The hybridization between oxygen 2p and transition-metal 3d states largely determines the electronic structure near the Fermi level and related functionalities of transition-metal oxides(TMOs).Considerable efforts hav...The hybridization between oxygen 2p and transition-metal 3d states largely determines the electronic structure near the Fermi level and related functionalities of transition-metal oxides(TMOs).Considerable efforts have been made to manipulate the p-d hybridization in TMOs by tailoring the spatial orbital overlap via structural engineering.Here,we demonstrate enhanced p-d hybridization in Ba^(2+)-doped LaNiO_(3)epitaxial films by simultaneously modifying both the spatial and energetic overlaps between the O-2p and Ni-3d orbitals.Combining x-ray absorption spectroscopy and firstprinciples calculations,we reveal that the enhanced hybridization stems from the synergistic effects of a reduced chargetransfer energy due to hole injection and an increased spatial orbital overlap due to straightening of Ni-O-Ni bonds.We further show that the enhanced p-d hybridization can be utilized to promote the oxygen evolution activity of LaNiO_(3).This work sheds new insights into the fine-tuning of the electronic structures of TMOs for enhanced functionalities.展开更多
Oxygen evolution reaction（OER） is one of the most important reactions in the energy storage devices such as metal–air batteries and unitized regenerative fuel cells（URFCs）. However, the kinetically sluggishness o...Oxygen evolution reaction（OER） is one of the most important reactions in the energy storage devices such as metal–air batteries and unitized regenerative fuel cells（URFCs）. However, the kinetically sluggishness of OER and the high prices as well as the scarcity of the most active precious metal electrocatalysts are the major bottleneck in these devices. Developing low-cost non-precious metal catalysts with high activity and stability for OER is highly desirable. A facile, in situ template method combining the dodecyl benzene sulfuric acid sodium（SDBS） assisted hydrothermal process with subsequent high-temperature treatment was developed to prepare porous Co3O4 with improved surface area and hierarchical porous structure as precious catalysts alternative for oxygen evolution reaction（OER）. Due to the unique structure, the as-prepared catalyst shows higher electrocatalytic activity than Co3O4 prepared by traditional thermal-decomposition method（noted as Co3O4-T） and commercial IrO2 catalyst for OER in 0.1M KOH aqueous solution. Moreover, it displays improved stability than Co3O4-T. The results demonstrate a highly efficient, scalable, and low cost method for developing highly active and stable OER electrocatalysts in alkaline solutions.展开更多
A spinel oxide NiCo204 prepared by thermal decomposition is of very high activity for the oxygen evolution reaction(OER)in alkaline solution.The oxygen evolution overpotential on NiCo204 is 0.252-0.262V in 10 M NaOH s...A spinel oxide NiCo204 prepared by thermal decomposition is of very high activity for the oxygen evolution reaction(OER)in alkaline solution.The oxygen evolution overpotential on NiCo204 is 0.252-0.262V in 10 M NaOH solution at 343K and current density 100 mAcm^(-2).展开更多
The development of low-cost,stable,and robust non-noble metal catalysts for water oxidation is a pivotal challenge for sustainable hydrogen production through electrocatalytic water splitting.Currently,such catalysts ...The development of low-cost,stable,and robust non-noble metal catalysts for water oxidation is a pivotal challenge for sustainable hydrogen production through electrocatalytic water splitting.Currently,such catalysts suffer from high overpotential and sluggish kinetics in oxygen evolution reactions(OERs).Herein,we report a“continuous”single-crystal honeycomb-like MXene/NiFeP_(x)–N-doped carbon(NC)heterostructure,in which ultrasmall NiFeP_(x)nanoparticles(NPs)encapsulated in the NC are tightly anchored on a layered MXene.Interestingly,this MXene/NiFeP_(x)–NC delivers outstanding OER catalytic performance,which stems from“continuous”single-crystal characteristics,abundant active sites derived from the ultrasmall NiFeP_(x)NPs,and the stable honeycomb-like heterostructure with an open structure.The experimental results are rationalized theoretically(by density functional theory(DFT)calculations),which suggests that it is the unique MXene/NiFeP_(x)–NC heterostructure that promotes the sluggish OER,thereby enabling superior durability and excellent activity with an ultralow overpotential of 240 mV at a current density of 10 mA×cm^(−2).展开更多
基金supported by the National Key R&D Program of China(Grant No.2022YFA1402902)the National Natural Science Foundation of China(Grant Nos.12374179,12074119,12374145,051B22001,12104157,12134003,and 12304218)the Shanghai Pujiang Program(Grant No.23PJ1402200).
