Look around you. How much plastic can you see from where you are right now? How much of it will end up in the recycling bin? How much of it will end up in landfill? What if, once it was no longer needed, all that plastic could be turned into something truly useful?

Professor Erwin Reisner is an expert in renewable energy and sustainable chemistry, in particular the sunlight-powered production of sustainable fuels and chemicals. At his laboratory in the Yusuf Hamied Department of Chemistry, Reisner and his team are developing prototype devices that convert waste, water and air into practical fuels and chemicals.

These devices take their inspiration from photosynthesis: the process by which plants convert sunlight into food. The devices don’t use any outside power: no cables, no batteries – all they need is the power of the sun.

Reisner’s team has developed devices that can convert contaminated water or seawater into clean hydrogen fuel and drinking water, floating ‘artificial leaves’ that could one day be used to generate clean fuel at sea, and devices that can convert CO₂ and plastic waste into sustainable fuels.

“We’re not just interested in decarbonisation, but de-fossilisation – we need to completely eliminate fossil fuels to create a truly circular economy,” said Reisner.

Reisner was recently awarded a prestigious Royal Academy of Engineering Chair in Emerging Technologies, which will help him and his team to focus on their ten-year mission to develop their prototypes to the point where they are ready for market. If scaled up, these solar-powered devices could help address the intertwined crises of plastic waste and carbon emissions.

To support his mission, Reisner hopes to establish the Cambridge Circular Chemistry Centre in the Department of Chemistry, which will accelerate the multi-disciplinary research and engineering that is needed to support the transition of solar chemical technologies to enable a circular chemical industry in a net zero future. He hopes to raise £3 to £5 million in funding from donations to launch the centre in the next two years, and a total of £20 million over the next 10 years to bring his plan to fruition.

“There is not yet enough public awareness of the critical role that chemistry must play in our ambition to meet net zero targets,” said Reisner. “We are all familiar with renewable electricity, wind energy and electric vehicles, but the most difficult part is still to come: making renewable fuels and transitioning the chemical industry sector.”

A sustainable chemical sector would affect everything we do and use, from the plastic bottles we drink from, to the keyboards we type on, to the chairs we sit on. All these things need to be made renewable, or at least in a circular way, but first, the catalysts to drive the required sustainable processes need to be developed.

“That’s exciting for me as a chemist, because we’ve got so many opportunities to solve complex problems,” said Reisner. “Exciting new technologies are being developed in chemical laboratories right now. Chemistry can solve the most important problems our society faces today, and there are huge opportunities for entrepreneurs to develop sustainable chemical technologies and companies.”

The technologies Reisner and his team are developing are fundamentally new. They’re not simply improving existing technologies; they’re working on totally new concepts and creating things that haven’t been thought of before.

“What I'm most enthusiastic about from a practical point of view is the conversion of waste such as plastic, biomass and the greenhouse gas CO₂ into green fuels and chemicals,” said Reisner. “Of course, there are known ways to recycle, but it’s quite different from our technology. We could have an entirely solar-powered recycling centre that could recycle things that can’t currently be recycled using conventional methods.”

Reisner says that another big advantage of the solar-powered technologies he’s developing is that small-scale applications are highly feasible, which could be particularly useful in remote environments or developing countries.

“For example, oil is currently refined in huge, centralised facilities, but with our technology, people could generate their own energy remotely,” he said. “Households – particularly in developing countries where cooking with dirty fuels such as kerosene causes up to four million deaths per year – could generate their own clean hydrogen for cooking and heating. And in the agricultural sector, farmers could use solar-powered solutions to make their own fertiliser in a green way.”

Reisner sees limitless possibilities for his lab’s work. He believes that his team has established a holistic framework to develop the solar chemical technologies of the future, but what is really needed to make this a reality is stable and unconstrained long-term support from donors, together with a genuine commitment from industry and the government to a future without fossil fuels.

“We’re working on ways we can redesign and fundamentally rebuild our chemical industry, and our entire economy, in a sustainable way to enable a liveable future on our planet without fossil fuels,” said Reisner. “There’s no bigger challenge right now, but I believe we can get there.”