Enhanced visible-light-active MOF-based PbO photocatalyst for binary dye decolorization: A comprehensive study

Abstract

Developing efficient and sustainable wastewater treatment technologies like photocatalysis is essential to combating global water pollution. Despite lead oxide's photocatalytic potential, its high recombination rate and low active sites restrict its application. In the current study, the first MOF-based PbO nanostructure has been successfully synthesized in a facile way. The as-synthesized sample, PbO/Aluminum fumarate metal–organic framework (PbO/AlFu), was characterized in multiple manners and applied to degrade mixtures of methyl green (MeG) and crystal violet (CV) dyes under visible light irradiation. The incorporation of AlFu metal–organic framework as a support for PbO significantly enhanced photo-degradation performance. This enhancement can be attributed to the increased visible light harvesting, adsorption capabilities facilitated by AlFu, and separation of photo-generated electron-hole pairs due to the formation of the step-scheme (S-scheme) heterojunction. Photocatalytic efficiencies and operational parameters were modeled and optimized respectively using the Box-Behnken design (BBD). Under optimized conditions, MeG and CV dyes were removed at 95.6 and 86.1 percent, respectively. •O2– and •OH radicals were identified as key contributors to the photo-degradation of both dyes. Kinetic studies revealed that photo-degradation of both dyes followed the Langmuir-Hinshelwood model, suggesting a surface-mediated reaction mechanism. PbO/AlFu demonstrated outstanding stability and reusability in five sequential photo-degradation cycles. The present findings highlight the potential of PbO/AlFu as a promising photocatalyst for wastewater treatment.