Synergistic photoelectrochemical and photocatalytic properties of cobalt nanoparticles-embedded TiVO4 thin film

Abstract

To optimize the semiconductor properties of TiVO4 thin films and enhance their performance, we incorporated cobalt nanoparticles as an effective co-catalyst consisting of a non-noble metal. Through an investigation into the impact of cobalt loading on spray pyrolyzed TiVO4 thin films, we observed a significant enhancement in the photoelectrochemical performance. This was accomplished by carefully optimizing the concentrations of Co2+ (3 mM) to fabricate a composite electrode, resulting in a higher photocurrent density for the TiVO4:Co photoanode. When an applied potential of 1.23 V vs RHE was used, the photocurrent density reached 450 µA/cm2 , approximately five times higher than bare TiVO4. We conducted a thorough characterization of the composite structure and optical properties. Additionally, electrochemical impedance spectroscopy analysis indicated that the TiVO4:Co thin film exhibited a smaller semicircle, indicating a significant improvement in charge transfer at the interface. In comparison to bare TiVO4, the TiVO4:Co composite exhibited a notable improvement in photocatalytic activity when degrading methylene blue dye, a widely employed model dye. Under light illumination, a TiVO4:Co thin film exhibited a notable dye degradation rate of 97% within a 45 minute duration. The scalability of our fabrication method makes it suitable for large-area devices intended for sunlight-driven photoelectrochemical seawater splitting studies.