It is urgent to develop catalysts with application potential for oxidative coupling of methane(OCM)at relatively lower temperature.Herein,three-dimensional ordered macro porous(3 DOM)La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)(...It is urgent to develop catalysts with application potential for oxidative coupling of methane(OCM)at relatively lower temperature.Herein,three-dimensional ordered macro porous(3 DOM)La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)(A_(2)B_(2)O_(7)-type)catalysts with disordered defective cubic fluorite phased structure were successfully prepared by a colloidal crystal template method.3DOM structure promotes the accessibility of the gaseous reactants(O2and CH4)to the active sites.The co-doping of Ca and Sr ions in La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)catalysts improved the formation of oxygen vacancies,thereby leading to increased density of surface-active oxygen species(O_(2)^(-))for the activation of CH4and the formation of C2products(C2H6and C2H4).3DOM La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)catalysts exhibit high catalytic activity for OCM at low temperature.3DOM La1.7Sr0.3Ce1.7Ca0.3O7-δcatalyst with the highest density of O_(2)^(-)species exhibited the highest catalytic activity for low-temperature OCM,i.e.,its CH4conversion,selectivity and yield of C2products at 650℃are 32.2%,66.1%and 21.3%,respectively.The mechanism was proposed that the increase in surface oxygen vacancies induced by the co-doping of Ca and Sr ions boosts the key step of C-H bond breaking and C-C bond coupling in catalyzing low-temperature OCM.It is meaningful for the development of the low-temperature and high-efficient catalysts for OCM reaction in practical application.展开更多
Driven by safety issues,environmental concerns,and high costs,rechargeable aqueous zinc-ion batteries(ZIBs)have received increasing attention in recent years owing to their unique advantages.However,the sluggish kinet...Driven by safety issues,environmental concerns,and high costs,rechargeable aqueous zinc-ion batteries(ZIBs)have received increasing attention in recent years owing to their unique advantages.However,the sluggish kinetics of divalent charge Zn^(2+)in the cathode materials caused by the strong electrostatic interaction and their unsatisfactory cycle life hinder the development of ZIBs.Herein,organic cations and Zn^(2+)ions co-pre-inserted vanadium oxide([N(CH_(3))_(4)]_(0.77),Zn_(0.23))V_(8)O_(20)·3.8H_(2)O are reported as the cathode for ultra-stable aqueous ZIBs,in which the weaker electrostatic interactions between Zn^(2+)and organic ion-pinned vanadium oxide can induce the high reversibility of Zn^(2+)insertion and extraction,thereby improving the cycle life.It is demonstrated that([N(CH_(3))_(4)]_(0.77),Zn_(0.23))V_(8)O_(20)·3.8H_(2)O cathodes deliver a discharge capacity of 181 mA h g^(-1)at8 A g^(-1)and ultra-long life span(99.5%capacity retention after 2000 cycles).A reversible Zn^(2+)/H^(+)ions(de)intercalation storage process and pseudocapacitive charge storage are characterized.The weaker interactions between organic ion and Zn^(2+)open a novel avenue for the design of highly reversible cathode materials with long-term cycling stability.展开更多
A diode-pumped continuous-wave Tm:YVO_[4]laser operating on the^[3]H_[4]→^[3]H_[5]and3F4→^[3]H_[6]transitions was demonstrated for the first time,to the best of our knowledge.An a-cut Tm:YVO_[4]crystal with 1.5%[ato...A diode-pumped continuous-wave Tm:YVO_[4]laser operating on the^[3]H_[4]→^[3]H_[5]and3F4→^[3]H_[6]transitions was demonstrated for the first time,to the best of our knowledge.An a-cut Tm:YVO_[4]crystal with 1.5%[atomic fraction]Tm3+ion concentration was used to characterize the laser behavior.A common commercial laser diode with a central wavelength of 790 nm and a bandwidth of 3.2 nm was utilized as a pump source.With an output coupler for the^[3]H_[4]→^[3]H_[5]and3F4→^[3]H_[6]transitions,simultaneous three-wavelength laser operation was achieved.The laser emissions at 2292 and 2363 nm inπ-polarization and at 2108 nm inσ-polarization were realized.With an incident pump power of 22 W,the total output power of 1.17 W at 2292,2363,and 2108 nm was obtained.The output power at 2292 and 2363 nm was measured to be 750 mW,and the output power at 2108 nm was measured to be 420 mW.展开更多
