A strategy to fabricate hierarchical microporous architecture of polyimide nanofibrous aerogels with efficient electromagnetic wave absorption and thermal insulation

•MXene/polyimide nanofibrous (PINF) aerogels with unique 3D hierarchical microporous architecture were fabricated.•The size of the hierarchical micropores was regulated by controlling the freezing conditions.•The presence of PINF greatly reduced the shrinkage of the aerogels and eluded the stress concentration of necks.•The aerogel exhibited outstanding electromagnetic wave absorption, thermal insulation and compression properties.