Every year, rice cultivation (especially rice milling) generates about 100 million tons of waste. The inedible protective covering of actual rice grains, known as hulls or husks, can be used in a variety of ways, such as making cement, but there is much more demand for rice than for husks. rice.
Japanese scientists are tackling this problem by tackling another problem: the use of toxic heavy metals in the manufacture of LCD screens. You see, the production of modern liquid crystal displays using quantum dots requires the presence of materials like cadmium, lead and other heavy metals.
These can be toxic to humans and other life forms, so in a bit of genius, much like making synapses from honey, researchers at the Natural Science Center for Basic Research and Development from the University of Hiroshima have brought together two and two to find a way to make quantum dots from recycled rice husks.
A collection of figures demonstrating the source, the intermediate steps and the final result. Source: Hiroshima University
The shells are rich in silicon and silicon oxide. After processing them using a multi-step heat treatment, the researchers used chemical etching and an organic solvent to distill the shells into a liquid saturated with 3 nm crystalline particles of silicate, or…dots quantum.