The growth and thermal stability of Au clusters on a partially-reduced rutile TiO2 （110）-1 × 1 surface were investigated by high-resolution photoelectron spectroscopy using synchrotron- radiation-light. The val...The growth and thermal stability of Au clusters on a partially-reduced rutile TiO2 （110）-1 × 1 surface were investigated by high-resolution photoelectron spectroscopy using synchrotron- radiation-light. The valence-band photoelectron spectroscopy results demonstrate that the Ti^3＋3d feature attenuates quickly with the initial deposition of Au clusters, implying that Au clusters nucleate at the oxygen vacancy sites. The Au4f core-level photoelectron spectroscopy results directly prove the existence of charge transfer from oxygen vacancies to Au clusters. The thermal stability of Au clusters on the partially-reduced and stoichiometric TiO2（110） surfaces was also comparatively investigated by the annealing experiments. With the same film thickness, Au clusters are more thermally stable on the partially-reduced TiO2（110） surface than on the stoichiometric TiO2（110） surface. Meanwhile, large Au nanoparticles are more thermally stable than fine Au nanoparticles.展开更多
An alternate approach to parametrizing the expression for the total energy of Au clusters within the second moment approximation (SMA) of the tight binding (TB) theory has been described. A type of many body interatom...An alternate approach to parametrizing the expression for the total energy of Au clusters within the second moment approximation (SMA) of the tight binding (TB) theory has been described. A type of many body interatomic potential for Au from first principle’s calculations has been constructed. The key of the approach is adjusting the total-energy expression of the TB SMA method to augmented plane wave (APW) total energy results. The lattice constant, melting temperature, and the bulk modulus are in agreement with available experimental values. The method and results of Au cluster properties are shown to be very useful and suitable in describing the clusters and bulk metals.展开更多
Gold(Au)nanoclusters supported on various supports have been widely used in the fields of energy and catalysis.However,the poor thermal stability of Au nanoclusters on the support interface usually leads to a reductio...Gold(Au)nanoclusters supported on various supports have been widely used in the fields of energy and catalysis.However,the poor thermal stability of Au nanoclusters on the support interface usually leads to a reduction or even loss of catalytic activity.Herein,we used an in situ reduction method to synthesize Au nanoclusters on ceria(CeO_(2))carriers.In this method,sulfhydryl groups were used to modify CeO_(2) nanospheres first,and then Au clusters with an average diameter of 1.5 nm were grown on the surface of ceria reduced with sodium borohydride.The presence of the Au-S-Ce structure enhances the electron transfer efficiency,making the material exhibit high CO oxidation activity at room temperature.Furthermore,due to the strong binding energy of S and Au,the material exhibits a high stability for long time running process.This strategy provides an idea for designing stable and active supported ultrasmall Au nanoclusters catalytic materials.展开更多
The size of metal nanoparticles is a key factor to enhance the photocatalytic activity of photocatalysts.However,the mechanism of this factor to the improvement of photocatalytic CO_(2) reduction performance is still ...The size of metal nanoparticles is a key factor to enhance the photocatalytic activity of photocatalysts.However,the mechanism of this factor to the improvement of photocatalytic CO_(2) reduction performance is still unclear.Here,Au cluster/TiO_(2)/Ti_(3)C_(2) and Au nanoparticle/TiO_(2)/Ti_(3)C_(2) were successfully prepared by deposition-precipitation method.The experimental results show that the photocatalytic CO_(2) reduction performance of Au cluster/TiO_(2)/Ti_(3)C_(2) with quantum size effect is stronger than that of Au nanoparticle/TiO_(2)/Ti_(3)C_(2) with surface plasmon resonance.The enhanced photocatalytic CO_(2) reduction activity is assigned to the establishment of an overlapping orbital between the lowest unoccupied molecular orbital(LUMO)of the Au cluster and the anti-bonding orbital of CO_(2),which greatly promotes the activation efficiency of CO_(2).The existence of Au cluster and the mechanism of photocatalytic CO_(2) reduction performance were certified by high-angle annular dark-field scanning transmission electron microscopy(HAADF-STEM)and in situ Fourier transform infrared spectroscopy(ISFTIR).This work may open new opportunities for the establishment of stable and active metal nanocatalysts.展开更多
