The interaction of Ag atoms with a defective MgO（001） surface is systematically studied based on density functional theory. The Ag clusters are deposited on neutral and charged oxygen vacancies of the MgO（001） sur...The interaction of Ag atoms with a defective MgO（001） surface is systematically studied based on density functional theory. The Ag clusters are deposited on neutral and charged oxygen vacancies of the MgO（001） surface. The structures of Ag clusters take the shape of simple models of two- or three-dimensional （2D and 3D） metal particles deposited on the MgO surface. When the nucleation of the metal clusters occurs in the Fs （missing neutral O） centre, the interaction with the substrate is considerably stronger than that in the Fs^＋ （missing O-） centre. The results show that the adsorption of Ag atoms on the MgO surface with oxygcn vacancy is stronger than on a clear MgO surface, thereby attracting more Ag atoms to cluster together, and forming atomic islands.展开更多
High photogenerated carrier recombination rate and weak spectral response are the two main factors restricting photocatalytic activities of photocatalysts.In this work,a novel Ag/Bi_(24)O_(31)Cl_(10)heterojunction has...High photogenerated carrier recombination rate and weak spectral response are the two main factors restricting photocatalytic activities of photocatalysts.In this work,a novel Ag/Bi_(24)O_(31)Cl_(10)heterojunction has been developed by the in-situ photoreduction technique to address the preceding issues.Physico-chemical properties of as-synthesized 0.7 wt%Ag/Bi_(24)O_(31)Cl_(10)photocatalysts were investigated in detail.The Ag clusters can be seen as surface plasmon polaritons to light absorption capacity and photothermal effect,which was demonstrated via Raman and UV-Vis diffuse reflectance spectra(UV-Vis DRS).Den-sity functional theory(DFT)calculations show that the additional unoccupied crystal orbital by the silver(Ag)will accelerate the charge separation where some of the excited electrons to the conduction band of Bi_(24)O_(31)Cl_(10)will drift to these orbitals which in turn prevent charge recombination.Therefore,Ag metal cluster-decorated Bi_(24)O_(31)Cl_(10)photocatalysts can be identified as electron trappers to boost the spatial separation of the photogenerated carrier,and finally,the CH 4 generation rate and the rhodamine b(RhB)degraded efficiency of Ag/Bi_(24)O_(31)Cl_(10)photocatalysts are enhanced about 1.54 and 5.20 times,respectively.The Ag/Bi_(24)O_(31)Cl_(10)composite photocatalyst retained high photocatalytic activities after four cycles indi-cating the stability and repeatability of the Ag/Bi_(24)O_(31)Cl_(10)composite.This work aims to provide new insight into modifying ideal semiconductor materials for high photocatalytic activity.展开更多
Small Ag clusters confined in the channels of ordered mesoporous anatase TiO2 have been fabricated via a vacuum-assisted wet-impregnation method, utilizing well-ordered mesoporous anatase TiO2 with high thermal stabil...Small Ag clusters confined in the channels of ordered mesoporous anatase TiO2 have been fabricated via a vacuum-assisted wet-impregnation method, utilizing well-ordered mesoporous anatase TiO2 with high thermal stability as the host. The composites have been characterized in detail by X-ray diffraction, X-ray photoelectron spectroscopy X-ray absorption fine structure （XAFS） spectroscopy, N2 adsorption, UV-visible diffuse reflectance spectroscopy and transmission electron microscopy. The results indicate that small Ag clusters are formed and uniformly confined in the channels of mesoporous TiO2 with an obvious confinement effect. The presence of strong AgO interactions involving the Ag clusters in intimate contact with the pore walls of mesoporous TiO2 is confirmed by XAFS analysis, and favors the separation of photogenerated electron-hole pairs, as shown by steady-state surface photovoltage spectroscopy and transient-state surface photovoltage measurements. The ordered mesoporous Ag/TiO2 composites exhibit excellent solar-light-driven photocatalytic performance for the degradation of phenol. This is attributed to the synergistic effects between the small Ag clusters acting as traps to effectively capture the photogenerated electrons, and the surface plasmon resonance of the Ag clusters promoting the absorption of visible light. This study clearly demonstrates the high-efficiency utilization of noble metals in the fabrication of high-performance solar-light-driven photocatalysts.展开更多
