Evaluation of reactive oxygen species and photocatalytic degradation of ethylene using β-Ag2MoO4/g-C3N4 composites

Abstract

The photocatalytic degradation of ethylene is an efficient technology applied to the fruit ripening control. When photocatalytic reactions remove ethylene from the storage and transportation environment of fruits and vegetables, the respiration rate decreases, and the quality of food is preserved for a long time. It is well known that photocatalysis involves the photogeneration of electron-hole pairs (e−/h+) under light irradiation, separation, and migration of charges on the material surface, oxidation and reduction reactions involving electrons and holes pairs, and charge recombination on the catalyst surface. In this study, we report the syntheses, characterization, and evaluation of photocatalytic activity of the β-Ag2MoO4/g-C3N4 photocatalysts to degrade ethylene in the gas phase under UV-A irradiation. The effect of the β-Ag2MoO4:g-C3N4 ratio on reactive oxygen species (ROS) generation and increasing the electron/hole charge separation is evaluated in detail. Under UV-A illumination and the absence of water, superoxide radicals are most efficiently produced in hybrid samples containing a higher g-C3N4 percentage, but lower O2·− amount is formed in pure g-C3N4. The hybrid samples containing higher amounts of g-C3N4 are more efficient to degrade ethylene because of better e− and h+ charge separation and superoxide radicals’ formation, which participate in ethylene degradation.