Cobalt‐based materials have been considered as promising candidates to electrocatalyze water oxidation.However,the structure‐performance correlation remains largely elusive,due to the com‐plex material structures a...Cobalt‐based materials have been considered as promising candidates to electrocatalyze water oxidation.However,the structure‐performance correlation remains largely elusive,due to the com‐plex material structures and diverse performance‐influencing factors in those Co‐based catalysts.In this work,we designed two cobalt phosphates with distinct Co symmetry to explore the effect of coordination symmetry on electrocatalytic water oxidation.The two analogues have similar mor‐phology,Co valence and 6‐coordinated Co octahedron,but with different coordination symmetry.In contrast to symmetric Co_(3)(PO_(4))2·8H_(2)O,asymmetric NH_(4)CoPO_(4)·H_(2)O exhibited enhanced electrocata‐lytic water oxidation activity in a neutral aqueous solution.It is proven that,by experimental and theoretical studies,the asymmetric Co coordination sites can facilitate the surface reconstruction under anodic polarization to boost the electrocatalysis.Based on this contrastive platform with distinct symmetry differences,the preferred configuration in cobalt‐oxygen octahedrons for water oxidation has been straightforwardly assigned.展开更多
The cobalt phosphate-/cobalt borate-based oxygen-evolving catalysts （OECs） are the important class of earth-abundant electrocatalysts that can operate with high activity for water splitting under benign conditions. ...The cobalt phosphate-/cobalt borate-based oxygen-evolving catalysts （OECs） are the important class of earth-abundant electrocatalysts that can operate with high activity for water splitting under benign conditions. This article reports the integration of cobalt phosphate （Co- Pi） and cobalt borate （Co-Bi） OECs with three-dimensional （3D） graphene foam （GF） for the electrocatalytic water oxidation reaction. The GF showed a unique advantage to serve as a highly conductive 3D support with large capacity for anchoring and loading Co-OECs, thereby facilitating mass and charge transfer due to the large amount of active sites provided by the 3D graphene scaffold. As a result, this integrated system of GF and Co-OECs exhibits synergistically enhanced catalytic activity. The overpotential （η） of Co-Pi and Co-Bi/graphene catalysts is about 0.390 and 0.315 V in neutral solutions, respectively. Besides, the integrated Co-OECs/graphene catalysts have also exhibited improved and stable oxygen evolution catalytic ability in alkaline solution.展开更多
Tremendous efforts have been made to the development of highly active,stable hydrogen evolution reaction(HER)electrocatalysts based on earth-abundant metal compounds.Recently,cobalt phosphorus(Co-P)catalysts have rece...Tremendous efforts have been made to the development of highly active,stable hydrogen evolution reaction(HER)electrocatalysts based on earth-abundant metal compounds.Recently,cobalt phosphorus(Co-P)catalysts have received particular attention owing to their good performances for the HER.展开更多
The worldwide proliferation of portable electronics has resulted in a dramatic increase in the number of spent lithium-ion batteries(LIBs).However,traditional recycling methods still have limitations because of such h...The worldwide proliferation of portable electronics has resulted in a dramatic increase in the number of spent lithium-ion batteries(LIBs).However,traditional recycling methods still have limitations because of such huge amounts of spent LIBs.Therefore,we proposed an ecofriendly and sustainable double recycling strategy to concurrently reuse the cathode(LiCoO_(2))and anode(graphite)materials of spent LIBs and recycled LiCoPO_(4)/graphite(RLCPG)in Li^(+)/PF^(-)_(6) co-de/intercalation dual-ion batteries.The recycle-derived dualion batteries of Li/RLCPG show impressive electrochemical performance,with an appropriate discharge capacity of 86.2 mAh·g^(-1) at25 mA·g^(-1) and 69%capacity retention after 400 cycles.Dual recycling of the cathode and anode from spent LIBs avoids wastage of resources and yields cathode materials with excellent performance,thereby offering an ecofriendly and sustainable way to design novel secondary batteries.展开更多
LiCoPO4 micron-rods with an average diameter of about 500 nm and length of about 5 μm were synthesized by dispersant-aided hydrothermal method. Poly(n-vinylpyrrolidone) (PVP) was used as dispersant in the hydrotherma...LiCoPO4 micron-rods with an average diameter of about 500 nm and length of about 5 μm were synthesized by dispersant-aided hydrothermal method. Poly(n-vinylpyrrolidone) (PVP) was used as dispersant in the hydrothermal method. The starting solution and the concentration of dispersant have significant influences on the morphology of LiCoPO4,and the electrochemical performance is improved via controlling the particle size and morphology by the hydrothermal method. The cell using smaller particle LiCoPO4 as cat...展开更多
In this artide, highly [010]-oriented self-assembled LiCoPO4/C nanoflakes were prepared through simple and facile solution-phase strategies at low temperature and ambient pressure. The formation of 5-hydroxylmethylfur...In this artide, highly [010]-oriented self-assembled LiCoPO4/C nanoflakes were prepared through simple and facile solution-phase strategies at low temperature and ambient pressure. The formation of 5-hydroxylmethylfurfural and levoglucosan via the dehydration of glucose during the reaction played a key role in mediating the morphology and structure of the resulting products. LiCoPO4 highly oriented along the （010）-facets exposed Li^＋ ion transport channels, facilitating ultrafast lithium ion transportation. In turn, the unique assembled mesoporous structure and the flake-like morphology of the prepared products benefit lithium ion batteries constructed using two-dimensional （2D） LiCoPO4/C nanoflakes self- assembles as cathodes and commercial Li4Ti5O12 as anodes. The tested batteries provide high capacities of 154.6 mA·h·g^-1 at 0.1 C （based on the LiCoPO4 weight of 1 C = 167 mA·h·g^-1） and stable cycling with 93.1% capacity retention after 100 cycles, which is outstanding compared to other recently developed LiCoPO4 cathodes.展开更多
文摘Cobalt‐based materials have been considered as promising candidates to electrocatalyze water oxidation.However,the structure‐performance correlation remains largely elusive,due to the com‐plex material structures and diverse performance‐influencing factors in those Co‐based catalysts.In this work,we designed two cobalt phosphates with distinct Co symmetry to explore the effect of coordination symmetry on electrocatalytic water oxidation.The two analogues have similar mor‐phology,Co valence and 6‐coordinated Co octahedron,but with different coordination symmetry.In contrast to symmetric Co_(3)(PO_(4))2·8H_(2)O,asymmetric NH_(4)CoPO_(4)·H_(2)O exhibited enhanced electrocata‐lytic water oxidation activity in a neutral aqueous solution.It is proven that,by experimental and theoretical studies,the asymmetric Co coordination sites can facilitate the surface reconstruction under anodic polarization to boost the electrocatalysis.Based on this contrastive platform with distinct symmetry differences,the preferred configuration in cobalt‐oxygen octahedrons for water oxidation has been straightforwardly assigned.
