The synthesis of nanomaterials from renewable resources has emerged as an environmentally friendly alternative. This approach helps to reduce the use of chemical fertilizers in agricultural production, further reducing the potential harm to the ecosystem and effectively reducing the burden on the environment. In this work, we synthesized Rosa roxburghii derived carbon dots (CDs) using the microwave hydrothermal method (RR-CDs) and the electrolytic oxidation method (GRR-CDs), and the results showed that RR-CDs had a wider ultraviolet absorption range and emitted blue fluorescence. These properties make RR-CDs more effective as light-harvesting materials in plants, thus promoting photosynthesis. In the cultivation of lettuce, RR-CDs significantly enhanced both the biomass and the quality of the lettuce. In addition, compared to the control group, the chlorophyll content of lettuce treated with RR-CDs increased by 31.83%, the net photosynthetic rate increased by 60.76%, and the electron transport rate of photosystem II increased by 38.72%. Therefore, we found that the microwave hydrothermal method could bring better benefits, with a yield of up to 40.20% after just 2 h of reaction. RR-CDs promote photosynthesis by promoting light conversion and improving nutrient efficiency while also boasting the dual advantages of low cost and easy large-scale production, thus opening up avenues for sustainable agricultural production.
Keywords: Rosa roxburghii; carbon dots; nanofertilizers; photosynthesis; plant growth.