Coupling the Surface Plasmon Resonance of WO_3–x and Au for Enhancing the Photocatalytic Activity of the Nonoxidative Methane Coupling Reaction

Abstract

The surface plasmon resonance (SPR) effect of oxygen-deficient WO3–x has been utilized for photocatalysis in the literature. A unique feature of WO3–x is that its plasmonic peak can be adjusted to the visible light range, which is close to that of typical plasmonic metals like Au. In this work, we have demonstrated the coupling effect of the SPR of WO3–x and Au can significantly alter the photocatalytic activity toward the gas phase nonoxidative methane coupling reaction in terms of the C2 product rate and selectivity. A photocatalyst composed of Au and WO3–x nanoparticles of comparable size is prepared by the simple Pechini method and thermal reduction in a H2 containing atmosphere. The SPR of Au can mainly promote C2H6 production, while the SPR of WO3–x can mainly increase the selectivity to C2H4. Combining two such strategies can give a composite photocatalyst with a higher C2 production rate and almost 100% selectivity to C2H4 under visible light. Detailed characterization reveals that the coupling of Au and WO3–x can effectively prolong the charge lifetime and the charge generation rate, and improves the hydrogen evolution activity, which results in much higher photocatalytic activity.

Methane conversion coupled with hydrogen production from water using Au/Ga2O3 photocatalysts prepared by different methods

“…For Au/Ga 2 O 3 photocatalysts prepared by PF, BH and H 2 methods, the binding energies were 531.0 and 532.3 eV, 531.0 and 532.5 eV, 531.5 and 532.9 eV, respectively. The O V /O L ratio was estimated from peak areas, 45,46 and the value obtained for the b-Ga 2 O 3 material was 0.14. For Au/Ga 2 O 3 photocatalysts prepared by PF, BH and H 2 methods the values were 0.17, 0.10 and 0.12, respectively.…”

Deciphering the photocatalytic hydrogen generation process of Fresnoite Ba2TiGe2O8 by electronic structure and bond analyses

“…Moreover, Au and Ag were reported to exhibit a local surface plasmonic resonance (LSPR) effect in some cases and may endow the catalyst system with visible light activity. 41,42 Here, Au-and Ag-loaded Ba 2 TiGe 2 O 8 were both tested under xenon lamp irradiation with a 400 nm cut-off filter; however, no H 2 generation was detected. The powder XRD patterns for recovered catalyst powders after the photocatalytic reactions were all consistent with those before their use (see Fig.…”

Visible Light Photocatalytic Hydrogen Evolution Paired with Excellent Intramolecular Coupling of Dithiols into Sulfurous Heterocyclic Compounds over CdS/P25/Ni2P

“…Recent developments in hydrogen production have provided evidence that a dual-function photocatalytic system is an excellent project due to this technology, making green hydrogen evolution and nonhazardous substrate conversion under visible light. − Besides, as for the dual-function photocatalytic system, the photogenerated carriers can react with the substrates directly, avoiding the production of reactive radical intermediates; such systems exhibit a high yield for target products . A myriad of dual-function photocatalytic systems have been reported over the past few decades; − however, to the best of our knowledge, there is no prior study regarding photocatalytic hydrogen evolution coupled with the intramolecular coupling of dithiols into sulfurous heterocyclic compounds containing disulfide bonds.…”