Improved photocatalytic degradation of methylene blue by novel hexagonal ZnO particles

Abstract

Recently, the use of nanoparticles as photocatalysts has gained great importance. However, nanoparticles exhibit some drawbacks for this application and there is a need for new particle technologies to mitigate these drawbacks. A novel particle technology called MicNo based on ZnO has been designed and manufactured, which exhibits the advantages and properties of both micron and nano size. Although performance of MicNo-ZnO has been tested in various applications, it has not been tested as a photocatalyst in any photocatalytic degradation process. In this study, novel designed ZnO was used as a catalyst for methylene blue (MB) degradation in the presence of UV irradiation.  The MicNo-ZnO particles were characterized by structural and morphological properties by XRD, BET and SEM analyses. The effects of catalyst amount, pH, temperature and initial concentration on the degradation process were investigated.  In addition, a reusability study was carried out with 4 cycles under optimum conditions. The MicNo-ZnO particles showed excellent photocatalytic activity with a degradation rate of 96% for methylene blue in 180 min. The pseudo-first-order rate constant for the photocatalytic degradation of MB by MicNo-ZnO was as high as 0.0236 min⁻¹, confirming that MicNo-ZnO particles can be effectively utilized as an alternative catalyst material.