Sol-gel hybrid silicas as an useful tool to mercury removal

[Display omitted] •Synthesis of modified silicas by different sol-gel routes.•Influence of sol-gel route on inorganic mercury adsorption.•Relationship between silica textural properties and mercury adsorption potential.•Application of modified silicas as a tool for mercury removal in aqueous media. Due to high potential toxicity of mercury species and their characteristics of bioaccumulation and biomagnification, these pollutants have become a huge problem for environment, being able to spread along all trophic levels, including humans. This work describes the influence of hybrid silicas textural characteristics on mercury uptake capacity, revealing the possibility to use different sol-gel routes as a form to produce materials to interact with mercury species. The hybrid silicas prepared by basic catalyzed route showed more efficiency to remove inorganic mercury from aqueous media (1.5–1.9 μg. mg−1 of adsorbed mercury) if compared to those obtained by acid-catalyzed or two-steps routes (zero μg. mg−1 of adsorbed mercury). In addition, the hybrid silicas loaded with amino or sulfur-groups showed the high capacity to adsorb mercury, removing 82–99% from a 10 mg.L−1 Hg(II) solution with only 50 mg of the sorbents.