ReadMe – Dataset for Ultra-Thin Ru-Sputtered on Ti-Felt Gas Diffusion Layer as Anode for Proton Exchange Membrane Electrolyzer DOI: To be assigned Depositor: Dr. Alexey Y. Ganin Date: 01 July 2026 Institution: WestCHEM, School of Chemistry, University of Glasgow, University Avenue, Glasgow G12 8QQ, United Kingdom 1. Dataset Overview This dataset contains the raw data corresponding to the figures and supplementary information in the associated research work on ultra-thin ruthenium (Ru) sputtered titanium felt (Ti-felt) gas diffusion layer anodes for proton exchange membrane (PEM) water electrolysis. The dataset includes structural, surface, electrochemical, and single-cell performance data used to generate the figures presented in the manuscript. The experimental techniques include X-ray Photoelectron Spectroscopy (XPS), X-ray Diffraction (XRD), cyclic voltammetry (CV), chronoamperometry (CA), polarization measurements, and PEM electrolyzer performance testing. The dataset is provided as a single Microsoft Excel workbook containing all relevant numerical data. 2. File Description File name: ultra-thin Ru sputtered Ti-felt for PEM Data File.xlsx This Excel workbook contains twelve worksheets: Sheet 1 Figure 1: High-resolution XPS spectra (Ru 3p region) of Ru-sputtered Ti-felt electrodes under different thermal treatment conditions. Sheet 2 Figure 2: Electrochemical characterization including polarization curves and cyclic voltammetry measurements of the Ru-sputtered Ti-felt electrodes. Sheet 3 Figure 3: Chronoamperometry and cyclic voltammetry data evaluating catalytic activity and electrochemical stability. Sheet 4 Figure 4: Single-cell PEM water electrolyzer polarization performance comparing Ru-sputtered Ti-felt electrodes with commercial RuO₂ electrodes. Sheet 5 Figure S5: X-ray diffraction (XRD) patterns of Ti felt, Ru-coated samples, and reference diffraction data. Sheet 6 Figure S6: XPS survey spectra of Ru-sputtered Ti-felt electrodes before and after thermal treatments. Sheet 7 Figure S8: Supplementary electrochemical measurements including polarization and durability testing. Sheet 8 Figure S9: Supplementary XRD comparison of Ti felt substrates and RuO₂ reference materials. 3. Software Requirements File Type: .xlsx Required Software: Microsoft Excel, LibreOffice Calc, or any software supporting XLSX format (e.g., R, Python Pandas), Origin Lab (optional for plotting). Notes: Data are in standard tabular format with labelled columns. 4. Data Description Each worksheet contains tabulated numerical data with labelled columns corresponding to the measured variables. Typical X-axis variables include: Binding Energy (eV) Potential (V) Time (s) Current Density (mA cm⁻²) Current (mA) 2θ (degrees) Number of electrochemical cycles Typical Y-axis variables include: XPS Intensity (a.u.) XRD Intensity (a.u.) Current Density (mA cm⁻²) Cell Voltage (V) Mass Activity (mA mgRu⁻¹) Current (mA) Numerical values are reported as exported directly from the analytical instruments. Blank columns are included where necessary to separate individual datasets corresponding to different figure panels. Abbreviations used: a.u. – arbitrary units eV – electronvolt XPS – X-ray Photoelectron Spectroscopy EDS - Energy dispersive X-ray spectroscopy XRD – X-ray Diffraction CV – Cyclic Voltammetry CA – Chronoamperometry PEM – Proton Exchange Membrane 5. Instrument / Technique Details XRD: Rigaku Miniflex X-ray diffractometer (600 W X-ray tube, D/teX Ultra silicon strip detector). XPS: Shimadzu (AXIS Supra+) instrument, coupled with Al Kα1 radiation. Cyclic Voltammetry (CV): Biologic SP-150 - Electrochemical activity characterization. Chronoamperometry (CA):Biologic SP-150 Electrochemical stability measurements. Linear Sweep / Polarization Measurements: Biologic SP-150Evaluation of catalytic activity. PEM Water Electrolyzer Testing: Lanhe potentiostat (Battery cycler testing system)-high current (5A, 10 V) Single-cell performance evaluation under practical operating conditions. Instrument models and operating conditions are described in detail within the associated research article. 6. Chemicals / Materials Used The principal materials and components used include: Platinized titanium (Ti)-fiber felt: 53–56% porosity, thickness 0.25 ± 0.05 mm (Fuel Cell Store). Ruthenium (Ru) sputtering target: 99.95% purity, 3-inch diameter, 1 mm thickness (Moorfield Nanotechnology). Silicon dioxide/silicon (SiO₂/Si) reference substrate: 300 nm thermal oxide, used for Ru film thickness measurements by AFM. Acetone: ACS reagent, ≥99.5% (Merck), used for substrate cleaning. Deionized water: Used for substrate cleaning, membrane pretreatment, and electrolyte supply. Nitrogen (N₂) gas: 99.9% purity (BOC), used to maintain an inert atmosphere during electrochemical measurements. Argon (Ar) gas: Used as the sputtering gas and as the inert atmosphere during annealing. Perchloric acid (HClO₄): 0.1 M electrolyte prepared from 99.99% HClO₄ (Thermo Scientific Chemicals). Carbon felt: 3.18 mm thick, 99.0% purity (Thermo Scientific Chemicals), used as the counter electrode in three-electrode measurements. Ag/AgCl reference electrode: Saturated 3 M NaCl (CH Instruments, USA). Nafion N115 membrane: Proton exchange membrane (Ion Power, UK). Pt/C gas diffusion electrode: Platinum supported on Vulcan carbon cloth with Pt loading of 0.5 mg cm⁻², used as the cathode for PEM electrolyzer testing. Titanium flow fields: Serpentine-channel flow fields (Dioxide Materials) with an active area of 5 cm². PTFE gaskets: Fuel Cell Store, used for sealing and electrode compression during single-cell assembly. The Ru-sputtered Ti-felt electrodes were investigated in three conditions: As prepared (no post-treatment) 400 °C-Air: Annealed at 400 °C for 3 h in air 400 °C-Argon: Annealed at 400 °C for 3 h under flowing argon 7. Additional Information Data Format: Each data column represents a measurement series corresponding to a plotted line in the associated figure. Contact Information: For further information about this dataset, please contact: Dr. Alexey Y. Ganin alexey.ganin@glasgow.ac.uk WestCHEM, School of Chemistry, University of Glasgow, University Avenue, Glasgow G12 8QQ, United Kingdom