Molybdenum trioxide(MoO_(3))can be employed as an excellent host for intercalation due to its 2D lay-ered structure that connected by van der Waals interactions.Herein,a series of polyoxometalate-based MoO_(3) composi...Molybdenum trioxide(MoO_(3))can be employed as an excellent host for intercalation due to its 2D lay-ered structure that connected by van der Waals interactions.Herein,a series of polyoxometalate-based MoO_(3) composites(Al_(13)@MoO_(3))were successfully prepared by interpolating the Keggin-type polycationic AlO_(4)Al_(12)(OH)_(24)H_(2)O_(12)^(7+)(Al_(13))into MoO_(3)gallery.These composites can be applied to rapidly adsorb the anionic dye methyl orange(MO)through strong electrostatic interactions lead to compact and sta-ble gathering in the surrounding of the numerous charged Al_(13).Adsorption behaviors of composites with the different amount of Al_(13) were determined,these results revealed that Al_(13)-3.34%@MoO_(3)exhibited the most remarkable adsorption capacity.More importantly,the composite maintains superior adsorption capacity for five consecutive adsorption/desorption cycles,suggesting that Al_(13)@MoO_(3)can be an efficient and durable adsorbent.展开更多
A long wavelength emission fluorescent(612 nm)chemosensor with high selectivity for H_(2)PO_(4)^(−)ions was designed and synthesized according to the excited state intramolecular proton transfer(ESIPT).The sensor can ...A long wavelength emission fluorescent(612 nm)chemosensor with high selectivity for H_(2)PO_(4)^(−)ions was designed and synthesized according to the excited state intramolecular proton transfer(ESIPT).The sensor can exist in two tautomeric forms(‘keto’and‘enol’)in the presence of Fe^(3+)ion,Fe^(3+)may bind with the‘keto’form of the sensor.Furthermore,the in situ generated GY-Fe^(3+)ensemble could recover the quenched fluorescence upon the addition of H_(2)PO_(4)^(−)anion resulting in an off-on-type sensing with a detection limit of micromolar range in the same medium,and other anions,including F^(−),Cl^(−),Br^(−),I^(−),AcO^(−),HSO^(−)_(4),ClO^(−)_(4)and CN−had nearly no influence on the probing behavior.The test strips based on 2-[2-hydroxy-4-(diethylamino)phenyl]-1H-imidazo[4,5-b]phenazine and Fe^(3+)metal complex(GY-Fe^(3+))were fabricated,which could act as convenient and efficient H_(2)PO_(4)^(−)test kits.展开更多
Photoelectrochemical oxygen reduction reaction(ORR)toward H_(2)O_(2)is highly desirable because only sunlight,O_(2)and water are required in the process.However,the corresponding studies are still at its infancy becau...Photoelectrochemical oxygen reduction reaction(ORR)toward H_(2)O_(2)is highly desirable because only sunlight,O_(2)and water are required in the process.However,the corresponding studies are still at its infancy because of the lack of suitable photocathodes,especially inorganic semiconductor photocathodes.In this work,we report CuBi_(2)O_(4)/CuO(CBO/CuO)heterojunction submicrocrystalline film photocathodes with efficient ORR activity for H_(2)O_(2)production.The heterojunction film photocathodes were prepared through thermal evaporation of Cu and Bi metals under vacuum and subsequent annealing treatment.Furthermore,the doping of Gd^(3+)ions into CBO/CuO could significantly enhance the yield of H_(2)O_(2).As a result,the concentration of H_(2)O_(2)could reach 1.3 mM within 30 min,which is 6 times higher than that obtained on the pristine CBO/CuO photocathode.The theoretical calculations suggested that the introduction of Gd could adjust the electronic structure of CBO surface and promote 2e ORR pathway for selective production of H_(2)O_(2).Our work not only provides a new strategy for designing highly efficient photocathode for H_(2)O_(2)production but also will evoke more interest in photoelectrocatalytic ORR through inorganic semiconductor photocathode.展开更多