The Ag clusters have been investigated widely theoretically and experimentally. In particular, it has recently shown that the neutral Ag8 clusters embedded in an argon matrix have a strong fluorescence signal. As we c...The Ag clusters have been investigated widely theoretically and experimentally. In particular, it has recently shown that the neutral Ag8 clusters embedded in an argon matrix have a strong fluorescence signal. As we can know, the metal clusters may have important effects on the structures and properties of biomolecules. More and more attention is paid to the interaction between nanomaterials and biomolecules. In this work, the B3LYP method in density functional theory was used on the complexes between the 6-mercaptopurine（6MP） and Ag8 clusters combined with 6-311＋＋G＊＊ as well as LANL2DZ base sets. The geometries of all the complexes were optimized with full degree of freedom and the structures, chemical bonds, orbital properties as well as Mulliken charges for ten possible complexes were analyzed based on the same theory level. In addition, the influence of temperature and pressure on the stabilities of the four complexes was further explored using standard statistical thermodynamic methods ranging from 50 to 500 K and at 100 kPa or 100 bar. The results show that the complex Ag8-6 MP-7-5 can be the most stable one among the investigated complexes, in which the Ag（11） atom interacts with the S（10） atom forming the strong chemical bond. The Mulliken charges also show that the Ag–S chemical bond is formed and the related charge has transferred. Additionally, the temperature and pressure can significantly influence the stability of the four stable complexes.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
The unique plasmon resonance characteristics of nanostructures based on metal clusters have always been the focus of various plasmon devices and different applications. In this work, the plasmon resonance phenomena of...The unique plasmon resonance characteristics of nanostructures based on metal clusters have always been the focus of various plasmon devices and different applications. In this work, the plasmon resonance phenomena of polyhedral silver clusters under the adsorption of NH_(3) , N_(2), H_(2), and CH_(4) molecules are studied by using time-dependent density functional theory. Under the adsorption of NH_(3) , the tunneling current of silver clusters changes significantly due to the charge transfer from NH_(3) to silver clusters. However, the effects of N_(2), H_(2), and CH_(4) adsorption on the tunneling current of silver clusters are negligible. Our results indicate that these silver clusters exhibit excellent selectivities and sensitivities for NH_(3) detection. These findings confirm that the silver cluster is a promising NH_(3) sensor and provide a new method for designing high-performance sensors in the future.展开更多
Aging of secondary organic aerosol（SOA） particles formed from OH– initiated oxidation of ethylbenzene in the presence of high mass（100–300 μg/m^3） concentrations of（NH_4）_2SO_4seed aerosol was investigated in...Aging of secondary organic aerosol（SOA） particles formed from OH– initiated oxidation of ethylbenzene in the presence of high mass（100–300 μg/m^3） concentrations of（NH_4）_2SO_4seed aerosol was investigated in a home-made smog chamber in this study.The chemical composition of aged ethylbenzene SOA particles was measured using an aerosol laser time-of-flight mass spectrometer（ALTOFMS） coupled with a Fuzzy C-Means（FCM） clustering algorithm.Experimental results showed that nitrophenol,ethyl-nitrophenol,2,4-dinitrophenol,methyl glyoxylic acid,5-ethyl-6-oxo-2,4-hexadienoic acid,2-ethyl-2,4-hexadiendioic acid,2,3-dihydroxy-5-ethyl-6-oxo-4-hexenoic acid,1H-imidazole,hydrated N-glyoxal substituted1H-imidazole,hydrated glyoxal dimer substituted imidazole,1H-imidazole-2-carbaldehyde,N-glyoxal substituted hydrated 1H-imidazole-2-carbaldehyde and high-molecular-weight（HMW） components were the predominant products in the aged particles.Compared to the previous aromatic SOA aging studies,imidazole compounds,which can absorb solar radiation effectively,were newly detected in aged ethylbenzene SOA in the presence of high concentrations of（NH_4）_2SO_4seed aerosol.These findings provide new information for discussing aromatic SOA aging mechanisms.展开更多
