Efficient photocatalytic degradation of crystal violet dye using time-dependent ZnO nano spindle

Abstract

Photocatalysis, utilizing metal–semiconductor oxides, has emerged as a promising technique for the oxidation of organic molecules due to its efficiency, cost-effectiveness, and eco-friendly nature. This study presents the synthesis and application of time-dependent ZnO nano spindles for the efficient photocatalytic degradation of crystal violet dye. ZnO nanostructures, known for their high photocatalytic activity, were synthesized using a simple and low-cost coprecipitation method, with the spindle morphology being fine-tuned by varying reaction times. The resulting nano spindles were characterized using X-ray diffraction (XRD), Fourier transmission infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and UV–vis spectroscopy to confirm their structural, morphological, and optical properties. XRD analysis revealed that the ZnO samples possess a hexagonal wurtzite crystal structure with a space group of P63mc. SEM analysis confirmed the formation of spindle-like morphologies, with the synthesized samples measuring just a few nanometers in size. The surface area and porosity of the ZnO samples have been observed by using the Brunauer–Emmett–Teller (BET) analysis. The obtained surface area of all ZnO samples is in the range of 15 to 30 m2g−1. Photocatalytic performance was evaluated under UV light irradiation, demonstrating that the degradation efficiency of CV dye significantly depends on the exposure duration and the morphological attributes of the ZnO nano spindles. The degradation kinetics followed a pseudo-first-order model, with the optimized ZnO nano spindles achieving up to 99 % degradation efficiency within 150 min. This study highlights the potential of time-dependent morphological control in ZnO nanostructures to enhance photocatalytic processes, presenting a viable solution for the treatment of dye-laden wastewater.