Highly Intensified Molecular Oxygen Activation on Bi@Bi₂MoO₆ via a Metallic Bi-Coordinated Facet-Dependent Effect

Abstract

Construction of the semimetal/semiconductor composite interface is widely used to promote the O 2 molecule adsorption and charge transfer for boosting solardriven molecular oxygen activation (MOA). Herein, a Bi@ Bi 2 MoO 6 heterostructure is fabricated via a two-step wet chemical method as a typical photocatalyst to investigate the underlying mechanism of Bi-coordinated facet-dependent MOA under visible-light illumination. Density functional theory and systematical characterization methods reveal the distinct charge transfer and O 2 activation processes on the surface of Bi nanoparticle-deposited Bi 2 MoO 6 nanosheets with different facets exposed. By virtue of a particular and efficient [Bi 2 O 2 ] 2+ → Bi → MoO 4 2− interfacial charge-transfer channel, Bi deposited on the (001) facet of Bi 2 MoO 6 can observably intensify MOA, thereby giving birth to more generation of reactive oxygen species and endowing the Bi@Bi 2 MoO 6 with excellent photocatalytic performance in sodium pentachlorophenate (NaPCP) removal. The decomposition pathway of NaPCP is also proposed based on the intermediate determination and mineralization analysis. This work provides deep insights into the mechanism of facet-dependent MOA over a semimetal−semiconductor system and also sheds light on designing effective molecular oxygen-activated interface for environmental remediation.

Highly Selective Production of Ethanol Over Hierarchical Bi@Bi2MoO6 Composite via Bicarbonate‐Assisted Photocatalytic CO2 Reduction

“…Meanwhile, the Fourier‐transform (FT)IR spectra displayed that the absorption bands of Bi−O bond and Mo−O bond of Bi 2 MoO 6 −Vo and Bi@Bi 2 MoO 6 are weaker than that of pure Bi 2 MoO 6 , indicating that both samples contain oxygen defects (Figure S3). Abundant oxygen vacancies on the surface of Bi 2 MoO 6 nanosheets not only change the chemical coordination of Bi 3+ ions to form metal nanoparticles, but also facilitate chemical adsorption of CO 2 molecules on the surface of the photocatalysts [2b,8a,19] . Figure S4 shows the XPS spectra of Mo 3d; the two peaks at 232.73 and 235.88 eV were assigned to Mo 3d 5/2 and Mo 3d 3/2 of Bi 2 MoO 6 , respectively [20] .…”

Facile preparation of hierarchical heterostructured TiO2/Bi/Bi2MoO6 photocatalyst for phocatalytic degradation of toluene gas

“…8(b) displays the DMPO‐•O 2 − ESR signal distribution of TiO 2 /Bi 2 MoO 6 . The signal strength of adduct heightens with prolonging the illumination time, which represents the concentration grade of •O 2 − 44, 45 . According to the above results, it can be concluded that the free radicals (•OH and •O 2 − ) with strong oxidizing ability can be generated on the surface of the composite materials, so the degradation rate of pollutants is improved by the high oxidation ability.…”

“…As shown in Fig. 9, there is no obvious ESR signal under dark conditions, suggesting that there is no production or transformation of •OH 45 . While lighting for 1 min, 5, and 10 min, the ESR signals of DMPO‐•OH are enhanced sharply for the composite.…”

Review on Bismuth‐Based Photocatalyst for CO2 Conversion

“…reported semimetal bismuth mediated Bi 4 O 5 I 2 for CO 2 conversion [76] . The semimetal Bi also can be used as a co‐catalyst [77] . Then, the photo‐induced electron of Bi 4 O 5 I 2 converted to bismuth surface.…”