Fig. 7

(a) XRD patterns of pristine ZnO, pristine Al2O3, and ZnO–Al2O3 nanocomposite, confirming phase composition and structural integrity. (b) Experimental FTIR spectra of pristine ZnO and ZnO–Al2O3 nanocomposite, ighlighting surface functional groups and interfacial bonding. (c) Theoretical (DFT-calculated) infrared (IR) spectrum of the ZnO–Al2O3 nanocomposite, illustrating vibrational modes and validating the experimental FTIR features.