Improvements in structural, surface, PL response and shielding parameters of PVA/CeO 2 /CNTs polymer nanocomposite

Abstract

PVA/CeO 2 /CNTs hybrid nanocomposite in form of free-standing films were successfully synthesized by the solution casting approach to investigate their structural, surface and PL (photoluminescence) properties. XRD (X-ray diffraction) analysis confirmed the semicrystalline nature of PVA and the cubic fluorite structure of CeO 2 nanoparticles, while peak broadening indicated nanoscale crystallinity and oxygen vacancy defects. FESEM (field emission surface electron microscopy) images showed the better dispersion and interfacial interaction of the nanofillers at higher concentrations which was confirmed by EDAX analysis showing the presence of Ce, O and C elements. PL studies revealed broad visible emission in the range 350–520 nm under excitation at 300 nm which was attributed to the near-band-edge transitions, oxygen vacancies and interfacial charge transfer between CeO 2 and CNTs. CNT incorporation enhanced charge transfer and reduced radiative recombination, leading to PL quenching at higher filler concentrations. The enhanced optical response and charge transport behaviour suggest the developed PVA/CeO 2 /CNTs nanocomposites as potential materials for optoelectronic and flexible photonic applications. The shielding parameters (i.e., LAC, HVL, C eff and G–P fitting parameters) confirm that gamma-ray shielding performance of the nanocomposite is improved by increasing material’s density as confirmed by increased LAC and reduced HVL values. The C eff and G–P parameters further confirm its effective photon attenuation capability.