Intercalation of iron oxide in layered H2Ti4O9 and H4Nb6O17: visible-light induced photocatalytic properties

Abstract

H₂Ti₄O₉/Fe₂O₃·nH₂O and H₄Nb₆O₁₇/Fe₂O₃·nH₂O nanocomposites containing intercalated Fe₂O₃·nH₂O, particles of <1 nm thickness, were fabricated by the photochemical decomposition of [Fe₃(CH₃CO₂)₇(OH)· H₂O)]⁺ incorporated in the inter-layer of H₂Ti₄O₉ and H₄Nb₆O₁₇. Both nanocomposites were capable of hydrogen evolution to the extent of 8.1–8.7 cm³ over 5 h, following irradiation with visible light (λ > 400 nm) from a 450 W Hg lamp in the presence of Na₂SO₃ as a sacrificial donor. The hydrogen production activity of these nanocomposites was superior to that of unsupported Fe₂O₃·nH₂O. The hydrogen production was enhanced to 11.3–13.6 cm³ over 5 h by doping Pt together with Fe₂O₃·nH₂O in the interlayer. Hydrogen evolution was linear with time with the niobate system being slightly more efficient.