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
The epidermal growth factor receptor （EGFR） has become an important target protein in anticancer drug development. Meanwhile, peptide-Au cluster has been proposed as potential targeted nano-drug assembled by targeti...The epidermal growth factor receptor （EGFR） has become an important target protein in anticancer drug development. Meanwhile, peptide-Au cluster has been proposed as potential targeted nano-drug assembled by targeting peptide. Here, we designed and synthesized a novel peptide-Au cluster as AuloPeptides to target to EGFR. We found AumPeptides could target to the natural binding sites of all EGFRs at mem- brane in both active and inactive states by molecular simulations. Its targeted ability was further verified by the co-localization and blocking experiments. We also study the configuration modifications of both active and inactive EGFRs after binding by AumPeptides. For active EGFR, the absorbed AuloPeptide5 might replace the natural ligand in EGFR endocytosis process. Then, the peptide-Au cluster in endochylema could inhibit the cancer relating enzyme activity including thioredoxin reductasel （TrxR1） and induce the oxidative stress mediated apoptosis in tumor cells. For inactive EGFR, it was retained in inactive state by Au10 Peptides binding to inhibit dimerization of EGFR for anticancer. Both pathways might be applied in anticancer drug development based on the theoretical and experimental study here.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
A systematic study on the structure and electronic properties of gold clusters doped each with one copper atom has been performed using the density functional theory. The average bond lengths in the Aun-1Cu （n ≤ 9）...A systematic study on the structure and electronic properties of gold clusters doped each with one copper atom has been performed using the density functional theory. The average bond lengths in the Aun-1Cu （n ≤ 9） bimetallic clusters are shorter than those in the corresponding pure gold clusters. The ionization potentials of the bimetallic clusters Aun-1Cu （n 〈 9） are larger than those of the corresponding homoatomic gold clusters except for Aus. The energy gaps of the Au-Cu binary clusters are narrower than those of the Aun clusters except AuCu and Au3Cu. No obvious even-odd effect exists in the variations of the electron affinities and ionization potentials for the Aun-1Cu （n ≤ 9） clusters, which is in contrast to the case of gold clusters Aun.展开更多
Cobalt-doped gold clusters AunCo （n=1-7） are systematically investigated for the possible stable geometrical configurations and relative stabilities of the lowest-lying isomers using density-functional theory at B3L...Cobalt-doped gold clusters AunCo （n=1-7） are systematically investigated for the possible stable geometrical configurations and relative stabilities of the lowest-lying isomers using density-functional theory at B3LYP/LanL2DZ level. Several low-lying isomers were determined, and many of them are in electronic configurations with a high spin multiplicity. The results indicate that the ground-state AunCo（n=1-7） clusters adopt a planar structure except for n=7. The stability trend of the AunCo （n=1-7） clusters shows that the Au2Co clusters are magic cluster with high stability.展开更多
CO poisoning to platinum catalysts has long been recognized as one of the major technical obstacles in heterogeneous catalysis and its successful removal represents a significant challenge to a wide variety of applica...CO poisoning to platinum catalysts has long been recognized as one of the major technical obstacles in heterogeneous catalysis and its successful removal represents a significant challenge to a wide variety of applications. Using density functional theory (DFT), we performed systematic theoretical calcula-tions to explore the CO removal mechanisms, in the presence of hydrogen, via oxidation by oxygen to form CO2 or reduction by hydrogen to form formaldehyde using a subnano Pt cluster as a model for catalyst nanoparticles. We show that CO oxidation is both thermochemically and kinetically difficult at low H coverage but becomes very exothermic with a moderate activation barrier at high H coverage, suggesting that the oxidation can be carried out readily at elevated temperatures. Doping the Pt cluster with Ru can significantly improve the oxidation thermochemical energy and moderately reduce the activation barrier. The results are consistent with experimental observations. We found that CO reduction by hydrogen to form formaldehyde is moderately endothermic. However, the reaction is predicted to be kinetically difficult due to the relatively high activation barriers associated with the sequential H attacks to the CO molecule.展开更多
