{
  "abstract": "The pervasive contamination of water by synthetic dyes such as methyl orange (MO) presents a critical global challenge, compounded by the vast, underutilized volumes of industrial solid waste such as steel slag. This study addresses this dual problem via a circular-economy strategy that transforms waste into a functional material. A novel, magnetically separable adsorbent was developed via nickel-ion crosslinking of chitosan (CS) onto a composite of slag and slag-derived magnetic iron nanoparticles (Chitosan@Slag/Fe-MNPs). The material was characterized by FTIR, XRD, BET, and FESEM, and its adsorption performance was evaluated through systematic batch studies. The composite achieved a maximum monolayer adsorption capacity of 98.52 mg g−1 for MO at 25 °C, following the Elovich model and a Langmuir isotherm. MO removal is primarily driven by electrostatic attraction and surface complexation between the anionic dye and the protonated amine/metal-oxide sites of the composite, with pseudo-second-order-consistent kinetics indicating a possible partial contribution from surface-reaction-limited (chemisorption-type) steps. The composite showed high selectivity for anionic dyes at acidic pH, excellent magnetic recovery, and moderate reusability, retaining approximately 47% of its initial removal efficiency after four regeneration cycles. Beyond adsorption, the spent MO-saturated composite was successfully repurposed as an electrocatalyst for the urea oxidation reaction (UOR), achieving a current density of 234.30 mA cm−2 at 1.0 M urea, representing a result attributable to urea oxidation rather than MO redox activity, as confirmed by the urea-concentration-dependence of the response. This waste-to-adsorbent-to-electrocatalyst strategy supports a sequential remediation-to-energy conversion pathway consistent with circular economy principles.",
  "abstract_shown": true,
  "affiliations": [
    "Materials Science and Nanotechnology Department, Faculty of Postgraduate Studies for Advanced Sciences, Beni-Suef University, Beni-Suef 62528, Egypt",
    "Department of Biology, College of Science, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh 11623, Saudi Arabia",
    "Department of Biology, College of Science, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia",
    "Minerals Beneficiation and Agglomeration Department, Central Metallurgical Research and Development Institute, El Tebbin, P.O. Box 87, Cairo 11421, Egypt",
    "Environmental Science and Industrial Development Department, Faculty of Postgraduate Studies for Advanced Science, Beni-Suef University, Beni-Suef 62511, Egypt",
    "Department of Pathology, College of Veterinary Medicine, King Faisal University, Al-Ahsa 31982, Saudi Arabia",
    "Chemistry Department, Faculty of Science, Beni-Suef University, Beni-Suef 62511, Egypt"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 8,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Samar M. Mahgoub",
      "orcid": "0000-0002-2896-7569"
    },
    {
      "affs": [
        1
      ],
      "name": "Ahmed A. Allam"
    },
    {
      "affs": [
        0
      ],
      "name": "Hala Mohamed"
    },
    {
      "affs": [
        2
      ],
      "name": "Haifa E. Alfassam"
    },
    {
      "affs": [
        3
      ],
      "name": "Ahmed Abdelazim Khalifa",
      "orcid": "0000-0003-3092-1516"
    },
    {
      "affs": [
        4
      ],
      "name": "Amal Zaher",
      "orcid": "0000-0001-6004-920X"
    },
    {
      "affs": [
        5
      ],
      "name": "Asmaa F. Khafaga",
      "orcid": "0000-0003-4235-669X"
    },
    {
      "affs": [
        6
      ],
      "name": "Rehab Mahmoud",
      "orcid": "0000-0003-2274-2016"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/7mtbeqxdnh963.bib",
  "cited_by": 0,
  "doi": "10.3390/catal16110968",
  "fulltext_url": null,
  "id": "7mtbeqxdnh963",
  "issns": [
    "2073-4344"
  ],
  "landing_url": "https://www.mdpi.com/2073-4344/16/11/968",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [],
  "openalex": null,
  "pdf_url": null,
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-30",
  "publisher": "MDPI AG",
  "ris": "https://research.draconitic.com/paper/7mtbeqxdnh963.ris",
  "sources": [
    {
      "first_seen": "2026-10-31T00:20:50Z",
      "native_id": "10.3390/catal16110968",
      "source": "crossref",
      "url": "https://www.mdpi.com/2073-4344/16/11/968"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "issn:2073-4344",
      "subfield": "catalysis"
    }
  ],
  "title": "Novel Magnetic Chitosan@Slag/Fe-MNP Nanocomposites for Methyl Orange Removal and Circular Valorization",
  "title_text": "Novel Magnetic Chitosan@Slag/Fe-MNP Nanocomposites for Methyl Orange Removal and Circular Valorization",
  "type": "peer-reviewed",
  "updated_at": "2026-11-01T00:20:48Z",
  "url": "https://research.draconitic.com/paper/7mtbeqxdnh963",
  "venue": "Catalysts",
  "versions": []
}