Facile synthesis of novel hierarchical graphene–Bi2O2CO3 composites with enhanced photocatalytic performance under visible light

Abstract

A facile template-free hydrothermal approach is developed to synthesize hierarchical flower-like graphene–Bi₂O₂CO₃ microcomposites. The as-prepared samples were systematically characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, N₂ adsorption–desorption and UV-visible diffuse reflectance spectroscopy. The photocatalytic activity of the as-prepared samples was evaluated towards degradation of Rhodamine B (RhB) under visible light. Compared to hierarchical Bi₂O₂CO₃, hierarchical flower-like graphene–Bi₂O₂CO₃ microcomposites show enhanced photocatalytic activity. In addition, our results indicate that both the physico-chemical properties and associated photocatalytic activity of graphene–Bi₂O₂CO₃ composites are shown to be dependent on graphene loadings. The highest photocatalytic performance can be achieved for the graphene–Bi₂O₂CO₃ microcomposites with 1.0 wt% graphene. The underlying mechanism responsible for the formation of graphene–Bi₂O₂CO₃ composites and enhanced photoreactivity was discussed. Results from this study illustrate an entirely new approach to fabricate semiconductor composites containing graphene–bismuth with high visible-responsive photocatalytic performance.