Highly efficient reduction of 4-nitrophenolate to 4-aminophenolate by Au/γ-Fe2O3@HAP magnetic compositesElectronic supplementary information (ESI) available. See DOI: 10.1039/c9ra00345b

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. 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.