The activation of reactants and intermediates promotes the selective photocatalytic NO conversion on electron-localized Sr-intercalated g-C3N4

• Published in: Applied catalysis. B, Environmental Environmental, 2018-09, Vol.232, p.69-76
• Main Authors: Dong, Xing’an, Li, Jieyuan, Xing, Qian, Zhou, Ying, Huang, Hongwei, Dong, Fan
• Format: Article
• Language: English
• Subjects: DRIFTS; Electron localization; In situ; NO oxidation; Reactants activation; Selective photocatalysis
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2018.03.054

[Display omitted] •The Sr-intercalated g-C3N4 has been theoretically designed and prepared.•The vertical charge channel and localized excess electrons have been achieved.•Localized excess electrons promote the activation of O2 and pollutants.•The yield of target products were monitored and quantified by in situ DRIFTS.•Adsorption energy of pollutant and intermediates production was calculated. Photocatalysis technology has been widely adapted to address air pollution. However, the photocatalysis efficiency and selectivity should be optimized to achieve efficient and safe air purification. Take the g-C3N4 (CN) as a case study, in order to promote the photocatalytic performance and the selectivity of g-C3N4 in oxidizing NO into target products of NO2− and NO3−, the electron localization has been built in Sr-intercalated g-C3N4 (CN-Sr) to promote the activation of reactants and intermediates, as well as the charge separation and transfer. The intercalated Sr atom causes the uneven electron distribution on the plane of CN. The O2 could capture the localized excess electrons and be activated producing O2− radicals. The NO and the reaction intermediates could deplete the electrons more easily and be activated on the surface of CN-Sr. The activated species possess longer bond length and have higher reactivity during photocatalysis, making them easier to be destroyed by active radicals and transforming to target products of NO2− and NO3− rather than other toxic byproducts. With the pivotal effect of localized electrons in CN-Sr, the photocatalytic activity and selectivity can be simultaneously promoted. With the in situ DRIFTS investigation and theoretical calculation, the present work specified the transportation and transformation of photogenerated carriers and revealed the mechanism of photocatalytic NO oxidation. This work could provide a new approach to enhance the photocatalytic activity and selectivity for efficient and safe air pollution control.