Synergistic Spatial Confining Effect and O Vacancy in WO3 Hollow Sphere for Enhanced N2 Reduction

Yuzhou Xia; Xinghe Xia; Shuying Zhu; Ruowen Liang; Guiyang Yan; Feng Chen; Xuxu Wang

doi:10.3390/molecules28248013

Synergistic Spatial Confining Effect and O Vacancy in WO₃ Hollow Sphere for Enhanced N₂ Reduction

Molecules. 2023 Dec 8;28(24):8013. doi: 10.3390/molecules28248013.

Authors

Yuzhou Xia^{1

2

3}, Xinghe Xia^{1

2}, Shuying Zhu¹, Ruowen Liang², Guiyang Yan², Feng Chen², Xuxu Wang³

Affiliations

¹ College of Chemistry, Fuzhou University, Fuzhou 350116, China.
² Fujian Province University Key Laboratory of Green Energy and Environment Catalysis, Ningde Normal University, Ningde 352100, China.
³ State Key Laboratory of Photocatalysis on Energy and Environment, Research Institute of Photocatalysis, College of Chemistry, Fuzhou University, Fuzhou 350116, China.

Abstract

Visible-light-driven N₂ reduction into NH₃ in pure H₂O provides an energy-saving alternative to the Haber-Bosch process for ammonia synthesizing. However, the thermodynamic stability of N≡N and low water solubility of N₂ remain the key bottlenecks. Here, we propose a solution by developing a WO_3-x hollow sphere with oxygen vacancies. Experimental analysis reveals that the hollow sphere structure greatly promotes the enrichment of N₂ molecules in the inner cavity and facilitates the chemisorption of N₂ onto WO_3-x-HS. The outer layer's thin shell facilitates the photogenerated charge transfer and the full exposure of O vacancies as active sites. O vacancies exposed on the surface accelerate the activation of N≡N triple bonds. As such, the optimized catalyst shows a NH₃ generation rate of 140.08 μmol g^-1 h^-1, which is 7.94 times higher than the counterpart WO₃-bulk.

Keywords: N2 reduction; O defect; WO3; hollow sphere; photocatalysis.

Abstract

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