A comprehensive melamine sponge decorated with 3D flowerlike Ag/NiCo-layered double hydroxide for wastewater remediation

In this work, 3D flowerlike Ag NPs/NiCo-layered double hydroxide (NiCo-LDH) decorated on melamine sponge was fabricated through a facile hydrothermal and in-situ reduction method. 3D flowerlike Ag NPs/NiCo-LDH were demonstrated to immobilize on the skeleton of polydopamine-pretreated melamine sponge. The melamine sponge decorated with 3D flowerlike Ag NPs/ NiCo-LDH presented outstanding catalytic activity for reduction of various water-soluble organic dyes in the appearance of NaBH4 as reducing agent, including 4-nitrophenol (4-NP), rhodamine B (RhB), methylene blue (MB) and methyl orange (MO), respectively. Owing to the appearance of Ag NPs, the melamine sponge decorated with 3D flowerlike Ag NPs/NiCo-LDH also showed efficient antibacterial activities against Gram-positive Staphylococcus aureus and Bacillus cereus, and Gram-negative Escherichia coli and Pseudomonas aeruginosa, suggesting its broad-spectrum antibacterial property. Moreover, the melamine sponge decorated with 3D flowerlike Ag NPs/ NiCo-LDH could also achieve the separation process for insoluble oils/organics from water by a facile surface modification technology after being treated toward low-surface-energy chemical of octadecylamine. The octadecylamine-coated sponge exhibited superhydrophobicity (WCA=158.6°) and superoleophilicity (OCA=0°), which could adsorb a wide range of oils/organics without the adsorption of any water, thus realizing the process of oil/water separation. The novel comprehensive melamine sponge demonstrates a new strategy for the remediation of complex polluted water.