Green catalysts based on bio-inspired polymer coatings and electroless plating of silver nanoparticles

Herein, a simple but versatile method to develop supported-metal catalysts based on a polydopamine (PDOP) coating and electroless plating of silver nanoparticles (AgNPs) onto nanomaterials (e.g., anodic aluminum oxide (MO) membranes and polystyrene (PS) nanotubes) for catalytic reduction is demonstrated. The PDOP coating was inspired by the composition of adhesive proteins in mussels. A comparative study on the catalytic activities of the individual AgNPs, AgNPs/PDOP/AAOs with different pore sizes (20-200 nm) and AgNPs/PDOP/PS nanotubes in the reduction of o-nitroaniline (o-NA) to 1,2-benzenediamine (BDA) was carried out. The results indicated that both AgNPs/PDOP/AAO (200 nm) and AgNPs/PDOP/PS exhibited significantly higher catalytic activities than individual AgNPs. We also observed that the PDOP coating alone had the ability to reduce o-NA to BDA. Given their simplicity, efficiency, and flexibility, we believe that these types of green catalysts might find a wide range of applications in organic synthesis and catalysis. (C) 2011 Elsevier B.V. All rights reserved.