Some of the most expensive and difficult-to-source materials found in smartphone screens and solar cells may soon be phased out for a cheaper, exponentially more common substitute. This substitute isn’t a new find—it is actually most often associated with kitchen appliances and motorcycles.
Whenever a company’s fridge, tool, or other item is advertised as “stainless steel,” they have chromium to thank. Manufacturers have long valued the hard, shiny metal’s anticorrosive properties, and adding it into steel allows it to resist degradation and tarnishing. Meanwhile, electroplating a thin layer of chromium atop another metal produces what is commonly known as chrome plating—think Harley-Davidson motorcycles, or hot-rod cars. Chrome can reflect as much as 70 percent of visible spectrum light, as well as 90 percent of infrared radiation.
According to findings recently published in Nature Chemistry from a team at Switzerland’s University of Basel, carefully substituting chromium into catalysts and luminescent materials also works nearly as well as their traditional noble metal components, osmium and ruthenium, but for a fraction of the cost. What’s more, chromium is 20,000 times more common within the Earth’s crust than either noble meta—both of which are nearly as rare as gold or platinum.
[Related: Solar panels are getting more efficient, thanks to perovskite.]
As The Independent explained on August 14, the team first inserted chromium atoms next to hydrogen, carbon, and nitrogen within a stiff molecular framework. In this array, chromium was much more reactive than its noble metal counterpoints, while simultaneously keeping energy loss at a minimum during molecular vibrations.
When irradiated by a red lamp, the chromium compound also stored energy within its molecules for potential later use, much like a plant’s photosynthesis. “Because of this, there’s also the potential to use our new materials in artificial photosynthesis to produce solar fuels,” Oliver Wenger, research lead and a professor within the University of Basel’s department of chemistry, said in a recent statement.
Although previous research into noble metal alternatives investigated the potential of using iron and copper to some success, chromium initially appears to perform much better than either option. That said, Wenger concedes that “it seems unclear which metal will ultimately win the race when it comes to future applications in luminescent materials and artificial photosynthesis.”
Going forward, Wenger’s team hopes to scale their research to be tested in other applications, which could allow molecules to glow across the color spectrum to include red, green, and blue hues. Additionally, optimizing its catalytic attributes could further push it towards a viable alternative material to use in solar power arrays.
