首次将尖晶石相的纳米Fe3S4材料用作镁二次电池的正极材料。采用水热法一步合成了具有纳米结构的Fe3S4材料,并采用XRD、SEM测试手段对产物的物相、形貌进行了表征。实验结果表明,在160℃能够合成纯相的Fe3S4材料,该材料具有银耳状纳米...首次将尖晶石相的纳米Fe3S4材料用作镁二次电池的正极材料。采用水热法一步合成了具有纳米结构的Fe3S4材料,并采用XRD、SEM测试手段对产物的物相、形貌进行了表征。实验结果表明,在160℃能够合成纯相的Fe3S4材料,该材料具有银耳状纳米结构。电化学测试结果显示,水热法合成的纳米Fe3S4材料能够在镁二次电池体系中进行有效的可逆充放电,放电平台电压为0.9 V,首次放电容量高达267 m Ah·g-1,50次循环后衰减至110 m Ah·g-1。电化学交流阻抗测试结果表明镁离子能够在Fe3S4晶格中扩散。展开更多
Fe3S4 is important magnetic mineral that widely exists in the sediments of lakes and oceans. It can not only instruct reducing environment that contains organic matter and sulfate, but also provide paleomagnetic signa...Fe3S4 is important magnetic mineral that widely exists in the sediments of lakes and oceans. It can not only instruct reducing environment that contains organic matter and sulfate, but also provide paleomagnetic signal for paleoenvironmet research. Simultaneously, as a new type of magnetic material, it causes attention. Because Fe3S4 generally exists as an unstable intermediate, it is stringent in preparation conditions. Although some scholars have conducted on the synthesis experiments of Fe3S4 materials, the research on its stable conditions, formation mechanism and evolution process is not yet depth. Accordingly, defining the stable conditions and revealing evolution law of Fe3S4 nanocrystals have important significance for the determination of environmental conditions and the preparation of pure Fe3S4 nanomaterials.展开更多
Achieving an efficient and stable heterogeneous Fenton reaction over a wide pH range is of great significance for wastewater treatment.Here,a pollen-derived biochar catalyst with a unique honeycomb-like structure,coup...Achieving an efficient and stable heterogeneous Fenton reaction over a wide pH range is of great significance for wastewater treatment.Here,a pollen-derived biochar catalyst with a unique honeycomb-like structure,coupled with the dispersion of magnetic Fe_(3)O_(4)/FeS(Fe/S)nanoparticles,was synthesized by simple impregnation precursor,followed by pyrolysis.The prepared Fe/S-biochar catalyst demonstrated outstanding phenol degradation efficiency across a wide pH range,with 98%of which eliminated even under neutral conditions(pH 7.0).The high catalytic activity was due to the multilevel porous structure of pollenderived biochar provided enough active sites and allowed for better electron transfer,then increases oxidation ability to promote the reaction.Moreover,the acid microenvironment formed by SO_(4)^(2-)group from Fe/S composite extended the pH range for Fenton reaction,and S^(2-)facilitated the conversion of≡Fe^(3+)to≡Fe^(2+),resulting in remarkable degradation efficiency.Further,biochar can effectively promote cycling stability by limiting Fe leaching.This work may provide a general strategy for designing 3D framework biochar-based Fe/S catalysts with excellent performance for heterogeneous Fenton reactions.展开更多
文摘首次将尖晶石相的纳米Fe3S4材料用作镁二次电池的正极材料。采用水热法一步合成了具有纳米结构的Fe3S4材料,并采用XRD、SEM测试手段对产物的物相、形貌进行了表征。实验结果表明,在160℃能够合成纯相的Fe3S4材料,该材料具有银耳状纳米结构。电化学测试结果显示,水热法合成的纳米Fe3S4材料能够在镁二次电池体系中进行有效的可逆充放电,放电平台电压为0.9 V,首次放电容量高达267 m Ah·g-1,50次循环后衰减至110 m Ah·g-1。电化学交流阻抗测试结果表明镁离子能够在Fe3S4晶格中扩散。
基金Supported by National Natural Science Foundation (Grant No.:40872045 41172047)The Opening Project of Key Laboratory of Solid Waste Treatment and Resource Recycle (SWUST), Ministry of Education (12zxgk01)
文摘Fe3S4 is important magnetic mineral that widely exists in the sediments of lakes and oceans. It can not only instruct reducing environment that contains organic matter and sulfate, but also provide paleomagnetic signal for paleoenvironmet research. Simultaneously, as a new type of magnetic material, it causes attention. Because Fe3S4 generally exists as an unstable intermediate, it is stringent in preparation conditions. Although some scholars have conducted on the synthesis experiments of Fe3S4 materials, the research on its stable conditions, formation mechanism and evolution process is not yet depth. Accordingly, defining the stable conditions and revealing evolution law of Fe3S4 nanocrystals have important significance for the determination of environmental conditions and the preparation of pure Fe3S4 nanomaterials.
基金financially supported by the National Natural Science Foundation of China (Nos.21876139 and 21922606)Yulin Science and Technology Project of China (No.CXY2021-134)。
文摘Achieving an efficient and stable heterogeneous Fenton reaction over a wide pH range is of great significance for wastewater treatment.Here,a pollen-derived biochar catalyst with a unique honeycomb-like structure,coupled with the dispersion of magnetic Fe_(3)O_(4)/FeS(Fe/S)nanoparticles,was synthesized by simple impregnation precursor,followed by pyrolysis.The prepared Fe/S-biochar catalyst demonstrated outstanding phenol degradation efficiency across a wide pH range,with 98%of which eliminated even under neutral conditions(pH 7.0).The high catalytic activity was due to the multilevel porous structure of pollenderived biochar provided enough active sites and allowed for better electron transfer,then increases oxidation ability to promote the reaction.Moreover,the acid microenvironment formed by SO_(4)^(2-)group from Fe/S composite extended the pH range for Fenton reaction,and S^(2-)facilitated the conversion of≡Fe^(3+)to≡Fe^(2+),resulting in remarkable degradation efficiency.Further,biochar can effectively promote cycling stability by limiting Fe leaching.This work may provide a general strategy for designing 3D framework biochar-based Fe/S catalysts with excellent performance for heterogeneous Fenton reactions.
