Facile ion-exchanged synthesis of Sn~(2+) incorporated potassium titanate nanoribbons and their visible-light-responded photocatalytic activity

摘要

Sn~(2+)-incorporated potassium titanate (K_2Ti_6O_(13) nanoribbons were prepared by a facile acid-free ion-exchanged method in a dehydrated methanol solution at room temperature. XRD patterns suggested that K_2Ti6O_(13) (KTO) and Sn~(2+) -incorporated KTO (SKTO) are well crystallized with monoclinic phase structures. The mole ratio of incorporated Sn~(2+) to K~(2+) in SKTO was estimated to be 2. X-ray photoelectron spectrum showed that the Sn species of SKTO consisted of 90% of Sn~(2+) and 10% of Sn~(2+), suggesting that part of Sn~(2+) was oxidized to Sn~(2+) in the incorporation process. The band gap of SKTO was 0.7 eV narrower than that of KTO, which was derived from lift of the top of the valence band due to the hybridization of SnBs and O2p orbitals. The SKTO nanoribbons showed remarkable photocatalytic activities for H_2 evolution and rhodamine B degradation under visible light irradiation (λ > 420 nm). The photocatalytic mechanism and durability were studied in detail. The advantage of this acid-free ion-exchange method is ease of ion-exchange of K~+ with H~+ and maintenance of the integrity of the ID nanoribbon structures. This method can be applied to preparation of other Sn~(2+)-incorporated compounds with special nanostructures.