Design and synthesis of novel microporous materials have received tremendous attention in both CO2 storage and sequestration (CSS) and electrochemical energy storage (EES). We report molecular design and synthesis of conjugated microporous polycarbazole networks as new precursors for nitrogen enriched porous carbons in a low-cost pathway, using nitromethane as solvent, in which FeCl3 is fully soluble. As-prepared porous carbons exhibit a high nitrogen content (6.1 wt%), ultramicropore size (0.7-1 nm) and large surface area (1280 m2 g-1). As result, these novel nitrogen enriched carbons show highly efficient and reversible CO2 capture (can store 20.4 wt% at 1 bar and 11.1 wt% at 0.15 bar and at 273 K, whilst maintain 100% CO2 uptake capacity after 5 times use). Moreover, they can be applied as electrodes and enable high-performance EES devices with fast charge/discharge rate (8 seconds), high electrochemical capacity (558 F g-1), and good cycle ability (retain 95% capacity after 1000 cycles).