Surface modification of gold nanotubules via microwave radiation, sonication and chemical etching

We present here the results of smoothing the rough surface of as-prepared gold tubular nanoshells or nanotubules which were produced by reacting aged gold salts with tetrakis-hydroxymethyl-phosphonium chloride (THPC)-capped gold nanoparticles on amine terminated silica nanowires (SiNWs) or silica nanocoils (SiNCs). These as-prepared rough nanotubules exhibited metallic properties as determined by optical absorption spectroscopy. Microwave radiation, sonication, and chemical etching were used to effectively smooth the surface. Two parameters were used to define the surface smoothness on the nanoscale, and the outcomes of these three surface modification methods were compared.