Platinum-coated polystyrene (PT-PS) rough colloids were employed as catalysts to degrade methylene blue (MB), a representative organic pollutant, at the air-water interface. The particles were synthesized and examined using electron and light microscopy together with complementary analytical techniques to verify their morphology and surface features. Degradation tests were carried out at the air–water interface using an interface-trapping configuration under controlled circulation. At 50 RPM (Reynolds number of 1686) and a particle packing fraction of 0.8, MB was fully degraded within 30 minutes, while the same treatment in bulk solution required 75 minutes. The reaction followed the Langmuir–Hinshelwood model with a rate constant of 0.018 min. Kinetic predictions were evaluated using an Artificial Neural Network (ANN) model, giving a root mean square error (RMSE) of 5.5 and a correlation coefficient (R) of 0.9656. The approach allows rapid MB degradation while enabling catalyst recovery and low reagent consumption, offering a practical route for wastewater treatment.