We describe stable intercalation compounds of the composition xN 2̇WO 3 (x = 0.034-0.039), formed by trapping N 2 in WO 3. The incorporation of N 2 significantly reduced the absorption threshold of WO 3; notably, 0.039N 2̇WO 3 anodes exhibited photocurrent under illumination at wavelengths ≥640 nm with a faradaic efficiency for O 2 evolution in 1.0 M HClO 4(aq) of nearly unity. Spectroscopic and computational results indicated that deformation of the WO 3 host lattice, as well as weak electronic interactions between trapped N 2 and the WO 3 matrix, contributed to the observed red shift in optical absorption. Noble-gas-intercalated WO 3 materials similar to xN 2̇WO 3 are predicted to function as photoanodes that are responsive to visible light.
ASJC Scopus subject areas
- Colloid and Surface Chemistry