Graphitic nitride decorated with silver oxide nanoparticles as p–n heterostructured catalyst for photoelectrochemical properties and visible-light photodegradation of tetracycline from wastewater

Effective photodegradation of tetracycline from wastewater is critical to conserve or restore the marine environment. In this study, p–n-type heterostructured photocatalysts are prepared to show good photoexcited charge separation and quick surface catalytic reactions that are used to photodegrade tetracycline from wastewater as well as for photoelectrochemical studies. The p–n heterostructured photocatalyst was synthesized by decorating Ag 2 O nanoparticles onto graphitic carbon nitride (g-C 3 N 4 ) sheets via hydrothermal method. The crystal structure, surface morphology, optical properties, and elemental composition were investigated to confirm the presence of Ag 2 O nanoparticles on the surface of g-C 3 N 4 nanosheets. The prepared Ag 2 O/g-C 3 N 4 composite photocatalyst showed tetracycline degradation up to 95.6 % in 90 min under visible light illumination, which was higher than just Ag 2 O (38.7 %) and g-C 3 N 4 (17.5 %) under the same conditions. Additionally, photoelectrode showed a higher photocurrent (0.525 mA cm −2 ) than g-C 3 N 4 (0.119 mA cm −2 ) and Ag 2 O (0.1236 mA cm −2 ). Enhanced photocatalytic and photoelectrochemical activity of the composite catalyst was attributed to active interfacial charge transfer, which increased the lifespan of photogenerated charge carriers and electron density. The developed composite was used for dual purpose of leveraging the synergy between p–n-type materials for wastewater treatment and green hydrogen generation through photoelectrochemical water splitting. • Novel Ag 2 O/g-C 3 N 4 p-n catalysts were prepared by hydrothermal method. • Morphology confirmed that p-type Ag 2 O particles uniformly distributed onto g-C 3 N 4 . • Catalysts were examined for photodegradation of tetracycline and PEC water oxidation. • Catalyst showed 95.6 % photodegradation of tetracycline under visible light illumination. • Photoelectrode had photocurrent density of 0.525 mA/cm −2 , higher than pristine g-C 3 N 4 .