Hydrothermal Synthesis and Photocatalytic Properties of Chromium(VI)-Doped Tungsten Oxide

The substitutional solid solution based on hexagonal tungsten trioxide h-W1−xCrxO3, where 0.01 ≤ x ≤ 0.03, was obtained for the first time using the hydrothermal synthesis. It was found that the homogeneity region of the solid solution for the dopant ion is determined by the acidity of the working solution. The interstitial solid solution with the maximum dopant ion content (x = 0.03) is formed at pH 2.0. The compounds h-W1−xCrxO3 are composed of agglomerated particles with spherical (pH 2.0) or rod-like (pH 1.6) morphology. The synthesized samples were tested as photocatalysts for the oxidation of 1,2,4-trichlorobenzene under UV irradiation. The results of quantum chemical modeling indicate that the electronic factor does not play a crucial role in chromium(VI) doping of h-WO3, with all possible changes in the catalytic activity of the doped compound being caused by the emerging features of its texture or defectiveness.