Silica-coated magnetite nanoparticles prepared by the one-step electrochemical method for dye removal

Abstract

Abstract:In this paper, the synthesis of silica-coated magnetite nanoparticles using a one-step electrochemical method and their application for dye removal are presented. In this method, pure iron in a dilute aqueous sodium silicate solution that served as a silica precursor was electro-oxidized. The silica-coated magnetite nanoparticles produced by this method is nearly spherical with the size of approximately 10 nm and follows the spinel structure of Fe3O4. The silica-coated magnetite nanoparticles exhibit nearly superparamagnetic properties and excellent performance to remove methylene blue from wastewater. The adsorption capacity of the nanoparticles was approximately 24.2 mg methylene blue/g adsorbent, which was much higher than that of pure magnetite nanoparticles (1.1 mg methylene blue/g adsorbent). Also, the percentage removal was higher than 90% with the initial concentration of methylene blue up to 40 mg/L. It can be regenerated and reused with an only slight reduction in percentage removal.

High Surface Area Silica Particles Using Anionic Surfactant Template Prepared by One-step Spray Drying System for Dye Removal Application

“…The silica adsorbent with the SLS template at a concentration of 2 CMC, 1 CMC, and without the SLS template were 82.0, 31.8, and 20.5 mg/g, respectively. The theoretical maximum monolayer adsorption capacity of silica adsorbent synthesized using SLS concentration of 3 CMC shows a higher value than previous studies of silica gel synthesized from coal fly ash and silica-coated magnetite of 23.31 and 24.21 mg/g, respectively [2,39]. In this case, the adsorption ability of silica particles using the SLS template at a concentration of 3 CMC was almost the same with activated carbon nanofiber without further treatment, which was 149.3 mg/g with the specific surface area of 1,093.845 m 2 /g [40].…”

Amine-functionalized porous silica production via ex- and in-situ method using silicate precursors as a selective adsorbent for CO2 capture applications

“…Silica is widely applied as an absorbent-adsorbent material, catalyst support, membrane, and slow-release drug delivery material. Besides having good mechanical properties and non-toxicity, silica-based functional materials can be modified to improve their performance in specific applications [ [1] , [2] , [3] , [4] , [5] , [6] , [7] ]. Modifying silica is carried out by grafting active functional groups on the surface of the support material either physically or chemically [ [8] , [9] , [10] , [11] ].…”