Green Science Alliance Made Quantum Dot from Municipal Solid Waste

KAWANISHI-CITY, Japan, Nov. 11, 2025 /PRNewswire/ -- Green Science Alliance is the GreenTech Startup company to develop cutting-edge materials and technologies for sustainable, carbon neutral society in energy and environmentally friendly field.

This time, Dr. Ryohei Mori at Green Science Alliance has successfully synthesized carbon quantum dots from municipal solid waste (MSW).

Quantum dots are extremely tiny man-made nanoparticles typically between 10 to 10000 atoms or molecules (1 to 9 nanometers) in diameter, which is smaller than 1/10000th the width of a human hair. They are sometimes called artificial atoms or molecules. At this size range, the energy levels of electrons are no longer continuous and are separated due to the physical phenomenon known as the quantum confinement effect. The electronic characteristics of quantum dots are determined by quantum confinement effect depending on their chemical composition, size, shape so that the wavelength of emission light depends on those characteristics. The unique properties of quantum dot can be utilized for solar cell, display, bio imaging, photonic crystal, laser, LED, artificial photosynthesis and quantum dot computer etc…

Environmental problems such as global warming, climate change, water pollution and deforestation etc… are serious issues caused by population growth. In particular, plastic pollution is becoming a devastating level that destroys ecosystems.

Municipal solid waste (MSW), commonly known as trash or garbage in the United States and rubbish in Britain, is a waste type consisting of everyday items that are discarded by the public, residence. Garbage also includes food waste, as in a garbage disposal. In Europe region, the semantic definition is mixed municipal waste. 

The composition of MSW is different depending upon each municipality which also changes with time and season. It may contain intractable wastes such as plastic film and non-recyclable packaging materials. They also include food wastes, mixed plastic waste and other miscellaneous solid wastes from residential, commercial and industrial sources. Meanwhile, particular industrial wastes, agricultural wastes, medical waste, radioactive waste or sewage sludge are not referred to as MSW in general. The amount of MSW is huge as population increased all over the world in the last century, and continues to increase as long as human lives. Nowadays, this enormous amount of MSW is either incinerated or landfilled which causing also the environmental problems. Thus, it will be a great achievement if one can utilize this MSW for some valuable and profitable products.

In this regard, Dr. Ryohei Mori at Green Science Alliance has successfully synthesized carbon quantum dots from MSW. In the past, he has been successfully made carbon quantum dots from food waste, paper waste, agricultural waste, organic waste and plastic waste. So that since MSW are composed of these wastes, it was possible to prepare carbon quantum dots from MSW. It should be noted that metal waste, ceramic waste cannot be raw materials for quantum dots even if they were contained in MSW.

Owing to its unique optical property and physicochemical characteristics, this quantum dots made from MSW can be applied to sensor, bio-imaging, catalyst, LED, energy and agricultural industry. Dr. Ryohei Mori will continue to research on application of MSW derived carbon quantum dots.

Contact:
Ryohei Mori
81-90-85282305
[email protected]

SOURCE Green Science Alliance Co., Ltd.