Reduction of 4-nitrophenol and 2-nitroaniline using immobilized CoMn₂O₄ NPs on lignin supported on FPS

In the present work, fibrous phosphosilicate (FPS) was functionalized by using octakis[3-(3-aminopropyltriethoxysilane)propyl]octasilsesquioxane (APTPOSS) groups that act as strong performers. In this regard, the nanoparticles of CoMn₂O₄ were dispersed, properly, on FPS microsphere (CoMn₂O₄/APTPOSS@FPS) fibers. Agricultural and industrial waste waters contain nitrophenols. They are amongst the most common organic pollutants. In water, low concentrations are harmful to human health and aquatic life owing to the potential mutagenic and carcinogenic influences of nitrophenols. 4-Nitrophenol (4-NP), as well as 2-nitroaniline (2-NA), are known hazardous toxic waste contaminants and are included in the United States Environmental Protection Agency (USEPA) list. Thus, to eliminate them, novel methods are necessary. In addition, o-phenylenediamine (o-PDA) and 4-aminophenol (4-AP) are considered as significant intermediates for the synthesis of dyes and drugs, which are synthesized from 2-NA and 4-NP. Nanoparticles of CoMn₂O₄/APTPOSS@FPS utilized for the reduction of 2-NA and 4-NP, increase the efficiency of the reaction with considerable chemoselectivity. The results showed that the P and O atoms of lignin-FPS gold nanoparticles (NPs) were stable and the morphology and structure of FPS increased the catalytic activity.