Mussel chemistry inspired synthesis of Pd/SBA-15 for the efficient reduction of 4-nitrophenol

In this study, N-doped platelet-like metal-loaded Zr/SBA-15 was synthesized and employed for reducing 4-nitrophenol to remove this contaminant from water. Dopamine hydrochloride was used as a novel CN source for the modification of ZrSBA-15. The N doping process occurred readily at a low temperature due to the polymerization of dopamine, which could save energy and simplify the experimental fabrication of catalysts. In addition, polydopamine can immobilize Pd ions in a facile manner and the trapped Pd ions are reduced to Pd nanoparticles due to the reducibility of the polydopamine polymer. The utilization of dopamine allows the catalyst to be obtained in a facile and cost-effective synthetic process, while the production of the CN layer as well as the reduction and immobilization of the Pd ions can occur simultaneously. Characterization of the product showed that the catalyst had a platelet-like structure after decoration with elemental Zr, which enhanced the catalytic reaction compared with the natural fiber-like SBA-15. The optimal Pd loading capacity was determined as ~3.0 wt% and the materials obtained could reduce 4-nitrophenol to 4-aminophenol within 120 s with a conversion ratio above 90%.