采用常规的固相反应法结合机械球磨制备了含碳质量分数23.7%的Li_(2)Ni_(2)(MoO_(4))3@C复合材料,并应用于锂离子电池负极。与纯Li_(2)Ni_(2)(MoO_(4))3相比,Li_(2)Ni_(2)(MoO_(4))3@C具有优异的电化学性能,在电流密度为200 mA ·g^...采用常规的固相反应法结合机械球磨制备了含碳质量分数23.7%的Li_(2)Ni_(2)(MoO_(4))3@C复合材料,并应用于锂离子电池负极。与纯Li_(2)Ni_(2)(MoO_(4))3相比,Li_(2)Ni_(2)(MoO_(4))3@C具有优异的电化学性能,在电流密度为200 mA ·g^(-1)时,50周循环后,可逆容量高达845 mAh·g^(-1)。值得注意的是,Li_(2)Ni_(2)(MoO_(4))3@C的首周库仑效率高达85%。此外,运用循环伏安法对Li_(2)Ni_(2)(MoO_(4))3@C复合物存储锂行为进行了初步探索。展开更多
Herein,the catalysts of ultrathin g-C_(3)N_(4)surface-modified hollow spherical Bi2MoO6(g-C_(3)N_(4)/Bi2MoO6,abbreviated as CN/BMO)were fabricated by the co-solvothermal method.The variable valence Mo^(5+)/Mo^(6+)ioni...Herein,the catalysts of ultrathin g-C_(3)N_(4)surface-modified hollow spherical Bi2MoO6(g-C_(3)N_(4)/Bi2MoO6,abbreviated as CN/BMO)were fabricated by the co-solvothermal method.The variable valence Mo^(5+)/Mo^(6+)ionic bridge in CN/BMO catalysts can boost the rapid transfer of photogenerated electrons from Bi2MoO6to g-C_(3)N_(4).And the synergy effect of g-C_(3)N_(4)and Bi2MoO6components remarkably enhance CO_(2)adsorption capability.CN/BMO-2 catalyst has the best performances for visible light-driven CO_(2)reduction compared with single Bi2MoO6and g-C_(3)N_(4),i.e.,its amount and selectivity of CO product are 139.50μmol g-1and 96.88%for 9 h,respectively.Based on the results of characterizations and density functional theory calculation,the photocatalytic mechanism for CO_(2)reduction is proposed.The high-efficient separation efficiency of photogenerated electron-hole pairs,induced by variable valence Mo^(5+)/Mo^(6+)ionic bridge,can boost the rate-limiting steps(COOH*-to-CO*and CO*desorption)of selective visible light-driven CO_(2)conversion into CO.It inspires the establishment of efficient photocatalysts for CO_(2)conversion.展开更多
Charging P2-Na_(2/3)Ni_(1/3)Mn_(2/3)O_(2)to 4.5 V for higher capacity is enticing.However,it leads to severe capacity fading,ascribing to the lattice oxygen evolution and the P2-O2 phase transformation.Here,the Mg Fe_...Charging P2-Na_(2/3)Ni_(1/3)Mn_(2/3)O_(2)to 4.5 V for higher capacity is enticing.However,it leads to severe capacity fading,ascribing to the lattice oxygen evolution and the P2-O2 phase transformation.Here,the Mg Fe_(2)O_(4) coating and Mg,Fe co-doping were constructed simultaneously by Mg,Fe surface treatment to suppress lattice oxygen evolution and P2-O2 phase transformation of P2-Na_(2/3)Ni_(1/3)Mn_(2/3)O_(2)at deep charging.Through ex-situ X-ray diffraction(XRD)tests,we found that the Mg,Fe bulk co-doping could reduce the repulsion between transition metals and Na+/vacancies ordering,thus inhibiting the P2-O2 phase transition and significantly reducing the irreversible volume change of the material.Meanwhile,the internal electric field formed by the dielectric polarization of Mg Fe_(2)O_(4) effectively inhibits the outward migration of oxidized O^(a-)(a<2),thereby suppressing the lattice oxygen evolution at deep charging,confirmed by in situ Raman and ex situ XPS techniques.P2-Na NM@MF-3 shows enhanced high-voltage cycling performance with capacity retentions of 84.8% and 81.3%at 0.1 and 1 C after cycles.This work sheds light on regulating the surface chemistry for Na-layered oxide materials to enhance the high-voltage performance of Na-ion batteries.展开更多
