Facile synthesis of ZnBi_2O_4-graphite composites as highly active visible-light photocatalyst for the mineralization of rhodamine B

摘要

Novel highly active visible-light photocatalysts in the form of zinc bismuth oxide (ZnBi2O4) and graphite hybrid composites were prepared by coupling via a co-precipitation method followed by calcination at 450 degrees C. The as-prepared ZnBi2O4-graphite hybrid composites were tested for the degradation of rhodamine B (RhB) solutions under visible-light irradiation. The existence of strong electronic coupling between the two components within the ZnBi2O4-graphite heterostructure suppressed the photogenerated recombination of electrons and holes to a remarkable extent. The prepared composite exhibited excellent photocatalytic activity, leading to more than 93% of RhB degradation at an initial concentration of 50mg L -1 with 1.0 g catalyst per liter in 150min. The excellent visible-light photocatalytic mineralization of ZnBi2O4-1.0graphite in comparison with pristine ZnBi2O4 could be attributed to synergetic effects, charge transfer between ZnBi2O4 and graphite, and the separation efficiency of the photogenerated electrons and holes. The photo-induced h+ and the superoxide anion were the major active species responsible for the photodegradation process. The results demonstrate the feasibility of ZnBi2O4-1.0graphite as a potential heterogeneous photocatalyst for environmental remediation.