Heberton Wender
Associate professor, Federal University of Mato Grosso do Sul, Institute of Physics, Campo Grande, 79070900, Brazil
Title: Discussing the visible-light photoactivity and energy band alignment of CuBi2O4/CuO heterojunctions photocatalysts
Biography
Biography: Heberton Wender
Abstract
A one-step solvothermal method was recently applied to produce heterojunctions made of CuBi2O4 nanocolumns with small platelike CuO nanoparticles homogeneously distributed over its surface. Simulated solar light and visible light irradiation was used to investigate and study the photocatalytic activity of the heterojunctions through the photodegradation of Methylene Blue (MB) dye and Metronidazole (MTZ), respectively. The heterojunction CuBi2O4/CuO with 16.8 w/w% of CuO showed an enhanced photocatalytic performance with 98% removal of MB (@2 sun simulated solar irradiation) and 36% removal of MTZ (@1 sun visible light) within 60 min of irradiation. Using the optimized photocatalyst an apparent quantum efficiencyof ∼2.1% was achieved for MB photocatalytic degradation under excitation at 540 nm. This presentation will discuss the band energy alignement in this photocatalytic system and also correlate it with other published results in the literature. Finally, the enhanced photocatalytic performance of this system is attributed to an effective charge separation through a type-II heterojunction, indicating that photoinduced electrons transfer from CuBi2O4 to CuO nanoparticles with the photoholes migrating in the opposite direction. The main reactive species responsible for the photocatalytic degradation of organic pollutant molecules will be debated as well as the photocatalyst stability over repeating cycles.