Here,we report cobalt nanoparticles encapsulated in nitrogen‐doped carbon(Co@NC)that exhibit excellent catalytic activity and chemoselectivity for room‐temperature hydrogenation of nitroarenes.Co@NC was synthesized ...Here,we report cobalt nanoparticles encapsulated in nitrogen‐doped carbon(Co@NC)that exhibit excellent catalytic activity and chemoselectivity for room‐temperature hydrogenation of nitroarenes.Co@NC was synthesized by pyrolyzing a mixture of a cobalt salt,an inexpensive organic molecule,and carbon nitride.Using the Co@NC catalyst,a turnover frequency of^12.3 h?1 and selectivity for 4‐aminophenol of>99.9%were achieved for hydrogenation of 4‐nitrophenol at room temperature and 10 bar H2 pressure.The excellent catalytic performance can be attributed to the cooperative effect of hydrogen activation by electron‐deficient Co nanoparticles and energetically preferred adsorption of the nitro group of nitroarenes to electron‐rich N‐doped carbon.In addition,there is electron transfer from the Co nanoparticles to N‐doped carbon,which further enhances the functionality of the metal center and carbon support.The catalyst also exhibits stable recycling performance and high activity for nitroaromatics with various substituents.展开更多
Nature-inspired artificial Z-scheme photocatalyst offers great promise in solar overall water splitting,but its rational design,construction and interfacial charge transfer mechanism remain ambiguous.Here,we design an...Nature-inspired artificial Z-scheme photocatalyst offers great promise in solar overall water splitting,but its rational design,construction and interfacial charge transfer mechanism remain ambiguous.Here,we design an approach of engineering interfacial band bending via work function regulation,which realizes directional charge transfer at interface and affords direct Z-scheme pathway.Taking BiVO_(4)as prototype,its oxygen vacancy concentration is reduced by slowing down the crystallization rate,thereby changing the work function from smaller to larger than that of polymeric carbon nitride(PCN).Consequently,the photoinduced charge transfer pathway of BiVO_(4)/PCN is switched from type-Ⅱto Z-scheme as evidenced by synchronous illuminated X-ray photoelectron spectroscopy(XPS)and femtosecond transient absorption spectroscopy.Specifically,the direct Z-scheme BiVO_(4)/PCN shows superior photocatalytic performance in water splitting.This work provides deep insights and guidelines to constructing heterojunction photocatalysts for solar utilization.展开更多
文摘Here,we report cobalt nanoparticles encapsulated in nitrogen‐doped carbon(Co@NC)that exhibit excellent catalytic activity and chemoselectivity for room‐temperature hydrogenation of nitroarenes.Co@NC was synthesized by pyrolyzing a mixture of a cobalt salt,an inexpensive organic molecule,and carbon nitride.Using the Co@NC catalyst,a turnover frequency of^12.3 h?1 and selectivity for 4‐aminophenol of>99.9%were achieved for hydrogenation of 4‐nitrophenol at room temperature and 10 bar H2 pressure.The excellent catalytic performance can be attributed to the cooperative effect of hydrogen activation by electron‐deficient Co nanoparticles and energetically preferred adsorption of the nitro group of nitroarenes to electron‐rich N‐doped carbon.In addition,there is electron transfer from the Co nanoparticles to N‐doped carbon,which further enhances the functionality of the metal center and carbon support.The catalyst also exhibits stable recycling performance and high activity for nitroaromatics with various substituents.
基金supported by the National Natural Science Foundation of China(22161142002 and 21978200)。
文摘Nature-inspired artificial Z-scheme photocatalyst offers great promise in solar overall water splitting,but its rational design,construction and interfacial charge transfer mechanism remain ambiguous.Here,we design an approach of engineering interfacial band bending via work function regulation,which realizes directional charge transfer at interface and affords direct Z-scheme pathway.Taking BiVO_(4)as prototype,its oxygen vacancy concentration is reduced by slowing down the crystallization rate,thereby changing the work function from smaller to larger than that of polymeric carbon nitride(PCN).Consequently,the photoinduced charge transfer pathway of BiVO_(4)/PCN is switched from type-Ⅱto Z-scheme as evidenced by synchronous illuminated X-ray photoelectron spectroscopy(XPS)and femtosecond transient absorption spectroscopy.Specifically,the direct Z-scheme BiVO_(4)/PCN shows superior photocatalytic performance in water splitting.This work provides deep insights and guidelines to constructing heterojunction photocatalysts for solar utilization.
