Correlation of crystal structures, electronic structures and photocatalytic properties in W-based oxides

We reported a novel W-based oxide NaBi(WO4)(2) with WO4 tetrahedral crystal structure as a photocatalyst for decomposition of 2-propanol. The physical characteristics of the sample were examined by XRD, BET measurement and SEM, respectively. The band gap of NaBi(WO4)(2) was determined to be 3.6 eV according to the diffuse reflectance spectra of the sample. The photocatalytic activity of NaBi(WO4)(2) was confirmed by decomposing 2-propanol into acetone and CO2. It showed a higher acetone generation rate (211 ppm h(-1)) in contrast to that of WO3 (120 ppm h(-1)), which consisted of WO6 octahedra. Their electronic structures were further investigated by the plane-wave based density function theory. The results suggested that the crystal field (WO6 and WO4) significantly influenced the electronic structures and hence affected the photocatalytic activity.