Clean Pt nanoclusters with a diameter of1.0-2.4 nm,supported on reduced graphene oxide（rGO）nanosheets,were successfully synthesized by simple in situ thermolysis of a Pt-carbonyl complex.The supported Pt nanocluster...Clean Pt nanoclusters with a diameter of1.0-2.4 nm,supported on reduced graphene oxide（rGO）nanosheets,were successfully synthesized by simple in situ thermolysis of a Pt-carbonyl complex.The supported Pt nanoclusters are in an electron-deficient state because of the electron transfer between the nanoclusters and the rGO sheets.The as-prepared Pt-1 nm/rGO shows high catalytic activity for the 100%selective hydrogenation of nitrobenzene,with the turnover frequency（TOF） reaching 975.4 h^（-1）at 25℃ and 1 atm.This number is higher than the previously reported value for the heterogeneously catalyzed hydrogenation of nitrobenzene.The proposed process follows a direct hydrogenation mechanism,as is revealed by the analyses of the intermediate products.This work presents a facile and effective synthetic approach for achieving highly efficient nanocatalysts,and can be extended to obtain other metal catalysts with ultra-small sizes and excellent performance.展开更多
In this work, we reported the synthesis of twodimensional spinel structure of ultrathin Co2AlO4 nanosheets via dealloying and subsequent annealing processes. Oxygen vacancy defects were further introduced into Co2AlO4...In this work, we reported the synthesis of twodimensional spinel structure of ultrathin Co2AlO4 nanosheets via dealloying and subsequent annealing processes. Oxygen vacancy defects were further introduced into Co2AlO4 nanosheets by a mild solvothermal reduction method, resulting in large electrochemical surface area and high active site densities, making the related Co atoms get electrons, and producing more empty orbitals. The positive charge of Co and Al atoms adjacent to the O vacancies in VO-rich Co2AlO4 reduced significantly, that is, more electrons are concentrated on the Co and Al atoms. Those electrons closed to the Fermi level have a promoting effect during the H2O activation. As a result, the obtained ultrathin Co2AlO4 nanosheets with oxygen vacancies show a low overpotential of 280 m V at the current density of 10 mA cm^-2 and a small Tafel slope of70.98 m V dec^-1. Moreover, it also displays a remarkable stability in alkaline solution, which is superior to most of the reported Co3O4 electrocatalysts. The present work paves a new way to achieve efficient new energetic materials for sustainable community.展开更多
Ultrathin MnO_2 decorated hierarchical urchinlike FeOOH hollow micro-nanospheres have been designed and synthesized through a facile hydrothermal route.The microspheres are made of FeOOH nanofibers with a diameter of ...Ultrathin MnO_2 decorated hierarchical urchinlike FeOOH hollow micro-nanospheres have been designed and synthesized through a facile hydrothermal route.The microspheres are made of FeOOH nanofibers with a diameter of 10 nm.Due to the synergetic effect between the unique FeOOH hollow micro/nanostructures and ultrathin MnO_2 layer,the as-fabricated FeOOH@MnO_2 hybrid electrode exhibits a high specific capacitance of 1192 F g^（-1）at a current density of 1 A g^（-1）.It also reveals high rate capabilities and superior stability.Moreover,the asymmetric supercapacitor（ASC）assembled from the FeOOH@MnO_2 and the active carbon（AC）delivers a high energy density of 40.2 W h kg^（-1）at a power density of 0.78 kW kg^（-1）,and the energy density could remain 10.4 W h kg^（-1）under a condition of high power density of 11.7 kW kg^（-1）.展开更多
基金supported by the National Natural Science Foundation of China(51402362 and 21471160)Shandong Provincial Natural Science Foundation,China(ZR2014EMQ012 and ZR2016BM12)+1 种基金the Fundamental Research Funds for the Central Universities(15CX08010A,16CX05016 and 16CX05014A)start-up fund from Tianjin University of Technology
文摘Clean Pt nanoclusters with a diameter of1.0-2.4 nm,supported on reduced graphene oxide（rGO）nanosheets,were successfully synthesized by simple in situ thermolysis of a Pt-carbonyl complex.The supported Pt nanoclusters are in an electron-deficient state because of the electron transfer between the nanoclusters and the rGO sheets.The as-prepared Pt-1 nm/rGO shows high catalytic activity for the 100%selective hydrogenation of nitrobenzene,with the turnover frequency（TOF） reaching 975.4 h^（-1）at 25℃ and 1 atm.This number is higher than the previously reported value for the heterogeneously catalyzed hydrogenation of nitrobenzene.The proposed process follows a direct hydrogenation mechanism,as is revealed by the analyses of the intermediate products.This work presents a facile and effective synthetic approach for achieving highly efficient nanocatalysts,and can be extended to obtain other metal catalysts with ultra-small sizes and excellent performance.
基金the financial support by the National Natural Science Foundation of China (21771137)the Natural Science Foundation of Tianjin City (18JCJQJC47700)+1 种基金111 project (D17003)the Training Project of Innovation Team of Colleges and Universities in Tianjin (TD13-5020)
文摘In this work, we reported the synthesis of twodimensional spinel structure of ultrathin Co2AlO4 nanosheets via dealloying and subsequent annealing processes. Oxygen vacancy defects were further introduced into Co2AlO4 nanosheets by a mild solvothermal reduction method, resulting in large electrochemical surface area and high active site densities, making the related Co atoms get electrons, and producing more empty orbitals. The positive charge of Co and Al atoms adjacent to the O vacancies in VO-rich Co2AlO4 reduced significantly, that is, more electrons are concentrated on the Co and Al atoms. Those electrons closed to the Fermi level have a promoting effect during the H2O activation. As a result, the obtained ultrathin Co2AlO4 nanosheets with oxygen vacancies show a low overpotential of 280 m V at the current density of 10 mA cm^-2 and a small Tafel slope of70.98 m V dec^-1. Moreover, it also displays a remarkable stability in alkaline solution, which is superior to most of the reported Co3O4 electrocatalysts. The present work paves a new way to achieve efficient new energetic materials for sustainable community.
基金supported by the National Natural Science Foundation of China (21771137)Shandong Provincial Natural Science Foundation (ZR2016BM12)+1 种基金the Fundamental Research Funds for the Central Universities (15CX08010A)the starting-up fund from TJUT
文摘Ultrathin MnO_2 decorated hierarchical urchinlike FeOOH hollow micro-nanospheres have been designed and synthesized through a facile hydrothermal route.The microspheres are made of FeOOH nanofibers with a diameter of 10 nm.Due to the synergetic effect between the unique FeOOH hollow micro/nanostructures and ultrathin MnO_2 layer,the as-fabricated FeOOH@MnO_2 hybrid electrode exhibits a high specific capacitance of 1192 F g^（-1）at a current density of 1 A g^（-1）.It also reveals high rate capabilities and superior stability.Moreover,the asymmetric supercapacitor（ASC）assembled from the FeOOH@MnO_2 and the active carbon（AC）delivers a high energy density of 40.2 W h kg^（-1）at a power density of 0.78 kW kg^（-1）,and the energy density could remain 10.4 W h kg^（-1）under a condition of high power density of 11.7 kW kg^（-1）.
