{
  "abstract": "Earth-abundant photocatalysts for solar H₂ struggle to absorb deep visible light and separate charges at the same time. Here we show that a small amount of reduced ceria on carbon nitride achieves both. Non covalent CexOy/C3N4 heterostructures with 4% and 7% cerium oxide were compared with CeO2 and C3N4 references for H₂ evolution at 410 and 465 nm. The key turns out to be not how much ceria is added, but in which state and how well it is spread. At 4%, ceria forms finely dispersed, oxygen-deficient nanoparticles rich in Ce3+/oxygen-vacancy (Ov) defects, as revealed by Ce M4,5- and O K-edge NEXAFS and supported by XPS, which shows reduced cerium, no fluorite lattice oxygen and the highest surface exposure of Ce. At 7%, the particles agglomerate. These defects extend light absorption into the visible range and act as electron traps: time-resolved microwave conductivity and photoluminescence reveal faster, productive electron transfer from C3N4 to ceria at 4%. As a result, the 4% composite delivers ~682 µmol g-1 h -1 (AQY ~0.57% at 410 nm), outperforming all other samples at both wavelengths. With a surface area similar to C3N4, the gain is electronic and defect-driven, not textural.",
  "abstract_shown": true,
  "affiliations": [
    "Departamento de Quimica, ICEx",
    "Universidade Federal de Minas Gerais",
    "Chair 'Chemistry of Thin Film Materials', Materials Chemistry section, Department of Chemistry and Pharmacy, IZNF, Cauerstraße 3, Erlangen, Germany, 91058",
    "Institute of Materials for Electronics and Energy Technology (i-MEET",
    "Friedrich-Alexander-Universität Erlangen-Nürnberg",
    "Chemistry Division, School of Science and Technology",
    "University of Camerino",
    "Laboratoire de Physique des Solides, Université Paris Saclay, 1 rue Nicolas Appert, Orsay, France, 91405",
    "Department of Materials Science and Engineering, Friedrich-Alexander-Universität Erlangen-, 15 Nürnberg, Martensstraße 5, Erlangen, Germany, D-91058",
    "Institute of Polymer Materials",
    "Friedrich-Alexander-University Erlangen-Nürnberg",
    "Laboratory for Molecular Engineering of Optoelectronic Nanomaterials (LIMNO",
    "Institute of Chemical Sciences",
    "Harwell Science and Innovation Campus",
    "HarwellXPS, Research Complex at Harwell, Rutherford Appleton Lab, Didcot, United Kingdom, OX11 0FA",
    "Department of Chemistry, University College London, 20 Gower Street, London, United Kingdom, WC1H 0AJ",
    "Institute of Chemical Sciences and Engineering",
    "École Polytechnique Fédérale de",
    "Department of Chemical and Pharmaceutical Sciences, University of Trieste, via Licio Giorgieri 1, Trieste, Italy, 34127",
    "Centre for Energy and Environmental Technologies",
    "VŠB–Technical University of Ostrava",
    "Institute for Solar Fuels, Helmholtz-Zentrum Berlin für Materialien und Energy GmbH, Hahn-Meitner-Platz 1, Berlin, Germany, 14109",
    "Faculty of Science,",
    "Paderborn University",
    "Profile Center Solar (FAU Solar, Freyeslebenstraße 1, Erlangen, Germany, 91058"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 19,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Ingrid F. Silva"
    },
    {
      "affs": [
        2
      ],
      "name": "Heer Shah"
    },
    {
      "affs": [
        3,
        4
      ],
      "name": "Christian Kupfer"
    },
    {
      "affs": [
        5,
        6
      ],
      "name": "Asia Patriarchi"
    },
    {
      "affs": [
        7
      ],
      "name": "Erwan Paineau"
    },
    {
      "affs": [
        8
      ],
      "name": "Maria Rita Cicconi"
    },
    {
      "affs": [
        9,
        10
      ],
      "name": "Linda Rockmann"
    },
    {
      "affs": [
        11,
        12
      ],
      "name": "Kevin Sivula"
    },
    {
      "affs": [
        9,
        10
      ],
      "name": "Marcus Halik"
    },
    {
      "affs": [
        13
      ],
      "name": "David C. Grinter"
    },
    {
      "affs": [
        14,
        15
      ],
      "name": "Robert Palgrave"
    },
    {
      "affs": [
        16,
        17
      ],
      "name": "Michael Grätzel"
    },
    {
      "affs": [
        18
      ],
      "name": "Paolo Fornasiero"
    },
    {
      "affs": [
        18,
        19,
        20
      ],
      "name": "Michele Melchionna"
    },
    {
      "affs": [
        21
      ],
      "name": "Dennis Friedrich"
    },
    {
      "affs": [
        22,
        23
      ],
      "name": "Nieves Lopez-Salas"
    },
    {
      "affs": [
        5,
        6
      ],
      "name": "Miguel Ángel Muñoz-Márquez"
    },
    {
      "affs": [
        14,
        15
      ],
      "name": "Mark Isaacs",
      "orcid": "0000-0002-0335-4272"
    },
    {
      "affs": [
        2,
        24
      ],
      "name": "Pablo Jiménez-Calvo",
      "orcid": "0000-0002-9826-6995"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/8qa2wwpfy847d.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15010119/v1",
  "fulltext_url": null,
  "id": "8qa2wwpfy847d",
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  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010119/v1",
  "language": null,
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2105|Advanced Photocatalysis Techniques"
    ]
  ],
  "openalex": "W7221066308",
  "pdf_url": "https://chemrxiv.org/doi/pdf/10.26434/chemrxiv.15010119/v1",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-08",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/8qa2wwpfy847d.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:22Z",
      "native_id": "10.26434/chemrxiv.15010119",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010119/v1"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "source:chemrxiv",
      "subfield": "general"
    }
  ],
  "title": "TRMC and NEXAFS Reveal Fast Electron Transfer to Ce3+/Oxygen-Vacancy Traps in Non-Covalent CexOy/C3N4 Interface for Photocatalytic H2",
  "title_text": "TRMC and NEXAFS Reveal Fast Electron Transfer to Ce3+/Oxygen-Vacancy Traps in Non-Covalent CexOy/C3N4 Interface for Photocatalytic H2",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:22Z",
  "url": "https://research.draconitic.com/paper/8qa2wwpfy847d",
  "venue": "ChemRxiv",
  "versions": []
}