Constructing the stable,low-cost,efficient,and highly adaptable visible light-driven photocatalyst to implement the synergistic effect of photocatalysis and adsorption has been excavated a promising strategy to deal w...Constructing the stable,low-cost,efficient,and highly adaptable visible light-driven photocatalyst to implement the synergistic effect of photocatalysis and adsorption has been excavated a promising strategy to deal with antibiotic pollution in water bodies.Herein,a novel 3 D ternary Z-scheme heterojunction photocatalyst Ni_(2)P/Bi_(2)MoO_(6)/g-C_(3)N_(4)(Ni_(2)P/BMO/CN)was fabricated by a simple solvothermal method in which the broad spectrum antibiotics(mainly tetracyclines and supplemented by quinolones)were used as target pollution sources to evaluate its adsorption and photocatalytic performance.Notably,the Zscheme composite significantly exhibit the enhancement for degradation efficiency of tetracycline and other antibiotic by using Ni_(2)P nanoparticles as electron conductor.Active species capture experiment and electron spin resonance(ESR)technology reveal the mechanism of Z-scheme Ni_(2)P/BMO/CN photocatalytic reaction in detail.In addition,based on the identification of intermediates by liquid chromatography–mass spectroscopy(LC–MS),the possible photocatalytic degradation pathways of TC were proposed.展开更多
以五氧化二钒干凝胶、碳酸锰、磷酸二氢铵、碳酸锂、乙炔黑为原料,采用固相法在相对较低的温度条件下合成了x Li Mn PO4·y Li3V2(PO4)3锂离子电池复合正极材料。采用X射线衍射(XRD)、扫描电镜(SEM)对其晶体结构和表面形貌进行表征...以五氧化二钒干凝胶、碳酸锰、磷酸二氢铵、碳酸锂、乙炔黑为原料,采用固相法在相对较低的温度条件下合成了x Li Mn PO4·y Li3V2(PO4)3锂离子电池复合正极材料。采用X射线衍射(XRD)、扫描电镜(SEM)对其晶体结构和表面形貌进行表征。结果表明,750℃下烧结15 h合成的3Li Mn PO4·Li3V2(PO4)3为结晶良好的两相结构,颗粒粒径较小且分布比较均匀,其在室温、0.2 C倍率下首次充放电容量分别为144.8 m Ah/g和139.8 m Ah/g,循环50次后容量为130.5 m Ah/g。展开更多
文摘采用常规的固相反应法结合机械球磨制备了含碳质量分数23.7%的Li_(2)Ni_(2)(MoO_(4))3@C复合材料,并应用于锂离子电池负极。与纯Li_(2)Ni_(2)(MoO_(4))3相比,Li_(2)Ni_(2)(MoO_(4))3@C具有优异的电化学性能,在电流密度为200 mA ·g^(-1)时,50周循环后,可逆容量高达845 mAh·g^(-1)。值得注意的是,Li_(2)Ni_(2)(MoO_(4))3@C的首周库仑效率高达85%。此外,运用循环伏安法对Li_(2)Ni_(2)(MoO_(4))3@C复合物存储锂行为进行了初步探索。
基金supported by the National Natural Science Foundation of China(21972166)the Beijing Natural Science Foundation(2202045)the National Key Research and Development Program of China(2019YFC1907600)。
文摘Herein,the catalysts of ultrathin g-C_(3)N_(4)surface-modified hollow spherical Bi2MoO6(g-C_(3)N_(4)/Bi2MoO6,abbreviated as CN/BMO)were fabricated by the co-solvothermal method.The variable valence Mo^(5+)/Mo^(6+)ionic bridge in CN/BMO catalysts can boost the rapid transfer of photogenerated electrons from Bi2MoO6to g-C_(3)N_(4).And the synergy effect of g-C_(3)N_(4)and Bi2MoO6components remarkably enhance CO_(2)adsorption capability.CN/BMO-2 catalyst has the best performances for visible light-driven CO_(2)reduction compared with single Bi2MoO6and g-C_(3)N_(4),i.e.,its amount and selectivity of CO product are 139.50μmol g-1and 96.88%for 9 h,respectively.Based on the results of characterizations and density functional theory calculation,the photocatalytic mechanism for CO_(2)reduction is proposed.The high-efficient separation efficiency of photogenerated electron-hole pairs,induced by variable valence Mo^(5+)/Mo^(6+)ionic bridge,can boost the rate-limiting steps(COOH*-to-CO*and CO*desorption)of selective visible light-driven CO_(2)conversion into CO.It inspires the establishment of efficient photocatalysts for CO_(2)conversion.
