Towards mass production of Au nanoparticles supported on montmorillonite microspheres for catalytic reduction of 4-nitrophenol

However, their large-scale applications are still limited by the problems of fouling and transport during the mass production process. Herein, we first fabricated a spherical montmorillonite (Mt) substrate via spray drying technique, followed by the deposition of Au NPs through polydopamine chemistry to synthesize spherical Au nanoparticles supported Mt (Au@Mt) microspheres.

The Au loading is 14.5 wt%, whereas the specific surface area of the Au@Mt microspheres is 47.3m2 g−1, endowing the prepared Au@Mt microspheres with excellent catalytic activity to the reduction of 4-nitrophenol (4-NP) in the presence of NaBH4 with the optimized apparent reduction rate constant higher than 1.05 min−1. Furthermore, the microspheres can be easily recycled with self-sedimentation without any devices involved and showed excellent stability and recyclability for at least 20 cycles without almost unchanged spherical morphology and catalytic performance.