The geometrical structure of semiconductor clusters including Zn_(3)O_(3) was optimized by the DFT B3LYP method. With the same basis sets, dipole moments, polarizabilities and secondorder hyperpolarizabilities have be...The geometrical structure of semiconductor clusters including Zn_(3)O_(3) was optimized by the DFT B3LYP method. With the same basis sets, dipole moments, polarizabilities and secondorder hyperpolarizabilities have been calculated and compared with the results obtained by TDDFT B3LYP method combined with sum-over-state (SOS) formula. The calculation results indicate that the dipole moments of the ground state depend on the atom radius and electronegative differences between elements and are their balance point as well. The polarizabilities of the clusters accord with the rule of the corresponding energy transformation from ground to excited state. The results predict an increase of second-order hyperpolarizabilities with increasing the distances between atoms in the clusters as well as a decrease of the polarizabilities and second-order hyperpolarizabilities in the same serial of semiconductor clusters with increasing the dipole moments of the ground states. The changes of dipole moments in ground states are inconsistent with transition moments. Spatial structure, charge transfer and other factors play an important role in composing the transition moments.展开更多
Plasmon-induced hot energy in metal nanostructures holds great promise for photocatalytic organic conversions.However,maintaining the high-energy state of hot electrons within these structures remains challenging,even...Plasmon-induced hot energy in metal nanostructures holds great promise for photocatalytic organic conversions.However,maintaining the high-energy state of hot electrons within these structures remains challenging,even in hybrid metal-semiconductor heterojunctions.The rapid relaxation of hot electrons(<1 ps)due to a thick-shell and loosely bound semiconductor layer limits their extraction efficiency and utilization effectiveness during photocatalysis.Herein,we fabricated a novel metalsemiconductor heterojunction(P2-Au)with ultrathin-shell semiconductor layer by combing ultra-small metal chalcogenide semiconductor clusters(P2)with gold nanorods(Au NRs),which exhibits high-efficiency extraction of hot electrons and photocatalytic application.The robust binding of P2 cluster,with its smaller volume and larger energy level splitting compared to large-sized quantum dots,not only significantly increases the yield of hot electrons but also enables their rapid extraction and sustains long-lived(>2 ns)high-energy states.As a proof of concept,the composite photocatalyst achieves near-infrared-lightdriven C(sp^(3))-S cross-coupling reactions for the first time.This protocol effectively produces over 50 alkylthioethers from a wide scope range of non-active alkyl bromides and chlorides,aryl and alkyl thiols.This work provides a new strategy for highefficiency extraction of hot electrons within plasmonic metal nanostructures and paves the way for hot electron-driven photocatalytic organic transformations.展开更多
Potential surfaces and equilibrium geometries of InAs 2, In 2As, InAs 2 + and In 2As + were studied using the complete active space multi configuration self consistent field (CASMCSCF) technique. Two electronic stat...Potential surfaces and equilibrium geometries of InAs 2, In 2As, InAs 2 + and In 2As + were studied using the complete active space multi configuration self consistent field (CASMCSCF) technique. Two electronic states, namely 2B 2 and 2B 1, were found to prevail as the ground states for the InAs 2 and In 2As trimers, respectively. The corresponding adiabatic ionization energies were computed and the leading configurations of the ground states were analyzed according to the wavefunctions.展开更多
The structure and electronic properties of Co_(2)Ge_(10)^(-)anion and its neutral counterpart were investigated by anion photoelectron spectroscopy and theoretical calculations.The experimental vertical detachment ene...The structure and electronic properties of Co_(2)Ge_(10)^(-)anion and its neutral counterpart were investigated by anion photoelectron spectroscopy and theoretical calculations.The experimental vertical detachment energy of Co_(2)Ge_(10)^(-)was measured to be 2.86±0.08 eV.The lowest-energy isomer of Co_(2)Ge_(10)^(-)is in a doublet state and has a cage-like structure with Cs symmetry,which can be constructed by a tetragonal bipyramid on top of a pentagonal bipyramid and these two bipyramid structures share a common Co atom.The most stable structure of neutral Co_(2)Ge_(10)resembles its anionic counterpart and it is in a triplet state.The natural population analysis showed that the inner Co atom of both the anionic and neutral Co_(2)Ge_(10)acquires negative charge from the neighboring Ge atoms.The outer Co atom has a larger spin moment than the inner Co atom,indicating that the magnetic moments of Co_(2)Ge_(10)^(-/0)are mainly contributed by the outer Co atom.Analyses of the density of states and molecular orbitals indicated that there are a few highly delocalized molecular orbitals in Co_(2)Ge_(10)^(-),which are mainly contributed by Ge 4s atomic orbitals.展开更多
In the paper, the results of investigations of temperature and frequency dependences of dielectric permeability and dielectric loss of compositions LDPE + xvol%Bi<sub>2</sub>Te<sub>3</sub> are ...In the paper, the results of investigations of temperature and frequency dependences of dielectric permeability and dielectric loss of compositions LDPE + xvol%Bi<sub>2</sub>Te<sub>3</sub> are stated. The investigations were carried out at frequency 10 – 10<sup>5</sup> Hz and temperature 20°C - 150°C intervals, respectively. It was revealed that increase of percentage of the filler Bi<sub>2</sub>Te<sub>3</sub> in the matrix, reduces to increase of dielectric permeability and dielectric loss of composites LDPE + xvol%Bi<sub>2</sub>Te<sub>3</sub> in connection with the change reducing to Maxwell-Wagner’s volume polarization and emergence of comparative strong inner field in semiconductor clusters.展开更多
基金supported by the National Natural Science Foundation of China (No. 60176003 and 60376006)
文摘The geometrical structure of semiconductor clusters including Zn_(3)O_(3) was optimized by the DFT B3LYP method. With the same basis sets, dipole moments, polarizabilities and secondorder hyperpolarizabilities have been calculated and compared with the results obtained by TDDFT B3LYP method combined with sum-over-state (SOS) formula. The calculation results indicate that the dipole moments of the ground state depend on the atom radius and electronegative differences between elements and are their balance point as well. The polarizabilities of the clusters accord with the rule of the corresponding energy transformation from ground to excited state. The results predict an increase of second-order hyperpolarizabilities with increasing the distances between atoms in the clusters as well as a decrease of the polarizabilities and second-order hyperpolarizabilities in the same serial of semiconductor clusters with increasing the dipole moments of the ground states. The changes of dipole moments in ground states are inconsistent with transition moments. Spatial structure, charge transfer and other factors play an important role in composing the transition moments.
