Development of a MOF-5/g-CN nanocomposite: an effective type 2 heterojunction photocatalyst for rhodamine B dye degradation.

The field of environmental and water remediation faces a significant challenge in removing organic dyes from wastewater, particularly Rhodamine B (RhB), a stubborn dye used in various industries. Traditional treatment methods struggle with its resistance to decomposition, posing risks to water quality, human health, and aquatic life. This study demonstrates a novel approach to enhance photocatalytic efficiency for RhB degradation by constructing a MOF-5/g-CN composite through a facile mechanical grinding method, which is unprecedented. The composite addresses the limitations of g-CN, such as rapid recombination of electron-hole pairs, low electron transfer rates, and small surface area, by forming a heterojunction with MOF-5. The composite exhibits enhanced photocatalytic efficiency for the degradation of RhB under sunlight, with a degradation of 91.5% achieved within 90 min. Optimization studies highlight the importance of pH and catalyst dosage in the degradation process. The reusability test shows consistent performance over five successive cycles, maintaining a degradation efficiency of over 90%. Total organic carbon (TOC) analyses confirm the mineralization of the dye solution to 82.05% after 90 min of irradiation, demonstrating the environmental benignity of the composite. Trapping experiments suggest the involvement of superoxide radicals, electrons, and holes in the photocatalytic mechanism. This study introduces a promising strategy for addressing challenges in dye degradation through innovative composite materials.