Enhancing the thermoelectric performance of SnSe by the introduction of Au nano dots

•The 0D–2D (0 Dimension-2 Dimension) Au-SnSe nanocomposites with intensive interface barriers and beneficial phonon scattering were designed.•The interface barriers between Au NDs and SnSe nanoplates can effectively filter low energy holes and scatter mid and long wavelength phonons.•A higher ZT value of 0.6 for 1 mol% Au/SnSe nanocomposites at 773 K compared with that of 0.16 for pure SnSe nanoplates.