Highly efficient reduction of 4-nitrophenolate to 4-aminophenolate by Au/γ-Fe2O3@HAP magnetic composites

摘要

In this article, the catalyst Au/γ-Fe _(2) O _(3) @hydroxyapatite (Au/γ-Fe _(2) O _(3) @HAP) consisting of Au nanoparticles supported on the core–shell structure γ-Fe _(2) O _(3) @HAP was prepared through a deposition–precipitation method. The catalyst was characterized by transmission electron microscopy, X-ray powder diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, N _(2) adsorption–desorption and atomic absorption spectrometry. The as-prepared Au/γ-Fe _(2) O _(3) @HAP exhibited excellent performance for the reduction of 4-nitrophenolate (4-NP) to 4-aminophenolate (4-AP) in the presence of NaBH _(4) at room temperature. Thermodynamic and kinetic data on the reduction of 4-NP to 4-AP catalyzed by the as-prepared catalyst were studied. The as-prepared catalyst could be easily separated by a magnet and recycled 6 times with over 92% conversion of 4-NP to 4-AP. In addition, the as-prepared catalyst showed excellent catalytic performance on other nitrophenolates. The TOF value of this work on the reduction of 4-NP to 4-AP was 241.3 h ~(?1) . Au/γ-Fe _(2) O _(3) @HAP might have a promising potential application on the production of 4-AP and its derivatives.