Construction of plasmonic Bi/Bismuth oxycarbonate/Zinc bismuth oxide ternary heterojunction for enhanced charge carrier separation and photocatalytic performances

Abstract

In this work, a novel plasmonic ternary Bi/Bismuth oxycarbonate/Zinc bismuth oxide (Bi-Bi2O2CO3-ZnBi2O4) is synthesized synergistically by a one-step hydrothermal method. The results show that the metallic Bi spheres and ZnBi2O4 nanoparticles are uniformly distributed on the surface of flower-like Bi2O2CO3 layer. Compared with the bare ZnBi2O4 and Bi-Bi2O2CO3, the ternary Bi-Bi2O2CO3-ZnBi2O4 heterojunction displays a significantly improved solar energy harvesting efficiency and enhanced photocatalytic degradation activity for environmental organic pollutants. The degradation efficiency of organics reaches to 98.4% under simulated solar light illumination. The degradation kinetics indicates that the photocatalytic reaction rate constant of ternary system is about 4.4 and 29.5 times higher than that of pure ZnBi2O4 and Bi-Bi2O2CO3, respectively. Moreover, O2− and h+ are the main active species in the photodegradation reaction. The improvement of the photocatalytic activity of the composites is attributed to the synergistic effect of ternary heterostructure and surface plasmon resonance (SPR), which promotes charge transfer and effectively inhibits the recombination of photogenerated carriers.