Antimonite Photocatalysis — Reaction-Diffusion Field

This is the same photocatalytic water-treatment chemistry as the 3D nanoparticle-bed sim — UV-activated metal-oxide surfaces oxidizing toxic Sb(III) antimonite to the far less mobile Sb(V) antimonate — but solved as a genuinely 2D-native mechanism: a finite-difference reaction-diffusion field instead of discrete particles colliding with spheres. Two concentration maps diffuse across a membrane while a fixed catalyst-density map sets where the conversion sink term is active; UV intensity, catalyst loading, solution pH and a stirring-rate diffusion control let you watch the same pseudo-first-order kinetics emerge from continuum chemistry, cross-checked live against a least-squares fit through the decay curve.