From coconut petiole residues to fluorescent carbon dots via a green hydrothermal method for Fe3+ detection

• Published in: Cellulose (London) 2021-02, Vol.28 (3), p.1647-1661
• Main Authors: Gao, Shiyu, Wang, Xi, Xu, Nan, Lian, Hailan, Xu, Li, Zhang, Wenqing, Xu, Changyan
• Format: Article
• Language: English
• Subjects: Benzene; Bioorganic Chemistry; Carbon; Carbon dots; Ceramics; Chemistry; Chemistry and Materials Science; Composites; Fluorescence; Functional groups; Glass; Natural Materials; Organic Chemistry; Original Research; Outdoor air quality; Physical Chemistry; Polymer Sciences; Public health; Quality assessment; Raw materials; Residues; Ring structures; Selectivity; Sustainable Development; Ultraviolet radiation; Water pollution; Water quality; Water sampling
• ISSN: 0969-0239; 1572-882X
• DOI: 10.1007/s10570-020-03637-1

Incinerating agricultural residues to recover energy is a popular method for reducing solid waste pollution and resource waste caused by the huge amount of coconut petiole residues. However, this process not only has the risk of secondary air pollution, but also the added value of comprehensive utilization is not high. In this paper, coconut petiole residues were used as eco-friendly and economical raw materials to synthesize carbon dots (CCDs) via a simple hydrothermal method. Furthermore, given the important reference significance of Fe 3+ concentration in assessing the quality of water environment and human body health, the obtained CCDs were utilized for Fe 3+ detection. The prepared spherical CCDs with an average diameter of 1.39 nm and a carbon skeleton dominated by benzene ring structure have surface functional groups that endow them with good water solubility. The CCDs with a quantum yield of 1.39% emit strong blue fluorescence under ultraviolet radiation (365 nm), and show favorable fluorescence stability with excitation-dependent and concentration-dependent emission behaviors. Based on the synergetic effect of static and dynamic quenching, the CCDs exhibit favorable selectivity and detection sensitivity toward Fe 3+ with a linear range of 0.005 to 0.2 mM and a detection limit of 2.3 μM, and also show the feasibility of Fe 3+ detection in real water samples. This work is in favor of the high value-added conversion of coconut petiole residues. In addition, the development and use of bio-based CCDs as fluorescence sensors may be beneficial to monitoring and protecting public health and the environment. Graphic abstract