Due to coexistence of huge number of structural isomers,global search for the ground-state structures of atomic clusters is a challenging issue.The difficulty also originates from the computational cost of ab initio m...Due to coexistence of huge number of structural isomers,global search for the ground-state structures of atomic clusters is a challenging issue.The difficulty also originates from the computational cost of ab initio methods for describing the potential energy surface.Recently,machine learning techniques have been widely utilized to accelerate materials discovery and molecular simulation.Compared to the commonly used artificial neural network,graph network is naturally suitable for clusters with flexible geometric environment of each atom.Herein we develop a cluster graph attention network(CGANet)by aggregating information of neighboring vertices and edges using attention mechanism,which can precisely predict the binding energy and force of silver clusters with root mean square error of 5.4 meV/atom and mean absolute error of 42.3 meV/Å,respectively.As a proof-of-concept,we have performed global optimization of mediumsized Agn clusters(n=14–26)by combining CGANet and genetic algorithm.The reported ground-state structures for n=14–21,have been successfully reproduced,while entirely new lowest-energy structures are obtained for n=22–26.In addition to the description of potential energy surface,the CGANet is also applied to predict the electronic properties of clusters,such as HOMO energy and HOMO-LUMO gap.With accuracy comparable to ab initio methods and acceleration by at least two orders of magnitude,CGANet holds great promise in global search of lowest-energy structures of large clusters and inverse design of functional clusters.展开更多
The electromagnetic interaction between Ag nanoparticles on the top of the Si substrate and the incident light has been studied by numerical simulations. It is found that the presence of dielectric layers with differe...The electromagnetic interaction between Ag nanoparticles on the top of the Si substrate and the incident light has been studied by numerical simulations. It is found that the presence of dielectric layers with different thicknesses leads to the varied resonance wavelength and scattering cross section and consequently the shifted photocurrent response for all wavelengths. These different behaviours are determined by whether the dielectric layer is beyond the domain where the elcetric field of metallic plasmons takes effect, combined with the effect of geometrical optics. It is revealed that for particles of a certain size, an appropriate dielectric thickness is desirable to achieve the best absorption. For a certain thickness of spacer, an appropriate granular size is also desirable. These observations have substantial applications for the optimization of surface plasmon enhanced silicon solar cells.展开更多
Single-atom catalysis recently attracts great attentions,however,whether single atom or their nanoparticle(NP)has the advantage in its intrinsic activity remains under heated debate.Ag/Al_(2)O_(3) is a widely used cat...Single-atom catalysis recently attracts great attentions,however,whether single atom or their nanoparticle(NP)has the advantage in its intrinsic activity remains under heated debate.Ag/Al_(2)O_(3) is a widely used catalyst for many catalytic reactions,while the effect of Ag particle size on the actity is seldom investigated due to the great difficulty in synthesizing single atom Ag and Ag clusters/particles with different sizes.Herein,we firstly prepared an atomically dispersed Ag/Al_(2)O_(3) catalyst using a nano-sized y-Al_(2)O_(3) as the support,subsequently obtained a series of Ag/Al_(2)O_(3) catalysts with different Ag particle sizes by H_(2) reducing single-atom Ag/Al_(2)O_(3) catalyst at various temperatures.The Ag/Al_(2)O_(3) treated at 600℃demonstrated superior CO oxidation performance over single-atom Ag/Al_(2)O_(3) and the Ag/Al_(2)O_(3) treated at 400 and 800℃.Based on experimental data and dpnsity functional theory(DFT)calculation results,we reveal that the larger Ag°particle is beneficial to oxygen activation and improves the valence stability during oxidation reaction,while the aggregation of Ag°particle also accordingly decreases the concentration of surface active sites,hence,there is an optimum Ag0 particle size.Our findings clearly confirm that Ag0nanoparticle has the advantage over single-atom Ag species in its intrinsic activity for CO oxidation.展开更多
基金Project supported by the Scientific Research Fund of Hunan Provincial Education Department, China (Grant No. 09B021)
文摘The interaction of Ag atoms with a defective MgO（001） surface is systematically studied based on density functional theory. The Ag clusters are deposited on neutral and charged oxygen vacancies of the MgO（001） surface. The structures of Ag clusters take the shape of simple models of two- or three-dimensional （2D and 3D） metal particles deposited on the MgO surface. When the nucleation of the metal clusters occurs in the Fs （missing neutral O） centre, the interaction with the substrate is considerably stronger than that in the Fs^＋ （missing O-） centre. The results show that the adsorption of Ag atoms on the MgO surface with oxygcn vacancy is stronger than on a clear MgO surface, thereby attracting more Ag atoms to cluster together, and forming atomic islands.
