A phase separation in a protonated layered nickel titanate to form Ni-doped anatase/rutile TiO2 nanocomposite with efficient visible-light responsive photocatalytic activity. Issue 3 (2nd July 2020)

• Record Type: Journal Article
• Authors: Saito, Kanji; Komiya, Yusuke; Sohmiya, Minoru; Ogasawara, Masataka; Kato, Sumio
• Is Part Of: Journal of Asian ceramic societies. Volume 8:Issue 3(2020)
• Page Start: 915
• Page End: 924
• Publication Date: 2020-07-02
• Subjects: Layered titanate -- phase separation -- anatase/rutile nanocomposite -- Ni-doping -- visible-light responsive photocatalyst; Ceramics -- East Asia -- Periodicals; Materials science -- Periodicals; 620.1405
• DOI: 10.1080/21870764.2020.1793875
• Languages: English
• ISSNs: 2187-0764

Abstract

ABSTRACT: We report a simple methodology for the preparation of an efficient visible-light responsive TiO2 photocatalyst through acid treatment of a lepidocrocite-type layered nickel cesium titanate (Cs0.7 Ti1.65 Ni0.35 O4 ) for interlayer protonation and subsequent calcination at different temperatures (400–600°C) to induce structural transformation. The Ni-doped anatase/rutile nanocomposite possessing a morphology similar to that of protonated layered nickel titanate is obtained at all calcination temperatures. The sample obtained at 600°C exhibits the highest visible-light responsive photocatalytic activity for decomposition of the aqueous methylene blue dye under visible-light (λ > 420 nm) irradiation. The activity is 14 times higher than that of P25 (standard TiO2 photocatalyst) modified with Ni 2+ and 3 times higher than that of NiTiO3 (visible-light responsive photocatalyst). The efficient visible-light responsive photocatalytic activity is ascribable to the visible-light absorption ability of the TiO2 phase owing to Ni-doping. Also, an efficient electron transfer across anatase–rutile interfaces for inhibition of charge recombination could be responsible for the activity. This methodology is a new route for efficient visible-light responsive photocatalysts based on TiO2 doped with various elemental species. This is because lepidocrocite-type layered titanates are available in a variety of chemical compositions. GRAPHICAL ABSTRACT: uf0001