HighlightsrGO/MXene/TiO2/Fe2C heterointerface porous microspheres prepared via scalable method to boost polarization.Customization of hierarchical structure by precisely tuning 2D rGO/MXene intercalation.Optimal reflection loss of -67.4 dB and EAB = 5.47 GHz at low filler loading of 5 wt%. Simulations showed the benefits of 2D nanosheets intercalation on polarization loss.Supplementary InformationThe online version contains supplementary material available at 10.1007/s40820-023-01123-4.