Zinc ion hybrid supercapacitors(ZHS)have received much attention due to the enhanced potential window range and high specific capacity.However,the appropriate positive materials with high electrochemical performance a...Zinc ion hybrid supercapacitors(ZHS)have received much attention due to the enhanced potential window range and high specific capacity.However,the appropriate positive materials with high electrochemical performance are still a challenge.Herein,NH_(4)^(+)and glycerate anions pre-inserted Mo glycerate(N-MoG)spheres are synthesized and serve as the template to form NH_(4)^(+)intercalated Ni_(3)S_(2)/Ni_(3)O_(2)(OH)_(4)@MoS_(2)core–shell nanoflower(N-NiMo-OS)in-situ grown on nickel foam(NF)(N-NiMo-OS/NF)by sulfurization treatment.Compared with the product using traditional MoG as a template,N-NiMo-OS/NF inheriting a larger core structure from N-MoG delivers enhanced space for ions transport and volume expansion during the energy storage process,together with the synergistic effects of multi-components and the heterostructure,the as-prepared N-NiMo-OS/NF nanoflower exhibits excellent performance for the battery-type hybrid supercapacitors(BHS)and ZHS devices.Notably,the ZHS device delivers superior electrochemical performance to the BHS device,such as a higher specific capacity of 327.5 mAh·g^(−1)at 1 A·g^(−1),a preeminent energy density of 610.6 Wh·kg^(−1)at 1710 W·kg^(−1),long cycle life.The in-situ Raman,ex-situ X-ray photoelectron spectroscopy(XPS),theoretical calculation demonstrate the extra Zn^(2+)insertion/extraction storage mechanism provides enhanced electrochemical performance for ZHS device.Therefore,the dual-ion pre-inserted strategy can be extended for other advanced electrode materials in energy storage fields.展开更多
基金supported by the National Key Research and Development Program of China(Nos.2022YFB3504100,2022YFB3506200)the National Natural Science Foundation of China(Nos.22208373,22376217)+1 种基金the Beijing Nova Program(No.20220484215)the Science Foundation of China University of Petroleum,Beijing(No.2462023YJRC030)。
文摘It is urgent to develop catalysts with application potential for oxidative coupling of methane(OCM)at relatively lower temperature.Herein,three-dimensional ordered macro porous(3 DOM)La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)(A_(2)B_(2)O_(7)-type)catalysts with disordered defective cubic fluorite phased structure were successfully prepared by a colloidal crystal template method.3DOM structure promotes the accessibility of the gaseous reactants(O2and CH4)to the active sites.The co-doping of Ca and Sr ions in La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)catalysts improved the formation of oxygen vacancies,thereby leading to increased density of surface-active oxygen species(O_(2)^(-))for the activation of CH4and the formation of C2products(C2H6and C2H4).3DOM La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)catalysts exhibit high catalytic activity for OCM at low temperature.3DOM La1.7Sr0.3Ce1.7Ca0.3O7-δcatalyst with the highest density of O_(2)^(-)species exhibited the highest catalytic activity for low-temperature OCM,i.e.,its CH4conversion,selectivity and yield of C2products at 650℃are 32.2%,66.1%and 21.3%,respectively.The mechanism was proposed that the increase in surface oxygen vacancies induced by the co-doping of Ca and Sr ions boosts the key step of C-H bond breaking and C-C bond coupling in catalyzing low-temperature OCM.It is meaningful for the development of the low-temperature and high-efficient catalysts for OCM reaction in practical application.