基金supported by the National Natural Science Foundation of China(No.12274361)Natural Science Foundation of Jiangsu Province(No.BK20211361)+1 种基金Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX21_3145)school-level research projects of Yancheng Institute of Technology(Nos.xjr2019028 and xjr2019059).
文摘High photogenerated carrier recombination rate and weak spectral response are the two main factors restricting photocatalytic activities of photocatalysts.In this work,a novel Ag/Bi_(24)O_(31)Cl_(10)heterojunction has been developed by the in-situ photoreduction technique to address the preceding issues.Physico-chemical properties of as-synthesized 0.7 wt%Ag/Bi_(24)O_(31)Cl_(10)photocatalysts were investigated in detail.The Ag clusters can be seen as surface plasmon polaritons to light absorption capacity and photothermal effect,which was demonstrated via Raman and UV-Vis diffuse reflectance spectra(UV-Vis DRS).Den-sity functional theory(DFT)calculations show that the additional unoccupied crystal orbital by the silver(Ag)will accelerate the charge separation where some of the excited electrons to the conduction band of Bi_(24)O_(31)Cl_(10)will drift to these orbitals which in turn prevent charge recombination.Therefore,Ag metal cluster-decorated Bi_(24)O_(31)Cl_(10)photocatalysts can be identified as electron trappers to boost the spatial separation of the photogenerated carrier,and finally,the CH 4 generation rate and the rhodamine b(RhB)degraded efficiency of Ag/Bi_(24)O_(31)Cl_(10)photocatalysts are enhanced about 1.54 and 5.20 times,respectively.The Ag/Bi_(24)O_(31)Cl_(10)composite photocatalyst retained high photocatalytic activities after four cycles indi-cating the stability and repeatability of the Ag/Bi_(24)O_(31)Cl_(10)composite.This work aims to provide new insight into modifying ideal semiconductor materials for high photocatalytic activity.
文摘Small Ag clusters confined in the channels of ordered mesoporous anatase TiO2 have been fabricated via a vacuum-assisted wet-impregnation method, utilizing well-ordered mesoporous anatase TiO2 with high thermal stability as the host. The composites have been characterized in detail by X-ray diffraction, X-ray photoelectron spectroscopy X-ray absorption fine structure （XAFS） spectroscopy, N2 adsorption, UV-visible diffuse reflectance spectroscopy and transmission electron microscopy. The results indicate that small Ag clusters are formed and uniformly confined in the channels of mesoporous TiO2 with an obvious confinement effect. The presence of strong AgO interactions involving the Ag clusters in intimate contact with the pore walls of mesoporous TiO2 is confirmed by XAFS analysis, and favors the separation of photogenerated electron-hole pairs, as shown by steady-state surface photovoltage spectroscopy and transient-state surface photovoltage measurements. The ordered mesoporous Ag/TiO2 composites exhibit excellent solar-light-driven photocatalytic performance for the degradation of phenol. This is attributed to the synergistic effects between the small Ag clusters acting as traps to effectively capture the photogenerated electrons, and the surface plasmon resonance of the Ag clusters promoting the absorption of visible light. This study clearly demonstrates the high-efficiency utilization of noble metals in the fabrication of high-performance solar-light-driven photocatalysts.
