One-dimensional carbon nano-materials （ODCNMs） synthesized from ethanol flames exhibit various agglomerated morphologies, such as ＂chrysanthemum-like＂, ＂hairball-like＂ or ＂orange-peel-like＂, ＂vertically alig...One-dimensional carbon nano-materials （ODCNMs） synthesized from ethanol flames exhibit various agglomerated morphologies, such as ＂chrysanthemum-like＂, ＂hairball-like＂ or ＂orange-peel-like＂, ＂vertically aligned＂ and ＂wrinkling-pileup＂. The present work studied the agglomerating process and the growth mechanism by using scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. It is thought that the size and distribution of the catalyst particles produced from pretreatment of the substrates play a key role during the formation of agglomerations. It is expected that the steady growth of ODCNMs in flames will be improved through the preparation of the catalysts.展开更多
A dynamic quasi-continuum model is presented to analyze free vibration of plate-type cubic crystal nano-materials.According to the Hamilton principle,fundamental governing equations in terms of displacement components...A dynamic quasi-continuum model is presented to analyze free vibration of plate-type cubic crystal nano-materials.According to the Hamilton principle,fundamental governing equations in terms of displacement components and angles of rotations are given.As an application of the model,the cylindrical bending deformation of the structure fixed at two ends is analyzed,and a theoretical formula evaluating the fundamental frequency is obtained by using Galerkin's method.Meanwhile,the solution for the classical continuous plate model is also derived,and the size-dependent elastic modulus and Poisson's ratio are taken in computation.The frequencies corresponding to different atomic layers are numerically presented for the plate-type NaC l nano-materials.Furthermore,a molecular dynamics(MD)simulation is conducted with the code LAMMPS.The comparison shows that the present quasi-continuum model is valid,and it may be used as an alternative model,which reflects scale effects in analyzing dynamic behaviors of such plate-type nano-materials.展开更多
On February 28th, 2005, AQSIQ (the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China), and SAC (the Standardization Administration of P. R. China)jointly ho...On February 28th, 2005, AQSIQ (the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China), and SAC (the Standardization Administration of P. R. China)jointly hosted the press conference on seven items of national standards on nano-materials in Beijing. The seven items of national standards were approved on Sept. 29th and Dec. 27th, 2004 respectively by SAC, and publicized in Jan. 2005. They will be formally put into practice from April 1st, 2005.展开更多
The design of efficient and low-cost multifunctional electrocatalysts for hydrogen evolution reaction(HER), oxygen evolution reaction(OER) and oxygen reduction reaction(ORR) is critical for the development of clean en...The design of efficient and low-cost multifunctional electrocatalysts for hydrogen evolution reaction(HER), oxygen evolution reaction(OER) and oxygen reduction reaction(ORR) is critical for the development of clean energy. Two-dimensional(2D) carbon-based nano-materials are becoming more and more popular in heterogeneous catalysis due to their cost-effective and multi-scale tunability as single-atom catalysis(SACs) substrates. In this paper, by using first-principles calculation, we designed and demonstrated a novel macropore T-carbon [110](TC) monolayer as 2D electrocatalyst substrate for HER/OER/ORR, and the synergistic modification of the transition metal and nonmetal atoms(TM-X) were investigated to enhance the multifunctional electrocatalytic performance. We screened out the Co embedded in N-doped TC(Co3@N-TC) from 30 TM@X-TC monolayers as a trifunctional electrocatalysts, which exhibits superior performance for HER/ORR/OER on both thermodynamic and kinetic scales, and with excellent thermal and electrochemical stability. Then, the TC monolayer is naturally macropore with a diameter of 5.36 A and exhibits excellent adsorption capacity for the intermediates and products of the redox reactions. Moreover, we revealed the origin of the electrocatalytic activity using the crystal orbital Hamilton population(COHP) and the molecular orbitals(MOs). The d orbital of Co3@N-TC is significantly hybridized with the p orbital of the intermediates, so that the lone electrons initially occupied in the antibonding state pair up and occupy the downward bonding state, allowing *OH to be appropriately adsorbed onto the TC monolayer. This work not only demonstrates that the TM@X-TC monolayer is a superior synergistic trifunctional electrocatalyst, but also reveals a macropore monolayer material with potential applications in electrocatalysis.展开更多
Nano-scale Ni（OH）2 doped with Zn was prepared by precipitation transformation method and characterized by XRD and TEM. The electrochemical performance was investigated by cyclic voltammetry （CV） and constant curre...Nano-scale Ni（OH）2 doped with Zn was prepared by precipitation transformation method and characterized by XRD and TEM. The electrochemical performance was investigated by cyclic voltammetry （CV） and constant current technology. The measurement results indicate that the lattice parameters of nano-scale Ni（OH）2 are changed and the agglomeration of particles becomes obvious with the increased Zn-doped content. Compared with un-doped one, the discharge specific capacities ofnano-scale Ni（OH）2 doped with 10% Zn are enhanced by 8% and 6%, respectively, at the discharge rate of 0.2C and 3C. After 110 cycles, the discharge specific capacity of the sample doped with 10% zinc is still above 85% of its initial capacity discharged at 0.2C. Therefore, a suitable Zn-doped content is beneficial to improving the discharge performance of nano-scale Ni（OH）2.展开更多
基金Supported by the Scientific Research Foundationfor the Returned Overseas Chinese Scholars of Chinese Ministry Edu-cation (200233)
文摘One-dimensional carbon nano-materials （ODCNMs） synthesized from ethanol flames exhibit various agglomerated morphologies, such as ＂chrysanthemum-like＂, ＂hairball-like＂ or ＂orange-peel-like＂, ＂vertically aligned＂ and ＂wrinkling-pileup＂. The present work studied the agglomerating process and the growth mechanism by using scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. It is thought that the size and distribution of the catalyst particles produced from pretreatment of the substrates play a key role during the formation of agglomerations. It is expected that the steady growth of ODCNMs in flames will be improved through the preparation of the catalysts.
