1：Experimental Design and Method Selection:

The study involved the preparation of TiO2 coatings through a sol–gel process combined with the addition of commercial TiO2 particles (Degussa-Evonik P25). Simple and composite sols were prepared and deposited on glass plates via dip-coating. The order of reagent addition, P25 incorporation, and thermal treatments were varied to optimize photocatalytic activity.

2：5). Simple and composite sols were prepared and deposited on glass plates via dip-coating. The order of reagent addition, P25 incorporation, and thermal treatments were varied to optimize photocatalytic activity. Sample Selection and Data Sources:

2. Sample Selection and Data Sources: Pyrex glass microslides were used as supports for the films. The photocatalytic activity was evaluated using 4-chlorophenol degradation and Cr(VI) reduction in the presence of EDTA as model systems.

3：List of Experimental Equipment and Materials:

Titanium tetraisopropoxide, absolute ethanol, HCl, 4-chlorophenol, potassium dichromate, ethylenediaminetetraacetic acid, and Degussa-Evonik P25 TiO2 particles were used. Equipment included a Philips HPA 400S 9G lamp for photocatalytic irradiations, a Hewlett-Packard diode array UV-visible spectrophotometer for measurements, and a Philips PW-3710 diffractometer for XRD analysis.

4：Experimental Procedures and Operational Workflow:

Sols were prepared with specific molar ratios of reagents, deposited on glass plates by dip-coating, dried, and thermally treated. The photocatalytic activity was assessed by irradiating the samples with the model pollutants and measuring degradation over time.

5：Data Analysis Methods:

The photocatalytic degradation was analyzed using pseudo-first order kinetics for 4-CP degradation and a combination of first and zero order kinetics for Cr(VI) reduction.