Abstract:
This paper focuses on the synthesis of a new silver nanocomposite adsorbent derived from
rice husk as raw material. The synthesis is based on triethoxysilane chemistry and the reduction of
silver without the aid of reductant chemicals. The derived AgNPs@SiO2 nanocomposites are fully
characterized and then used for the removal of mercury (II) from aqueous solutions. The results
demonstrated that the affinity of the composite for mercury is high and the removal mechanism is
adsorption accompanied by a redox reaction between mercury and silver followed by the formation of
calomel and amalgams between silver and mercury. The silver–mercury reaction is complex, and its
stoichiometry seems to scale with the silver content. Besides the importance of the surface reactions,
the successful implementation of biosourced silica for mercury removal from water is useful for the
development of strategies for the valorization of agricultural waste and boosts the concept of circular
economy and bioeconomy