Milling rice to separate the grain from the husks produces about 100 million tons of rice husk waste globally each year. Scientists searching for a scalable method to fabricate quantum dots have developed a way to recycle rice husks to create the first silicon quantum dot (QD) LED light. Their new method transforms agricultural waste into state-of-the-art light-emitting diodes in a low-cost, environmentally friendly way.
The research team from the Natural Science Center for Basic Research and Development, Hiroshima University, published their findings on January 28, 2022, in the American Chemical Society journal ACS Sustainable Chemistry & Engineering.
“Since typical QDs often involve toxic material, such as cadmium, lead, or other heavy metals, environmental concerns have been frequently deliberated when using nanomaterials. Our proposed process and fabrication method for QDs minimizes these concerns,” said Ken-ichi Saitow, lead study author and a professor of chemistry at Hiroshima University.
Since porous silicon (Si) was discovered in the 1950s, scientists have explored its uses in applications in lithium-ion batteries, luminescent materials, biomedical sensors, and drug delivery systems. Non-toxic and found abundantly in nature, Si has photoluminescence properties, stemming from its microscopic (quantum-sized) dot structures that serve as semiconductors.
Read more at Hiroshima University
Image: Scientists from Hiroshima University created world’s first LED light by using rice husks and chemically obtained products. (Credit: Reproduced from ACS Sustainable Chem. Eng. 2022, 10, 1765-1776. Copyright ACS)