Effect of controlled periodic-based illumination on the photonic efficiency of photocatalytic degradation of methyl orange

► Photocatalytic oxidation of methyl orange using a UV-LED based reactor and periodic illumination. ► Photonic efficiency and degradation studied by independently controlling light and dark times. ► Photonic efficiency increases and photodegradation decreases with reducing light times (TON). ► Photonic efficiency was inversely related to duty cycle. ► Photonic efficiency under periodic and continuous illumination at same average power comparable.