Photocatalytic Degradation of Methylene Blue by Engineering Tungstic Acid@ZIF-67 Cocatalyst

The zeolitic imidazolate frameworks have gained significant attention in various applications owing to their exceptional surface area, customizable porosity, and excellent thermal and chemical stability, making them a remarkable nanomaterial. The present study involved the utilization of ultrasonic-assisted techniques to integrate tungstic acid into the zeolitic imidazolate framework (TA@ZIF-67) with the aim of augmenting the photocatalytic activity. The as-synthesized nanocomposite was characterized using X-ray diffraction and scanning electron microscopic analysis to inspect the structural aspects and morphology. The reduction in particle size of TA@ZIF-67 due to the incorporation of tungstic acid results in a higher surface area, leading to a significant improvement in the photocatalytic activity of ZIF-67. The assessment of the photocatalytic performance of ZIF-67 and TA@ZIF-67 was conducted through the degradation of methylene blue (MB) under sunlight. The degradation efficiency of ZIF-67 and TA@ZIF-67 was observed to be 61% and 85%, respectively, of the MB solution following a 60 min irradiation period. The investigation of the kinetics study based on rate constant values revealed that the utilization of TA@ZIF-67 presented a greater efficiency in the removal of MB from an aqueous solution. The results pave a new avenue toward the design of MOF-based photocatalysts for water treatments.