The dual selective adsorption mechanism on low-concentration Cu(II): Structural confinement and bridging effect.

In this study, sulfur was introduced into the graphene oxide-based aerogel system based on the theory of bridging effect, and an oxygen-sulfur synergistic system was established to realize the dual-mechanism selective adsorption to low-concentration Cu(II) with slit structure and targeted binding sites. Based on the difference of chemical properties between organic acids and surfactants, the surface of graphene oxide (GO) was functionalized to realize the regulation of the order of its lamellar structure and the construction of carbon defects. On this basis, sulfur source modified GO-based aerogel was created to accomplish selective adsorption to low-concentration Cu(II) by combining the self-accumulation of montmorillonite and GO with the cross-linking mechanism of Ca(II) and sodium alginate. Based on the density functional theory, the formation process of radicals on the material's surface both prior to and following the adsorption to Cu(II) was simulated, and the effective improvement on the catalytic ability of the material after loading Cu(II) was verified. This means that using Cu(II) saturated adsorbent as a photocatalyst to degrade organic pollutants, is a promising reuse strategy for hazardous waste. The above research provides a new research idea for the subsequent removal of low-concentration metal ions and the potential application of hazardous wastes.