Preparation of nZVI/MCM‐41/rGO for Adsorption of Nickel Ions from Water

Abstract Emissions of nickel (Ni) are harmful to the environment and people‘s health. Although nano zero‐valent iron (nZVI) has a lot of potential for treating water pollution, its instability and tendency for aggregation have limited its application. In order to improve its properties, composite adsorbent MCM‐41/rGO supported nZVI (nZVI/MCM‐41/rGO) is designed for improving the properties of nZVI, and it is characterized by SEM, XRD, FTIR and BET. The results show that it has an apparent Fe (0) crystallinity and modest rGO crystallinity, as well as a rough and porous structure. There are many oxygen‐containing groups found on the surface of nZVI/MCM‐41/rGO, such as −OH, −COOH, and Si−O. The pore diameter is concentrated at 23.82 nm, and the specific surface area is 15.94 cm 2 /g. The consequences of several parameters such as contact time, initial metal ion concentration, adsorbent dosage, and pH for adsorption efficiency were investigated. The best performance is occurred at pH 6, C 0 =80 mg/L with a 2 g/L adsorbent dosage, and after 180 min, a maximum adsorption capacity of 41.82 mg/g is reached at 333 K. The Dubinin‐Radushkevich isotherm and second order kinetic models fit the Ni(II) adsorption process well. It is determined through analysis of the thermodynamic parameters that the adsorption progress is endothermic ( ΔH 0 >0) and spontaneous ( ΔG 0 <0). nZVI/MCM‐41/rGO has proven to be an effective and alternative material for the removal of Ni(II) ions from aqueous media due to its excellent removal ability, availability, and low cost.