Photocatalytic degradation of ethylene by Ga 2 O 3 polymorphs.

In this work, we fabricated four different Ga 2 O 3 polymorphs, namely, α-, β-, γ-, δ-Ga 2 O 3, and investigated their photocatalytic activities by the degradation of ethylene under ultraviolet (UV) light irradiation. Owing to the more positive valence band, all these Ga 2 O 3 polymorphs are more photocatalytic reactive than P25 during the degradation of ethylene. The normalized photocatalytic ethylene degradation rate constants of the as-prepared Ga 2 O 3 polymorphs follow the order: α-Ga 2 O 3 > β-Ga 2 O 3 > γ-Ga 2 O 3 > δ-Ga 2 O 3 , which is mainly determined by the position of VBM and the crystallinity of the samples. Among these Ga 2 O 3 polymorphs, γ-Ga 2 O 3 , 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-Ga 2 O 3 produces the least CO. These attributes are beneficial for ethylene degradation during post-harvest storage of fruits and vegetables, which makes γ-Ga 2 O 3 a potential candidate for practical photocatalytic ethylene degradations.