The photochemical oxidation of benzylic alcohols using N-hydroxyphthalimide (NHPI) catalyst, with Rose Bengal as a singlet oxygen photosensitizer, and the production of hydrogen peroxide (H2O2) under metal-free conditions is presented. Computational and experimental investigations support 1O2 as the oxidant that converts NHPI to the active radical intermediate phthalimide-N-oxyl (PINO). This is a green alternative to current methods of H2O2 production.