Charge-controllable mussel-inspired magnetic nanocomposites for selective dye adsorption and separation

Yintung Lam, Suju Fan, Liang He, Yan Ki Ho, Bin Fei, John H. Xin

Research output: Journal article publicationJournal articleAcademic researchpeer-review

9 Citations (Scopus)


Magnetic polydopamine (PDA) nanocomposites were prepared with a facile and sustainable synthetic method. The as-synthesized polymer-based hybrid composites inherited the intrinsic adhesiveness contributed by catechol and amino moieties of PDA as well as the magnetic property of Fe3O4. With the unique properties of PDA, the surface charges of Fe3O4@PDA could be easily tuned by pH for smart adsorption-desorption behaviors. Four commercially available dyestuffs including crystal violet, rhodamine B, direct blue 71 and orange G with different structures and surface charges in solution were selected to investigate the adsorption ability and universality of Fe3O4@PDA in wastewater treatment. It was found that the nanocomposites could successfully adsorb these cationic and anionic dyes under suitable pH conditions. This confirmed the ability of the nanoadsorbents for the removal of common textile dyes. The dispersed magnetic nanoadsorbents also demonstrated the ease of collection from dye mixtures, and the possibility of reusing them for several cycles. Selective dye separation was found to be achievable via simple charge control without large consumption of organic solvent and energy. These bio-inspired nanocomposite adsorbents have shown high potential in wastewater treatment and selective recovery of dye waste, especially for wastewater containing ionic dyes.

Original languageEnglish
Article number134404
Publication statusPublished - Aug 2022


  • Charge control
  • Magnetic polydopamine
  • Selective dye adsorption
  • Wastewater treatment

ASJC Scopus subject areas

  • Environmental Engineering
  • General Chemistry
  • Environmental Chemistry
  • Pollution
  • Public Health, Environmental and Occupational Health
  • Health, Toxicology and Mutagenesis


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