Catalyst role of Nd³⁺ions for the precipitation of silver nanoparticles in phosphate glass

The present work proposes that neodymium(III) performs as catalyst enhancing the precipitation of Ag nanoparticles (NPs) in silver-doped phosphate glass. In situ optical isothermal microspectroscopy was employed for evaluating the influence of the rare-earth dopant on the kinetics of Ag NP precipitation in real time in the solid-state host. A temperature-dependent first-order exponential increase with time of the peak optical density of the surface plasmon resonance of Ag NPs was observed in relation to concomitant particle nucleation and diffusion-driven growth. An Arrhenius-type plot was used for the activation energy estimation of the plasmonic Ag particles precipitation at 2.3 eV. This value is about 56% lower than the activation energy of 5.2 eV measured previously in our group [46] for the diffusion-based Ag NP growth in the glass without Nd³⁺ions. Further characterizations were performed by differential scanning calorimetry, transmission electron microscopy, solid-state³¹P nuclear magnetic resonance spectroscopy, and Raman scattering, in support of the in situ optical measurements. The distinctive results were discussed in the context of glass composition and structure.