Photocatalytic degradation of ethylene by TiO2 nanotubes/ reduced graphene oxide prepared by gamma irradiation

Abstract

A nanocomposite photocatalyst of TiO2 nanotubes/reduced graphene oxide (rGO-TNTAs) were prepared by γ-ray radiolysis. The rGO-TNTAs were studied for photocatalytic decomposition of ethylene (C2H4) in a refrigerated environment. Degradation efficiency of ethylene by these materials was described by the apparent first-order rate constant (K). The composite was characterized by Raman spectroscopy (RS), X-ray photoelectron spectroscopy (XPS), Atomic force microscopy (AFM) and Field emission electron microscopy (FESEM). The preparing parameters for materials affecting the degradation efficiency in terms of the rate constant were studied, including the GO addition and the irradiation dose. The results showed that (1) gamma irradiation can induce GO to partial rGO, the rGO surface of rGO-TNTAs was smooth and loosely lamellar structure. (2) The K of the rGO-TNTAs is highly dependent on the GO addition and the irradiation dose. With a GO addition of 0.1 g and an irradiation dose of 20 kGy, the maximum K value of rGO-TNTAs could be obtained under the experimental conditions. (3) From analysis of the Raman spectroscopy spectrum, optimum changes had occurred in the intensity ratio of D-band to G-band of the GO that had been γ-ray-irradiated with a dose of 20 kGy, resulting in the K of rGO-TNTAs increased by 40.9% compared with that of TNTAs.