[en] Highlights: • Nitrogen and oxygen dual-doped (NODC-800) and oleophylic carbon aerogel (OCA) were prepared from poplar catkins via different technologies. • NODC-800 delivers excellent ORR electrochemical characteristics. • NODC-800 shows a high capacity for SCs (251 F g⁻¹ at 0.5 A g⁻¹) with nearly 100% retention rate after 1000 cycles. • OCA exhibits high absorption capacity of 81-171 times its own weight and excellent recyclability for different oils and organic solvents. Directly pyrolyzing biowastes has attracted intensive interest, probably because this economical and facile method provides an efficient and versatile platform for synthesizing functional carbons. This study describes the synthesis of different functional carbons from poplar catkins via different processes for multi-purpose applications. Nitrogen and oxygen dual-doped carbon (NODC-800) derived from catkins delivers superior electrochemical characteristics as oxygen reduction reaction (ORR) catalyst in alkaline fuel cell to that of commercial Pt/C in terms of catalytic activity, stability, resistance to methanol cross-over and CO poisoning. In addition, NODC-800 exhibits a high capacity (~251 F g⁻¹ at 0.5 A g⁻¹) with nearly 100% retention rate after 1000 cycles as supercapacitors electrodes. An oleophylic carbon aerogel derived from catkins is proven to be superoleophilic and porous enough to “wet” with oils and organic liquids and repel water completely to achieve oil/water separation. This work is a successful case to take full advantage of raw materials from nature via multiple technologies to achieve energy sustainable development and protect environmental from oils and organic solvents spill.