Mercury ion （Hg2＋） pollution exists in water, soil, and food. By interacting with the thiol groups in protein, Hg2＋ ions can ac- cumulate in ways that cause serious damage to the central nervous system and threate...Mercury ion （Hg2＋） pollution exists in water, soil, and food. By interacting with the thiol groups in protein, Hg2＋ ions can ac- cumulate in ways that cause serious damage to the central nervous system and threaten human health and natural environment. Undoubtedly, Hg2＋ ion detection is a significant issue in environment and health monitoring. A variety of sensor platforms for Hg2＋ ion detection based on organic molecules, DNA, oligonucleotides, inorganic materials, etc, have been reported. In this paper, an artificial peptide PHg, with a cluster bio-mineralize sequence （CCY） and a multi-charge hydrophilic sequence is de- signed as a template for the one-step synthesis of a peptide-Au cluster probe. Briefly： the peptide PHg in situ anchors Au ions to form a peptide-Au （I） intermediate and the reaction pH with NaOH is adjusted; alter 12 h incubation at room temperature, the peptide PGg-Au nanocluster probe with red fluorescence is obtained. The probe has a super-small core size of approximately 1.26 nm and a maximum emission peak at 650 rim. The presence of Hg2＋ ions cause the fluorescence of the probe to greatly decrease. Based on the differences in fluorescence intensity of the PHg-Au nanocluster in the absence and presence of Hg2＋ ions, Hg2＋ ions could be quantitatively detected in concentrations ranging from 5 nmol/L to 1 lamol/L. The limit of detection （LOD） is 7.5 nmol/L. Compared with some interference ions such as, K＋, Mg2＋, Ca2＋, Pb2＋, Ni2＋, Fe3＋, and Cue＋, the selectivity was excellent. The sensing of Hg2＋ ion is not affected by the chelate agents： EDTA, which imparts a significant advantage in a range of applications. As a result, a simple, sensitive and oped for the detection of Hg2＋ ions. selective fluorescent assay based on peptide PHg-Au cluster is devel-展开更多
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
In this article, we present a facile, direct, synthetic approach of preparing monodisperse [Au2s（SePh）ls]- nanoclusters in high yield. In this synthetic approach, two-phase Brust-Schiffrin method is used. Both PhSeH...In this article, we present a facile, direct, synthetic approach of preparing monodisperse [Au2s（SePh）ls]- nanoclusters in high yield. In this synthetic approach, two-phase Brust-Schiffrin method is used. Both PhSeH and NaBH4 should be added drop-wise to the solution of Au （III） at the same time. The formula and molecular purity of [Au25（SePh）ls] TOA＋ clusters are characterized by MALDI-TOF mass spectrometry, NMR and TGA analysis. Furthermore, some critical parameters to obtain pure [Au25（SePh）18]-TOA＋ are identified, including the NaBH4-to-Au ratio, the selenolate-to-Au ratio and the temperature. The facile, direct, high yield synthetic method can be widely applied in the theoretical research of Au clusters protected by selenol.展开更多
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supported by the National Natural Science Foundation of China(31571026,11404333)the Special Program for Applied Research on Super Computation of the NSFC-Guangdong Joint Fund(the second phase)under Grant No.U1501501
文摘The epidermal growth factor receptor （EGFR） has become an important target protein in anticancer drug development. Meanwhile, peptide-Au cluster has been proposed as potential targeted nano-drug assembled by targeting peptide. Here, we designed and synthesized a novel peptide-Au cluster as AuloPeptides to target to EGFR. We found AumPeptides could target to the natural binding sites of all EGFRs at mem- brane in both active and inactive states by molecular simulations. Its targeted ability was further verified by the co-localization and blocking experiments. We also study the configuration modifications of both active and inactive EGFRs after binding by AumPeptides. For active EGFR, the absorbed AuloPeptide5 might replace the natural ligand in EGFR endocytosis process. Then, the peptide-Au cluster in endochylema could inhibit the cancer relating enzyme activity including thioredoxin reductasel （TrxR1） and induce the oxidative stress mediated apoptosis in tumor cells. For inactive EGFR, it was retained in inactive state by Au10 Peptides binding to inhibit dimerization of EGFR for anticancer. Both pathways might be applied in anticancer drug development based on the theoretical and experimental study here.
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.
文摘A systematic study on the structure and electronic properties of gold clusters doped each with one copper atom has been performed using the density functional theory. The average bond lengths in the Aun-1Cu （n ≤ 9） bimetallic clusters are shorter than those in the corresponding pure gold clusters. The ionization potentials of the bimetallic clusters Aun-1Cu （n 〈 9） are larger than those of the corresponding homoatomic gold clusters except for Aus. The energy gaps of the Au-Cu binary clusters are narrower than those of the Aun clusters except AuCu and Au3Cu. No obvious even-odd effect exists in the variations of the electron affinities and ionization potentials for the Aun-1Cu （n ≤ 9） clusters, which is in contrast to the case of gold clusters Aun.
