We report on the magnetic,magnetocaloric,thermal,and electrical transport properties of Tb_(4)Coln alloy,which crystallizes in two phases,Tb_6Co_(2.1)In_(0.8)(space group Immm)and Tb_(2)In_(0.9)Co_(0.1)(space group P6...We report on the magnetic,magnetocaloric,thermal,and electrical transport properties of Tb_(4)Coln alloy,which crystallizes in two phases,Tb_6Co_(2.1)In_(0.8)(space group Immm)and Tb_(2)In_(0.9)Co_(0.1)(space group P6_(3)/mmc),respectively.The alloy reveals three successive magnetic transitions around T_(1)(163 K),T_(2)(50 K),and T_(3)(29 K),respectively,associated with paramagnetic to ferromagnetic transition and two sequential antiferromagnetic transitions.The low-temperature transition T_(3) follows the first-order magnetic behavior and exhibits the field-induced magnetic transition.Meanwhile,T_(2) and T_(1) are found to be second-order in nature which opens a possibility for hysteresis-free magnetocaloric application.The magnetocaloric properties are determined using different magnetocaloric figures of merits such as-ΔS_(M),ΔT_(ad).RCP,and TEC(10).Additionally,the universal curve behavior in the isothermal entropy change unveils the variation in critical exponents around T_(1) and T_(2) due to the magnetic inhomogeneity in the alloy.Besides,the electrical transport properties of the metallic alloy denote the maximum magnetoresistance of-10%around T_(1).展开更多
The design and preparation of economic and efficient electrolysis water catalysts is an important part in effectively developing and utilizing hydrogen energy.In this work,novel N-doped carbon nanospheres supported mu...The design and preparation of economic and efficient electrolysis water catalysts is an important part in effectively developing and utilizing hydrogen energy.In this work,novel N-doped carbon nanospheres supported multiple transition metal sulfides(NiWCoS/NC)electrocatalysts were prepared by combining the radiation oxidation synthesis and synchronous carbonization-sulfurization.Initially,the precursor material(NiWCoS/OANI,here OANI refers to oligoaniline)containing sulfurand multiple transition metal(Ni,W,and Co)ions loaded on oligoaniline nanospheres was directly one-pot synthesized at room temperature under γ-ray radiation.Subsequently,NiWCoS/NC electrocatalysts were successfully prepared by calcining the NiWCoS/OANI precursor at 800℃.The electrocatalytic performance of NiWCoS/NC for the hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)was characterized by electrochemical analysis methods including linear sweep voltammetry,cyclic voltammetry,chronoamperometry,and electrochemical impedance spectroscopy.The influence of the relative content of the loaded transition metals on the electrocatalytic performance was also investigated.The results indicate that the novel NiWCoS/NC electrocatalyst can significantly reduce the overpotential and Tafel slope for both HER and OER compared to corresponding electrocatalysts with single metal or metal sulfide component.When NiWCoS/NC with a molar ratio of 3:6:10 for W,Co,and S elements was used as electrode material,the overpotentials for HER in 0.5 mol/L H_(2)SO_(4) and OER in 1 mol/L KOH are only 161 mV and 243 mV at a current density of 10 mA/cm^(2),respectively.The Tafel slopes are 74 mV/dec and 88 mV/dec,respectively.The work provides a new direction and method for the design and green facile preparation of high-efficiency overall water splitting catalysts.展开更多
Searching anodes with excellent electrochemical performance has been in great demand for rechargeable metal ion batteries. In this contribution, Fe/Co co-doped Ni S with N-based carbon(Fe Co-NiS@NC) derived from trime...Searching anodes with excellent electrochemical performance has been in great demand for rechargeable metal ion batteries. In this contribution, Fe/Co co-doped Ni S with N-based carbon(Fe Co-NiS@NC) derived from trimetallic Prussian blue analogue is designed and synthesized. The composition can be easily adjusted and modulated by multi-metals. In addition, the well-designed carbon nanocubes effectively promote electronic conductivity and buffer the volume change upon charge and discharge cycling, resulting in good capacity and long-term cycle life for both lithium-ion batteries and sodium-ion batteries, with capacities of 1018 m Ah g^(-1)(vs. Li/Li^(+)) and 454 m Ah g^(-1)(vs. Na/Na^(+)), respectively, after 100 cycles.Kinetics studies indicate that the electrochemical behaviors are manipulated by both diffusion and pseudocapacitance processes. These strategies would open new opportunities and potention for novel energy storage.展开更多
