Photocatalytic Degradation of Ethylene Emitted by Fruits with TiO2 Nanoparticles

The photocatalytic degradation of ethylene (emitted by fruits) by novel TiO 2 nanoparticles (TNPs), at 3 °C, has been investigated to consider the possibility of its use for the cold storage of fruits. TNP exhibits a high specific surface area, a good anatase-to-rutile mixed phase ratio, and more surface OH groups than commercially available Degussa P 25, as characterized by nitrogen adsorption, static light scattering, energy dispersive X-ray spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. TNPs, tested in an ad-hoc designed Pyrex glass photocatalytic reactor, showed higher photodegradation activity of ethylene than Degussa P 25. The superior characteristics of TNPs, compared to Degussa P 25, might induce the adsorption of ethylene and water and the generation of OH groups which act as oxidizing agents on the TNP surface, leading to higher photocatalytic activity. In the absence of water the photocatalytic degradation of ethylene reduced significantly. Moreover, a positive effect was observed when UV light was converged on the catalyst and an increase in ethylene degradation was achieved when UV light converging pipes and lens were used.