Herein, 3D-crumpled g-C3N4 (DCN) is synthesized through a direct top-down thermal etching strategy.  The thermal exfoliation of layered bulk g-C3N4 (BCN) in air atmosphere induces partial distortion of heptazine-based g-C3N4 nanosheet, which further self-assemble into 3D-crumpled network structure. 
THERM