基金supported by the funding from the National Natural Science Foundation of China(grant nos.51902187,52072224,and 51732007)the Natural Science Foundation of Shandong Province(ZR2018BEM010)+3 种基金the Science Fund for Distinguished Young Scholars of Shandong Province(ZR2019JQ16)the Fundamental Research Funds of Shandong UniversityYoung Elite Scientist Sponsorship Program by CAST(YESS)the support from Collaborative Innovation Center of Technology and Equipment for Biological Diagnosis and Therapy in Universities of Shandong
文摘Driven by safety issues,environmental concerns,and high costs,rechargeable aqueous zinc-ion batteries(ZIBs)have received increasing attention in recent years owing to their unique advantages.However,the sluggish kinetics of divalent charge Zn^(2+)in the cathode materials caused by the strong electrostatic interaction and their unsatisfactory cycle life hinder the development of ZIBs.Herein,organic cations and Zn^(2+)ions co-pre-inserted vanadium oxide([N(CH_(3))_(4)]_(0.77),Zn_(0.23))V_(8)O_(20)·3.8H_(2)O are reported as the cathode for ultra-stable aqueous ZIBs,in which the weaker electrostatic interactions between Zn^(2+)and organic ion-pinned vanadium oxide can induce the high reversibility of Zn^(2+)insertion and extraction,thereby improving the cycle life.It is demonstrated that([N(CH_(3))_(4)]_(0.77),Zn_(0.23))V_(8)O_(20)·3.8H_(2)O cathodes deliver a discharge capacity of 181 mA h g^(-1)at8 A g^(-1)and ultra-long life span(99.5%capacity retention after 2000 cycles).A reversible Zn^(2+)/H^(+)ions(de)intercalation storage process and pseudocapacitive charge storage are characterized.The weaker interactions between organic ion and Zn^(2+)open a novel avenue for the design of highly reversible cathode materials with long-term cycling stability.
基金supported by the Fundamental Research Funds for the Central Universities and the National Natural Science Foundation of China(No.61378027)。
文摘A diode-pumped continuous-wave Tm:YVO_[4]laser operating on the^[3]H_[4]→^[3]H_[5]and3F4→^[3]H_[6]transitions was demonstrated for the first time,to the best of our knowledge.An a-cut Tm:YVO_[4]crystal with 1.5%[atomic fraction]Tm3+ion concentration was used to characterize the laser behavior.A common commercial laser diode with a central wavelength of 790 nm and a bandwidth of 3.2 nm was utilized as a pump source.With an output coupler for the^[3]H_[4]→^[3]H_[5]and3F4→^[3]H_[6]transitions,simultaneous three-wavelength laser operation was achieved.The laser emissions at 2292 and 2363 nm inπ-polarization and at 2108 nm inσ-polarization were realized.With an incident pump power of 22 W,the total output power of 1.17 W at 2292,2363,and 2108 nm was obtained.The output power at 2292 and 2363 nm was measured to be 750 mW,and the output power at 2108 nm was measured to be 420 mW.
基金the National Natural Science Foundation of China(Nos.21872021,21671033,22172022 and 22071019).
文摘Molybdenum trioxide(MoO_(3))can be employed as an excellent host for intercalation due to its 2D lay-ered structure that connected by van der Waals interactions.Herein,a series of polyoxometalate-based MoO_(3) composites(Al_(13)@MoO_(3))were successfully prepared by interpolating the Keggin-type polycationic AlO_(4)Al_(12)(OH)_(24)H_(2)O_(12)^(7+)(Al_(13))into MoO_(3)gallery.These composites can be applied to rapidly adsorb the anionic dye methyl orange(MO)through strong electrostatic interactions lead to compact and sta-ble gathering in the surrounding of the numerous charged Al_(13).Adsorption behaviors of composites with the different amount of Al_(13) were determined,these results revealed that Al_(13)-3.34%@MoO_(3)exhibited the most remarkable adsorption capacity.More importantly,the composite maintains superior adsorption capacity for five consecutive adsorption/desorption cycles,suggesting that Al_(13)@MoO_(3)can be an efficient and durable adsorbent.
基金This work was supported by the National Natural Science Foundation of China(Nos.21064006,21262032 and 21161018)the Program for Changjiang Scholars and Innovative Research Team in University of Ministry of Education of China(No.IRT1177)+2 种基金the Natural Science Foundation of Gansu Province(No.1010RJZA018)the Youth Foundation of Gansu Province(No.2011GS04735)NWNU-LKQN-11-32.
