Spin engineering is recognized as a promising strategy that modulates the association between d‐orbital electrons and the oxygenated species,and enhances the catalytic kinetics.However,few efforts have been made to c...Spin engineering is recognized as a promising strategy that modulates the association between d‐orbital electrons and the oxygenated species,and enhances the catalytic kinetics.However,few efforts have been made to clarify whether spin engineering could make a considerable enhancement for electrocatalytic water oxidation.Herein,we report the spin engineering of a nanocage‐structured(Co,Ni)Se_(2)/C@FeOOH,that showed significant oxygen evolution reaction(OER)activity.Magnetization measurement presented that the(Co,Ni)Se_(2)/C@FeOOH sample possesses higher polarization spin number(μb=6.966μB/f.u.)compared with that of the(Co,Ni)Se_(2)/C sample(μb=6.398μB/f.u.),for which the enlarged spin polarization number favors the adsorption and desorption energy of the intermediate oxygenated species,as confirmed by surface valance band spectra.Consequently,the(Co,Ni)Se_(2)/C@FeOOH affords remarkable OER product with a low overpotential of 241 mV at a current of 10 mA cm^(-2) and small Tafel slope of 44 mV dec^(-1) in 1.0 mol/L KOH alkaline solution,significantly surpassing the parent(Co,Ni)Se_(2)/C catalyst.This work will trigger a solid step for the design of highly‐efficient OER electrocatalysts.展开更多
It has been shown that a quantum state could be perfectly transferred via a spin chain with engineered'always-on interaction'.In this paper,we study a more realistic problem for such a quantum state transfer (...It has been shown that a quantum state could be perfectly transferred via a spin chain with engineered'always-on interaction'.In this paper,we study a more realistic problem for such a quantum state transfer (QST)protocol,how the efficacy of QST is reduced by the quantum decoherence induced by a spatially distributed environment.Here,the environment is universally modeled as a bath of fermions located in different positions.By making use of theirreducible tensor method in angular momentum theory,we investigate the effect of environment on the efficiency of QSTfor both cases at zero and finite temperatures.We not only show the generic exponential decay of QST efficiency as thenumber of sites increase,but also find some counterintuitive effect,the QST can be enhanced as temperature increasesin some cases.展开更多
The correlation between crystal facets and electronic configurations of perovskite is closely related to the intrinsic activity for water splitting.Herein,we proposed a unique molten-salt method(MSM)to manipulate the ...The correlation between crystal facets and electronic configurations of perovskite is closely related to the intrinsic activity for water splitting.Herein,we proposed a unique molten-salt method(MSM)to manipulate the electronic properties of LaCoO_(3) by fine-tuning its crystal facet and atomic doping.LaCoO_(3) samples with oriented(110)(LCO(110))and(111)(LCO(111))facets were motivated by a capping agent(Sr^(2+)).Compared with the LCO(111)plane,the LCO(110)and Sr-doped LCO(111)(LSCO(111))planes possessed higher O 2p positions,stronger Co 3d-O 2p covalencies,and higher Co spin states by inducing CoO_(6) distortion,thus leading to superior oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)performances.Specifically,the overpotentials at 10 mA cm^(−2) were 299,322,and 289 mV for LCO(110),LCO(111),and LSCO(111),respectively.In addition,the(110)crystal facet and Sr substitution bestowed enhanced stability on LaCoO_(3) due to the strengthened Co-O bonding.The present work enlightens new avenues of regulating electronic properties by crystal facet engineering and atom doping and provides a valuable reference for the electron structure-electrocatalytic activity connection for OER and HER.展开更多
The spin relaxation time is long in organic semiconductors because of the weak spin-orbit and hyperfine interactions,leading to intensive study on spin transport in organic semiconductors.The rapid progress towards ut...The spin relaxation time is long in organic semiconductors because of the weak spin-orbit and hyperfine interactions,leading to intensive study on spin transport in organic semiconductors.The rapid progress towards utilizing spin degree of freedom in organic electronic devices is occurring.While the spin injection,transport and detection in organic semiconductors are demonstrated,the fundamental physics of these phenomena remains unclear.This paper highlights recent progress that has been made,focusing primarily on present experimental work.展开更多
