Photocatalytic Reduction of Cr(VI) under Visible Light over Bi2WO6 with Different Morphologies

Abstract

Bi2WO6 samples with different morphologies were hydrothermally synthesized and applied to the photoreduction of hexavalent chromium under visible-light irradiation. It was found that nanosheets with high exposure of {100} facets and crystallinity exhibited the best photocatalytic performance: two times as active as nanoparticles based on specific rate constant.

Facile Synthesis of Hierarchically Structured Bi2S3/Bi2WO6 Photocatalysts for Highly Efficient Reduction of Cr(VI)

“…The synthesized Bi 2 WO 6 and Bi 2 S 3 /Bi 2 WO 6 composites with hierarchical heterostructures were used as photocatalysts for a reduction of Cr (VI) ions. Deng et al previously reported high reduction efficiency for Cr­(VI) using Bi 2 WO 6 with different morphologies by irradiating LED white light rather than using simulated solar light Figure shows the photoreduction efficiencies of Cr­(VI) in the presence of different catalysts after exposure to visible light for 60 min at room temperature and ambient pressure.…”

“…Deng et al previously reported high reduction efficiency for Cr(VI) using Bi 2 WO 6 with different morphologies by irradiating LED white light rather than using simulated solar light. 11 Figure 7 shows the photoreduction efficiencies of Cr(VI) in the presence of different catalysts after exposure to visible light for 60 min at room temperature and ambient pressure. For comparison, photocatalytic experiments were also performed with no catalyst, nonporous and cubic structured Bi 2 S 3 /Bi 2 WO 6 and P25 of TiO 2 as reference photocatalysts.…”

“…Bismuth tungstate (Bi 2 WO 6 ) is one such ternary oxide, having a band gap of 2.8 eV. Bi 2 WO 6 has been utilized primarily for dye degradation and water splitting appications. − In addition, by varying the morphologies of Bi 2 WO 6 or forming different heterostructures through hybridization, such as with BiVO 4 , BiOCl, and Bi 2 O 3 , it has demonstrated its promising potential in highly efficient photocatalytic applications. − Similar to bismuth tungstate, bismuth sulfide (Bi 2 S 3 ) is a metal sulfide with a lamellar-like structure with a direct band gap of 1.3 eV, and exhibits promising photocatalytic activity toward dye degradation and heavy metal ion reduction reactions. , Bi 2 S 3 has also been shown to form heterostructures with BiOCl, BiVO 4 , Bi 2 O 2 CO 3 , and Bi 2 WO 6 in photochemical applications. − …”

Visible Light Active Single-Crystal Nanorod/Needle-like α-MnO2@RGO Nanocomposites for Efficient Photoreduction of Cr(VI)

“…Among all of these, photocatalytic removal of Cr­(VI) by semiconductor photocatalysts is considered as an attractive and gainful method. In the photocatalytic reduction process, Cr­(VI) is reduced to Cr­(III) which is nontoxic and plays a vital role in plant and animal metabolism. , Therefore, semiconductor photocatalysts such as TiO 2 , ZnO, SnS 2 , ZnGeO 4 , Sn 2 S 3 , and Bi 2 WO 6 have been reported for the reduction of Cr­(VI) to Cr­(III). − …”