Facile and low-energy-consumption synthesis of dual-functional carbon dots from Cornus walteri leaves for detection of p-nitrophenol and photocatalytic degradation of dyes

An attempt for sustainable preparation of green-emitting carbon dots (G-CDs) is made from Cornus walteri leaves through low-temperature hydrothermal treatment. This synthetic approach is low cost, environmental friendliness, and renewability. Significantly, the as-fabricated G-CDs show outstanding fluorescence properties, and the quantum yield (QY) is as high as 18.3%. The G-CDs exhibit a rapid, selective and sensitive response to p-NP, which makes them promising for p-NP sensing. The linearity is in the range of 0–50 μM, and the LOD is as low as 0.0175 μM. Following careful investigations, static quenching was used to explain the fluorescence mechanism. In addition, G-CDs can be regarded as a fast and efficient photocatalyst for the degradation of organic dyes malachite green (MG), methyl orange (MO), and methyl violet (MV). Under the irradiation conditions of 40 min, 50 min, and 90 min, the degradation rates can reach ~98.0%, ~97.1%,and ~63.6%, respectively.