In situ loading MnO onto 3D Aramid nanofiber aerogel as High-Performance lead adsorbent.

Fabricating a high-performance adsorbent as a desirable candidate for removing Pb from aqueous water remains a challenge. Aramid nanofibers (ANFs) are promising building blocks that have realized multifunctional applications due to their intrinsic mechanical and chemical stability. Herein, an in situ loading strategy for preparing nanofiber composite aerogel was proposed by assembling ANFs into a 3D aerogel and applying it as host media for the in situ polymerization of pyrrole followed by facile redox reaction between the polypyrrole (PPy) and MnO to load manganese dioxide (MnO). The idea was to fully exploit the structural advantages of ultra-low bulk density, large specific surface area, and high porosity of ANFs, and the possible chemical adsorption characteristics of MnO on the basis of ion exchange reaction. The adsorption capacity of 3D ANF/MnO composite aerogel was as large as 554.36 mg/g for Pb. The adsorption mechanism based on an exchange reaction between Pb and protons on the surface of MnO was also investigated. The desorption results showed that the adsorption performance could remain up to 90% after five times of usage. In conclusion, this research provides promising insights into the preparation of high-performance lead adsorbent for water treatment.