news is that this cell is a hybrid, combining organic semiconductors and enzymes to convert _CO2 and sunlight into formate with high efficiency. This composition gives it durability, but it is remarkable for being completely non-toxic and operating without fossil fuels, paving the way for a greener chemical industry.

Formate – which can be sodium or calcium – is a versatile compound with wide application in various industries, from cement adhesion promoter and fabric bleaching agent to food additive and chemical intermediate for the manufacture of other products.

This is the first time that organic semiconductors have been used as a light-harvesting component, forming a biohybrid system and paving the way for a new generation of eco-friendly artificial leaves.

"If we want to build a circular and sustainable economy, the chemical industry is a large and complex problem that we need to address," said Professor Erwin Reisner of the University of Cambridge in the United Kingdom. "We need to find ways to decarbonize this important sector, which produces so many essential products that we all need. It's a great opportunity if we can do it right."

The chemical industry is responsible for about 6% of the world's total carbon emissions.

The elimination of toxic compounds elevated the artificial leaf to the category of semi-artificial leaf. [Image: Celine Wing See Yeung et al. - 10.1016/j.joule.2025.102165]

Semi-artificial leaf

The innovation consists of a hybrid device that combines light-absorbing organic polymers and bacterial enzymes to transform sunlight, water, and carbon dioxide into formate.

The use of organic components – based on carbon and nitrogen – has allowed the team to take their cell to a new level, calling it a "semi-artificial leaf." The goal, as always, is to replicate photosynthesis, the natural process that plants use to transform sunlight into energy, dispensing with any other external energy input. Unlike previous projects, which relied on toxic or unstable light absorbers, this new biohybrid model uses non-toxic materials, works more efficiently, and remains stable without extra additives.

The researchers also overcame a long-standing challenge: Most artificial leaves require chemical additives, known as buffers, to keep the enzymes functioning, but these often degrade rapidly and limit cell stability. By incorporating an auxiliary enzyme, carbonic anhydrase, into a porous titania (titanium oxide) structure, the researchers enabled their semi-artificial leaf to function in a simple bicarbonate solution, similar to sparkling water, without harmful additives.

Architecture of semi-artificial bio-hybrid leaves. [Image: Celine Wing See Yeung et al. - 10.1016/j.joule.2025.102165]

Testing and improvements

In demonstration tests, the team used sunlight to convert carbon dioxide into formate and then applied it directly in a domino reaction to synthesize a valuable compound used in pharmaceuticals, achieving high yield and purity.

The researchers will now focus on optimizing the design to extend the device's lifespan and adapt it to produce different types of chemicals.

"We have demonstrated that it is possible to create solar- powered devices that are not only efficient and durable, but also free of toxic or unsustainable components," said Reisner. "This could be a fundamental platform for the production of green fuels and chemicals in the future – it's a real opportunity to conduct exciting and important chemical research."

Other news about:

More topics