In-situ synthesis of mixed phase electrospun TiO2 nanofibers: a novel visible light photocatalyst

Abstract

TiO2 nanofibers were synthesized by electrospinning method using mixed titanum isopropoxide and polyvinylpyrrolidone precursors in ethanol followed by calcination at high temperature. The obtained TiO2 e-spun nanofibers were characterized by FESEM, TEM, XRD, XPS and BET surface area analytical techniques. XRD result shows that the nanofibers contain both anatase and rutile mixed phases. FESEM and TEM study indicates the development of precise fine tiny nanoparticles with diameter in the range of 10–20 nm, which are oriented along one dimensional direction to form the fibrous structure with diameter in the range of 300–500 nm. The mixed phase TiO2 nanofibers were used as photocatalysts for degradation of Rhodamine-B and Methyl orange under solar light irradiation and also under visible light irradiation. More than 99% degradation was achieved within 90 min of irradiation time for both the dyes. Furthermore, it is observed that the TiO2 photocatalyst is efficiently degrading (98%) the tetracycline hydrochloride solution within 70 min of contact time. The excellent visible light photocatalytic activity may be attributed to the combine factors of hetero-conjunction at anatase–rutile interface and immediate charge transfer due to 1D structure, which inhibit the electron–hole recombination. Rutile-Anatase dual phase TiO2 nanofibers exhibit excellent visible light photocatalytic activity due to the combine factors of hetero-conjunction at anatase-rutile interface and immediate charge transfer due to 1D structure, which inhibits the electron-hole recombination.