文摘The hybridization between oxygen 2p and transition-metal 3d states largely determines the electronic structure near the Fermi level and related functionalities of transition-metal oxides(TMOs).Considerable efforts have been made to manipulate the p-d hybridization in TMOs by tailoring the spatial orbital overlap via structural engineering.Here,we demonstrate enhanced p-d hybridization in Ba^(2+)-doped LaNiO_(3)epitaxial films by simultaneously modifying both the spatial and energetic overlaps between the O-2p and Ni-3d orbitals.Combining x-ray absorption spectroscopy and firstprinciples calculations,we reveal that the enhanced hybridization stems from the synergistic effects of a reduced chargetransfer energy due to hole injection and an increased spatial orbital overlap due to straightening of Ni-O-Ni bonds.We further show that the enhanced p-d hybridization can be utilized to promote the oxygen evolution activity of LaNiO_(3).This work sheds new insights into the fine-tuning of the electronic structures of TMOs for enhanced functionalities.
基金supported by the Youth Innovation Promotion Association(no.2015147)CAS and National Program on Key Basic Research Project(973 Program,2012CB215500)+1 种基金the Outstanding Youngest Scientist FoundationChinese Academy of Sciences(CAS)
文摘Oxygen evolution reaction（OER） is one of the most important reactions in the energy storage devices such as metal–air batteries and unitized regenerative fuel cells（URFCs）. However, the kinetically sluggishness of OER and the high prices as well as the scarcity of the most active precious metal electrocatalysts are the major bottleneck in these devices. Developing low-cost non-precious metal catalysts with high activity and stability for OER is highly desirable. A facile, in situ template method combining the dodecyl benzene sulfuric acid sodium（SDBS） assisted hydrothermal process with subsequent high-temperature treatment was developed to prepare porous Co3O4 with improved surface area and hierarchical porous structure as precious catalysts alternative for oxygen evolution reaction（OER）. Due to the unique structure, the as-prepared catalyst shows higher electrocatalytic activity than Co3O4 prepared by traditional thermal-decomposition method（noted as Co3O4-T） and commercial IrO2 catalyst for OER in 0.1M KOH aqueous solution. Moreover, it displays improved stability than Co3O4-T. The results demonstrate a highly efficient, scalable, and low cost method for developing highly active and stable OER electrocatalysts in alkaline solutions.
文摘A spinel oxide NiCo204 prepared by thermal decomposition is of very high activity for the oxygen evolution reaction(OER)in alkaline solution.The oxygen evolution overpotential on NiCo204 is 0.252-0.262V in 10 M NaOH solution at 343K and current density 100 mAcm^(-2).
基金supported by the National Natural Science Foundation of China(No.22269010)the Training Program for Academic and Technical Leaders of Major Disciplines in Jiangxi Province(No.20212BCJ23020)+1 种基金the Science and Technology Project of Jiangxi Provincial Department of Education(No.GJJ211305)Jingdezhen Science and Technology Planning Project(No.20212GYZD009-04)。
文摘The development of low-cost,stable,and robust non-noble metal catalysts for water oxidation is a pivotal challenge for sustainable hydrogen production through electrocatalytic water splitting.Currently,such catalysts suffer from high overpotential and sluggish kinetics in oxygen evolution reactions(OERs).Herein,we report a“continuous”single-crystal honeycomb-like MXene/NiFeP_(x)–N-doped carbon(NC)heterostructure,in which ultrasmall NiFeP_(x)nanoparticles(NPs)encapsulated in the NC are tightly anchored on a layered MXene.Interestingly,this MXene/NiFeP_(x)–NC delivers outstanding OER catalytic performance,which stems from“continuous”single-crystal characteristics,abundant active sites derived from the ultrasmall NiFeP_(x)NPs,and the stable honeycomb-like heterostructure with an open structure.The experimental results are rationalized theoretically(by density functional theory(DFT)calculations),which suggests that it is the unique MXene/NiFeP_(x)–NC heterostructure that promotes the sluggish OER,thereby enabling superior durability and excellent activity with an ultralow overpotential of 240 mV at a current density of 10 mA×cm^(−2).
