Facile construction of djembe-like ZnO and its composite with g-C3N4 as a visible-light-driven heterojunction photocatalyst for the degradation of organic dyes

In this work, djembe like ZnO microstructures was successfully synthesized by surfactant-assisted hydrothermal method and its composite with g-C3N4 was prepared by an ethanolic reflux method for the first time. Moreover, the structural, morphological, electrical, optical properties and its photocatalytic activities were studied. The result revealed that the formation heterojunction between djembe like ZnO and g-C3N4, decreased the optical band gap energy thereby the light absorption was shifted towards visible region. The photocatalytic performance was studied by dye degradation experiment under visible light irradiation. The degradation efficiency of the ZnO/g-C3N4 composite for MB and RhB degradation was found to be similar to 95% and similar to 97% respectively, which is higher than that of the same for pure ZnO and g-C3N4. The scavenger studies indicated the active role of hydroxyl radicals in the degradation process. Furthermore, djembe like ZnO/g-C3N4 composite was successfully reused for five cycles of photodegradation without any drastic change in its activity and crystalline properties.