Photothermal carbon dioxide hydrogenation represents a promising route to reduce the emission of greenhouse gas CO_(2)and produce value-added chemicals,but the selectivity and stability of photothermal catalysts need ...Photothermal carbon dioxide hydrogenation represents a promising route to reduce the emission of greenhouse gas CO_(2)and produce value-added chemicals,but the selectivity and stability of photothermal catalysts need to be improved.Herein,we report the rational fabrication of well-defined Ag_(24)Au cluster decorated highly ordered nanorod-like mesoporous Co_(3)O_(4)(Ag_(24)Au/mesoCo_(3)O_(4))for highly efficient and selective CO_(2)hydrogenation.The orderly assembled meso-Co_(3)O_(4)nanorods were prepared via a nanocasting method,offering large surface area and abundant active sites for CO_(2)adsorption and conversion.Moreover,the catalytic activity and selectivity were further improved by molecule-like Ag_(24)Au cluster decoration and reaction temperature optimization.The Ag_(24)Au/meso-Co_(3)O_(4)composite catalyst exhibited an ultrahigh CH_(4)yield rate of 204 mmol·g^(−1)·h^(−1)and a greatly improved CH_(4)selectivity of 82%for CO_(2)hydrogenation,significantly higher than those of pristine meso-Co_(3)O_(4)catalyst.The mechanism of the photothermal catalytic performance improvement was verified by CO_(2)temperature-programmed desorption and time-resolved transient photoluminescence,revealing that CO_(2)molecules underwent a vigorous adsorption and rapid activation process over Ag_(24)Au/meso-Co_(3)O_(4).The hot electrons created by the localized surface plasmon resonance effect of Ag_(24)Au clusters facilitated the charge transfer for subsequent multi-electron CO_(2)hydrogeneration processes,resulting in a significant increase in the productivity and selectivity for CO_(2)-to-CH_(4)conversion.This work suggests that the rational coupling of well-defined metal atom clusters and ordered transition metal compound nanostructures could open a new avenue towards photoinduced green chemistry processes for efficient CO_(2)recycling and reutilization.展开更多
Increasingly serious microbial infections call for the development of new simpler methods for the precise diagnosis and specific inhibition of such pathogens. In this work, a peptide mineralized Au cluster probe was a...Increasingly serious microbial infections call for the development of new simpler methods for the precise diagnosis and specific inhibition of such pathogens. In this work, a peptide mineralized Au cluster probe was applied as a new simplified strategy to both recognize and inhibit a single bacteria species of Staphylococcus aureus(S. aureus) simultaneously. The probes are composed of peptides and Au clusters. Moreover, the peptides specifically target S. aureus cells and the Au clusters provide fluorescent imaging and have an antibacterial effect. These new probes enable the simultaneous specific detection and effective destruction S. aureus cells in situ.展开更多
We have systematically investigated the adsorption and hydrogenation process of p-chloronitrobenzene on Au20 cluster using density functional theory-DFT） calculations.The adsorption of two types of all species,vertic...We have systematically investigated the adsorption and hydrogenation process of p-chloronitrobenzene on Au20 cluster using density functional theory-DFT） calculations.The adsorption of two types of all species,vertical adsorption and parallel adsorption,is compared,revealing that former model is more stable than the latter,and all of the species prefer to adsorb at the vertex site.After adsorption,electrons transferred from Au20 cluster to the p-chloronitrobenzene molecule.Almost all hydrogenation processes are exothermic,and the C–Cl bond scissions are considered as the rate-limiting step for both Paths A-p-CNB→p-CAN→AN） and B-p-CNB→NB→AN） with the energy barriers of 2.62 and 2.95 e V,respectively.These suggest that the C–Cl bond scission is not easy to occur on Au20 cluster due to the high energy barrier,especially the path B.The p-chloroaniline is the main hydrogenation product catalyzed by Au20.展开更多
The possible stable geometrical configurations and the relative stabilities of the lowest-lying isomers of copperdoped gold clusters, AunCu （n = 1-7）, are investigated using the density functional theory. Several lo...The possible stable geometrical configurations and the relative stabilities of the lowest-lying isomers of copperdoped gold clusters, AunCu （n = 1-7）, are investigated using the density functional theory. Several low-lying isomers are determined. The results indicate that the ground-state AunCu clusters have planar structures for n = 1-7. The stability trend of the AunCu clusters （n = 1-7）, shows that odd-numbered AunCu clusters are more stable than the neighbouring even-numbered ones, thereby indicating the AusCu clusters are magic cluster with high chemical stability.展开更多
