Efficient visible-light-driven removal of persistent antibiotics and synthetic dyes from wastewater using an engineered 2D/2D Bi₂MoO₆/NiAl–LDH S-scheme heterocatalyst with enhanced interfacial contact

Highly efficient photocatalysts for degrading persistent antibiotics and synthetic dye pollutants under visible light are crucial for sustainable environmental remediation. In this study, we engineered a novel Bi₂MoO₆ (BMO)/NiAl–LDH (layered double hydroxide) hybrid catalyst with a unique 2D/2D heterostructure, optimized for the visible-light-driven elimination of ciprofloxacin (CPF) and hazardous synthetic dyes such as rhodamine B and methylene blue. The optimized BMO-30/LDH hybrid demonstrated exceptional photocatalytic performance, achieving nearly complete degradation of CPF and synthetic dyes with high mineralization efficiency, surpassing many previously reported state-of-the-art photocatalysts. This superior activity is primarily attributed to the formation of an S-scheme heterojunction, which enhances charge separation while maintaining strong redox potentials in both components. This mechanism enables the simultaneous generation of reactive O₂^•− and ^•OH radicals. The hybrid's enhanced efficiency is further driven by synergistic effects, including strong visible light absorption, a large surface area, and a well-integrated 2D/2D configuration with face-to-face interfacial contact. These structural features maximize charge carrier separation, reduce recombination, and ensure robust photocatalytic activity. Additionally, the hybrid exhibited excellent reusability, retaining over 93% of its initial activity after five cycles. This study introduces a novel approach to engineering advanced 2D/2D heterojunction photocatalysts, highlighting their potential for practical water treatment and environmental remediation applications.