Pure Co3O4 and 5% Ba-doped Co3O4 were synthesized using the solid-state route, followed by an investigation into their multiferroic properties. X-ray diffraction analysis confirmed the presence of the pure cobalt oxide phase in the 5% Ba-doped Co3O4 sample. The structural analysis via XRD patterns indicated successful doping, with no additional peaks observed. Additionally, FTIR data exhibited peak shifts, further confirming the Ba doping in Co3O4. Dielectric properties, including dielectric constant and dielectric loss, showcased strong Maxwell–Wagner polarization in wet states. Impedance spectroscopy analysis provided insights into the types of charge carriers and grain/grain boundary effects. The doped material, i.e., 5% Ba-doped Co3O4, exhibited high resistance, attributed to potential factors such as increased defect concentration, higher material porosity, and mobile charge carriers. In wet states, the Co3O4 and 5% Ba-doped Co3O4 demonstrated an enhanced ion diffusion mechanism, leading to reduced impedance. These findings suggest potential applications in hydroelectric cells for eco-friendly fuel alternatives.