Economic Photocatalytic Degradation of Environmental Pollutants Over CuBi2O4/Ag2CrO4 Photocatalyst with Core-Shell Heterostructure: S-Scheme Mechanism

Abstract

Developing solar-light-responsive photocatalysts attracted exciting prospects in the energy and environmental sectors. This study focuses on coating CuBi₂O₄ nanorods with Ag₂CrO₄ shell to yield robust S-scheme CuBi₂O₄/Ag₂CrO₄ composites with a core-shell heterostructure. The CuBi₂O₄/Ag₂CrO₄ photocatalyst exhibited boosted charge separation behavior and upgraded surface area, reflecting beneficial impacts on the catalytic capacity. Under visible light (117 W-LED) irradiation, CuBi₂O₄/Ag₂CrO₄ could enhance the methylene blue (MB) and Congo red (CR) degradation by exhibiting 75% and 85% of removal efficiency within 75 min, respectively. The optimized CuBi₂O₄/Ag₂CrO₄-25% recorded the best MB degradation kinetics (0.01918 min⁻¹), surpassing pure CuBi₂O₄ (0.00739 min⁻¹) and Ag₂CrO₄ (0.00910 min⁻¹) by factors of 2.59 and 2.11, respectively. Besides, the MB degradation over CuBi₂O₄/Ag₂CrO₄-25% was evaluated based on catalyst dosage, reaction temperature, and MB concentration. Besides, the S-type reaction mechanism demonstrated the improved light absorption, accelerated charge dynamics, hampered recombination rate, and strengthened redox potential. The trapping results indicated the key influence of ^•O₂⁻ and h⁺ and the auxiliary efforts of ^•OH in the catalytic reaction. Finally, our innovative photocatalyst encourages the harvesting of low-energy LED light and offers cost-effective remediation processes for environmental issues.