Mesoporous Nb₂O₅/SiO₂ material obtained by sol-gel method and applied as adsorbent of crystal violet dye

In this work, SiO₂/Nb₂O₅ (SiNb) material was prepared using sol-gel method and employed as adsorbent for removal of crystal violet dye (CV). The material was characterized using nitrogen adsorption-desorption isotherms, FTIR spectroscopy, pH_pzc, and SEM-EDS. The analysis of N₂ isotherms revealed the presence of micro- and mesopores in the SiNb sample with specific surface area as high as 747 m² g^-1. For the CV adsorption process, variations of several parameters such as of pH, temperature, contact time, and concentration of dye of the process were evaluated. The optimum initial pH of the CV dye solution was 7.0. The adsorption kinetic and equilibrium data for CV adsorption were suitably represented by the general-order and Liu models, respectively. The maximum adsorption capacity of the CV dye by SiNb was achieved at 303 K, which attained 116 mg g^-1 at this temperaure. Dye effluents were simulated and used to check the applicability of the SiNb material for treatment of effluents - the material showed very good efficiency for decolorization of dye effluents.