Electrical, optical, and electrochemical performances of phosphate-glasses-doped with ZnO and CuO and their composite with polyaniline

Abstract

Phosphate-based glasses (PBG) with appropriate doping agents have been used as solid electrolytes in solid-state ionic devices. Therefore, more light was shed on the electrical, optical, and electrochemical behavior of the phosphate-based glasses (PBG), containing ZnO or CuO in the absence and existence of conductive polyaniline (PANI), since no publications are available concerning this work. The glass samples were prepared by the rapid quenching method, then mixing phosphate glass and polyaniline (PANI) with metal oxide (ZnO, CuO). They were characterized by different techniques; diffuse reflectance spectrophotometer (DRS), broadband dielectric spectrometer (BDS), cyclic voltammetry (CV), and charge–discharge techniques. In the DRS study, the direct and indirect band gap were calculated from Tauc’s relationship where CuO-doped glasses have higher values than ZnO-doped glasses. In the BDS study, the permittivity of all glass compositions decreased while AC conductivity increased with increasing frequency. AC conductivity of PBG doped with metal oxides and mixed with PANI exhibited semiconducting features (6.8 × 10–4 S/cm). Further, these composites exhibited lower loss tangent (0.11), and giant permittivity (186,000) compared to the pure PBG. Also, the electrochemical study exhibited that the composite with 7% CuO content has the highest specific capacitance value (82.3 F/g at 1.0 A/g) which increased to about 113% of its first cycle and then decreased to about 55% after 2500 cycles and finally increased again to 77% after 4500 cycles, indicating its good stability. The combination of optical, electrical, and electrochemical features of these composites suggests their use for energy generation and storage devices.