Herein,an external crosslinker facilitated the hypercrosslinking of ferrocene and a nitrogen heterocyclic compound(either melamine or imidazole)through a direct Friedel-Crafts reaction,which led to the formation of ni...Herein,an external crosslinker facilitated the hypercrosslinking of ferrocene and a nitrogen heterocyclic compound(either melamine or imidazole)through a direct Friedel-Crafts reaction,which led to the formation of nitrogen-containing hypercrosslinked fer-rocene polymer precursors(HCP-FCs).Subsequent carbonization of these precursors results in the production of iron-nitrogen-doped por-ous carbon absorbers(Fe-NPCs).The Fe-NPCs demonstrate a porous structure comprising aggregated nanotubes and nanospheres.The porosity of this structure can be modulated by adjusting the iron and nitrogen contents to optimize impedance matching.The uniform dis-tribution of Fe-N_(x)C,N dipoles,andα-Fe within the carbon matrix can be ensured by using hypercrosslinked ferrocenes in constructing porous carbon,providing the absorber with numerous polarization sites and a conductive network.The electromagnetic wave absorption performance of the specially designed Fe-NPC-M_(2)absorbers is satisfactory,revealing a minimum reflection loss of-55.3 dB at 2.5 mm and an effective absorption bandwidth of 6.00 GHz at 2.0 mm.By utilizing hypercrosslinked polymers(HCPs)as precursors,a novel method for developing highly efficient carbon-based absorbing agents is introduced in this research.展开更多
在工业水处理领域,以亚铁[Fe(Ⅱ)]为催化剂,利用硝酸盐依赖亚铁氧化(nitrate-dependent ferrous oxidation,NDFO)和铁氨氧化(anaerobic ammonium oxidation coupled to ferric iron reduction,Feammox)的耦合可实现不同形态氮的去除,但...在工业水处理领域,以亚铁[Fe(Ⅱ)]为催化剂,利用硝酸盐依赖亚铁氧化(nitrate-dependent ferrous oxidation,NDFO)和铁氨氧化(anaerobic ammonium oxidation coupled to ferric iron reduction,Feammox)的耦合可实现不同形态氮的去除,但Fe(Ⅱ)是否可以促进湖泊沉积物中NDFO和Feammox的循环或交替发生,目前尚不明确。为此,以太湖梅梁湾沉积物为研究对象,通过厌氧培养实验对该耦合过程进行研究。结果显示,Fe(Ⅱ)添加后体系内硝酸盐氮(NO_(3)^(-)-N)和Fe(Ⅱ)质量浓度呈同步快速下降趋势(p<0.01),且表层沉积物出现棕褐色絮状物,X射线光电子能谱分析也证实沉积物中的三价铁[Fe(Ⅲ)]占比显著提升,表明硝酸盐(NO_(3)^(-))还原与Fe(Ⅱ)氧化发生了耦合。通过高分辨率透射电镜、X射线吸收近边结构谱与X射线衍射联合表征,明确γ-FeOOH为Fe(Ⅱ)氧化的主要产物。进一步添加氨氮(NH_(4)^(+)-N)后,沉积物表层的棕褐色絮状物逐渐消失,同时氨氮浓度降低,表明NDFO产物可有效驱动Feammox进程。宏基因组测序进一步表明,Rhodanobacter和Geothrix等可介导NDFO或Feammox反应的菌属的相对丰度显著提升,揭示了铁、氮循环功能菌群的协同代谢关系。研究所揭示的外源Fe(Ⅱ)介导的NDFO-Feammox耦合机制,深化了沉积物中铁、氮理论,也为富营养化湖泊的氮污染治理提供了基于铁循环调控的生物强化新途径。展开更多
基金supported by the National Natural Science Foundation of China(No.51803041)the University and Local Integration Development Project of Yantai,China(No.2022 XDRHXMXK08).
文摘Herein,an external crosslinker facilitated the hypercrosslinking of ferrocene and a nitrogen heterocyclic compound(either melamine or imidazole)through a direct Friedel-Crafts reaction,which led to the formation of nitrogen-containing hypercrosslinked fer-rocene polymer precursors(HCP-FCs).Subsequent carbonization of these precursors results in the production of iron-nitrogen-doped por-ous carbon absorbers(Fe-NPCs).The Fe-NPCs demonstrate a porous structure comprising aggregated nanotubes and nanospheres.The porosity of this structure can be modulated by adjusting the iron and nitrogen contents to optimize impedance matching.The uniform dis-tribution of Fe-N_(x)C,N dipoles,andα-Fe within the carbon matrix can be ensured by using hypercrosslinked ferrocenes in constructing porous carbon,providing the absorber with numerous polarization sites and a conductive network.The electromagnetic wave absorption performance of the specially designed Fe-NPC-M_(2)absorbers is satisfactory,revealing a minimum reflection loss of-55.3 dB at 2.5 mm and an effective absorption bandwidth of 6.00 GHz at 2.0 mm.By utilizing hypercrosslinked polymers(HCPs)as precursors,a novel method for developing highly efficient carbon-based absorbing agents is introduced in this research.
文摘在工业水处理领域,以亚铁[Fe(Ⅱ)]为催化剂,利用硝酸盐依赖亚铁氧化(nitrate-dependent ferrous oxidation,NDFO)和铁氨氧化(anaerobic ammonium oxidation coupled to ferric iron reduction,Feammox)的耦合可实现不同形态氮的去除,但Fe(Ⅱ)是否可以促进湖泊沉积物中NDFO和Feammox的循环或交替发生,目前尚不明确。为此,以太湖梅梁湾沉积物为研究对象,通过厌氧培养实验对该耦合过程进行研究。结果显示,Fe(Ⅱ)添加后体系内硝酸盐氮(NO_(3)^(-)-N)和Fe(Ⅱ)质量浓度呈同步快速下降趋势(p<0.01),且表层沉积物出现棕褐色絮状物,X射线光电子能谱分析也证实沉积物中的三价铁[Fe(Ⅲ)]占比显著提升,表明硝酸盐(NO_(3)^(-))还原与Fe(Ⅱ)氧化发生了耦合。通过高分辨率透射电镜、X射线吸收近边结构谱与X射线衍射联合表征,明确γ-FeOOH为Fe(Ⅱ)氧化的主要产物。进一步添加氨氮(NH_(4)^(+)-N)后,沉积物表层的棕褐色絮状物逐渐消失,同时氨氮浓度降低,表明NDFO产物可有效驱动Feammox进程。宏基因组测序进一步表明,Rhodanobacter和Geothrix等可介导NDFO或Feammox反应的菌属的相对丰度显著提升,揭示了铁、氮循环功能菌群的协同代谢关系。研究所揭示的外源Fe(Ⅱ)介导的NDFO-Feammox耦合机制,深化了沉积物中铁、氮理论,也为富营养化湖泊的氮污染治理提供了基于铁循环调控的生物强化新途径。
