By using first principles calculations, four two-dimensional B-C-N ternary sheets with ordered and uniform element distribution are predicted based on the C, B, or N filled g-C3N4 sheet. These B-C-N ternary sheets are...By using first principles calculations, four two-dimensional B-C-N ternary sheets with ordered and uniform element distribution are predicted based on the C, B, or N filled g-C3N4 sheet. These B-C-N ternary sheets are metallic except for B4-C3N4 monolayer, which is a semiconductor with an energy band gap of 1.18 eV. In particular, the BnC-C3N4 is a ferromagnetic metal with a net magnetic moment of 0.57 μB/cell, which can be used to develop metal-free spintronic device. The calculated formation energy indicates these B-C-N ternary sheets are highly thermal stable. It presents a new route to obtain uniform B-C-N ternary sheet for electronic and spintronic applications.展开更多
Gold(Au)plasmonic nanoparticles were grown evenly on monolayer graphitic carbon nitride(g‐C3N4)nanosheets via a facile oil‐bath method.The photocatalytic activity of the Au/monolayer g‐C3N4 composites under visible...Gold(Au)plasmonic nanoparticles were grown evenly on monolayer graphitic carbon nitride(g‐C3N4)nanosheets via a facile oil‐bath method.The photocatalytic activity of the Au/monolayer g‐C3N4 composites under visible light was evaluated by photocatalytic hydrogen evolution and environmental treatment.All of the Au/monolayer g‐C3N4 composites showed better photocatalytic performance than that of monolayer g‐C3N4 and the 1%Au/monolayer g‐C3N4 composite displayed the highest photocatalytic hydrogen evolution rate of the samples.The remarkable photocatalytic activity was attributed largely to the successful introduction of Au plasmonic nanoparticles,which led to the surface plasmon resonance(SPR)effect.The SPR effect enhanced the efficiency of light harvesting and induced an efficient hot electron transfer process.The hot electrons were injected from the Au plasmonic nanoparticles into the conduction band of monolayer g‐C3N4.Thus,the Au/monolayer g‐C3N4 composites possessed higher migration and separation efficiencies and lower recombination probability of photogenerated electron‐hole pairs than those of monolayer g‐C3N4.A photocatalytic mechanism for the composites was also proposed.展开更多
Self-assembled monolayers of novel C60 derivative, N-3-γ-pyridyl Aza[60]fulleroid (C60Py), on Au(111) were studied by a scanning tunneling microscope under ultrahigh vacuum (UHV). C60Py molecules were assembled on Au...Self-assembled monolayers of novel C60 derivative, N-3-γ-pyridyl Aza[60]fulleroid (C60Py), on Au(111) were studied by a scanning tunneling microscope under ultrahigh vacuum (UHV). C60Py molecules were assembled on Au (111) via pyridyl nitrogen-Au interaction. The sole assembly of C60Py molecules on Au (111) only exhibited randoml aggregation of C60Py even the films were annealed at 50 and 105℃. By co-assembling with benzyl mercaptan (BM), the C60Py- BM films showed highly dense aggregation, but C60Py assemblies still had disordered structure. After the co-assembled C60Py-BM films were annealed at 50℃, BM molecules were partially desorbed, but the assembly of C60Py remained without obvious change. After the co-assembled C60Py-BM films were further annealed at 105℃, the C60Py monolayers with ordered structure were obtained, while the BM molecules were nearly thoroughly desorbed from the surface. Here, the BM molecules play a key role as a surfactant in the formation of the ordered C60Py monolayer.展开更多
This is a paper for the sub-solidus phase relationships in the full system Si_3N_4-A1NAl_2O_3-SiO_2-Y_2O_3-YN. Within this system there exist seventy-six compatibility tetrahedra.
基金V. ACKNOWLEDGMENTS This work was supported by the National Key Basic Research Program （No.2012CB922001 and No.2011CB921404）, the National Natural Science Foundation of China （No.21121003 and No.51172223）, the Strategic Priority Research Program of CAS （No.XDB01020300）, One Hundred Talent Program of CAS, the National Young Top Talent Program of Organization Department of China, the Fundamental Research Funds for the Central Universities （No.WK2060140014 and No.WK2060190025）, and USTCSCC, SCCAS, Tianjin, and Shanghai Supercomputer Centers.
文摘By using first principles calculations, four two-dimensional B-C-N ternary sheets with ordered and uniform element distribution are predicted based on the C, B, or N filled g-C3N4 sheet. These B-C-N ternary sheets are metallic except for B4-C3N4 monolayer, which is a semiconductor with an energy band gap of 1.18 eV. In particular, the BnC-C3N4 is a ferromagnetic metal with a net magnetic moment of 0.57 μB/cell, which can be used to develop metal-free spintronic device. The calculated formation energy indicates these B-C-N ternary sheets are highly thermal stable. It presents a new route to obtain uniform B-C-N ternary sheet for electronic and spintronic applications.
文摘Gold(Au)plasmonic nanoparticles were grown evenly on monolayer graphitic carbon nitride(g‐C3N4)nanosheets via a facile oil‐bath method.The photocatalytic activity of the Au/monolayer g‐C3N4 composites under visible light was evaluated by photocatalytic hydrogen evolution and environmental treatment.All of the Au/monolayer g‐C3N4 composites showed better photocatalytic performance than that of monolayer g‐C3N4 and the 1%Au/monolayer g‐C3N4 composite displayed the highest photocatalytic hydrogen evolution rate of the samples.The remarkable photocatalytic activity was attributed largely to the successful introduction of Au plasmonic nanoparticles,which led to the surface plasmon resonance(SPR)effect.The SPR effect enhanced the efficiency of light harvesting and induced an efficient hot electron transfer process.The hot electrons were injected from the Au plasmonic nanoparticles into the conduction band of monolayer g‐C3N4.Thus,the Au/monolayer g‐C3N4 composites possessed higher migration and separation efficiencies and lower recombination probability of photogenerated electron‐hole pairs than those of monolayer g‐C3N4.A photocatalytic mechanism for the composites was also proposed.
基金supported by the National Project for the Development of Key Fundamental Science in China(G2001CB3095)the National Natural Science Foundation of China(Grant Nos.50121202,50132030&10374083).
文摘Self-assembled monolayers of novel C60 derivative, N-3-γ-pyridyl Aza[60]fulleroid (C60Py), on Au(111) were studied by a scanning tunneling microscope under ultrahigh vacuum (UHV). C60Py molecules were assembled on Au (111) via pyridyl nitrogen-Au interaction. The sole assembly of C60Py molecules on Au (111) only exhibited randoml aggregation of C60Py even the films were annealed at 50 and 105℃. By co-assembling with benzyl mercaptan (BM), the C60Py- BM films showed highly dense aggregation, but C60Py assemblies still had disordered structure. After the co-assembled C60Py-BM films were annealed at 50℃, BM molecules were partially desorbed, but the assembly of C60Py remained without obvious change. After the co-assembled C60Py-BM films were further annealed at 105℃, the C60Py monolayers with ordered structure were obtained, while the BM molecules were nearly thoroughly desorbed from the surface. Here, the BM molecules play a key role as a surfactant in the formation of the ordered C60Py monolayer.
基金Materials Science and Engineering Department, The University of Michigan, U. S. A
文摘This is a paper for the sub-solidus phase relationships in the full system Si_3N_4-A1NAl_2O_3-SiO_2-Y_2O_3-YN. Within this system there exist seventy-six compatibility tetrahedra.
