Iranian Nanotechnology Society International Journal of Nanoscience and Nanotechnology 1735-7004 21 1 2025 03 23 Synthesis of Carbon Quantum Dots from Rice Straw Using Hydrothermal Method 31 39 733183 10.22034/ijnn.2025.2047781.2610 EN Nguyen Duy-Hoang Faculty of Mechanical Engineering, Industrial University of Ho Chi Minh City. Nguyen Van Son Advanced Technology Center - Le Quy Don Technical University Nguyen Khoa Trieu 12 Nguyen Van Bao, Go Vap. 0000-0003-2922-1512 Journal Article 2024 12 09 As a form of nanomaterial, Carbon Dots (CDs) attracted the attention of researchers, due to their diverse raw material sources, low cost, ease of preparation, and numerous applications in optics, biomedicine, and energy. Our research article focused on the production of Carbon Quantum Dots (CQDs) derived from rice straw using a bottom-up approach. As the next steps, UVA lamps, SEM, FTIR, UV-Vis, and PL were used as the main analysis techniques for CDs aqueous solution as well as dried CDs. Under UV light, the color of the CDs aqueous solution changed from yellow-brown to green, indicating that CDs had formed. Subsequent SEM images showed that the average particle size of the CDs was 20 nm. Besides, FTIR analysis illustrated functional groups such as O-H, C-H, C=O, N-H, C-OH, and C-O of CQDs. Furthermore, the UV-Vis spectrum indicated suitable optical properties for pollutant interaction, while the PL spectrum confirmed strong fluorescence with excitation-dependent behavior, making these CQDs excellent candidates for sensing applications. Thus, the analytical results showed that the synthesized CQDs had suitable properties for wastewater treatment applications. Hence, this study highlighted the feasibility of converting agricultural waste into functional nanomaterials, contributing to sustainable nanotechnology and environmental management. https://www.ijnnonline.net/article_733183_3315d6a8b03f325a6a380be0c6c1f36d.pdf