Sunlight-driven photocatalytic degradation of methyl orange dye using a CoGd bimetallic metal organic framework for environmental remediation

Cobalt-Gadolinium (Co-Gd)-bimetallic metal-organic framework (MOF) was prepared via solvothermal method and tested for photocatalytic degradation of dyes. X-ray diffraction-powder revealed the appearance of a well-formed crystalline framework with an average crystallite size of 48 nm and a low level of lattice strain, a good structure integrity level. SEM analysis showed tightly packed polyhedral micro-aggregates, while EDX and FTIR spectra confirmed the incorporation of Co and Gd ions and the effective metal-ligand coordination. Co-Gd bimetallic MOF demonstrated a high photocatalytic activity with sunlight energy in the degradation of Methyl Orange, with the appearance of a rapid decrease in the typical absorption peak and near to decolorization. Kinetic investigations were performed according to a pseudo-first-order Langmuir-Hinshelwood mechanism having a large apparent rate constant. These results showed that Co-Gd bimetallic MOFs can be used as sunlight-reactive photocatalyst in water purification and wastewater treatment applications.