Sunlight-Induced Photocatalytic Degradation of Pollutant Dye by Highly Fluorescent Red-Emitting Mg-N-Embedded Carbon Dots

A straightforward and simpler use of an age-old technique was utilized for the fabrication of “red-emitting magnesium-nitrogen-embedded carbon dots” (r-Mg-N-CD) from the leaves extract of Bougainvillea plant as a natural source of carbon. This technique is similar to the solvent-based technique, which is used for the extraction of fragrances and essential oils from flowers and leaves. The as-derived leaves extract was further carbonized using a simple domestic microwave to obtain the small-sized red-emitting carbonaceous material as r-Mg-N-CD. The r-Mg-N-CD showed excitation-independent emissions at ∼678 nm with excellent photostability and a high quantum yield value (∼40%). Moreover, the important perspective of the present finding is to use this r-Mg-N-CD as a potential photocatalyst material for the degradation of pollutant dye (methylene blue) under the presence of sunlight. To infer the significant influence of using natural sunlight in the process of dye degradation, a comparative analysis was performed, demonstrating the higher rate of photodegradation (∼6 times faster) under the influence of sunlight compared to the artificial visible-light from a 100 W tungsten bulb.