Fabrication of 3D hierarchical networks adsorbent immobilized MoS2 for adsorption of Ag(I) from aqueous solution

[Display omitted] •A flexible, easily separable adsorbent with 3D hierarchical networks was successfully constructed.•The adsorbent is in favor of mass production.•The maximum adsorption capacity was 1012.51 mg/g.•Ag2S and silver elemental were generated during the adsorption process. MoS2 as a nanomaterial, is popular in the field of water treatment due to the large specific surface area and abundant sulfur groups. However, the application of MoS2 as the powder absorbent is limited by the difficulty of separation and reuse in aqueous systems. Hence, we used the self-assembly characteristic of graphene oxide (GO) to immobilize MoS2 in three-dimensional (3D) reduced graphene oxide (rGO) system while loading inside melamine foam (MF) with 3D network structure by a one-step method, and then constructed sodium alginate (SA) cross-linked network by Ca2+ to fabricate a novel flexible, easy separable and structurally stable 3D hierarchical networks adsorbent (SA@MoS2/rGO/MF). The SA@MoS2/rGO/MF was applied for adsorption of Ag(I) in aqueous solution, and the maximum adsorption capacity was 1012.51 mg/g. The SA@MoS2/rGO/MF as a promising adsorbent could be used in the treatment of wastewater containing high concentration Ag(I). Interesting, the redox reaction and coordination reaction occurred simultaneously during the adsorption process to generate silver elemental and Ag2S, which are valuable sources for application in other fields. It’s worth noting that the SA@MoS2/rGO/MF could be constructed into arbitrary shape in favor of mass production. This work provides a feasible strategy for the separation of powder adsorbents.