2. Comparative Performance of Representative Photocatalytic Systems Reported for Diclofenac Degradation under Different Irradiation and Reaction Conditions.

Photocatalyst	Light source	Reaction time	Initial diclofenac concentration	Degradation efficiency	Key operational consideration	Reference
TiO2 P25	150 W medium-pressure mercury lamp.	15 min	30 mg L–1	Complete removal	Prompt removal of 0.10 g L–1 TiO2 P25 at pH 6.2 required an artificial UV-rich source and immersion-well reactor design
Ag3PO4/g-C3N4 (30 mol % Ag3PO4 relative to g-C3N4	300 W Xe lamp, λ ≥ 400 nm	12 min	1 mg L–1	Complete DCF removal; 43.2% TOC removal	Use of 0.10 g L–1 catalyst resulted in partial reduction of Ag3PO4 to metallic Ag, but not total mineralization as DCF disappeared
Ag–BiOI–rGO nanocomposite	300 W halogen lamp, visible light	80 min	10 mg L–1	Approximately 99–100%	Ag and decreased graphene oxide modification are required; multicomponent synthesis and probable Ag leaching should be considered
g-C3N4 nanosheets	Four 10 W white light LEDs	150 min of irradiation	3 mg L–1	Apparent rate constant, k = 0.031 min–1 in tap water and 0.015 min–1 in ultrapure water	The catalyst loading was 0.65 g/L–1.Approximately 5% adsorption occurred during the 40 minute dark equilibration stage, and the photocatalytic rate depended heavily on the water matrix
NH2-MIL-125/g-C3N4 composite, MOF3N4 mass ratio = 50:50	UV-LED irradiation at 384 nm	120 min	10 mg L–1	Complete DCF disappearance	This technique used near-UV radiation rather than visible light. To increase activity, a Ti-based MOF was combined with g-C3N4
TiO2–carbon microspheres	Simulated solar light	180 min	5 mg L–1	Complete DCF disappearance; approximately 50% mineralization	Preparation involves carbonization and solvothermal TiO2 deposition, with a long irradiation time and low starting contaminant concentrations
Cu2ZnSnS4 nanoparticles	300 W xenon lamp fitted with a UV-exclusion filter; visible-light-only irradiation at 1 sun	120 min	10 mg L–1	80 ± 10% DCF degradation; final DCF concentration = 1.9 ± 0.2 mg L–1	A catalyst concentration of 1.0 g L–1 was utilized. Catalyst recycling was yet to be investigated, and the authors recognized optimization of catalyst loading and recyclability as important follow-up studies
BiSI nanorods	500 W halogen lamp with UV cutoff	120 min	1.0 × 10–4 M diclofenac potassium, approximately 33.4 mg L–1	95.2%	predominantly orthorhombic BiSI, narrow band gap (1.65 eV); robust visible harvest	This work