Synthesis and characterization of graphene oxide-zinc oxide nanocomposite thin films: Enhanced photocatalytic and electrochemical properties

Graphene, an innovative material, holds transformative potential for industry and technology due to its exceptional properties. This study investigates the fabrication and characterization of a graphene oxide-zinc oxide (ZnO/GO) nanocomposite thin film via electrodeposition and evaluates its electrochemical and photocatalytic performance. The film was thoroughly characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDAX), Fourier-transform infrared (FTIR) spectroscopy, and UV-visible spectroscopy. Results confirmed the successful integration of zinc oxide nanoparticles and graphene oxide nanosheets in the composite film. Incorporating 3D graphene into zinc oxide nanocomposites significantly enhances their photocatalytic activity for degrading methylene orange. Electrochemical studies, including chronopotentiometry and cyclic voltammetry, showed that the ZnO film forms within the range of -0.8 to 1.2 V. Additionally, corrosion resistance for E24 mild steel in 3.5% NaCl solution was demonstrated using electrochemical impedance spectroscopy (EIS), which indicated that zinc oxide effectively adsorbs graphene oxide onto the steel surface, reducing defects and blocking active corrosion sites. The ZnO/GO coating exhibited the lowest double-layer capacitance (1.67 × 10⁻³ F/cm²) and the highest charge transfer resistance (253 Ωcm²), providing effective protection against corrosive degradation of underlying materials. KEY WORDS: Electrodeposition, Graphene oxide, ZnO, Photocatalytic activity Bull. Chem. Soc. Ethiop. 2025, 39(10), 1893-1907. DOI: https://dx.doi.org/10.4314/bcse.v39i10.2