1 resultado para COLLOIDAL GOLD
em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo
Resumo:
In this paper we report a simple and environmentally friendly synthesis of gold nanoparticles (AuNps) and their electrocatalytic activity for borohydride oxidation reaction (BOR). Ultraviolet spectroscopy (UV- vis) and transmission electron microscopy (TEM) confirmed the formation of poly(vinyl pyrrolidone)protected colloidal AuNps through direct reduction of Au3+ by glycerol in alkaline medium at room temperature. For the BOR tests the AuNps were directly produced onto carbon to yield the Au/C catalyst. Levich plots revealed that the process occured via 7.2 electrons, therefore near the theoretical value of 8 electrons. When compared to bulk Au, the gold nanoparticles presented enhanced catalytic properties since the onset potential for BOR was shifted 200 mV towards negative potentials. (C) 2012 Elsevier B.V. All rights reserved.