Pt Single-Atom Catalysts on FTO for Optically Invisible pH-Universal Hydrogen Evolution Electrodes

Kim JH, Zhou X, Doronkinb DE, Sarmac BB, Dobrota AS, Skorodumova NV, Pašti IA, Schmidt J, Schmuki P (2026)

Publication Type: Journal article

Publication year: 2026

Journal

Advanced Energy Materials Wiley

Book Volume: 16

Article Number: e71493

Journal Issue: 37

DOI: 10.1002/aenm.71493

Abstract

Transparent hydrogen-evolution electrodes are essential for photoelectrochemical and optoelectronic energy-conversion devices, yet typically suffer from a trade-off between catalytic activity and optical transmission. Here, we demonstrate that an ultra-low loading of Pt single atoms (SA, 0.03 at%) directly anchored on fluorine-doped tin oxide (FTO) via a reactive deposition delivers hydrogen evolution reaction (HER) kinetics approaching bulk Pt, while remaining optically invisible. At this low SA loading, HAADF-STEM directly resolves atomically isolated Pt sites, while x-ray photoelectron and absorption spectroscopy confirm exclusively cationic Ptδ+ (δ ≈ 2) in Pt–O4 coordination. The Pt SA/FTO electrodes exhibit pH-universal HER activity, alongside turnover frequencies exceeding 500 s−1 at moderate overpotentials. Density Functional Theory calculations support the high stability of Pt SA/FTO and explain exceptional HER activity by optimized energetics of intermediate formation. Achieving comparable kinetics with conventional sputtered Pt films requires >1000-fold higher Pt loading and leads to substantial optical losses. Owing to its optical neutrality, the Pt SA/FTO electrode enables 2–3 × higher photocurrents than activity-matched Pt films when used as a counter electrode in sandwich-type photoelectrochemical cells. These results on Pt SA-decorated FTO thus describe a general strategy to unite noble-metal utilization, high catalytic efficiency, and optical transparency in electro- and photoelectrochemical devices.

Authors with CRIS profile

Ji Hyeon Kim Lehrstuhl für Werkstoffwissenschaften (Korrosion und Oberflächentechnik) (LKO) Xin Zhou Lehrstuhl für Werkstoffwissenschaften (Korrosion und Oberflächentechnik) (LKO) Jochen Schmidt Institute of Interfaces and Particle Technology (IPT) Patrik Schmuki Lehrstuhl für Werkstoffwissenschaften (Korrosion und Oberflächentechnik) (LKO)

Involved external institutions

Université Fédérale de Toulouse Midi-Pyrénées FR France (FR) University of Belgrade / Универзитет у Београду RS Serbia (RS) Luleå University of Technology SE Sweden (SE) Karlsruhe Institute of Technology (KIT) DE Germany (DE)

How to cite

APA:

Kim, J.H., Zhou, X., Doronkinb, D.E., Sarmac, B.B., Dobrota, A.S., Skorodumova, N.V.,... Schmuki, P. (2026). Pt Single-Atom Catalysts on FTO for Optically Invisible pH-Universal Hydrogen Evolution Electrodes. Advanced Energy Materials, 16(37). https://doi.org/10.1002/aenm.71493

MLA:

Kim, Ji Hyeon, et al. "Pt Single-Atom Catalysts on FTO for Optically Invisible pH-Universal Hydrogen Evolution Electrodes." Advanced Energy Materials 16.37 (2026).

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