Preparation of nano-Zn2GeO4/rGO composite photocatalyst and its treatment of synthetic dye wastewater

Abstract

Zn2GeO4/rGO composite photocatalysts were prepared by hydrothermal method with Zn2GeO4 and GO as precursors, and ethanol/water solvent as a reducing agent. Reduced graphene oxide was combined with Zn2GeO4 nanorods in order to improve photocatalytic activity of Zn2GeO4 through improving its surface area, adsorption capacity, charges separation and transportation ability. Then the composite photocatalysts were characterized by XRD, FESEM, EDS and UV–vis DRS. RhB synthetic dye wastewater was used as the target to investigate the effect of each reaction parameter on the degradation rate; the catalytic performance stability of the composite photocatalyst was investigated under the obtained optimal reaction conditions; and the reaction kinetics and reaction mechanism of the synthetic wastewater treatment process were preliminarily analyzed. The study shows that the Zn2GeO4/rGO composite photocatalyst prepared by hydrothermal method has better photocatalytic activity under xenon light illumination, and the wastewater treatment process conforms first-order reaction kinetic characteristics; during the treatment, the dye molecules are directly degraded by the composite photocatalyst, and no other luminescent groups are produced. The Zn2GeO4/rGO composite photocatalyst with good photocatalytic activity and stability under visible light irradiation can be prepared by hydrothermal method for dye wastewater treatment.