Electroless plating is commonly associated with metallizing macroscopic work pieces, but also represents a surprisingly powerful nanomanufacturing tool. This review details the technique's use for creating nanomaterials of arbitrary dimensionality, ranging from nanoparticles over nanotubes, nanowires, and ultrathin films to nanostructured lattices, focusing on the solution chemistry and mechanistic aspects. The synthesis of defined nanostructures serves as overarching perspective, which is enriched by drawing connections to and insights from related fields. Strategies for controlling the size, shape, crystallinity, porosity, composition, and arrangement of electrolessly plated nanostructures are outlined, including templating (which harnesses the method's exceptional conformality to guide and limit deposit formation), the complementary approach of selective growth, tailored seeding, and bath design. Being able to strike convincing compromises between material quality and ease of preparation, electroless nanoplating has a distinct potential to facilitate the application of metal nanomaterials.
A facile electroless plating procedure for the controlled synthesis of nanoscale silver thin films and derived structures such as silver nanotubes was developed and the products were characterized by SEM, TEM and EDS. The highly stable plating baths consist of AgNO(3) as the metal source, a suitable ligand and tartrate as an environmentally benign reducing agent. Next to the variation of the coordinative environment of the oxidizing component, the influence of the pH value was evaluated. These two governing factors strongly affect the plating rate and the morphology of the developing silver nanoparticle films and can be used to adapt the reaction to synthetic demands. The refined electroless deposition allows the fabrication of homogeneous high aspect-ratio nanotubes in ion track etched polycarbonate. Template-embedded metal nanotubes can be interpreted as parallelled microreactors. Following this concept, both the silver nanotubes and spongy gold nanotubes obtained by the use of the silver structures as sacrificial templates were applied in the reduction of 4-nitrophenol by sodium borohydride, proving to be extraordinarily effective catalysts.
27 December 2016 in ACS Applied Materials & Interfaces