These LED Lights Are Made from Rice Husks

Quantum dot LED lights often require toxic, heavy metals like lead or cadmium, but recent research out of Japan suggests there may be a more sustainable and environmentally friendly way to manufacture them. The research team from the Natural Science Center for Basic Research and Development at Hiroshima University has been exploring new methods for making LEDs and found that rice husks are rich in silica, which has photoluminescence properties good for use in lighting. And since the process of milling rice to separate the grain from the husks produces about 100 million tons of rice husk waste globally each year, there’s plenty of it available. There are multiple steps to getting silica out of the rice husks. The team first milled the rice husks and extracted silica powders by burning off organic compounds. Then they heated the silica powder in an electric furnace to obtain silica powders via a reduction reaction. Then they purified the silica powder that was further reduced to 3 nanometer in size by chemical etching. Finally, they chemically functionalized the surface for high chemical stability and high dispersivity in solvent.