Novel Carbon [email protected] Silicate Composite Porous Films: Design, Fabrication, and Adsorption Behavior for Heavy Metal Ions in Aqueous Solution

It is of great and increasing interest to explore porous adsorption films to reduce heavy metal ions in aqueous solution. Here, we for the first time fabricated carbon [email protected] silicate ([email protected]) composite films for the high-efficiency removal of Zn2+ and Cu2+ by a solid-phase transformation from hydromagnesite-coated CP ([email protected]) precursor film in a hydrothermal route and detailedly examined adsorption process for Zn2+ and Cu2+ as well as the adsorption mechanism. The suitable initial pH range is beyond 4.0 for the adsorption of the [email protected] to remove Zn2+ under the investigated conditions, and the adsorption capacity is mainly up to the pore size of the porous film. The composite film exhibits excellent adsorption capacity for both of Zn2+ and Cu2+ with the corresponding maximum adsorption quantity of 198.0 mg g–1 for Zn2+ and 113.5 mg g–1 for Cu2+, which are advantageous over most of those reported in the literature. Furthermore, the adsorption behavior of the [email protected] film follows the pseudo-second-order kinetic model and the Langmuir adsorption equation for Zn2+ with the cation-exchange mechanism. Particularly, the [email protected] film shows promising practical applications for the removal of heavy metal ions in water by an adsorption–filtration system