文摘Cobalt-doped gold clusters AunCo （n=1-7） are systematically investigated for the possible stable geometrical configurations and relative stabilities of the lowest-lying isomers using density-functional theory at B3LYP/LanL2DZ level. Several low-lying isomers were determined, and many of them are in electronic configurations with a high spin multiplicity. The results indicate that the ground-state AunCo（n=1-7） clusters adopt a planar structure except for n=7. The stability trend of the AunCo （n=1-7） clusters shows that the Au2Co clusters are magic cluster with high stability.
基金Supported by the National Natural Science Foundation of China for Youth (Grant No. 20703040)
文摘CO poisoning to platinum catalysts has long been recognized as one of the major technical obstacles in heterogeneous catalysis and its successful removal represents a significant challenge to a wide variety of applications. Using density functional theory (DFT), we performed systematic theoretical calcula-tions to explore the CO removal mechanisms, in the presence of hydrogen, via oxidation by oxygen to form CO2 or reduction by hydrogen to form formaldehyde using a subnano Pt cluster as a model for catalyst nanoparticles. We show that CO oxidation is both thermochemically and kinetically difficult at low H coverage but becomes very exothermic with a moderate activation barrier at high H coverage, suggesting that the oxidation can be carried out readily at elevated temperatures. Doping the Pt cluster with Ru can significantly improve the oxidation thermochemical energy and moderately reduce the activation barrier. The results are consistent with experimental observations. We found that CO reduction by hydrogen to form formaldehyde is moderately endothermic. However, the reaction is predicted to be kinetically difficult due to the relatively high activation barriers associated with the sequential H attacks to the CO molecule.
基金financially supported by the National Basic Research Program of China(2013CB932703)the National Natural Science Foundation of China(21390414,31300827,31271072)
文摘Mercury ion （Hg2＋） pollution exists in water, soil, and food. By interacting with the thiol groups in protein, Hg2＋ ions can ac- cumulate in ways that cause serious damage to the central nervous system and threaten human health and natural environment. Undoubtedly, Hg2＋ ion detection is a significant issue in environment and health monitoring. A variety of sensor platforms for Hg2＋ ion detection based on organic molecules, DNA, oligonucleotides, inorganic materials, etc, have been reported. In this paper, an artificial peptide PHg, with a cluster bio-mineralize sequence （CCY） and a multi-charge hydrophilic sequence is de- signed as a template for the one-step synthesis of a peptide-Au cluster probe. Briefly： the peptide PHg in situ anchors Au ions to form a peptide-Au （I） intermediate and the reaction pH with NaOH is adjusted; alter 12 h incubation at room temperature, the peptide PGg-Au nanocluster probe with red fluorescence is obtained. The probe has a super-small core size of approximately 1.26 nm and a maximum emission peak at 650 rim. The presence of Hg2＋ ions cause the fluorescence of the probe to greatly decrease. Based on the differences in fluorescence intensity of the PHg-Au nanocluster in the absence and presence of Hg2＋ ions, Hg2＋ ions could be quantitatively detected in concentrations ranging from 5 nmol/L to 1 lamol/L. The limit of detection （LOD） is 7.5 nmol/L. Compared with some interference ions such as, K＋, Mg2＋, Ca2＋, Pb2＋, Ni2＋, Fe3＋, and Cue＋, the selectivity was excellent. The sensing of Hg2＋ ion is not affected by the chelate agents： EDTA, which imparts a significant advantage in a range of applications. As a result, a simple, sensitive and oped for the detection of Hg2＋ ions. selective fluorescent assay based on peptide PHg-Au cluster is devel-
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.
基金the financial support by the National Natural Science Foundation of China (20871112, 21072001, 21372006)Changjiang Scholars Program+1 种基金the Scientific Research Foundation for Returning Overseas Chinese Scholars, State Education Ministry, Ministry of Human Resources and Social Security, Anhui Province International Scientific and Technological Cooperation Project211 Project of Anhui University
文摘In this article, we present a facile, direct, synthetic approach of preparing monodisperse [Au2s（SePh）ls]- nanoclusters in high yield. In this synthetic approach, two-phase Brust-Schiffrin method is used. Both PhSeH and NaBH4 should be added drop-wise to the solution of Au （III） at the same time. The formula and molecular purity of [Au25（SePh）ls] TOA＋ clusters are characterized by MALDI-TOF mass spectrometry, NMR and TGA analysis. Furthermore, some critical parameters to obtain pure [Au25（SePh）18]-TOA＋ are identified, including the NaBH4-to-Au ratio, the selenolate-to-Au ratio and the temperature. The facile, direct, high yield synthetic method can be widely applied in the theoretical research of Au clusters protected by selenol.
