Comprehensive characterizations and enhanced photocatalytic performance of zirconium based metal-organic framework integrated with multiwall carbon nanotubes under UV light irradiation

This study aims to comprehensively characterize structural, morphological, and optical properties of Zirconium based metal organic framework (MOF-841) integrated with multiwall carbon nanotubes (Zr-MOF@MWCNT) and evaluate their photocatalytic efficiency under UV light irradiation. The synthesized Zr-MOF@MWCNT composites exhibits a significant improvement in photocatalytic activity compared to pristine Zr-MOF. Characterization techniques, including X-Ray Diffraction (XRD), Dynamic Light Scattering (DLS), X-Ray Photoelectron Spectroscopy (XPS), Field Emission Scanning Electron Microscopy (FESEM), Raman Spectroscopy, Fourier Transform Infrared Spectroscopy (FT-IR), Ultraviolet-Visible Spectroscopy (UV-VIS) and Photoluminescence (PL) confirmed successful integration of MWCNT with Zr-MOF. A slight shift towards higher wavelength was observed in the absorption spectrum which indicates enhanced light harvesting capabilities. Also, the integration of MWCNT led to a reduction in band gap energy which was calculated using the Tauc plot method. Photocatalytic studies demonstrated that the Zr-MOF@MWCNT composites achieved a degradation efficiency of up to 97% under UV light, significantly outperforming the individual components. Several factors like initial dye concentration, catalyst dosage, solution pH and temperature were examined. Kinetic data of dye adsorption best fitted with pseudo-zeroth-order model. Methylene blue (MB) dye adsorption was more favorable at lower temperature and neutral pH (around 7–9). The incorporation of MWCNT into Zr-MOF not only improved the structural stability and light absorption of the photocatalysts but also enhances charge carrier dynamics, leading to superior photocatalytic performance under sunlight irradiation.