Flower-like ZnO microstructures were successfully produced using a hydrothermal method employing ZnSO_(4)/(NH_(4))_(2)SO_(4) as a raw material.The effect of the operating parameters of the hydrothermal temperature, OH...Flower-like ZnO microstructures were successfully produced using a hydrothermal method employing ZnSO_(4)/(NH_(4))_(2)SO_(4) as a raw material.The effect of the operating parameters of the hydrothermal temperature, OH^(-)/Zn^(2+) molar ratio, time, and amount of dispersant on the phase structure and micromorphology of the ZnO particles were investigated.The synthesis conditions of the flower-like ZnO microstructures were: hydrothermal temperature of 160℃, OH^(-)/Zn^(2+) molar ratio of 5:1, reaction time of 4 h, and 4 mL of dispersant.The flower-like ZnO microstructures were comprised of hexagon-shaped ZnO rods arranged in a radiatively.Degradation experiments of Rhodamine B with the flower-like ZnO microstructures demonstrated a degradation efficiency of 97.6% after 4 h of exposure to sunshine, indicating excellent photocatalytic capacity.The growth mechanism of the flower-like ZnO microstructures was presented.展开更多
Due to the high specific capacity and energy density, lithium–sulfur battery is regarded as a potential energy storage conversion system. However, the serious shuttle effect and the sluggish electrochemical reaction ...Due to the high specific capacity and energy density, lithium–sulfur battery is regarded as a potential energy storage conversion system. However, the serious shuttle effect and the sluggish electrochemical reaction kinetics impede the practical use of lithium–sulfur battery. In the interests of breaking through the above knotty problems, herein we propose to use the polar flower-like Zn O modified by Bi OI nanoparticles as bifunctional host with catalytic and adsorption ability for polysulfides in lithium–sulfur battery.It can be found that this adsorption/catalytic host integrates the functions of adsorption and mutual catalytic conversion of polysulfides, in which the polar flower-like Zn O can effectively capture the polysulfides through strong polar-polar interaction, simultaneously the BiOI nanoparticles can accelerate the mutual conversion of polysulfides to Li2 S through reducing the activation energy and conversion energy barrier required for the electrochemical reaction. As a result, under a sulfur loading of 2.5 mg cm^(-2), the lithium–sulfur battery with Zn O/Bi OI/CNT/S as cathode reveals a considerable initial specific capacity of1267 mAh g^(-1) at a current density of 0.1 C. Even the current density increased to 1 C, the capacity can reach as 873.4 mAh g^(-1), together with a good capacity retention of 67.1% after 400 cycles. Therefore,after systematically study the positive effects of the flower-like ZnO modified by catalytic BiOI nanoparticles on the adsorption and catalytic conversion of polysulfides, this work provides a new idea for the development and application of high-performance lithium–sulfur batteries.展开更多
基金financially supported by the Funding of Shenyang Ligong University’s Research Support Program for High-level Talents (No.1010147000802)the National Natural Science Foundation of China (Nos.52004165 and 51774070)。
文摘Flower-like ZnO microstructures were successfully produced using a hydrothermal method employing ZnSO_(4)/(NH_(4))_(2)SO_(4) as a raw material.The effect of the operating parameters of the hydrothermal temperature, OH^(-)/Zn^(2+) molar ratio, time, and amount of dispersant on the phase structure and micromorphology of the ZnO particles were investigated.The synthesis conditions of the flower-like ZnO microstructures were: hydrothermal temperature of 160℃, OH^(-)/Zn^(2+) molar ratio of 5:1, reaction time of 4 h, and 4 mL of dispersant.The flower-like ZnO microstructures were comprised of hexagon-shaped ZnO rods arranged in a radiatively.Degradation experiments of Rhodamine B with the flower-like ZnO microstructures demonstrated a degradation efficiency of 97.6% after 4 h of exposure to sunshine, indicating excellent photocatalytic capacity.The growth mechanism of the flower-like ZnO microstructures was presented.
基金supported financially by the National Key Research and Development Program of China (2018YFB0104200)the Key Project of Strategic New Industry of Hunan Province (No. 2019GK2032)。
文摘Due to the high specific capacity and energy density, lithium–sulfur battery is regarded as a potential energy storage conversion system. However, the serious shuttle effect and the sluggish electrochemical reaction kinetics impede the practical use of lithium–sulfur battery. In the interests of breaking through the above knotty problems, herein we propose to use the polar flower-like Zn O modified by Bi OI nanoparticles as bifunctional host with catalytic and adsorption ability for polysulfides in lithium–sulfur battery.It can be found that this adsorption/catalytic host integrates the functions of adsorption and mutual catalytic conversion of polysulfides, in which the polar flower-like Zn O can effectively capture the polysulfides through strong polar-polar interaction, simultaneously the BiOI nanoparticles can accelerate the mutual conversion of polysulfides to Li2 S through reducing the activation energy and conversion energy barrier required for the electrochemical reaction. As a result, under a sulfur loading of 2.5 mg cm^(-2), the lithium–sulfur battery with Zn O/Bi OI/CNT/S as cathode reveals a considerable initial specific capacity of1267 mAh g^(-1) at a current density of 0.1 C. Even the current density increased to 1 C, the capacity can reach as 873.4 mAh g^(-1), together with a good capacity retention of 67.1% after 400 cycles. Therefore,after systematically study the positive effects of the flower-like ZnO modified by catalytic BiOI nanoparticles on the adsorption and catalytic conversion of polysulfides, this work provides a new idea for the development and application of high-performance lithium–sulfur batteries.