Everyday material from the kitchen could overhaul solar energy after breakthrough

Chromium best known for its use in motorcycles and kitchens

Solar panels and screens could become vastly more easy to make after a major breakthrough, according to the scientists who found it.

The new discovery swaps an everyday material for one almost as rare as gold, the researchers say, and so could drastically cut the price of manufacturing the technology that relies on it.

The breakthrough came after scientists discovered that chromium compounds can replace the metals osmium and ruthenium, which are used to harvest energy from the Sun and to create displays for uses such as mobile phones.

Chromium is a relatively common material, best known for its use in chromium steel in the kitchen, or for the shiny look of motorcycles. It is also relatively easy to find: chromium is 20,000 times more prevalent in the Earth’s crust than osmium, and much cheaper to make.

Scientists hope that it can be used for a variety of purposes, including a kind of artificial photosynthesis that will produce solar fuels. Plants are able to use that process to convert energy from sunlights into energy-rich glucose – and the scientists behind the new study say that it could help us do the same.

To test out the chromium atoms as a way of converting energy, they built them into a molecular framework alongside carbon, nitrogen, and hydrogen. That packaged the chromium atoms into a stiff framework, letting them avoid energy loss when the molecules vibrated, and to ensure they worked as best as possible.

The scientists warn that this framework is more complex than the one required to use the more expensive noble metals. But they say that could be overcome with future research.

Other alternatives to noble metals have so far focused more on iron and copper, and researchers have had some success with those elements. The researchers say their work on chromium shows better performance than those previous attempts – but that there is no guarantee which of those metals will win the race.

Scientists now hope to make the materials on a larger scale so that they can be used in other potential applications. That could allow the molecules to glow in a wide array of colours, and also to make them perform better as possible ways of mimicking photosynthesis, and allowing us to convert sunlight into chemical energy.

The findings are described in a new paper, ‘Photoredox-active Cr(0) luminophores featuring photophysical properties competitive with Ru(II) and Os(II) complexes’, published in Nature Chemistry.