文摘A dynamic quasi-continuum model is presented to analyze free vibration of plate-type cubic crystal nano-materials.According to the Hamilton principle,fundamental governing equations in terms of displacement components and angles of rotations are given.As an application of the model,the cylindrical bending deformation of the structure fixed at two ends is analyzed,and a theoretical formula evaluating the fundamental frequency is obtained by using Galerkin's method.Meanwhile,the solution for the classical continuous plate model is also derived,and the size-dependent elastic modulus and Poisson's ratio are taken in computation.The frequencies corresponding to different atomic layers are numerically presented for the plate-type NaC l nano-materials.Furthermore,a molecular dynamics(MD)simulation is conducted with the code LAMMPS.The comparison shows that the present quasi-continuum model is valid,and it may be used as an alternative model,which reflects scale effects in analyzing dynamic behaviors of such plate-type nano-materials.
文摘On February 28th, 2005, AQSIQ (the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China), and SAC (the Standardization Administration of P. R. China)jointly hosted the press conference on seven items of national standards on nano-materials in Beijing. The seven items of national standards were approved on Sept. 29th and Dec. 27th, 2004 respectively by SAC, and publicized in Jan. 2005. They will be formally put into practice from April 1st, 2005.
基金supported by the Natural Science Basic Research Program of Shaanxi (No. 2023-JC-YB-065)the Fund of State Key Laboratory of IPOC(BUPT)(No. IPOC2019A013)+2 种基金the Natural Science Foundation of Shaanxi Province (No. 2021JM-371)the Open-Foundation of Key Laboratory of Laser Device Technology,China North Industries Group Corporation Limited (No. KLLDT202103)the Project funded by China Postdoctoral Science Foundation(No. 2022M720516)。
文摘The design of efficient and low-cost multifunctional electrocatalysts for hydrogen evolution reaction(HER), oxygen evolution reaction(OER) and oxygen reduction reaction(ORR) is critical for the development of clean energy. Two-dimensional(2D) carbon-based nano-materials are becoming more and more popular in heterogeneous catalysis due to their cost-effective and multi-scale tunability as single-atom catalysis(SACs) substrates. In this paper, by using first-principles calculation, we designed and demonstrated a novel macropore T-carbon [110](TC) monolayer as 2D electrocatalyst substrate for HER/OER/ORR, and the synergistic modification of the transition metal and nonmetal atoms(TM-X) were investigated to enhance the multifunctional electrocatalytic performance. We screened out the Co embedded in N-doped TC(Co3@N-TC) from 30 TM@X-TC monolayers as a trifunctional electrocatalysts, which exhibits superior performance for HER/ORR/OER on both thermodynamic and kinetic scales, and with excellent thermal and electrochemical stability. Then, the TC monolayer is naturally macropore with a diameter of 5.36 A and exhibits excellent adsorption capacity for the intermediates and products of the redox reactions. Moreover, we revealed the origin of the electrocatalytic activity using the crystal orbital Hamilton population(COHP) and the molecular orbitals(MOs). The d orbital of Co3@N-TC is significantly hybridized with the p orbital of the intermediates, so that the lone electrons initially occupied in the antibonding state pair up and occupy the downward bonding state, allowing *OH to be appropriately adsorbed onto the TC monolayer. This work not only demonstrates that the TM@X-TC monolayer is a superior synergistic trifunctional electrocatalyst, but also reveals a macropore monolayer material with potential applications in electrocatalysis.
基金Project(BK2008591) supported by the Natural Science Foundation of Jiangsu Province,ChinaProject(2009RFQXG065) supported by Harbin Special Foundation of Technological Innovation Talent,China
文摘Nano-scale Ni（OH）2 doped with Zn was prepared by precipitation transformation method and characterized by XRD and TEM. The electrochemical performance was investigated by cyclic voltammetry （CV） and constant current technology. The measurement results indicate that the lattice parameters of nano-scale Ni（OH）2 are changed and the agglomeration of particles becomes obvious with the increased Zn-doped content. Compared with un-doped one, the discharge specific capacities ofnano-scale Ni（OH）2 doped with 10% Zn are enhanced by 8% and 6%, respectively, at the discharge rate of 0.2C and 3C. After 110 cycles, the discharge specific capacity of the sample doped with 10% zinc is still above 85% of its initial capacity discharged at 0.2C. Therefore, a suitable Zn-doped content is beneficial to improving the discharge performance of nano-scale Ni（OH）2.
