Green synthesis of carbon quantum dots from organic waste on environmental protection: A bibliometric analysis

The rapid expansion of industrial and agricultural activities has led to the excessive generation of organic waste, intensifying environmental pollution and resource depletion. This study presents the first comprehensive bibliometric analysis of green-synthesised CQDs derived from organic waste and their environmental applications. A total of 323 peer-reviewed articles and reviews published between 2012 and 2024 were retrieved from the Web of Science database and analysed using VOSviewer. The dataset was compiled from 10,515 citations, with an average of 32.55 citations per document and an H-index of 53, indicating a steep rise and growing influence of the research area. The network and co-occurrence analyses revealed four prevailing thematic clusters, namely eco-friendly waste valorisation, wastewater treatment and pollutant sensing, green synthesis of graphene and carbon quantum dots, and CQD-based energy storage systems. Most highly cited studies have used food, agricultural, and sewage wastes as sustainable carbon precursors and have shown that these materials can be used for heavy-metal detection, photocatalytic destruction of organic pollutants, bioimaging, and supercapacitors. The keyword analysis revealed a focus on photoluminescence, nanoparticles, selective detection, and low-cost synthesis methods. The findings highlight the importance of waste-derived CQDs for circular-economy and clean-water applications, while identifying research gaps in scalability, stability, and waste-stream diversity.