The active sites of monodisperse transition metal Ni-clusters were anchored on carbon nitride(CN)by an in situ photoreduction deposition method to promote the efficient separation of photogenerated charges and achieve...The active sites of monodisperse transition metal Ni-clusters were anchored on carbon nitride(CN)by an in situ photoreduction deposition method to promote the efficient separation of photogenerated charges and achieve high-efficiency photocatalytic activity for hydrogen evolution.The Ni-cluster/CN exhibited a photocatalytic hydrogen production rate of 16.5 mmol·h^(-1)·g^(-1) and a total turnover frequency(TOF(H_(2)))value of 461.14 h^(-1).X-ray absorption spectroscopy based on synchrotron radiation indicated that CN had two reaction centers to form stable interface interactions with monodispersed Ni-clusters,in which carbon can act as an electron acceptor,while nitrogen can act as an electron donor.Meanwhile,the hybrid electronic structure of the Ni-cluster/CN system was constructed,which was favorable for photocatalytic activity for hydrogen production.An in-depth understanding of the interfacial interaction between CN and Ni-clusters will have important reference significance on the mechanistic study of development based on the cocatalyst.展开更多
As cathodes,iron-series(Fe,Co,Ni)clusters supported by carbon materials exhibit outstanding electrocatalytic reduction activities in many electrocatalytic applications.To date,this general characteristic of ironseries...As cathodes,iron-series(Fe,Co,Ni)clusters supported by carbon materials exhibit outstanding electrocatalytic reduction activities in many electrocatalytic applications.To date,this general characteristic of ironseries clusters that should be related to the inherent attributes of these electrodes has not been fully understood from the perspectives of thermodynamics and electronic structure alone.Electron transport is a necessary process in electrocatalysis,and therefore,the study of the change of the electronic state in electron transport is beneficial for understanding this general characteristic of iron-series cluster catalysts.In this work,the electron transport properties,including the conductivity and transport spin-polarization at the Ni-cluster/graphene interface are carefully investigated as an example of carbon-supported iron-series electrodes.Using first-principles calculations within the framework of the nonequilibrium Green’s function density functional theory(NEGF-DFT),we reveal that the electronic transport states of the coupled Ni-cluster/graphene are strongly changed compared to those of their isolated Ni-cluster and graphene component.It is found that graphene dominates the overall conductivity of the interface,while the morphology of Ni-clusters controls the spin polarization efficiency.High spin polarization can lead to the self-excitation effect of the electrons that raises the energy of the electronic system,improves the thermodynamics of the reduction reaction and promotes catalytic activity.Our work hints that iron-series elements(Fe,Co,Ni)based electrodes may generally show transport polarization that is likely to give rise to a high electrocatalytic reduction activity and such transport polarizability can be used as a new factor in the further exploration and design for electrocatalytic materials.展开更多
文摘The active sites of monodisperse transition metal Ni-clusters were anchored on carbon nitride(CN)by an in situ photoreduction deposition method to promote the efficient separation of photogenerated charges and achieve high-efficiency photocatalytic activity for hydrogen evolution.The Ni-cluster/CN exhibited a photocatalytic hydrogen production rate of 16.5 mmol·h^(-1)·g^(-1) and a total turnover frequency(TOF(H_(2)))value of 461.14 h^(-1).X-ray absorption spectroscopy based on synchrotron radiation indicated that CN had two reaction centers to form stable interface interactions with monodispersed Ni-clusters,in which carbon can act as an electron acceptor,while nitrogen can act as an electron donor.Meanwhile,the hybrid electronic structure of the Ni-cluster/CN system was constructed,which was favorable for photocatalytic activity for hydrogen production.An in-depth understanding of the interfacial interaction between CN and Ni-clusters will have important reference significance on the mechanistic study of development based on the cocatalyst.
基金supported by‘111’Project in China(B20029)the Fundamental Research Funds for the Central Universities(N2007011)Major R&D Project of Yunnan Province,China(Grant No.2018ZE001 and 202002AB080001-1)。
文摘As cathodes,iron-series(Fe,Co,Ni)clusters supported by carbon materials exhibit outstanding electrocatalytic reduction activities in many electrocatalytic applications.To date,this general characteristic of ironseries clusters that should be related to the inherent attributes of these electrodes has not been fully understood from the perspectives of thermodynamics and electronic structure alone.Electron transport is a necessary process in electrocatalysis,and therefore,the study of the change of the electronic state in electron transport is beneficial for understanding this general characteristic of iron-series cluster catalysts.In this work,the electron transport properties,including the conductivity and transport spin-polarization at the Ni-cluster/graphene interface are carefully investigated as an example of carbon-supported iron-series electrodes.Using first-principles calculations within the framework of the nonequilibrium Green’s function density functional theory(NEGF-DFT),we reveal that the electronic transport states of the coupled Ni-cluster/graphene are strongly changed compared to those of their isolated Ni-cluster and graphene component.It is found that graphene dominates the overall conductivity of the interface,while the morphology of Ni-clusters controls the spin polarization efficiency.High spin polarization can lead to the self-excitation effect of the electrons that raises the energy of the electronic system,improves the thermodynamics of the reduction reaction and promotes catalytic activity.Our work hints that iron-series elements(Fe,Co,Ni)based electrodes may generally show transport polarization that is likely to give rise to a high electrocatalytic reduction activity and such transport polarizability can be used as a new factor in the further exploration and design for electrocatalytic materials.
