High adsorption of cationic dyes from aqueous solution using worm-like porous nanosilica: Isotherm, kinetics and thermodynamics

Abstract

Organic dyes contaminant would pose a severe threat to human health and natural environments, which often were handled through adsorption. Herein, the porous nanosilica adsorbent (WPSN), with the worm-like channel structure, the large surface area of 968.61 m2/g, was fabricated through a green method, applying in the adsorption of dyes (methylene blue and rhodamine B). The WPSN exhibited high adsorption capacity and selectivity performance to cationic dyes, which max adsorption capacities of 552.00 mg/g and 537.00 mg/g towards methylene blue and rhodamine B, respectively, were achieved. It was noted that adsorption kinetic action well conformed to the pseudo-second-order model, and the adsorption isotherm experiment was discussed through the Langmuir isotherm. The adsorption thermodynamics presented that the adsorption process was exothermic and spontaneous. The reusability results indicated that the 90% of the adsorption rate could still be maintained even after 6 cycles.