CuBi2O4 surface-modified three-dimensional graphene hydrogel adsorption and in situ photocatalytic Fenton synergistic degradation of organic pollutants

Abstract

A CuBi2O4/rGH composite catalyst was prepared by modifying CuBi2O4 on the surface of a three-dimensional graphene hydrogel (rGH) via a simple water bath method. The large specific surface area and particular surface adsorption properties of rGH were beneficial for adsorbing and enriching pollutant molecules and could then be further degraded by the in situ photocatalytic Fenton synergistic effect with the addition of H2O2. The introduction of graphene not only increases the surface area and improves the adsorption properties but also accelerates the transfer and separation efficiency of the interface photogenerated charge, thereby promoting the photocatalytic Fenton degradation performance. The adsorption performance and catalytic degradation performance of the 20 % CuBi2O4/rGH composite for phenol were 1.4 and 1.3 times higher than those of CuBi2O4, respectively. Meanwhile, the removal efficiency of phenol in the adsorption and in situ photocatalytic Fenton synergistic system was as high as 80 % within 20 min. In addition, the cross-linked network structure of the 3D graphene hydrogel could be better recycled, which has significant potential in practical applications. Quenching and EPR experimental results showed that hydroxyl radicals (·OH) were the most active species in the synergistic degradation process, and the mechanism of CuBi2O4/rGH adsorption and in situ photocatalytic Fenton degradation was proposed.