Design and Manufacturing of Si–W–O Nanostructured Adsorbents: Processing–Property–Performance Relationships for Methylene Blue Removal

الملخص

This study presents the hydrothermal manufacturing and performance evaluation of silicon–tungsten oxide (Si–W–O) nanorods as engineered functional materials for wastewater treatment applications. Emphasis is placed on the process–structure–performance relationship governing adsorption behavior. The hydrothermal synthesis route enabled controlled formation of crystalline Si–W–O nanorods with uniform morphology and high surface area, resulting in a dense distribution of accessible active sites. Structural and morphological analyses confirmed the successful fabrication of rod-like nanostructures suitable for high-efficiency adsorption systems.

Batch adsorption experiments demonstrated rapid adsorption kinetics, with significant methylene blue (MB) removal occurring within the first 15 minutes, followed by equilibrium stabilization. At low dye concentration (25 ppm), the fabricated nanorods achieved near-complete removal efficiency (≈95–100%), while higher concentrations (100 ppm) led to reduced efficiency (~63%) due to active site saturation. Increasing material loading from 10 to 50 mg significantly improved removal performance from ~35% to ~98%, highlighting the scalability potential of the material system.Process conditions, including pH, ionic strength, and temperature, were found to strongly influence adsorption performance. Optimal removal efficiency (~98%) was achieved within a pH range of 3–7, while elevated ionic strength and temperature reduced adsorption capacity, indicating an exothermic and electrostatically governed mechanism. FTIR analysis confirmed strong interfacial interactions between MB molecules and surface oxygen functional groups.The adsorption mechanism is attributed to a synergistic combination of electrostatic attraction, hydrogen bonding, and surface complexation. From a manufacturing and materials engineering perspective, the results demonstrate that hydrothermally synthesized Si–W–O nanorods represent a promising class of functional nanomaterials, with tunable properties and high efficiency for integration into advanced water treatment systems.