Photocatalytic degradation of ethylene by Ga2O3 polymorphs.

Abstract

In this work, we fabricated four different Ga2O3 polymorphs, namely, α-, β-, γ-, δ-Ga2O3, and investigated their photocatalytic activities by the degradation of ethylene under ultraviolet (UV) light irradiation. Owing to the more positive valence band, all these Ga2O3 polymorphs are more photocatalytic reactive than P25 during the degradation of ethylene. The normalized photocatalytic ethylene degradation rate constants of the as-prepared Ga2O3 polymorphs follow the order: α-Ga2O3 > β-Ga2O3 > γ-Ga2O3 > δ-Ga2O3, which is mainly determined by the position of VBM and the crystallinity of the samples. Among these Ga2O3 polymorphs, γ-Ga2O3, with the highest surface area, exhibits the highest activity during photocatalytic ethylene degradation, and the degradation rate constant is almost 10 times as that of P25. Furthermore, with the most positive CBM, γ-Ga2O3 produces the least CO. These attributes are beneficial for ethylene degradation during post-harvest storage of fruits and vegetables, which makes γ-Ga2O3 a potential candidate for practical photocatalytic ethylene degradations.