基金supported by the National Natural Science Foundation of China(No.21643014)the Special Natural Science Foundation of Science and Technology Bureau of Xi’an City Government(No.2016CXWL02 and SGH17H249)
文摘The Ag clusters have been investigated widely theoretically and experimentally. In particular, it has recently shown that the neutral Ag8 clusters embedded in an argon matrix have a strong fluorescence signal. As we can know, the metal clusters may have important effects on the structures and properties of biomolecules. More and more attention is paid to the interaction between nanomaterials and biomolecules. In this work, the B3LYP method in density functional theory was used on the complexes between the 6-mercaptopurine（6MP） and Ag8 clusters combined with 6-311＋＋G＊＊ as well as LANL2DZ base sets. The geometries of all the complexes were optimized with full degree of freedom and the structures, chemical bonds, orbital properties as well as Mulliken charges for ten possible complexes were analyzed based on the same theory level. In addition, the influence of temperature and pressure on the stabilities of the four complexes was further explored using standard statistical thermodynamic methods ranging from 50 to 500 K and at 100 kPa or 100 bar. The results show that the complex Ag8-6 MP-7-5 can be the most stable one among the investigated complexes, in which the Ag（11） atom interacts with the S（10） atom forming the strong chemical bond. The Mulliken charges also show that the Ag–S chemical bond is formed and the related charge has transferred. Additionally, the temperature and pressure can significantly influence the stability of the four stable complexes.
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.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.11774248 and 11974253)the National Key Research and Development Program of China (Grant No.2017YFA0303600)。
文摘The unique plasmon resonance characteristics of nanostructures based on metal clusters have always been the focus of various plasmon devices and different applications. In this work, the plasmon resonance phenomena of polyhedral silver clusters under the adsorption of NH_(3) , N_(2), H_(2), and CH_(4) molecules are studied by using time-dependent density functional theory. Under the adsorption of NH_(3) , the tunneling current of silver clusters changes significantly due to the charge transfer from NH_(3) to silver clusters. However, the effects of N_(2), H_(2), and CH_(4) adsorption on the tunneling current of silver clusters are negligible. Our results indicate that these silver clusters exhibit excellent selectivities and sensitivities for NH_(3) detection. These findings confirm that the silver cluster is a promising NH_(3) sensor and provide a new method for designing high-performance sensors in the future.
基金supported by the National Natural Science Foundation of China (Nos.41575118,41305109,21502086,41575126)the Outstanding Youth Science Foundation of Fujian Province of China (No.2015J06009)the Natural Science Foundation of Fujian Province of China (No.2015J05028)
文摘Aging of secondary organic aerosol（SOA） particles formed from OH– initiated oxidation of ethylbenzene in the presence of high mass（100–300 μg/m^3） concentrations of（NH_4）_2SO_4seed aerosol was investigated in a home-made smog chamber in this study.The chemical composition of aged ethylbenzene SOA particles was measured using an aerosol laser time-of-flight mass spectrometer（ALTOFMS） coupled with a Fuzzy C-Means（FCM） clustering algorithm.Experimental results showed that nitrophenol,ethyl-nitrophenol,2,4-dinitrophenol,methyl glyoxylic acid,5-ethyl-6-oxo-2,4-hexadienoic acid,2-ethyl-2,4-hexadiendioic acid,2,3-dihydroxy-5-ethyl-6-oxo-4-hexenoic acid,1H-imidazole,hydrated N-glyoxal substituted1H-imidazole,hydrated glyoxal dimer substituted imidazole,1H-imidazole-2-carbaldehyde,N-glyoxal substituted hydrated 1H-imidazole-2-carbaldehyde and high-molecular-weight（HMW） components were the predominant products in the aged particles.Compared to the previous aromatic SOA aging studies,imidazole compounds,which can absorb solar radiation effectively,were newly detected in aged ethylbenzene SOA in the presence of high concentrations of（NH_4）_2SO_4seed aerosol.These findings provide new information for discussing aromatic SOA aging mechanisms.
