Synthesis of gold nanoparticle-loaded magnetic carbon microsphere based on reductive and binding properties of polydopamine for recyclable catalytic applications

摘要

An efficient and green method was proposed to synthesise Au nanoparticle (Au NP)-decorated Fe3O4@porous carbon core-shell nanoparticles (denoted as Fe3O4@C-Au). In this synthetic strategy, polydopamine (PDA) was prepared by spontaneous polymerization of dopamine, which works as both a carbon precursor and a reducing agent. The thickness of the carbon layer is about 50 nm and could be easily adjusted by changing the polymerization time. The as-prepared Fe3O4@C-Au, which was well characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), vibrating sample magnetometry (VSM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy (RS) and Fourier transform infrared (FTIR), showed excellent catalytic performance in the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in aqueous solution using sodium borohydride as a hydrogen source. Owing to its superparamagnetic property of the Fe(3)O(4)core and the stability of the carbon shell, the catalyst could be easily separated using an external magnet and shows excellent reusability (almost the same activity as the fresh catalyst after eight catalytic cycles). The facile and green preparation, high catalytic capability and recyclability give Fe3O4@C-Au a great development potential in the industrial wastewater treatment.