Investigations on structural and optical properties of chalcone dendrimer in Ag@TiO2 core–shell nanoparticles

Abstract

The main focus of this research article is to observe the contributions of chalcone dendrimer in Ag@TiO2 core shell nanoparticles. The samples were synthesized by Redox transmetalation method. The structure of the samples in three molar ratio viz.1:1, 1:2, 1:5 (noted as A,B,C) with Poly Vinyl Pyrrolidone (PVP) as stabilizing agent were compared with the sample Ag@TiO2 of 1:2 molar ratio (noted as D) using zeroth generation triazolyl chalcone dendrimer as stabilizing agent. The prepared samples were structurally characterized by XRD and HRTEM analysis. The XRD and SAED analysis exhibited tetragonal body centered crystal structure with dhkl = 1.6 A, 2.4 A and 3.4 A. The lattice parameters were calculated for all the samples and the variations observed were reported. The grain size and dislocation density of the synthesized nanoparticles were calculated using Debye–Scherrer formula. From Williamson–Hall plot, it was identified that the lattice strain was increased in sample D in which chalcone dendrimer acted as stabilizing agent. The structural investigation showed the impact of stabilizing agent on the surface elements. Similarly, the optical characteristics were discussed based on UV-DRS and Photoluminescence studies. Using Kubelka–Munk function, the band gap energy was calculated and the difference observed in the band gap energy due to the impact of stabilizing agents on metal–metaloxide (Ag@TiO2) combination was analysed. The molar absorptivity (e) was calculated for all the samples using Beer–Lambert’s law and the difference in absorbance on using different stabilizing agent was discussed.