Hybrid materials based on Al2O3, modified with polyaniline have been obtained. Samples have been synthesized by chemical polymerization of aniline monomer with Al2O3 nanoparticles, the ammonium persulfate have been used as oxidizers. The resulting samples were fully characterized by X‐ray photoelectron spectroscopy (XPS), X‐ray diffraction (XRD), Fourier transform infrared spectrometer (FTIR), scanning electron microscopy (SEM), and UV‐vis spectroscopies, which have shown that polymerizations have been carried out. Importantly, this work represents an efficacious way of setting the optical properties of the synthesized nanocomposites, obtained by adjusted the amounts of Al2O3 during polymerization, the analysis shows that the lowest evaluate of optical band gap is 2.88 eV for PANI@Al2O3 (4%) compared to PANI@Al2O3 (2%), and PANI@Al2O3 (6%) with 2.95 and 2.91 eV, respectively. Good electroactivity response where achieve two pairs oxidation/reduction with improved thermal stability for the synthesized hybrid materials have been observed.