ZnO heterojunction photocatalysts prepared via facile green synthesis process attaining improved photocatalytic function for degradation of methylene blue dye

Abstract

In the present work, hybanthus blossom extract was used to create environmentally-friendly synthesized ZnO NPs using dopants such as yttrium and activated charcoal. Based on X-ray diffraction (XRD) measurements, it was observed that the ZnO, Y@ZnO, AC@ZnO, and Y@AC@ZnO nanoparticles possess a wurtzite structure. Analysis of their X-ray diffraction patterns revealed average particle sizes of 47.64, 48.32, 49.21, and 49.68 nm for ZnO, Y@ZnO, AC@ZnO, and Y@AC@ZnO nanoparticles, respectively. The UV-visible spectrum displayed absorbance peaks within the range of 335 - 353 nm, indicating energy band gaps of 3.70, 3.64, 3.57, and 3.51 eV for ZnO, Y@ZnO, AC@ZnO, and Y@AC@ZnO nanoparticles, respectively. Morphological investigations revealed that the nanoparticles exhibit high permeability. Photoluminescence spectra exhibited intriguing blue, green, and red emissions when excited at 401, 491, and 525 nm for ZnO, Y@ZnO, AC@ZnO, and Y@AC@ZnO nanoparticles, respectively. Upon exposure to UV light, the nanoparticles demonstrated increased efficiency in utilizing light for the reduction of methylene blue dye. The ZnO, Y@ZnO, Y@AC@ZnO NPs synthesized showed superior antibacterial activity against the bacteria Pseudomonas aeruginosa. According to test results, the MB dye could remove up to 95.5% of its target material at a catalyst dosage of 0.005 g/L and an irradiation time of 120 minutes. This study effectively showcases a straightforward and environmentally friendly approach for producing flexible ZnO nanoparticles using green synthetic technology.