1：Experimental Design and Method Selection:

The study used a simple set-up focusing on kinetics and mechanistic pathways during H2O2 generation, detecting intermediates from sacrificial reagent degradation. A Langmuir-Hinshelwood kinetic model was employed for simulation, with numerical optimization using the Levenberg-Marquardt algorithm.

2：Sample Selection and Data Sources:

Sacrificial electron donors including alcohols, aldehydes, and carboxylic acids were selected. TiO2 (P25) suspensions in phosphate buffer (pH 7) were used, with samples taken at defined intervals.

3：List of Experimental Equipment and Materials:

Glass reactor, UV-LED (365 nm, M365LP1, Thorlabs), collimating optics (SM1P25-A, Thorlabs), magnetic stirrer, O2 bubbling system, ultrasound glass finger (UP200 St, Hielscher), centrifuge, GC-FID (Focus, Thermo Fischer), ion chromatography (Dionex, Thermo Fischer), microplate reader (PowerWave HT, BioTek and SynergyMx, BioTek), HPLC (Nexera X2, Shimadzu), LCMS (LCMS-8040, Shimadzu). Chemicals from Carl Roth, Merck EMD, Sigma-Aldrich, Alfa Aesar, VWR, abcr.

4：Experimental Procedures and Operational Workflow:

TiO2 suspensions were illuminated under UV light with O2 bubbling. Samples were taken, centrifuged, and analyzed using GC, IC, HPLC, and fluorescence methods for quantification of reactants, intermediates, and H2O

5：Data Analysis Methods:

Kinetic modeling with Langmuir-Hinshelwood equations, numerical simulation using Euler-Cauchy method, non-linear optimization with least squares. Statistical analysis of reaction rates and efficiencies.