Advanced oxidation processes, including photocatalysis, have been proven effective at organic dye degradation. Tailored porous materials with regulated pore size, shape and morphology offer a sustainable solution to the water pollution problem, by acting as support materials to grafted photocatalytic nanoparticles (NPs). This research investigates the influence of pore and particle sizes of photocatalytic MICROSCAFS®, on the degradation of methyl orange (MO) in aqueous solution (10 mg/L). Photocatalytic MICROSCAFS® are made of binder-less supported P25 TiO2 NPs within MICROSCAFS®, which are silica-titania microspheres with controlled size and intercon-nected macroporosity, synthesized by an adapted sol-gel method that involves a polymeriza-tion-induced phase separation process. Photocatalytic experiments were done both in batch and flow reactors, these latter ones targeting real-life conditions. Photocatalytic degradation of 87% in 2 hours (batch) and 29% in 5 hours (flow), was achieved, using a calibrated solar light simulator (1 sun) and a photocatalyst/pollutant mass ratio of 23. This study introduces a novel flow kinetic model which provides the modeling and simulation of the photocatalytic MICROSCAFS® per-formance. A scavenger study was performed enabling in-depth mechanistic understanding. Fi-nally, the transformation products resulting from the MO photocatalytic degradation were elu-cidated by high-resolution mass spectrometry experiments and subjected to in-silico toxicity as-sessment.