Photodegradation of o -Cresol Using Light Emitting Diodes with Various Wavelengths in the Presence of Photocatalysts

Abstract

Abstract

Thin films of pure TiO₂, silver-deposited TiO₂, and platinum-deposited TiO₂ were prepared on quartz substrates by a dip-coating process for the photodecomposition of o-cresol under light emitting diodes (LEDs) irradiation instead of a traditional lamp. In this work, effects of noble metal doping, periodic illumination, and LEDs wavelength on the photoactivity, electrical energy consumption, and quantum yield were explored in an effort to better understand the roles of noble metal and LEDs characterization in photocatalytic reactions. Degradation of o-cresol under LED irradiation increased with the decreased wavelength of LEDs, due to the higher power energy of a photon. Pt/TiO₂ films on quartz substrates prepared by a photodeposition method exhibited excellent optical characteristics, energy savings, and visible light–induced photocatalytic properties compared with Ag/TiO₂ and pure TiO₂ (P25). E_EO increased from 22 to 31 kWh/m³/order indicating that energy consumption for periodic illumination was significantly lower than continuous illumination under similar experimental conditions. This study showed the feasible and potential use of LEDs in photocatalysis.