Synthesis of highly active and reusable supported gold nanoparticles and their catalytic applications to 4-nitrophenol reduction

Gold nanoparticles (AuNPs) are first prepared for the first time by a one-step, green synthesis method using plant tannins as reductant as well as stabilizer. Subsequently, the resultant AuNPs were supported on γ-Al2O3 to prepare a heterogeneous AuNP catalyst (Al2O3-BT-AuNPs). The resultant Al2O3-BT-AuNPs catalyst was well characterized by N2adsorption/desorption, ultraviolet diffusion reflection (UV-DR) spectroscopy and transmission electron microscopy (TEM). It was found that the Al2O3-BT-AuNPs catalyst was highly active and reusable in the catalytic reduction of 4-nitrophenol to 4-aminophenol, and its catalytic activity was dependant on the loading percentage of BT.