摘要:SummaryMXene demonstrates high in-plane thermal transport merit as an emerging two-dimensional material, but its out-of-plane thermal transport did not fully explore. Here Ti3C2MXene nanosheets with either GO or CNF fillers were fabricated by using the vacuum-assisted filtration method. It was found that the addition of GO and CNF enlarged the interlayer spacing of the MXene layers, bringing about the opportunity for changeable spatial configuration of fillers and the thermal regulation function. If the GO nanosheets were interspersed parallel to the MXene layers, strong interference of increasing oxygen-containing functional group suppresses the out-of-plane thermal transport, resulting in the thermal conductivity decreasing from 0.5 W/(m·K) to 0.31 W/(m·K) for 20 wt% GO addition. Moreover, CNFs formed out-of-plane protruding on the surface of MXene nanosheets, resulting in the thermal conductivity increasing to 0.81 W/(m·K) for 20 wt% CNF addition. This discovery navigates how to prepare MXene composites with customized thermal properties.Graphical abstractDisplay OmittedHighlights•MXene nanosheet with nanometer lateral dimensions was produced by etching•Design and application of the flexible thermosensor-based third harmonic method•Thermal barrier effect of interfacial oxygen-containing functional groups•Thermal bridging effect of carbon nanofibers across multiple MXene nanosheetsNanomaterials; Thermal engineering; Thermal property