Insights into the interaction between PANI and Au NPs of magnetic core‐shell Fe₃O₄/PANI/Au catalysts with remarkable catalytic performance in 4‐NP reduction

Abstract

Magnetic Fe3O4/PANI core‐shell composites were prepared as the support of gold catalysts. The Fe3O4 magnetic core was prepared by solvothermal reaction and coated with polyaniline (PANI) shell via in situ aniline polymerization on Fe3O4 surface. Au nanoparticles were loaded on Fe3O4/PANI composites through gold sol adsorption and in situ reduction method to prepare Fe3O4/PANI/Au(Sol) and Fe3O4/PANI/Au(In Situ) catalysts, respectively. We found that the initial activities of Fe3O4/PANI/Au(Sol) were higher than that of Fe3O4/PANI/Au(In Situ) due to the small size effect of Au in catalysts. Although the size of Au in Fe3O4/PANI/Au(In Situ) was bigger than that in Fe3O4/PANI/Au(Sol), it should be noted that both of Fe3O4/PANI/Au(Sol) and Fe3O4/PANI/Au(In Situ) possessed good catalytic recycling stability. The conversion of 4‐NP was still above 97% and 99% after 15 cycles for Fe3O4/PANI/Au(Sol) and Fe3O4/PANI/Au(In Situ), respectively. The good catalytic stability for Fe3O4/PANI/Au(In Situ) could be attributed to the stronger interaction between PANI and Au NPs. We believe that our work provides an effective strategy for the preparation of long‐life catalysts and the investigations can be used to design other conductive polymers supported noble metal catalysts.