基金supported by the National Natural Science Foundation of China(21322304,11290161)the National Basic Research Program of China(2012CB933003,2013CB932603)
文摘The cobalt phosphate-/cobalt borate-based oxygen-evolving catalysts （OECs） are the important class of earth-abundant electrocatalysts that can operate with high activity for water splitting under benign conditions. This article reports the integration of cobalt phosphate （Co- Pi） and cobalt borate （Co-Bi） OECs with three-dimensional （3D） graphene foam （GF） for the electrocatalytic water oxidation reaction. The GF showed a unique advantage to serve as a highly conductive 3D support with large capacity for anchoring and loading Co-OECs, thereby facilitating mass and charge transfer due to the large amount of active sites provided by the 3D graphene scaffold. As a result, this integrated system of GF and Co-OECs exhibits synergistically enhanced catalytic activity. The overpotential （η） of Co-Pi and Co-Bi/graphene catalysts is about 0.390 and 0.315 V in neutral solutions, respectively. Besides, the integrated Co-OECs/graphene catalysts have also exhibited improved and stable oxygen evolution catalytic ability in alkaline solution.
基金The work was supported in part by grants from the Natural Science Foundation of Zhejiang Province(No.LR18E020001)the National Natural Science Foundation of China(Nos.51972238,21875166)the Science and Technology Project of Zhejiang Province(No.LGF18B050005)。
文摘Tremendous efforts have been made to the development of highly active,stable hydrogen evolution reaction(HER)electrocatalysts based on earth-abundant metal compounds.Recently,cobalt phosphorus(Co-P)catalysts have received particular attention owing to their good performances for the HER.
基金the National Natural Science Foundation of China(No.52173246)the Science and Technology Planning Project of Guangzhou City,China(No.2023B03J1278)。
文摘The worldwide proliferation of portable electronics has resulted in a dramatic increase in the number of spent lithium-ion batteries(LIBs).However,traditional recycling methods still have limitations because of such huge amounts of spent LIBs.Therefore,we proposed an ecofriendly and sustainable double recycling strategy to concurrently reuse the cathode(LiCoO_(2))and anode(graphite)materials of spent LIBs and recycled LiCoPO_(4)/graphite(RLCPG)in Li^(+)/PF^(-)_(6) co-de/intercalation dual-ion batteries.The recycle-derived dualion batteries of Li/RLCPG show impressive electrochemical performance,with an appropriate discharge capacity of 86.2 mAh·g^(-1) at25 mA·g^(-1) and 69%capacity retention after 400 cycles.Dual recycling of the cathode and anode from spent LIBs avoids wastage of resources and yields cathode materials with excellent performance,thereby offering an ecofriendly and sustainable way to design novel secondary batteries.
文摘LiCoPO4 micron-rods with an average diameter of about 500 nm and length of about 5 μm were synthesized by dispersant-aided hydrothermal method. Poly(n-vinylpyrrolidone) (PVP) was used as dispersant in the hydrothermal method. The starting solution and the concentration of dispersant have significant influences on the morphology of LiCoPO4,and the electrochemical performance is improved via controlling the particle size and morphology by the hydrothermal method. The cell using smaller particle LiCoPO4 as cat...
基金This work is financially supported by the National Natural Science Foundation of China （Nos. 51671072, 21303042, and 21671096）, the Natural Science Foundation of Shenzhen （Nos. JCYJ20170412153139454 and JCYJ20150331101823677）, and the Shenzhen Key Laboratory Project （No. ZDSYS201603311013489）.
文摘In this artide, highly [010]-oriented self-assembled LiCoPO4/C nanoflakes were prepared through simple and facile solution-phase strategies at low temperature and ambient pressure. The formation of 5-hydroxylmethylfurfural and levoglucosan via the dehydration of glucose during the reaction played a key role in mediating the morphology and structure of the resulting products. LiCoPO4 highly oriented along the （010）-facets exposed Li^＋ ion transport channels, facilitating ultrafast lithium ion transportation. In turn, the unique assembled mesoporous structure and the flake-like morphology of the prepared products benefit lithium ion batteries constructed using two-dimensional （2D） LiCoPO4/C nanoflakes self- assembles as cathodes and commercial Li4Ti5O12 as anodes. The tested batteries provide high capacities of 154.6 mA·h·g^-1 at 0.1 C （based on the LiCoPO4 weight of 1 C = 167 mA·h·g^-1） and stable cycling with 93.1% capacity retention after 100 cycles, which is outstanding compared to other recently developed LiCoPO4 cathodes.