文摘A long wavelength emission fluorescent(612 nm)chemosensor with high selectivity for H_(2)PO_(4)^(−)ions was designed and synthesized according to the excited state intramolecular proton transfer(ESIPT).The sensor can exist in two tautomeric forms(‘keto’and‘enol’)in the presence of Fe^(3+)ion,Fe^(3+)may bind with the‘keto’form of the sensor.Furthermore,the in situ generated GY-Fe^(3+)ensemble could recover the quenched fluorescence upon the addition of H_(2)PO_(4)^(−)anion resulting in an off-on-type sensing with a detection limit of micromolar range in the same medium,and other anions,including F^(−),Cl^(−),Br^(−),I^(−),AcO^(−),HSO^(−)_(4),ClO^(−)_(4)and CN−had nearly no influence on the probing behavior.The test strips based on 2-[2-hydroxy-4-(diethylamino)phenyl]-1H-imidazo[4,5-b]phenazine and Fe^(3+)metal complex(GY-Fe^(3+))were fabricated,which could act as convenient and efficient H_(2)PO_(4)^(−)test kits.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.21673160 and 12075154)Natural Science Foundation of Zhejiang for Distinguished Young Scholars(No.LR16B010002)startup funds of Shaoxing University.
文摘Photoelectrochemical oxygen reduction reaction(ORR)toward H_(2)O_(2)is highly desirable because only sunlight,O_(2)and water are required in the process.However,the corresponding studies are still at its infancy because of the lack of suitable photocathodes,especially inorganic semiconductor photocathodes.In this work,we report CuBi_(2)O_(4)/CuO(CBO/CuO)heterojunction submicrocrystalline film photocathodes with efficient ORR activity for H_(2)O_(2)production.The heterojunction film photocathodes were prepared through thermal evaporation of Cu and Bi metals under vacuum and subsequent annealing treatment.Furthermore,the doping of Gd^(3+)ions into CBO/CuO could significantly enhance the yield of H_(2)O_(2).As a result,the concentration of H_(2)O_(2)could reach 1.3 mM within 30 min,which is 6 times higher than that obtained on the pristine CBO/CuO photocathode.The theoretical calculations suggested that the introduction of Gd could adjust the electronic structure of CBO surface and promote 2e ORR pathway for selective production of H_(2)O_(2).Our work not only provides a new strategy for designing highly efficient photocathode for H_(2)O_(2)production but also will evoke more interest in photoelectrocatalytic ORR through inorganic semiconductor photocathode.
基金the National Natural Science Foundation of China(Nos.21702116,51772162,and 52072197)the 111 Project of China(No.D20017)+5 种基金Shandong Provincial Key Research and Development Program,China(No.2019GSF107087)Qingdao Postdoctoral Sustentation Fund,Youth Innovation and Technology Foundation of Shandong Higher Education Institutions,China(No.2019KJC004)Outstanding Youth Foundation of Shandong Province,China(No.ZR2019JQ14)Taishan Scholar Young Talent Program(No.tsqn201909114)Major Scientific and Technological Innovation Project(No.2019JZZY020405)Major Basic Research Program of Natural Science Foundation of Shandong Province(No.ZR2020ZD09).
文摘Zinc ion hybrid supercapacitors(ZHS)have received much attention due to the enhanced potential window range and high specific capacity.However,the appropriate positive materials with high electrochemical performance are still a challenge.Herein,NH_(4)^(+)and glycerate anions pre-inserted Mo glycerate(N-MoG)spheres are synthesized and serve as the template to form NH_(4)^(+)intercalated Ni_(3)S_(2)/Ni_(3)O_(2)(OH)_(4)@MoS_(2)core–shell nanoflower(N-NiMo-OS)in-situ grown on nickel foam(NF)(N-NiMo-OS/NF)by sulfurization treatment.Compared with the product using traditional MoG as a template,N-NiMo-OS/NF inheriting a larger core structure from N-MoG delivers enhanced space for ions transport and volume expansion during the energy storage process,together with the synergistic effects of multi-components and the heterostructure,the as-prepared N-NiMo-OS/NF nanoflower exhibits excellent performance for the battery-type hybrid supercapacitors(BHS)and ZHS devices.Notably,the ZHS device delivers superior electrochemical performance to the BHS device,such as a higher specific capacity of 327.5 mAh·g^(−1)at 1 A·g^(−1),a preeminent energy density of 610.6 Wh·kg^(−1)at 1710 W·kg^(−1),long cycle life.The in-situ Raman,ex-situ X-ray photoelectron spectroscopy(XPS),theoretical calculation demonstrate the extra Zn^(2+)insertion/extraction storage mechanism provides enhanced electrochemical performance for ZHS device.Therefore,the dual-ion pre-inserted strategy can be extended for other advanced electrode materials in energy storage fields.
