Facile fabrication of nanoporous Au-Pd bimetallic foams with high catalytic activity for 2-nitrophenol reduction and SERS property

Nanoporous Au-Pd bimetallic foams with a large BET surface area of 20.19 m(2) g(-1) have been successfully achieved via a mild hydrothermal process (100 degrees C) in the presence of dextran, which serves as both surfactant and reductant. X-Ray diffraction measurements confirm that the foams are bimetals with a face-centered cubic (fcc) structure, and electron microscopies show that the foams are composed of interlaced necklaces assembled from granular nanocrystals. The formation mechanism of the porous nanostructures has been clearly deduced from the measurements of Energy-dispersive X-ray spectroscopy (EDS) on different positions of some typical necklaces. The nanoporous bimetallic foams could catalyze the reduction of 2-nitrophenol to 2-aminophenol quite effectively at room temperature, and also exhibit good surface enhanced Raman spectroscopic (SERS) activity with Rhodamine 6G, which implies that the foams would be of great potential in catalysis and SERS applications.