Enhanced visible-light photocatalytic activity of Z-scheme graphitic carbon nitride/oxygen vacancy-rich zinc oxide hybrid photocatalysts

Abstract

With the objectives of enhancing the stability, optical properties and visible-light photocatalytic activity of photocatalysts, we modified oxygen vacancy-rich zinc oxide (Vo-ZnO) with graphitic carbon nitride (g-C3N4). The resulting g-C3N4/Vo-ZnO hybrid photocatalysts showed higher visible-light photocatalytic activity than pure Vo-ZnO and g-C3N4. The hybrid photocatalyst with a g-C3N4 content of 1 wt% exhibited the highest photocatalytic degradation activity under visible-light irradiation (λ ≥ 400 nm). In addition, the g-C3N4/Vo-ZnO photocatalyst was not deactivated after five cycles of methyl orange degradation, indicating that it is stable under light irradiation. Finally, a Z-scheme mechanism for the enhanced photocatalytic activity and stability of the g-C3N4/Vo-ZnO hybrid photocatalyst was proposed. The fast charge separation and transport within the g-C3N4/Vo-ZnO hybrid photocatalyst were attributed as the origins of its enhanced photocatalytic performance.