Using the meta-generalized gradient approximation （meta-GGA） exchange correlation TPSS functional, the geo-metric structures, the relative stabilities, and the electronic properties of bimetallic AgnX （X=Au, Cu; n=...Using the meta-generalized gradient approximation （meta-GGA） exchange correlation TPSS functional, the geo-metric structures, the relative stabilities, and the electronic properties of bimetallic AgnX （X=Au, Cu; n=1-8） clusters are systematically investigated and compared with those of pure silver clusters. The optimized structures show that the transition point from preferentially planar to three-dimensional structure occurs at n = 6 for the AgnAu clusters, and at n = 5 for AgnCu clusters. For different-sized AgnX clusters, one X （X=Au or Cu） atom substituted Agn＋l structure is a dominant growth pattern. The calculated fragmentation energies, second-order differences in energies, and the highest occupied molecular orbital-lowest unoccupied molecular orbital （HOMO LUMO） energy gaps show interesting odd-even oscillation behaviours, indicating that Ag2,4,6,s and Agl,3,5,7X （X=Au, Cu） clusters keep high stabilities in comparison with their neighbouring clusters. The natural population analysis reveals that the charges transfer from the Agn host to the impurity atom except for the Ag2Cu cluster. Moreover, vertical ionization potential （VIP）, vertical electronic affinity （VEA）, and chemical hardness （η） are discussed and compared in depth. The same odd even oscillations are found for the VIP and η of the AgnX （X=Au, Cu; n=1-8） clusters.展开更多
In the previous paper,the geometry of the triatomic clusters for Cu, Ag,and An was obtained using the Dy-Xa method. In this investigation the atomic. orbital interactions of atom Cu, Ag, An in the triatomic clusters a...In the previous paper,the geometry of the triatomic clusters for Cu, Ag,and An was obtained using the Dy-Xa method. In this investigation the atomic. orbital interactions of atom Cu, Ag, An in the triatomic clusters are analyzed. The magnitudes of the atomic orbital interactions of the atoms in the clusters are measured by the splitting of corresponding atomic orbital. The calculation results show the atomic orbital interactions of Cu triatomic cluster differ greatly from those of Ag and Au triatomic cluster house of the mixture radio of 4s-Orbital with 3d-Orbital in the Cu cluster more than those in the Ag and Au cluster. The values of atomic orbital interactions of Au in the of cluster are larger than corresponding atomic Orbital interactions of Ag in the cluster.展开更多
基金ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China （No.20773113 and No.20803072）, the Hundred Talent Program of Chinese Academy of Sciences, the MOE Program for Changjiang Scholars and Innovative Research Team （No.IRT0756）, and the MPG-CAS Partner-group Program.
文摘The growth and thermal stability of Au clusters on a partially-reduced rutile TiO2 （110）-1 × 1 surface were investigated by high-resolution photoelectron spectroscopy using synchrotron- radiation-light. The valence-band photoelectron spectroscopy results demonstrate that the Ti^3＋3d feature attenuates quickly with the initial deposition of Au clusters, implying that Au clusters nucleate at the oxygen vacancy sites. The Au4f core-level photoelectron spectroscopy results directly prove the existence of charge transfer from oxygen vacancies to Au clusters. The thermal stability of Au clusters on the partially-reduced and stoichiometric TiO2（110） surfaces was also comparatively investigated by the annealing experiments. With the same film thickness, Au clusters are more thermally stable on the partially-reduced TiO2（110） surface than on the stoichiometric TiO2（110） surface. Meanwhile, large Au nanoparticles are more thermally stable than fine Au nanoparticles.
文摘An alternate approach to parametrizing the expression for the total energy of Au clusters within the second moment approximation (SMA) of the tight binding (TB) theory has been described. A type of many body interatomic potential for Au from first principle’s calculations has been constructed. The key of the approach is adjusting the total-energy expression of the TB SMA method to augmented plane wave (APW) total energy results. The lattice constant, melting temperature, and the bulk modulus are in agreement with available experimental values. The method and results of Au cluster properties are shown to be very useful and suitable in describing the clusters and bulk metals.
基金This work has been supported by the National Natural Science Foundation of China under Grant No. 10471051, and also by the Key Project of Chinese National Programs for Fundamental Research and Development（973 program） through Grant No. 2004CB318000, and also by the Fundamental Research Funds for the Central Universities under Grant No. M2009027.
基金supported by the National Science and Technology Major Project of China(No.2021YFB3500700)the National Natural Science Foundation of China(Nos.22020102003,22025506)+1 种基金the Key Research Program of the Chinese Academy of Sciences(No.ZDRW-CN-2021-3-3)the K.C.Wong Education Foundation,China(No.GJTD-2018-09).
