Photocatalytic activity of CuBi2O4/CuO heterojunction for methylene blue degradation under visible light irradiation

We successfully synthesized CuBi2O4/CuO heterojunction with various mass ratios using a simple grindingannealing method. The synthesized materials exhibited optical band gap values around 1.70 eV, suggesting their capability to absorb visible light. CuBi2O4/CuO was synthesized using mass ratios of 1:1, 1:2, and 2:1, which are referred to as CuBi2O4/CuO I, CuBi2O4/CuO II, and CuBi2O4/CuO III, respectively. The photocatalytic efficacy of CuBi2O4/CuO was evaluated for methylene blue degradation. Among the various mass ratios of CuBi2O4/CuO that were tested, CuBi2O4/CuO II exhibited the highest photocatalytic degradation efficiency (81.1 %) when subjected to visible light within 180 min. HR-TEM analysis validated the heterojunction formation of CuBi2O4/CuO between CuBi2O4 and CuO. Utilizing an adequate quantity of CuBi2O4 and CuO at a mass ratio 1:2, produces a synergistic effect in the heterojunction system of exceptional superiority. This work examines how the CuBi2O4/CuO mass ratio affects the breakdown of organic pollutants under visible light exposure.