基金supported by the National Natural Science Foundation of China(U22A20432,92261205,22071165,22201103)the 111 Project(D20015)+2 种基金the Guangzhou Municipal Science and Technology Bureau(2024A04J3490)supported by the State Key Laboratory of Bioactive Molecules and Druggability Assessment(202402025)the Fundamental Research Funds for the Central Universities。
文摘Plasmon-induced hot energy in metal nanostructures holds great promise for photocatalytic organic conversions.However,maintaining the high-energy state of hot electrons within these structures remains challenging,even in hybrid metal-semiconductor heterojunctions.The rapid relaxation of hot electrons(<1 ps)due to a thick-shell and loosely bound semiconductor layer limits their extraction efficiency and utilization effectiveness during photocatalysis.Herein,we fabricated a novel metalsemiconductor heterojunction(P2-Au)with ultrathin-shell semiconductor layer by combing ultra-small metal chalcogenide semiconductor clusters(P2)with gold nanorods(Au NRs),which exhibits high-efficiency extraction of hot electrons and photocatalytic application.The robust binding of P2 cluster,with its smaller volume and larger energy level splitting compared to large-sized quantum dots,not only significantly increases the yield of hot electrons but also enables their rapid extraction and sustains long-lived(>2 ns)high-energy states.As a proof of concept,the composite photocatalyst achieves near-infrared-lightdriven C(sp^(3))-S cross-coupling reactions for the first time.This protocol effectively produces over 50 alkylthioethers from a wide scope range of non-active alkyl bromides and chlorides,aryl and alkyl thiols.This work provides a new strategy for highefficiency extraction of hot electrons within plasmonic metal nanostructures and paves the way for hot electron-driven photocatalytic organic transformations.
文摘Potential surfaces and equilibrium geometries of InAs 2, In 2As, InAs 2 + and In 2As + were studied using the complete active space multi configuration self consistent field (CASMCSCF) technique. Two electronic states, namely 2B 2 and 2B 1, were found to prevail as the ground states for the InAs 2 and In 2As trimers, respectively. The corresponding adiabatic ionization energies were computed and the leading configurations of the ground states were analyzed according to the wavefunctions.
基金supported by the National Natural Science Foundation of China(Nos.92461313,12074387,and 92161114)the Innovation Capability Support Program of Shaanxi Province(No.2023-CX-TD-49).
文摘The structure and electronic properties of Co_(2)Ge_(10)^(-)anion and its neutral counterpart were investigated by anion photoelectron spectroscopy and theoretical calculations.The experimental vertical detachment energy of Co_(2)Ge_(10)^(-)was measured to be 2.86±0.08 eV.The lowest-energy isomer of Co_(2)Ge_(10)^(-)is in a doublet state and has a cage-like structure with Cs symmetry,which can be constructed by a tetragonal bipyramid on top of a pentagonal bipyramid and these two bipyramid structures share a common Co atom.The most stable structure of neutral Co_(2)Ge_(10)resembles its anionic counterpart and it is in a triplet state.The natural population analysis showed that the inner Co atom of both the anionic and neutral Co_(2)Ge_(10)acquires negative charge from the neighboring Ge atoms.The outer Co atom has a larger spin moment than the inner Co atom,indicating that the magnetic moments of Co_(2)Ge_(10)^(-/0)are mainly contributed by the outer Co atom.Analyses of the density of states and molecular orbitals indicated that there are a few highly delocalized molecular orbitals in Co_(2)Ge_(10)^(-),which are mainly contributed by Ge 4s atomic orbitals.
文摘In the paper, the results of investigations of temperature and frequency dependences of dielectric permeability and dielectric loss of compositions LDPE + xvol%Bi<sub>2</sub>Te<sub>3</sub> are stated. The investigations were carried out at frequency 10 – 10<sup>5</sup> Hz and temperature 20°C - 150°C intervals, respectively. It was revealed that increase of percentage of the filler Bi<sub>2</sub>Te<sub>3</sub> in the matrix, reduces to increase of dielectric permeability and dielectric loss of composites LDPE + xvol%Bi<sub>2</sub>Te<sub>3</sub> in connection with the change reducing to Maxwell-Wagner’s volume polarization and emergence of comparative strong inner field in semiconductor clusters.
