Novel reduced graphene oxide/ZnBiO hybrid photocatalyst for visible light degradation of 2,4-dichlorophenoxyacetic acid.

A new highly efficient rGO/ZnBiO hybrid catalyst has been successfully synthesized through oxidation-reduction and co-precipitation methods, followed by heating at 450 °C. The obtained rGO/ZnBiO catalyst was characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). The catalytic activity of rGO/ZnBiO under visible light irradiation was tested using 2,4-dichlorophenoxyacetic acid (2,4-D) in aqueous solution. The rGO/ZnBiO hybrid catalyst containing 2% rGO (2.0rGO/ZnBiO) showed the best catalytic performance. More than 90% of 2,4-D in a 30 mg/L solution was degraded after 120 min of visible light irradiation using 2.0rGO/ZnBiO at 1.0 g/L concentration. Moreover, the 2.0rGO/ZnBiO catalyst showed excellent stability over four consecutive cycles, with no significant changes in the photocatalytic degradation rate. This study demonstrated that rGO/ZnBiO may be a promising, low-cost, and green photocatalyst for environmental remediation applications.