Carbon Dots Obtained from Pyrolysis Exhaust Gas for Sensitive Detection of Al³⁺ Ions

Abstract: Carbon dots (CDs) have attracted many researchers due to their excellent optical and electrical properties, diverse preparation methods, biocompatibility, etc. Many methods have been found to prepare CDs. In this paper, we studied the CDs obtained from exhaust gas entering water during the pyrolysis process. The fluorescent (FL) property and the morphology were measured and analyzed. The results show that these CDs dissolved in water have a relatively uniform diameter (3 nm average diameter) and emit bright purplish blue light centered at 425 nm as being excited by 360 nm UV light (The photoluminescence quantum yield is about 40.8%). When being used as a fluorescent probe for the detection of Al3+ ions, the FL intensity of these CDs shows a well-fitted exponential decay relationship with the concentration of Al3+ from 25 to 160 μM. The limit of detection is about 0.26 μM. Our study shows that the CDs obtained from exhaust gas entering water during the pyrolysis process have great potential to be used for Al3+ detection in the fields of environment and food safety.