▎ 摘　　要

The aqueous colloidal suspension of two-dimensional (2D) sp(2)carbon and carbide materials has promising thermal and electrical properties to be used as a coolant for heat transfer applications. However, the application of graphene nanoplatelets (GNPs) nanofluids is extensively limited by its insufficient dispersibility and stability in the base fluid of water. Therefore, surface modification and post-functionalization of GNPs should be considered as further treatments to enhance their nanofluid properties, which is not economical for large-scale production. In the current study, we presented the processing, thermophysical, electrical and optical properties of a new generation of carbon-based nanofluid containing highly exfoliated autofluorescent hydrophilic 2D titanium carbide MXene (Ti3C2Tx) nanosheets. For the first time, the microstructure and nanofluid properties of the water-based Ti(3)C(2)T(x)at two concentrations of 0.1 and 0.2 mass% have been further compared with covalently and non-covalently functionalized GNPs. Our results showed that the thermal/electrical conductivities of 0.1 and 0.2% MXene are remarkably higher (0.732 and 0.828 W m(1) K-1, 1213 and 2690 mu S cm(1), respectively) compared with non-covalent GNPs at same concentrations (0.679 and 0.702 W m(1) K-1, 723 and 1425 mu S cm(1), respectively) and competitive with COOH- and NH2-mediated GNPs samples. Additionally, the prominent stability and autofluorescence properties of MXene composite are other advantages supporting its nanofluid applications. The fluorescent MXene nanofluid at the different excitation/emission wavelengths (377-586 nm/447-647 nm) conferred a suitable optical contrast for visualization. Taken together, Ti(3)C(2)T(x)material might open up a robust gateway for the application of carbon-based nanofluids in advanced heat transfer systems.