Wood-inspired N, P-codoped hierarchically porous carbon aerogels decorated with Co3O4 nanoparticles for fast and sustainable emerging organic contaminants degradation

The design and synthesis of cost-effective, highly efficient, and easily recyclable heterogeneous catalysts via a green way is very attractive for emerging organic contaminants (EOCs) elimination but still challenging. Herein, by mimicking the hierarchical pore structure of wood, a Co₃O₄ nanoparticles decorated wood-derived N, P-codoped carbon aerogel (Co-NP/CA) was prepared as efficient peroxymonosulfate (PMS) activator for the elimination of EOCs in water. The wood-inspired N, P-codoped carbon aerogel exhibited a hierarchical pore structure composed of vertically aligned microchannels and micro/mesopores on the channel walls. This architecture not only facilitated the uniform loading of Co₃O₄ nanoparticles but also promotes the rapid transport of pollutants to the vicinity of catalytic active sites. Particularly, the degradation efficiency of sulfamethoxazole (30 mg/L) reached 96.3 % within 10 min in Co-NP/CA/PMS. Its degradation rate was 2.3 times higher than the isotropic N, P co-doped carbon aerogel decorated with Co₃O₄. Furthermore, the Co-NP/CA/PMS system eliminated 98 % of SMX within 30 min in a variety of water sources, including running water, pure water and lake water. The Co-NP/CA composite demonstrated outstanding mechanical performance, with the ability to withstand more than 2500 times its own weight. This exceptional mechanical stability contributed to its remarkable cyclic stability, maintaining over 80 % degradation efficiency after five cycles. Electron paramagnetic resonance (EPR) spectroscopy and electrochemical texting demonstrated that the Co-NP/CA/PMS system degrades pollutants through synergistic radical and non-radical pathways, involving singlet oxygen (¹O₂) evolution and interfacial charge transfer. This study advances the development of effective and sustainable catalysts for environmental remediation.