Gamma irradiation as an engineering tool: tailoring the electronic structure of TiO 2 /CNTs/GO nanocomposites in a PVC matrix with mechanical compromise

This study investigates the profound structural, thermal, optical, and mechanical modifications induced by gamma (γ) irradiation (absorbed doses of 0, 50, 100, and 150 kGy) on PVC/TiO2/CNTs/GO nanocomposites synthesized via the sol–gel method. Characterization results confirm that γ-irradiation serves as a precise engineering tool for tailoring the electronic and chemical properties of the embedded functional fillers. X-ray Diffraction (XRD) and Raman Spectroscopy revealed a dose-dependent reduction in TiO2 crystallite size and an increase in lattice defects (vacancies and interstitials), signaling effective electronic modification of the photocatalytic host. Concurrently, FTIR analysis confirmed that high-energy γ-rays act as a post-synthesis reducing agent, successfully decreasing oxygen-containing functional groups in Graphene Oxide (GO) and promoting its conversion to a more conductive reduced graphene oxide (rGO) structure. These structural changes yield significant functional benefits, including a widening of the TiO2 optical bandgap (blue-shift) as determined by Tauc plot analysis, which is favorable for enhancing charge separation efficiency. Furthermore, the material exhibited enhanced thermal stabilization; Thermogravimetric Analysis (TGA) showed a degradation onset shift of approximately 30 0C for the 100 kGy dose, while Differential Scanning Calorimetry (DSC) revealed enthalpy suppression, confirming the energetic pre-stabilization of the composite network.