Surface reconstruction yields real active species in electrochemical oxygen evolution reaction(OER)conditions;however,rationally regulating reconstruction in a targeted manner for constructing highly active OER electr...Surface reconstruction yields real active species in electrochemical oxygen evolution reaction(OER)conditions;however,rationally regulating reconstruction in a targeted manner for constructing highly active OER electrocatalysts remains a formidable challenge.Here,an electrochemical activation strategy with selective etching was utilized to guide the reconstruction process of a hybrid cobalt-molybdenum oxide(CoMoO_(4)/Co_(3)O_(4)@CC)in a favorable direction to improve the OER performance.Both in-situ Raman and multiple ex-situ characterization tools demonstrate that controlled surface reconstruction can be easily achieved through Mo etching,with the formation of a dynamically stable amorphous-crystalline heterostructure.Theoretical calculations together with experimental results reveal that the synergistic effects between amorphous CoOOH and crystalline Co_(3)O_(4) are crucial in enhancing the catalytic performance.Consequently,the reconstructed CoMoO_(4)/Co_(3)O_(4)@CC exhibits a low overpotential of 250 mV to achieve a current density of 10 mA cm^(-2) in 1 M KOH,and more importantly it can be practiced in electrolytic water splitting and rechargeable zinc-air batteries devices,achieving ultra-long stability for over 500 and 1200 h,respectively.This work provides a promising route for the construction of high-performance electrocatalysts.展开更多
Undoped and rare earth ions （Eu3＋, Ce3＋, Tb3＋） doped β-SrHPO4 nanomaterials were successfully prepared by a facile hydrothermal method. The crystal structure, morphology and luminescent properties were character...Undoped and rare earth ions （Eu3＋, Ce3＋, Tb3＋） doped β-SrHPO4 nanomaterials were successfully prepared by a facile hydrothermal method. The crystal structure, morphology and luminescent properties were characterized by X-ray powder diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, photoluminescence （PL） spectra and lumi- nescence decay curves. The results indicated that the tmdoped and rare earth ions doped SrHPO4 nanomaterials （the doping concen- tration was not above 7%） were well crystallized, with the same crystal structure （^-SrHPO4）. Nevertheless, the doping of rare earth ions could lead to the changing of morphology from nanoflakes to nanocrystals. Under the excitation of UV light, rare earth ions （Eu3＋, Ce3＋, Tb3＋） doped I3-SrHPO4 nanocrystals exhibited the characteristic emission of Eu3＋, Ce3＋ and Tb3＋ ions, respectively. The luminescence decay curves of [3-SrHPO4：Eu3＋ and D-SrHPO4：Ce3＋,Th3＋ nanocrystals conformed to the double exponential fluores- cence decay, and the average lifetimes were 1.14 and 4.12 ms, respectively. The luminescence decay curve of 13-SrHPO4：Ce3＋ was fitted into a single exponential function, and the lifetime was about 0.78 ns.展开更多
A novel type of sulfur-doped graphene fibers (S-GFs) were prepared by the hydrothermal strategy, the in situ interfacial polymerization method and the annealing method. Two S-GFs were assembled into an all-solid-state...A novel type of sulfur-doped graphene fibers (S-GFs) were prepared by the hydrothermal strategy, the in situ interfacial polymerization method and the annealing method. Two S-GFs were assembled into an all-solid-state fibriform micro-supercapacitor (micro-SC) that is flexible and has a high specific capacitance (4.55 mF·cm^-2) with the current density of 25.47 pA·cm^-2. The cyclic voltammetry (CV) curve of this micro-SC kept the rectangular shape well even when the scan rate reached 2 V·s^-1. There is a great potential for this type of S-GFs used in flexible wearable electronics.展开更多
基金supported by the financial support of the Guangxi Science and Technology Major Projects(Guike AA23023033)。
文摘Surface reconstruction yields real active species in electrochemical oxygen evolution reaction(OER)conditions;however,rationally regulating reconstruction in a targeted manner for constructing highly active OER electrocatalysts remains a formidable challenge.Here,an electrochemical activation strategy with selective etching was utilized to guide the reconstruction process of a hybrid cobalt-molybdenum oxide(CoMoO_(4)/Co_(3)O_(4)@CC)in a favorable direction to improve the OER performance.Both in-situ Raman and multiple ex-situ characterization tools demonstrate that controlled surface reconstruction can be easily achieved through Mo etching,with the formation of a dynamically stable amorphous-crystalline heterostructure.Theoretical calculations together with experimental results reveal that the synergistic effects between amorphous CoOOH and crystalline Co_(3)O_(4) are crucial in enhancing the catalytic performance.Consequently,the reconstructed CoMoO_(4)/Co_(3)O_(4)@CC exhibits a low overpotential of 250 mV to achieve a current density of 10 mA cm^(-2) in 1 M KOH,and more importantly it can be practiced in electrolytic water splitting and rechargeable zinc-air batteries devices,achieving ultra-long stability for over 500 and 1200 h,respectively.This work provides a promising route for the construction of high-performance electrocatalysts.
基金Project supported by the National Natural Science Foundation of China(211717921401218)+4 种基金the Excellent Youth Foundation of Henan Scientific Committee(134100510018)Program for Innovative Research Team(in Science and Technology)in University of Henan Province(14IRTSTHN009)Henan Province Key Discipline of Applied Chemistry(201218692)Innovation Scientists and Technicians Troop Construction Projects of Henan Province(2013259)Key Project of Henan Education Committee(13B150102)
文摘Undoped and rare earth ions （Eu3＋, Ce3＋, Tb3＋） doped β-SrHPO4 nanomaterials were successfully prepared by a facile hydrothermal method. The crystal structure, morphology and luminescent properties were characterized by X-ray powder diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, photoluminescence （PL） spectra and lumi- nescence decay curves. The results indicated that the tmdoped and rare earth ions doped SrHPO4 nanomaterials （the doping concen- tration was not above 7%） were well crystallized, with the same crystal structure （^-SrHPO4）. Nevertheless, the doping of rare earth ions could lead to the changing of morphology from nanoflakes to nanocrystals. Under the excitation of UV light, rare earth ions （Eu3＋, Ce3＋, Tb3＋） doped I3-SrHPO4 nanocrystals exhibited the characteristic emission of Eu3＋, Ce3＋ and Tb3＋ ions, respectively. The luminescence decay curves of [3-SrHPO4：Eu3＋ and D-SrHPO4：Ce3＋,Th3＋ nanocrystals conformed to the double exponential fluores- cence decay, and the average lifetimes were 1.14 and 4.12 ms, respectively. The luminescence decay curve of 13-SrHPO4：Ce3＋ was fitted into a single exponential function, and the lifetime was about 0.78 ns.
文摘A novel type of sulfur-doped graphene fibers (S-GFs) were prepared by the hydrothermal strategy, the in situ interfacial polymerization method and the annealing method. Two S-GFs were assembled into an all-solid-state fibriform micro-supercapacitor (micro-SC) that is flexible and has a high specific capacitance (4.55 mF·cm^-2) with the current density of 25.47 pA·cm^-2. The cyclic voltammetry (CV) curve of this micro-SC kept the rectangular shape well even when the scan rate reached 2 V·s^-1. There is a great potential for this type of S-GFs used in flexible wearable electronics.
