1：Experimental Design and Method Selection

The study involved preparing composite electrodes with different morphologies of TiO2 (nanoparticles and nanorods) incorporated into PEDOT:PSS. The electrocatalytic activities and impedance properties were analyzed using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS).

2：Sample Selection and Data Sources

Samples included TiO2 nanoparticles (<25 nm, Sigma-Aldrich) and TiO2 nanorods (diameter: 153±37 nm, length: 390±160 nm) prepared by electrospinning and ball milling. Composite electrodes were prepared with varying ratios of TiO2 NPs to TiO2 NRs.

3：List of Experimental Equipment and Materials

Equipment included X-ray diffraction spectrometer (Bruker? D8 X-Ray Diffractometer), FTIR-ATR system (Perkin-Elmer), Raman spectrometer (Thermo DXR Raman), SEM (FEI-QUANTA FEG 450), four-point probe resistivity stand (Lucas Labs S-302-4), and electrochemical analyzers (Gamry REF 600). Materials included PEDOT:PSS (Sigma-Aldrich), TiO2 nanoparticles (Sigma-Aldrich), and FTO glass (Teknoma).

4：Experimental Procedures and Operational Workflow

Composite pastes were prepared by mixing TiO2 with PEDOT:PSS, ultrasonically dispersing, and coating onto FTO glass. Films were dried at 85 °C. Thickness was measured using a micrometer and SEM. Electrochemical measurements were conducted in a three-compartment cell.

5：Data Analysis Methods

Data from CV and EIS were analyzed to determine electrocatalytic activity and charge transfer resistance. Surface area was measured using BET analysis. Spectroscopic data (XRD, FTIR, Raman) were used to confirm TiO2 presence and structure.