文摘Spin engineering is recognized as a promising strategy that modulates the association between d‐orbital electrons and the oxygenated species,and enhances the catalytic kinetics.However,few efforts have been made to clarify whether spin engineering could make a considerable enhancement for electrocatalytic water oxidation.Herein,we report the spin engineering of a nanocage‐structured(Co,Ni)Se_(2)/C@FeOOH,that showed significant oxygen evolution reaction(OER)activity.Magnetization measurement presented that the(Co,Ni)Se_(2)/C@FeOOH sample possesses higher polarization spin number(μb=6.966μB/f.u.)compared with that of the(Co,Ni)Se_(2)/C sample(μb=6.398μB/f.u.),for which the enlarged spin polarization number favors the adsorption and desorption energy of the intermediate oxygenated species,as confirmed by surface valance band spectra.Consequently,the(Co,Ni)Se_(2)/C@FeOOH affords remarkable OER product with a low overpotential of 241 mV at a current of 10 mA cm^(-2) and small Tafel slope of 44 mV dec^(-1) in 1.0 mol/L KOH alkaline solution,significantly surpassing the parent(Co,Ni)Se_(2)/C catalyst.This work will trigger a solid step for the design of highly‐efficient OER electrocatalysts.
基金Supported by the NSFC under Grant Nos.10775048,10704023NFRPC under Grant No.2007CB925204+1 种基金New Century Excellent Talents in University under Grant No.NCET-08-0682the Scientific Research Fund of Hunan Provincial Education Department of China under Grant No.07C579
文摘It has been shown that a quantum state could be perfectly transferred via a spin chain with engineered'always-on interaction'.In this paper,we study a more realistic problem for such a quantum state transfer (QST)protocol,how the efficacy of QST is reduced by the quantum decoherence induced by a spatially distributed environment.Here,the environment is universally modeled as a bath of fermions located in different positions.By making use of theirreducible tensor method in angular momentum theory,we investigate the effect of environment on the efficiency of QSTfor both cases at zero and finite temperatures.We not only show the generic exponential decay of QST efficiency as thenumber of sites increase,but also find some counterintuitive effect,the QST can be enhanced as temperature increasesin some cases.
基金supported by the National Natural Science Foundation of China(52174283)。
文摘The correlation between crystal facets and electronic configurations of perovskite is closely related to the intrinsic activity for water splitting.Herein,we proposed a unique molten-salt method(MSM)to manipulate the electronic properties of LaCoO_(3) by fine-tuning its crystal facet and atomic doping.LaCoO_(3) samples with oriented(110)(LCO(110))and(111)(LCO(111))facets were motivated by a capping agent(Sr^(2+)).Compared with the LCO(111)plane,the LCO(110)and Sr-doped LCO(111)(LSCO(111))planes possessed higher O 2p positions,stronger Co 3d-O 2p covalencies,and higher Co spin states by inducing CoO_(6) distortion,thus leading to superior oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)performances.Specifically,the overpotentials at 10 mA cm^(−2) were 299,322,and 289 mV for LCO(110),LCO(111),and LSCO(111),respectively.In addition,the(110)crystal facet and Sr substitution bestowed enhanced stability on LaCoO_(3) due to the strengthened Co-O bonding.The present work enlightens new avenues of regulating electronic properties by crystal facet engineering and atom doping and provides a valuable reference for the electron structure-electrocatalytic activity connection for OER and HER.
基金supported by the National Natural Science Foundation of China (Grant Nos. 10974084,11222435 and 11023002)the National Basic Research Program of China (Grant Nos. 2010CB923402 and 2013CB922103)+1 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe Fundamental Research Funds for the Central Universities
文摘The spin relaxation time is long in organic semiconductors because of the weak spin-orbit and hyperfine interactions,leading to intensive study on spin transport in organic semiconductors.The rapid progress towards utilizing spin degree of freedom in organic electronic devices is occurring.While the spin injection,transport and detection in organic semiconductors are demonstrated,the fundamental physics of these phenomena remains unclear.This paper highlights recent progress that has been made,focusing primarily on present experimental work.
