1：Experimental Design and Method Selection:

A simple hydrothermal method was used to synthesize the Cu/Bi2Ti2O7/rGO nanocomposite. The design aimed to trap photoexcited charge carriers using Cu nanoparticles and rGO sheets to enhance photocatalytic activity.

2：Sample Selection and Data Sources:

Pharmaceutical molecules tetracycline (TC) and ibuprofen (IBP) were used as target pollutants. All chemicals were analytical grade from Merck Chemical Company.

3：List of Experimental Equipment and Materials:

Materials included graphite flakes, copper sulphate pentahydrate, bismuth nitrate pentahydrate, titanium(IV) isopropoxide, sodium nitrate, hydrochloric acid, potassium permanganate, sulfuric acid, nitric acid, hydrogen peroxide, cetyltrimethylammonium bromide, sodium hydroxide, hydrazine hydrate, ethanolamine, ammonium hydroxide, ethanol, terephthalic acid, benzoquinone, isopropyl alcohol, triethanolamine, tetracycline, ibuprofen, and glacial acetic acid. Equipment included XRD (Rigaku Miniflex), XPS (Krotas analytical Instrument, Shimadzu Corporation, ESCA 3400), FTIR (Brucker Tensor 27), Raman spectrometer (LabRAM HR Horbia), SEM (Zeiss18 Evaluation), TEM (Jeol/JEM 2100), UV-Vis DRS (SHIMADZU-UV 1800), PL spectrophotometer (Perkin Elmer LS-45), TOC analyzer (Aurora 1030, O-I Analytical), and LC-TOF/MS (API 4000 Triple TOF 5600 LCQ Advantage MAX).

4：Experimental Procedures and Operational Workflow:

Synthesis involved preparing GO via modified Hummer's method, Cu nanoparticles via reduction, Bi2Ti2O7 via co-precipitation, and CBTG via hydrothermal self-assembly. Photocatalytic tests involved adding catalyst to pollutant solution, stirring in dark for adsorption-desorption equilibrium, irradiating with visible light (Xenon lamp with filter), sampling at intervals, and analyzing with UV-Vis. Trapping experiments used BQ, IPA, and TEOA as suppressors. Hydroxyl radical production was measured using terephthalic acid.

5：Data Analysis Methods:

Data were analyzed using pseudo first-order kinetics for degradation rates. Characterization techniques included XRD for crystalline structure, XPS for chemical states, FTIR for functional groups, Raman for bonding, SEM/TEM for morphology, UV-Vis DRS for optical properties, PL for charge recombination, and LC-TOF/MS for degradation intermediates.