Bottom-up molecular-assembly of Ru(ii)polypyridyl complex-based hybrid nanostructures decorated with silver nanoparticles: effect of Ag nitrate concentration

Abstract

Ruthenium functionalized silver nanocomposites (Ag NCs) and hybrid nanotubes (HNTs) were prepared in a one-pot process using tris(4,4′-dicarboxy-2,2′-bipyridyl)ruthenium(II)-sensitizer as a reducing and molecular capping reagent involving Ag nitrate as a metal precursor. Ag NCs and HNTs were architectured with unique structural features by tuning the Ag nitrate concentration while keeping the other parameters constant such as temperature, time, and solvent of the reaction by exploiting a bottom-up approach. The newly synthesized hybrid materials were well characterized by various electron microscopic methods such as transmission electron microscopy (TEM), scanning electron microscopy (SEM) and powder X-ray diffraction (PXRD) studies. TEM and SEM studies revealed the morphological features of Ag NCs and HNTs. The PXRD study showed the crystallinity of the Ag NPs having a (111) crystal plane on the HNTs. Optical properties have been studied through UV-vis, fluorescence and Raman spectroscopy and showed the formation of Ag NPs decorated hybrid nanostructures with fluorescent properties and enhanced Raman scattering properties. The presence of morphological diversity in Ag nanohybrids formation was studied in detail by comparing structural features of the capping molecules, the Ru(II)-sensitizer and the trisodium citrate.