基金supported by the Special Project for the Central Government to Guide Local Technological Development (GUIKE ZY20198008)the Guangxi Technology Base and talent Subject (GUIKE AD20238012,AD20297086)+5 种基金the Natural Science Foundation of Guangxi Province (2021GXNSFDA075012)the National Natural Science Foundation of China (51902108,52104298,22169004)the National Natural Science Foundation of China (U20A20249)the Regional Innovation and Development Joint Fundthe Guangxi Innovation Driven Development Subject (GUIKE AA19182020,19254004)the Special Fund for Guangxi Distinguished Expert。
文摘Charging P2-Na_(2/3)Ni_(1/3)Mn_(2/3)O_(2)to 4.5 V for higher capacity is enticing.However,it leads to severe capacity fading,ascribing to the lattice oxygen evolution and the P2-O2 phase transformation.Here,the Mg Fe_(2)O_(4) coating and Mg,Fe co-doping were constructed simultaneously by Mg,Fe surface treatment to suppress lattice oxygen evolution and P2-O2 phase transformation of P2-Na_(2/3)Ni_(1/3)Mn_(2/3)O_(2)at deep charging.Through ex-situ X-ray diffraction(XRD)tests,we found that the Mg,Fe bulk co-doping could reduce the repulsion between transition metals and Na+/vacancies ordering,thus inhibiting the P2-O2 phase transition and significantly reducing the irreversible volume change of the material.Meanwhile,the internal electric field formed by the dielectric polarization of Mg Fe_(2)O_(4) effectively inhibits the outward migration of oxidized O^(a-)(a<2),thereby suppressing the lattice oxygen evolution at deep charging,confirmed by in situ Raman and ex situ XPS techniques.P2-Na NM@MF-3 shows enhanced high-voltage cycling performance with capacity retentions of 84.8% and 81.3%at 0.1 and 1 C after cycles.This work sheds light on regulating the surface chemistry for Na-layered oxide materials to enhance the high-voltage performance of Na-ion batteries.
基金financially supported by the National Natural Science Foundation of China(No.21906072,22006057,21671084 and 51902140)the Natural Science Foundation of Jiangsu Province(BK20190982)+2 种基金Henan Postdoctoral Foundation(202003013)“Doctor of Mass entrepreneurship and innovation”Project in Jiangsu Province,Jiangsu 333 talents project funding(BRA2018342)Jiangsu provincial government scholarship for overseas studies,the Doctoral Scientific Research Foundation of Jiangsu University of Science and Technology(China)(1062931806 and 1142931803)。
文摘Constructing the stable,low-cost,efficient,and highly adaptable visible light-driven photocatalyst to implement the synergistic effect of photocatalysis and adsorption has been excavated a promising strategy to deal with antibiotic pollution in water bodies.Herein,a novel 3 D ternary Z-scheme heterojunction photocatalyst Ni_(2)P/Bi_(2)MoO_(6)/g-C_(3)N_(4)(Ni_(2)P/BMO/CN)was fabricated by a simple solvothermal method in which the broad spectrum antibiotics(mainly tetracyclines and supplemented by quinolones)were used as target pollution sources to evaluate its adsorption and photocatalytic performance.Notably,the Zscheme composite significantly exhibit the enhancement for degradation efficiency of tetracycline and other antibiotic by using Ni_(2)P nanoparticles as electron conductor.Active species capture experiment and electron spin resonance(ESR)technology reveal the mechanism of Z-scheme Ni_(2)P/BMO/CN photocatalytic reaction in detail.In addition,based on the identification of intermediates by liquid chromatography–mass spectroscopy(LC–MS),the possible photocatalytic degradation pathways of TC were proposed.
文摘以五氧化二钒干凝胶、碳酸锰、磷酸二氢铵、碳酸锂、乙炔黑为原料,采用固相法在相对较低的温度条件下合成了x Li Mn PO4·y Li3V2(PO4)3锂离子电池复合正极材料。采用X射线衍射(XRD)、扫描电镜(SEM)对其晶体结构和表面形貌进行表征。结果表明,750℃下烧结15 h合成的3Li Mn PO4·Li3V2(PO4)3为结晶良好的两相结构,颗粒粒径较小且分布比较均匀,其在室温、0.2 C倍率下首次充放电容量分别为144.8 m Ah/g和139.8 m Ah/g,循环50次后容量为130.5 m Ah/g。
