Coalescence of Au Nanoparticles in Silica Aerogel under Electron Beam Irradiation

Background: The coalescence of Au nanoparticles embedded in the silica gel matrix was observed by E-beam irradiation in a transmission electron microscope. Methods: It was examined that interparticle spacing between nanoparticles was reduced after incorporation into the matrix and particles came close to each other. TEM studies have shown that during E-beam irradiation ~13 nm Au nanoparticles contacted with each other along with the shrinkage of the silica aerogel or as well as the removal of surfactant layer, and transformed into different shapes of particles such as dumbbell and chain-like particles as per the interparticle gap. Results: This nanoparticle-aerogel matrix has the potential for applications in sensing, nonlinear optics, and catalysis. Conclusion: This work enhances the understanding of the role of silica aerogel and E-beam irradiation in directing the coalescence of nanoparticles.