文摘Gold(Au)nanoclusters supported on various supports have been widely used in the fields of energy and catalysis.However,the poor thermal stability of Au nanoclusters on the support interface usually leads to a reduction or even loss of catalytic activity.Herein,we used an in situ reduction method to synthesize Au nanoclusters on ceria(CeO_(2))carriers.In this method,sulfhydryl groups were used to modify CeO_(2) nanospheres first,and then Au clusters with an average diameter of 1.5 nm were grown on the surface of ceria reduced with sodium borohydride.The presence of the Au-S-Ce structure enhances the electron transfer efficiency,making the material exhibit high CO oxidation activity at room temperature.Furthermore,due to the strong binding energy of S and Au,the material exhibits a high stability for long time running process.This strategy provides an idea for designing stable and active supported ultrasmall Au nanoclusters catalytic materials.
基金financially supported by the National Natural Science Foundation of China(Nos.51672099 and 52073263)Sichuan Science and Technology Program(No.2021JDTD0026)+1 种基金the Fundamental Research Funds for the Central Universities(No.2017-QR-25)the Research Team Project of Dongguan University of Technology(Nos.TDYB2019014 and TDQN2019011)。
文摘The size of metal nanoparticles is a key factor to enhance the photocatalytic activity of photocatalysts.However,the mechanism of this factor to the improvement of photocatalytic CO_(2) reduction performance is still unclear.Here,Au cluster/TiO_(2)/Ti_(3)C_(2) and Au nanoparticle/TiO_(2)/Ti_(3)C_(2) were successfully prepared by deposition-precipitation method.The experimental results show that the photocatalytic CO_(2) reduction performance of Au cluster/TiO_(2)/Ti_(3)C_(2) with quantum size effect is stronger than that of Au nanoparticle/TiO_(2)/Ti_(3)C_(2) with surface plasmon resonance.The enhanced photocatalytic CO_(2) reduction activity is assigned to the establishment of an overlapping orbital between the lowest unoccupied molecular orbital(LUMO)of the Au cluster and the anti-bonding orbital of CO_(2),which greatly promotes the activation efficiency of CO_(2).The existence of Au cluster and the mechanism of photocatalytic CO_(2) reduction performance were certified by high-angle annular dark-field scanning transmission electron microscopy(HAADF-STEM)and in situ Fourier transform infrared spectroscopy(ISFTIR).This work may open new opportunities for the establishment of stable and active metal nanocatalysts.
基金supports from the National Key Research&Development Program of China(No.2017YFA0208200)the National Natural Science Foundation of China(Nos.22022505 and 21872069)+1 种基金the Fundamental Research Funds for the Central Universities(No.0205-14380266)the 2021 Suzhou Gusu Leading Talents of Science and Technology Innovation and Entrepreneurship in Wujiang District.
文摘Photothermal carbon dioxide hydrogenation represents a promising route to reduce the emission of greenhouse gas CO_(2)and produce value-added chemicals,but the selectivity and stability of photothermal catalysts need to be improved.Herein,we report the rational fabrication of well-defined Ag_(24)Au cluster decorated highly ordered nanorod-like mesoporous Co_(3)O_(4)(Ag_(24)Au/mesoCo_(3)O_(4))for highly efficient and selective CO_(2)hydrogenation.The orderly assembled meso-Co_(3)O_(4)nanorods were prepared via a nanocasting method,offering large surface area and abundant active sites for CO_(2)adsorption and conversion.Moreover,the catalytic activity and selectivity were further improved by molecule-like Ag_(24)Au cluster decoration and reaction temperature optimization.The Ag_(24)Au/meso-Co_(3)O_(4)composite catalyst exhibited an ultrahigh CH_(4)yield rate of 204 mmol·g^(−1)·h^(−1)and a greatly improved CH_(4)selectivity of 82%for CO_(2)hydrogenation,significantly higher than those of pristine meso-Co_(3)O_(4)catalyst.The mechanism of the photothermal catalytic performance improvement was verified by CO_(2)temperature-programmed desorption and time-resolved transient photoluminescence,revealing that CO_(2)molecules underwent a vigorous adsorption and rapid activation process over Ag_(24)Au/meso-Co_(3)O_(4).The hot electrons created by the localized surface plasmon resonance effect of Ag_(24)Au clusters facilitated the charge transfer for subsequent multi-electron CO_(2)hydrogeneration processes,resulting in a significant increase in the productivity and selectivity for CO_(2)-to-CH_(4)conversion.This work suggests that the rational coupling of well-defined metal atom clusters and ordered transition metal compound nanostructures could open a new avenue towards photoinduced green chemistry processes for efficient CO_(2)recycling and reutilization.
