Citrus limetta Organic Waste Recycled Carbon Nanolights: Photoelectro Catalytic, Sensing, and Biomedical Applications

The present work reports green route-waste recycled carbon nanolights, i.e., carbon dots (GCDs), synthesized via a facile one-step pyrolysis method from Citrus limetta waste pulp. The size of these obtained pristine GCDs is ∼4–7 nm (HR-TEM), with high optical and structural quality as revealed by FT-IR and Raman spectroscopic analysis. They exhibit the highest quantum yield of 63.3% over other similar green synthesized GCDs, favorable for many applications. Further, we demonstrate the multifunctional aspects of these synthesized GCDs for photoelectrochemical water splitting, photocatalytic methylene blue degradation, Fe(III) ions sensing, bactericidal activity (against E. coli and S. aureus ), and bioimaging with excellent performance. The visible light active characteristic of GCDs is observed to achieve an efficient current density of ∼6 mA/cm 2 toward water splitting. This study demonstrates the waste to wealth potential of recycled waste derived GCDs in a wide range of application domains.