Application of high power UV LEDs in heterogeneous photocatalysis

In our work, we designed and built a photochemical reactor with High Power LED light sources, and then tested its operation by heterogeneous photocatalytic decomposition of coumarin. The UV-LEDs emitting at a wavelength of 367(±10) nm were built into a frame with air-cooling elements. A well-controlled electrical power source was used to control and regulate the light output of the LEDs. The photon flux was measured at different electric power inputs, and was found to be linearly dependent on electrical power. Coumarin was used to test the new photoreactor during heterogeneous photocatalysis using TiO2 and ZnO as photocatalysts. At low photon flux the UV-LEDs outperformed a fluorescent mercury-vapor lamp in terms of efficiency and power consumption, but their usage at high electric input is not favorable.