基金supported by the National Natural Science Foundation of China(21727817,21390414,21425522,51571185)Beijing Science and Technology Commission Special Project for Frontier Technology in Life Sciences(Z171100000417008)
文摘Increasingly serious microbial infections call for the development of new simpler methods for the precise diagnosis and specific inhibition of such pathogens. In this work, a peptide mineralized Au cluster probe was applied as a new simplified strategy to both recognize and inhibit a single bacteria species of Staphylococcus aureus(S. aureus) simultaneously. The probes are composed of peptides and Au clusters. Moreover, the peptides specifically target S. aureus cells and the Au clusters provide fluorescent imaging and have an antibacterial effect. These new probes enable the simultaneous specific detection and effective destruction S. aureus cells in situ.
基金supported by the National Natural Science Foundation of China-No.21503188)the Natural Science Foundation of Zhejiang Province-No.LQ15B030002)
文摘We have systematically investigated the adsorption and hydrogenation process of p-chloronitrobenzene on Au20 cluster using density functional theory-DFT） calculations.The adsorption of two types of all species,vertical adsorption and parallel adsorption,is compared,revealing that former model is more stable than the latter,and all of the species prefer to adsorb at the vertex site.After adsorption,electrons transferred from Au20 cluster to the p-chloronitrobenzene molecule.Almost all hydrogenation processes are exothermic,and the C–Cl bond scissions are considered as the rate-limiting step for both Paths A-p-CNB→p-CAN→AN） and B-p-CNB→NB→AN） with the energy barriers of 2.62 and 2.95 e V,respectively.These suggest that the C–Cl bond scission is not easy to occur on Au20 cluster due to the high energy barrier,especially the path B.The p-chloroaniline is the main hydrogenation product catalyzed by Au20.
基金Project supported by the Foundation from the Education Commission of Sichuan Province,China (Grant No. 2006B042)
文摘The possible stable geometrical configurations and the relative stabilities of the lowest-lying isomers of copperdoped gold clusters, AunCu （n = 1-7）, are investigated using the density functional theory. Several low-lying isomers are determined. The results indicate that the ground-state AunCu clusters have planar structures for n = 1-7. The stability trend of the AunCu clusters （n = 1-7）, shows that odd-numbered AunCu clusters are more stable than the neighbouring even-numbered ones, thereby indicating the AusCu clusters are magic cluster with high chemical stability.
基金supported by the National Natural Science Foundation of China (Grant Nos. 10774103 and 10974138)
文摘Using the meta-generalized gradient approximation （meta-GGA） exchange correlation TPSS functional, the geo-metric structures, the relative stabilities, and the electronic properties of bimetallic AgnX （X=Au, Cu; n=1-8） clusters are systematically investigated and compared with those of pure silver clusters. The optimized structures show that the transition point from preferentially planar to three-dimensional structure occurs at n = 6 for the AgnAu clusters, and at n = 5 for AgnCu clusters. For different-sized AgnX clusters, one X （X=Au or Cu） atom substituted Agn＋l structure is a dominant growth pattern. The calculated fragmentation energies, second-order differences in energies, and the highest occupied molecular orbital-lowest unoccupied molecular orbital （HOMO LUMO） energy gaps show interesting odd-even oscillation behaviours, indicating that Ag2,4,6,s and Agl,3,5,7X （X=Au, Cu） clusters keep high stabilities in comparison with their neighbouring clusters. The natural population analysis reveals that the charges transfer from the Agn host to the impurity atom except for the Ag2Cu cluster. Moreover, vertical ionization potential （VIP）, vertical electronic affinity （VEA）, and chemical hardness （η） are discussed and compared in depth. The same odd even oscillations are found for the VIP and η of the AgnX （X=Au, Cu; n=1-8） clusters.
文摘In the previous paper,the geometry of the triatomic clusters for Cu, Ag,and An was obtained using the Dy-Xa method. In this investigation the atomic. orbital interactions of atom Cu, Ag, An in the triatomic clusters are analyzed. The magnitudes of the atomic orbital interactions of the atoms in the clusters are measured by the splitting of corresponding atomic orbital. The calculation results show the atomic orbital interactions of Cu triatomic cluster differ greatly from those of Ag and Au triatomic cluster house of the mixture radio of 4s-Orbital with 3d-Orbital in the Cu cluster more than those in the Ag and Au cluster. The values of atomic orbital interactions of Au in the of cluster are larger than corresponding atomic Orbital interactions of Ag in the cluster.
