Dual-site activation enhanced photocatalytic removal of no with Au/CeO2

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2020-04, Vol.386, p.124047, Article 124047
• Main Authors: Shang, Huan, Huang, Shun, Li, Hao, Li, Meiqi, Zhao, Shengxi, Wang, Jiaxian, Ai, Zhihui, Zhang, Lizhi
• Format: Article
• Language: English
• Subjects: Air purification; Dual-site activation; Oxygen vacancy; Photocatalytic NO removal
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2020.124047

[Display omitted] •A bicomponent Au/CeO2 photocatalyst was developed for photocatalytic NO removal under visible light irradiation.•Au/CeO2 photocatalyst exhibited an enhanced photocatalytic NO removal performance.•Au/CeO2 photocatalyst achieved NO oxidation via dual-site activation pathway by the L-H mechanism.•Au nanoparticles loaded on the CeO2 surface were active centers for adsorption and activation of NO.•Oxygen vacancies on the CeO2 could favorably initiate the adsorption and activation of O2. Photocatalytic technology provides an effective strategy for aerobic purification of dilute gaseous NO pollutant, but suffers from its low efficiency. In this study, we demonstrate that the bicomponent Au/CeO2 photocatalyst possesses an enhanced photocatalytic NO removal performance under visible light irradiation, with a higher NO conversion efficiency (65%) and triple rate constant (0.1451 min−1) versus CeO2 (50%, 0.0448 min−1). Density function theory calculations and experimental results revealed that oxygen vacancies on the CeO2 component could favorably initiate the adsorption and activation of O2 to generate O2−, simultaneously, Au nanoparticles loaded on the CeO2 surface were active centers for adsorption and activation of NO to produce NO+ by plasmonic holes of the Au under visible light irradiation. Subsequently, these O2− and NO+ species generated via dual-site activation pathway on Au/CeO2 photocatalyst reacted spontaneously to generate the final NO3−, leading to enhanced photocatalytic removal of NO. This study sheds light on a dual-site induced photocatalytic NO oxidation and advances the design of effective air purification photocatalyst.