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