Synthesis and Sorption Profiles of Graphene‐Decorated Silane‐Modified Layered Clays for As(V) Removal: A Quantitative Assessment and Mechanistic Insights

Abstract

A novel adsorbent material, graphene decorated silane modified layered clays enriched with Fe(III) (TEOS‐g‐LDH−Fe/rGO) was prepared via emulsion polymerization followed by in situ precipitation and its physicochemical characterization carried out by FTIR, XRD, SEM‐EDS, HRTEM, TG‐ DTG, XPS and Raman analysis. The TEOS‐g‐LDH−Fe/rGO composite utilized for the effective removal of As(V) from aqueous system and the process followed via inner‐sphere surface complexation through ligand exchange between hydroxyl groups in TEOS‐g‐LDH−Fe/rGO and As(V) species. The equilibrium data fitted well with Langmuir model and kinetic data with mixed batch model showed remarkable adsorption capacity of 103.91 mg/g at pH 5.5. The synergistic effects associated with precursors in the composite profoundly improved the removal efficiency of As(V). The optimal conditions for As(V) removal was evaluated by RSM coupled with central composite design(CCD) considering pH(3–6), dose(0.5–2.5) and time (1–80 min) at temperature 30 °C. The sorption efficacy of TEOS‐g‐LDH−Fe/rGO was found to be about four times greater than its precursors. In simulated water matrix, the TEOS‐g‐LDH−Fe/rGO exhibit a retention of sorption performance (90 %) from 98.8 % of its initial sorption capacity for As(V) removal during regeneration. This work proves TEOS‐g‐LDHFe/rGO as a promising candidate for addressing grievous environmental threats from arsenic contamination.