1：Experimental Design and Method Selection:

The study involved preparing Ti-doped hematite nanorod arrays via hydrothermal synthesis, followed by acid-treatment with acetic acid. Characterization included SEM, HRTEM, XRD, XPS, UV-vis spectroscopy, SPV transient, work function measurements, and various PEC measurements to analyze charge separation and surface states.

2：Sample Selection and Data Sources:

Samples were Ti-Fe2O3 nanorod arrays on FTO substrates, with and without acid-treatment. Data were obtained from laboratory experiments using synthesized materials.

3：List of Experimental Equipment and Materials:

Equipment included SU8020 SEM, HRTEM, Rigaku D/Max-2550 XRD, Thermo Scientific Escalab 250Xi XPS, Shimadzu UV-3600 spectrophotometer, home-made SPV and transient systems, Kelvin probe (SKP 5050), CHI 660e electrochemical analyzer, xenon lamps, monochromators, and oscilloscopes. Materials included FeCl3·6H2O, NaNO3, TiCl4, acetic acid, FTO glass, and KOH electrolyte.

4：Experimental Procedures and Operational Workflow:

Hydrothermal synthesis of Ti-Fe2O3 at 100°C for 4 h, annealing at 550°C for 2 h, acid-treatment in acetic acid for 5 min, drying, and annealing at 450°C for 30 min. PEC measurements in 1 M KOH with a three-electrode setup under AM 1.5G illumination.

5：5G illumination. Data Analysis Methods:

5. Data Analysis Methods: Data analysis involved calculating IPCE, LHE, injection efficiency, Mott-Schottky plots, EIS fitting, and integration of photocurrent spikes using standard equations and software tools like lock-in amplifiers and oscilloscopes.