Green approach synthesis of carbon quantum dots from agave bagasse and their use to boost seed germination and plant growth

This work releases research progress carried out on carbon quantum dots (CQDs) obtained from agave bagasse with the aim of applying their UV-blue luminescence properties, as a novel way to improve plant growth and protecting them from the solar UV harmful effects. This results in an increasing exposure to blue irradiation, which is avidly absorbed by chlorophyll, thus strengthening plant photosynthesis. The developed green route process is based on the pyrolysis of agave bagasse fibers, a cheap carbon precursor from the tequila’s industries waste. After drying and grinding the fibers, three samples of powdered agave were burned in the open air at 500 °C for 0.5 h, 1.0 h and 2.0 h seeking to synthesize CQDs samples of different sizes. The optical absorption and photoluminescence (PL) response of all samples were similar, that is, a strong UV absorption and a PL peak on the blue region. Furthermore, their highest PL quantum yield of 15.74% was obtained for the 2 h pyrolysis time sample that was applied on acrylic sheets in a greenhouse experiment. The groups of plants with this cover had faster germination rates and better plant growth rates than two control groups without CQDs.