基金the National Natural Science Foundation of China(Grant Nos.11804076 and 91961204)the Fundamental Research Funds for the Central Universities of China(No.B210202151)the Changzhou Science and Technology Plan(No.CZ520012712).
文摘Due to coexistence of huge number of structural isomers,global search for the ground-state structures of atomic clusters is a challenging issue.The difficulty also originates from the computational cost of ab initio methods for describing the potential energy surface.Recently,machine learning techniques have been widely utilized to accelerate materials discovery and molecular simulation.Compared to the commonly used artificial neural network,graph network is naturally suitable for clusters with flexible geometric environment of each atom.Herein we develop a cluster graph attention network(CGANet)by aggregating information of neighboring vertices and edges using attention mechanism,which can precisely predict the binding energy and force of silver clusters with root mean square error of 5.4 meV/atom and mean absolute error of 42.3 meV/Å,respectively.As a proof-of-concept,we have performed global optimization of mediumsized Agn clusters(n=14–26)by combining CGANet and genetic algorithm.The reported ground-state structures for n=14–21,have been successfully reproduced,while entirely new lowest-energy structures are obtained for n=22–26.In addition to the description of potential energy surface,the CGANet is also applied to predict the electronic properties of clusters,such as HOMO energy and HOMO-LUMO gap.With accuracy comparable to ab initio methods and acceleration by at least two orders of magnitude,CGANet holds great promise in global search of lowest-energy structures of large clusters and inverse design of functional clusters.
基金supported by the National Basic Research Program of China (Grant Nos.2010CB934104 and 2010CB933800)the National Natural Science Foundation of China (Grant Nos.60606024 and 61076077)
文摘The electromagnetic interaction between Ag nanoparticles on the top of the Si substrate and the incident light has been studied by numerical simulations. It is found that the presence of dielectric layers with different thicknesses leads to the varied resonance wavelength and scattering cross section and consequently the shifted photocurrent response for all wavelengths. These different behaviours are determined by whether the dielectric layer is beyond the domain where the elcetric field of metallic plasmons takes effect, combined with the effect of geometrical optics. It is revealed that for particles of a certain size, an appropriate dielectric thickness is desirable to achieve the best absorption. For a certain thickness of spacer, an appropriate granular size is also desirable. These observations have substantial applications for the optimization of surface plasmon enhanced silicon solar cells.
基金supported by the National Natural Science Foundation of China(No.52000093)the Chinese Post-doctoral Science Foundation(Nos.2020T130271 and 2019M663911XB)National Engineering Laboratory for Mobile Source Emission Control Technology(No.NELMS2019B03).
文摘Single-atom catalysis recently attracts great attentions,however,whether single atom or their nanoparticle(NP)has the advantage in its intrinsic activity remains under heated debate.Ag/Al_(2)O_(3) is a widely used catalyst for many catalytic reactions,while the effect of Ag particle size on the actity is seldom investigated due to the great difficulty in synthesizing single atom Ag and Ag clusters/particles with different sizes.Herein,we firstly prepared an atomically dispersed Ag/Al_(2)O_(3) catalyst using a nano-sized y-Al_(2)O_(3) as the support,subsequently obtained a series of Ag/Al_(2)O_(3) catalysts with different Ag particle sizes by H_(2) reducing single-atom Ag/Al_(2)O_(3) catalyst at various temperatures.The Ag/Al_(2)O_(3) treated at 600℃demonstrated superior CO oxidation performance over single-atom Ag/Al_(2)O_(3) and the Ag/Al_(2)O_(3) treated at 400 and 800℃.Based on experimental data and dpnsity functional theory(DFT)calculation results,we reveal that the larger Ag°particle is beneficial to oxygen activation and improves the valence stability during oxidation reaction,while the aggregation of Ag°particle also accordingly decreases the concentration of surface active sites,hence,there is an optimum Ag0 particle size.Our findings clearly confirm that Ag0nanoparticle has the advantage over single-atom Ag species in its intrinsic activity for CO oxidation.
