Synthesis of luminescent carbon quantum dots by microplasma process

Carbon dots have recently emerged and gained much interest as a new class of carbon nanomaterials especially suited for biological applications owing to their characteristic advantages such as non-toxicity, bio-compatibility, and element abundance. In this study, a fast and effective method was developed for the synthesis of fluorescent carbon dots by microplasma technology, at atmospheric pressure, using isopropanol as the only reactant. Characterizations of the synthesized carbon dots including the investigation of their structure, morphology and optical properties were performed. The results show that the carbon dots produced have a narrow size distribution (average diameter of 1.78 nm) and are amorphous and graphitic in nature. The photo-luminescent study indicates that the carbon dots present an excitation-dependent emission property with the excitation wavelengths in a range of 310-410 nm. The high density electrons produced by microplasma induce the chemical reactions and accelerate the formation process of functional groups doped carbon dots.