{
  "abstract": "Organic semiconductors are promising candidates for light-assisted electrocatalysis but interfacial design remains a key challenge for improving performance and durability. Design guidelines include: i) appropriate matching of the catalyst Fermi level to the transport level of charges in the organic semiconductor under operando; ii) controlling surface hydrophilicity for rapid bubble-release in the hydrogen evolution reaction; and iii) retained operation in acidic and alkaline media. Herein we demonstrate a surface-modification approach on five different soft photocathodes to create terminating phosphonic acid surfaces, yielding high-surface energy interfaces across pH ranges from 1 to 13. In acidic conditions, using Pt nanoparticle catalysts, photoelectrochemical devices exhibit photocurrent densities of ~9 mA cm−2 and onset potential of ~0.82 V, surpassing non-surface modified controls by approximately 35–95% and 10–30%, respectively. Improvements are attributed to efficient gas bubble desorption kinetics and increased photovoltages. Surface-enhanced Raman spectroscopy is then used to monitor the Stark shift of a vibrational probe molecule on a metal nanoparticle, enabling the quantification of the quasi-Fermi level of the catalytic site and photovoltage on the unmodified and modified polymer surfaces under operation (i.e., applied bias). The phosphonic acidterminated surfaces yield dramatically increased photovoltages relative to unmodified surfaces. Finally, to demonstrate the broader application of the modifier, we show the approach is readily amenable to increasing the pH~6 for Pt and the binding stability RuOx catalysts. Collectively, our observations suggest a scalable, robust, and efficient route to organic photoelectrochemical devices as well as energy conversion and storage and sensing platforms.",
  "abstract_shown": true,
  "affiliations": [
    "School of Materials Sciences and Engineering",
    "Georgia Institute of Technology",
    "Department of Chemistry",
    "University of Pennsylvania",
    "RASEI",
    "University of Colorado Boulder",
    "Department of Chemistry and Biochemistry",
    "University of Arizona",
    "Department of Chemical and Biochemical Engineering",
    "School of Chemistry and Biochemistry"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 9,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Eui Hyun Suh"
    },
    {
      "affs": [
        2,
        3
      ],
      "name": "Bo Dong"
    },
    {
      "affs": [
        4,
        5
      ],
      "name": "Yadong Zhang"
    },
    {
      "affs": [
        6,
        7
      ],
      "name": "Zhiting Chen"
    },
    {
      "affs": [
        2,
        3
      ],
      "name": "Giorgi Petriashvili"
    },
    {
      "affs": [
        4,
        5
      ],
      "name": "Stephen Barlow"
    },
    {
      "affs": [
        2,
        3
      ],
      "name": "Tianquan Lian"
    },
    {
      "affs": [
        4,
        5,
        8,
        2
      ],
      "name": "Seth R. Marder"
    },
    {
      "affs": [
        0,
        1,
        9
      ],
      "name": "Erin L. Ratcliff",
      "orcid": "0000-0002-2360-8436"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/8ekp6myhrbx43.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15009763/v1",
  "fulltext_url": null,
  "id": "8ekp6myhrbx43",
  "issns": [],
  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15009763/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": "W7215069444",
  "pdf_url": "https://chemrxiv.org/doi/pdf/10.26434/chemrxiv.15009763/v1",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-01",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/8ekp6myhrbx43.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:21Z",
      "native_id": "10.26434/chemrxiv.15009763",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15009763/v1"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "source:chemrxiv",
      "subfield": "general"
    }
  ],
  "title": "Surface functionalization of soft photocathodes with an azido-phosphonic acid monolayer for robust and efficient solar-to-H2 conversion",
  "title_text": "Surface functionalization of soft photocathodes with an azido-phosphonic acid monolayer for robust and efficient solar-to-H2 conversion",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:21Z",
  "url": "https://research.draconitic.com/paper/8ekp6myhrbx43",
  "venue": "ChemRxiv",
  "versions": []
}