Monitoring Fuel Quality by Hydrocarbon Dispersible Multifunctional Fluorescent Carbon Dots

Introduction and identification of a foreign substance in fuels is a promising technology for monitoring adulteration and maintaining fuel quality. However, tagging substances with excellent fuel dispersion stability and detecting them by a simple procedure and device is an urgent need for monitoring fuel quality. Here, fluorescent carbon dots (CDs) are proposed as the tagging substance to identify the fuel product, monitor adulteration, and improve the lubricity of the fuel. We synthesized hydrophobic fluorescent CDs, where the presence of oleylamine on the surface of CDs provides excellent dispersion stability in fuels without any aggregation and changes in fluorescence properties. The distinct greenish yellow emission of CDs enables tagging of fuel and monitoring adulteration. Our study reveals that by adding CDs to fuels, detection and monitoring of adulteration can be done up to the level of 2% (v/v). In addition, CD dispersion gives the required lubricity to the fuel without addition of any traditional lubricity improvers. Furthermore, CDs-additized diesel and gasoline meet the required fuel specification, reduce harmful emission in exhaust gas, and improve fuel economy. All these results strongly indicate the potential application of CD dispersion as a multifunctional additive for tagging and monitoring adulteration and also as a lubricity improver for liquid fuels such as gasoline and diesel.