Hybridization of CuO with Bi₂MoO₆ Nanosheets as a Surface Multifunctional Photocatalyst for Toluene Oxidation under Solar Irradiation

Abstract

Herein, CuO/Bi 2 MoO 6 hybrid nanosheets were prepared as a surface multifunctional photocatalyst for gas-phase toluene oxidation with high conversion (>99%). Aberration-corrected scanning transmission electron microscopy suggested that CuO species were highly dispersed on the nanosheets. X-ray absorption fine structure spectra indicated that the distorted and stretched Cu−O coordination structures in CuO/Bi 2 MoO 6 nanosheets would provide open active sites. In situ Fourier transform infrared and density functional theory results showed that toluene molecules could be chemisorbed and activated on the active sites of CuO/Bi 2 MoO 6 nanosheets by the C−H group forming CuO/ Bi 2 MoO 6 •••Ph-CH 3 surface complex compounds. These would induce electron−hole transfer and initiate photocatalytic reactions under visible light irradiation. The corresponding intermediates of benzaldehyde and benzoic acid would be detected by in situ diffuse reflectance infrared Fourier transform spectroscopy. Furthermore, the synergistic effect of CuO and Bi 2 MoO 6 nanosheets could monitor charge dynamics to facilitate their respective transmission from photoexcitation sites to active centers. This work provides new insights into the essence of visible-light-driven surface photocatalysis and is expected to promote the design of novel and more effective photocatalysts at the molecular level.

Constructing a Cs3Sb2Br9/g‐C3N4 Hybrid for Photocatalytic Aromatic C(sp3)H Bond Activation

“…As shown in Figure S9b, Supporting Information, the characteristic bands of toluene (≈3027 cm −1 ) assigned to the aromatic ring of CH bond vibration were gradually reduced with prolonging irradiation time, while the broad peak located at ≈1683 cm −1 corresponding to the carbonyl group of benzaldehyde emerged and slightly increased. [ 38,39 ] These results indicated that the toluene molecules absorbed on the surface of catalyst reacted rapidly with holes and ·O 2 − under light irradiation.…”

Morphology Modulated Photocatalytic Activity of CeO2 Nanostructures for Selective Oxidation of Biobased Alpha‐Pinene to Oxygenates

“…This confirmed the photocatalytic activity effect of CeO 2 semiconductor oxide with tuneable NRs morphology for the oxidation of pinene to oxygenated compounds. The obtained photocatalytic activity of CeO 2 nanostructures for oxyfunctionalization of the pinene inert CÀ H bond is comparable to the other multicomponents catalysts such as Zn 2 Tilayered double hydroxide, [44] heterojunction CdWO 4 /Bi 2 WO 6 , [45] TiO 2 /Bi 2 MoO 6 , [46] CuO/Bi 2 MoO 6 , [47] and bimetallic AuÀ Pd/g-C 3 N 4 [48] reported previously in the activitation of aromatic hydrocarbons CÀ H for the selective introduction of oxygen molecule.…”

Plasmonic Metal Bridge Leading Type III Heterojunctions to Robust Type B Photothermocatalysts

“…Regarding the PTC of VOCs, the WO 3 /Ag/GdCrO 3 presents a remarkably higher toluene degradation rate of 0.22 min –1 , which is ∼73 times higher than that of the Type III heterojunction WO 3 /GdCrO 3 , Ag/WO 3 , and Ag/GdCrO 3 with an initial ∼700 ppm toluene concentration and visible-light irradiation at 363 K and 6 times higher than the sum of the photocatalytic oxidation of toluene without heating and thermocatalytic oxidation of toluene at 363 K without irradiation (Figure a, b and Figure S11), as well as faster than the recently reported Type B heterojunction Ag 3 PO 4 /Ag/GdCrO 3 (0.16 min –1 ) and the other recently reported catalysts for the photocatalytic or photothermocatalytic toluene degradation reaction (Figure b and Table S2). ,,,− The WO 3 /Ag/GdCrO 3 also shows good cyclic stability for the photothermocatalytic toluene oxidation (Figure c) and excellent photothermocatalytic mineralization activity for benzene or xylene with the initial concentration of ∼700 ppm (Figure d). Thus, the introduction of Ag NP bridge into bandgap broken WO 3 /GdCrO 3 makes the as-developed Type B heterojunction WO 3 /Ag/GdCrO 3 a robust photothermocatalyst.…”

“…(b) Comparison of apparent reaction rate constants ( k ) of WO 3 /Ag/GdCrO 3 with the recently reported materials (Table S2). ,,,− (c) Cyclic stability of WO 3 /Ag/GdCrO 3 for toluene PTC. (d) Toluene, benzene, and xylene conversions versus time curves of WO 3 /Ag/GdCrO 3 under PTC conditions.…”