Synthesis and characterization of layered niobate K4Nb6O17 thin films by niobium-chelated precursor

Using niobium-chelated precursor, a novel method for synthesizing layered niobate (K4Nb6O17) thin films was developed. After annealing at 600 °C or above, the nanostructured K4Nb6O17 thin films with (0 4 0) preferred orientation were successfully produced by sol-gel process. XPS measurement showed that the atomic ratio of K:Nb:O in the thin film was 4.08:5.99:16.77, which was in good accordance with the stoichiometry of K4Nb6O17. Varying with annealing parameters, the layered structure of the thin films altered and the hydrated layered K4Nb6O17·3H2O thin films presented while low pyrolysis temperature was applied. The hydrogen evolution from water decomposition showed the excellent photocatalytic properties of the films. The static hydrogen evolution for the thin film annealed at 600 °C reached 105 μmol cm−2 h−1.