Three‐dimensional porous magnetic polyaniline supported Ag nanoparticles nanocomposites as an efficient and recyclable catalyst for nitrophenol reduction

Abstract Ag nanoparticles (Ag NPs) nanocomposites are promising catalysts for nitro compound reduction, but simultaneously meeting the requirements of high catalytic activity, stability, recyclability and facile preparation is highly difficult. Herein, the three‐dimensional (3D) porous magnetic polyaniline (PANI) was synthesized using phytic acid (PA) as the dopant/crosslinker, and a recyclable PANI/Ag NPs nanocomposite (PMPA) was obtained through the in situ redox between PANI and AgNO 3 . Characterization results demonstrate that PMPA exhibits a typical 3D porous structure constructed by coral‐like PANI framework with well‐dispersed Ag NPs (10–20 nm) firmly anchored. The PMPA can efficiently catalyze the 4‐nitrophenol (4‐NP) reduction, with a reaction rate constant of 9.5 × 10 −3 s −1 (and 1067.4 s −1 g −1 ), which is highly competitive to the previously reported high‐performance Ag NPs catalysts. This is probably due to the favorable mass/electron conduction of 3D porous structure and strong interaction between PA and Ag. Moreover, the magnetism renders PMPA recyclability via a simple magnetic attraction, and the reaction rate constant remains at a high level after six reuse cycles, up to 4.8 × 10 −3 s −1 . This work highlights the important role of 3D porous PANI in structure of Ag NPs nanocomposites, and paves a new way to develop recyclable catalysts with facile preparation and high catalytic performance. Highlights Facile synthesis via in situ reaction between 3D porous PANI and AgNO 3. Stable dispersion and strong anchor attributed to phytic acid. Conductive porous structure to facilitate mass/electron transportation. Outstanding catalytic performance for 4‐NP reduction and recycle by magnetism.