基金Project supported by the University Science Park TECHNICOM for Innovation Applications supported by Knowledge Technology (313011D232)supported by the Research&Development Operational Programme funded by the ERDFVEGA1/0705/20,1/0404/21。
文摘We report on the magnetic,magnetocaloric,thermal,and electrical transport properties of Tb_(4)Coln alloy,which crystallizes in two phases,Tb_6Co_(2.1)In_(0.8)(space group Immm)and Tb_(2)In_(0.9)Co_(0.1)(space group P6_(3)/mmc),respectively.The alloy reveals three successive magnetic transitions around T_(1)(163 K),T_(2)(50 K),and T_(3)(29 K),respectively,associated with paramagnetic to ferromagnetic transition and two sequential antiferromagnetic transitions.The low-temperature transition T_(3) follows the first-order magnetic behavior and exhibits the field-induced magnetic transition.Meanwhile,T_(2) and T_(1) are found to be second-order in nature which opens a possibility for hysteresis-free magnetocaloric application.The magnetocaloric properties are determined using different magnetocaloric figures of merits such as-ΔS_(M),ΔT_(ad).RCP,and TEC(10).Additionally,the universal curve behavior in the isothermal entropy change unveils the variation in critical exponents around T_(1) and T_(2) due to the magnetic inhomogeneity in the alloy.Besides,the electrical transport properties of the metallic alloy denote the maximum magnetoresistance of-10%around T_(1).
基金supported by the National Natural Science Foundation of China (No.51973205 and No.51773189)the Fundamental Research Funds for the Central Universities (WK3450000005 and WK3450000006)。
文摘The design and preparation of economic and efficient electrolysis water catalysts is an important part in effectively developing and utilizing hydrogen energy.In this work,novel N-doped carbon nanospheres supported multiple transition metal sulfides(NiWCoS/NC)electrocatalysts were prepared by combining the radiation oxidation synthesis and synchronous carbonization-sulfurization.Initially,the precursor material(NiWCoS/OANI,here OANI refers to oligoaniline)containing sulfurand multiple transition metal(Ni,W,and Co)ions loaded on oligoaniline nanospheres was directly one-pot synthesized at room temperature under γ-ray radiation.Subsequently,NiWCoS/NC electrocatalysts were successfully prepared by calcining the NiWCoS/OANI precursor at 800℃.The electrocatalytic performance of NiWCoS/NC for the hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)was characterized by electrochemical analysis methods including linear sweep voltammetry,cyclic voltammetry,chronoamperometry,and electrochemical impedance spectroscopy.The influence of the relative content of the loaded transition metals on the electrocatalytic performance was also investigated.The results indicate that the novel NiWCoS/NC electrocatalyst can significantly reduce the overpotential and Tafel slope for both HER and OER compared to corresponding electrocatalysts with single metal or metal sulfide component.When NiWCoS/NC with a molar ratio of 3:6:10 for W,Co,and S elements was used as electrode material,the overpotentials for HER in 0.5 mol/L H_(2)SO_(4) and OER in 1 mol/L KOH are only 161 mV and 243 mV at a current density of 10 mA/cm^(2),respectively.The Tafel slopes are 74 mV/dec and 88 mV/dec,respectively.The work provides a new direction and method for the design and green facile preparation of high-efficiency overall water splitting catalysts.
基金supported by the National Natural Science Foundation of China(Grant Nos.21974007 and 22090043)。
文摘Searching anodes with excellent electrochemical performance has been in great demand for rechargeable metal ion batteries. In this contribution, Fe/Co co-doped Ni S with N-based carbon(Fe Co-NiS@NC) derived from trimetallic Prussian blue analogue is designed and synthesized. The composition can be easily adjusted and modulated by multi-metals. In addition, the well-designed carbon nanocubes effectively promote electronic conductivity and buffer the volume change upon charge and discharge cycling, resulting in good capacity and long-term cycle life for both lithium-ion batteries and sodium-ion batteries, with capacities of 1018 m Ah g^(-1)(vs. Li/Li^(+)) and 454 m Ah g^(-1)(vs. Na/Na^(+)), respectively, after 100 cycles.Kinetics studies indicate that the electrochemical behaviors are manipulated by both diffusion and pseudocapacitance processes. These strategies would open new opportunities and potention for novel energy storage.
