Heterogeneous photocatalysis, utilizing light and semiconductor materials, offers a promising approach for degrading organic pollutants in water. This study explores the development and application of ZnO nanoparticles doped with eucalyptus bark biochar (ZnO@EB) for photocatalytic degradation of textile industry effluent.

The ZnO@EB composite was synthesized using a sol-gel-hydrothermal method, incorporating varying amounts of ZnO nanoparticles (10-50 wt%) into the biochar framework. The 30% ZnO@EB composite demonstrated exceptional activity for dye degradation under solar light irradiation.

Box-Behnken design was employed to optimize the photocatalytic process, revealing optimal conditions for achieving 94.8% decolorization efficiency: 2.99 g/L photocatalyst dosage, pHpH is a measure of how acidic or alkaline a substance is. A pH of 7 is neutral, while lower pH values indicate acidity and higher values indicate alkalinity. Biochars are normally alkaline and can influence soil pH, often increasing it, which can be beneficial More 3.04, and 101.7 min irradiation time. The pseudo-first-order Langmuir-Hinshelwood model accurately predicted the degradation kinetics, indicating efficient dye removal.

Furthermore, the spent 30% ZnO@EB composite exhibited excellent reusability, maintaining its activity even after ten cycles. This highlights the potential of this composite for sustainable and efficient treatment of textile wastewater.