Effect of additives on the photocatalytic degradation of malachite green using NiS:Tb3+ nanoparticle and their photoluminescence properties

Abstract

The contamination of wastewater with synthetic dyes presents a critical challenge, highlighting the need for advanced technologies and approaches to effectively manage, treat, and remediate polluted wastewater and mitigate its adverse environmental and health impacts. This study focuses on the photocatalytic degradation of malachite green dye, a widely used synthetic dye, using nickel sulfide nanoparticles doped with Tb3+ ions. The objective is to explore the potential of this approach in breaking down the dye into harmless components, thereby reducing its toxicological impacts on the environment and human health. The catalyst was characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), photoluminescence spectroscopy (PL), X-ray photoelectron spectroscopy (XPS), and ultraviolet-visible spectroscopy (UV). The effects of pH levels and various additives, including transition metals, inorganic oxidants, and inorganic anions, on the degradation process were systematically examined. The results demonstrate a high degradation efficiency of 94 % within 90 min, highlighting the efficacy of the photocatalytic process. Notably, adding transition-metal ions and inorganic oxidants enhanced the degradation rate, whereas inorganic anions had an inhibitory effect. Furthermore, an artificial neural network (ANN) model was developed to predict the degradation rate, demonstrating a strong correlation between experimental data and predicted values. This study provides valuable insights into optimizing photocatalytic degradation processes. It showcases the potential of ANN modelling in predicting the photocatalytic activity of nickel sulfide nanoparticles doped Tb3+ in the presence of various additives.