Photochemistry & Photocatalysis

Photochemistry studies what happens once a molecule absorbs a photon and jumps to an excited electronic state; photocatalysis harnesses that excitation on a semiconductor surface — most famously TiO2 — to drive redox chemistry that would not otherwise happen at room temperature. This simulation visualizes the whole chain: photons of a chosen wavelength falling on catalyst nanoparticles, excitation succeeding only above the material's bandgap energy, the resulting electron-hole pair either recombining and wasting the energy or reacting with an adsorbed pollutant molecule and slowly degrading it. Adjust wavelength, intensity, catalyst density and recombination rate to see how each one shifts the quantum yield of a real photocatalytic reactor.