层状无机材料的弱层间耦合和大面积表面为构建低导热性无机固体材料提供了基本框架.合成具有足够散射和非谐波性的稳定层状材料,从而降低热导率,仍是一项挑战.本文在层状无机FeOCl材料体系中,通过一步氧化还原反应成功获得了一种结构稳...层状无机材料的弱层间耦合和大面积表面为构建低导热性无机固体材料提供了基本框架.合成具有足够散射和非谐波性的稳定层状材料,从而降低热导率,仍是一项挑战.本文在层状无机FeOCl材料体系中,通过一步氧化还原反应成功获得了一种结构稳定的富含Fe^(2+)的层状材料,实现了表面和界面的同步改性,并实现了超低的热导率.具体而言,系统的X射线吸收精细结构(XAFS)分析和电子能量损失光谱(EELS)分析表明,碱金属原子的层间插层和表面缺陷的引入诱导了大量Fe^(2+)的存在,从而增强了其非谐波性和声子散射.此外,声子态密度(PDOS)分布也提供了确凿的证据,证明了散射概率的提高和声子模式整体的软化.所制得的层状无机材料Fe(III)_(1−n)Fe(II)_(n)O_(1−x)Cl[K^(+)]_(m)不仅结构稳定,而且在298 K时的热导率比原始FeOCl降低了近60%,低至0.29 W m^(−1) K^(−1),这在层状无机材料中是极低的.这项研究为低导热层状材料的设计提供了新的视角.展开更多
Layered inorganic materials provide an essential platform for constructing new structural configurations of materials with exceptional properties.However,precise control over the interlayer molecular arrangement remai...Layered inorganic materials provide an essential platform for constructing new structural configurations of materials with exceptional properties.However,precise control over the interlayer molecular arrangement remains a significant challenge,impeding in-depth exploration in physics and chemistry realm.Herein,we demonstrated a new layered organic-inorganic superlattice composed of a S-Ta-S inorganic lattice and bilayer linear molecules,providing superhigh heat insulation.A series of interlayer-confined intercalations of alkylamines with increasing chain length in the layered inorganic materials were achieved through precisely ordered molecule design(TaS_(2)-Cn,n=3,6,8,12).Systematic spectral analysis reveals that as the length of the intercalated alkyl chain increases,the alkyl chain between layers becomes more ordered and linear,and the gauche conformation decreases.Furthermore,the more linear and ordered alkyl chain conformation results in lower thermal conductivity.The thermal conductivity of TaS_(2)-C12 is 0.426 W m^(−1) K^(−1),which is only one-third that of the pristine TaS_(2) crystal.We anticipate that this layered organic-inorganic superlattice design will pave a new avenue for developing new organic-inorganic functional materials and probing the limits of ultralow thermal conductivity materials.展开更多
基金supported by the Chinese Academy of Sciences(CAS)Project for Young Scientists in Basic Research(YSBR-070)the National Natural Science Foundation of China(21925110,22321001 and 12147105)+5 种基金the USTC Research Funds of the Double FirstClass Initiative(YD2060002004)the National Key Research and Development Program of China(2022YFA1203600)the Anhui Provincial Key Research and Development Project(202004a050200760)the Key R&D Program of Shandong Province(2021CXGC010302)the Fellowship of China Postdoctoral Science Foundation(2022M710141)the Open Foundation of the Key Lab(Center)of Engineering Research Center of Building Energy Efficiency Control and Evaluation,Ministry of Education(AHJZNX-2023-04).
文摘层状无机材料的弱层间耦合和大面积表面为构建低导热性无机固体材料提供了基本框架.合成具有足够散射和非谐波性的稳定层状材料,从而降低热导率,仍是一项挑战.本文在层状无机FeOCl材料体系中,通过一步氧化还原反应成功获得了一种结构稳定的富含Fe^(2+)的层状材料,实现了表面和界面的同步改性,并实现了超低的热导率.具体而言,系统的X射线吸收精细结构(XAFS)分析和电子能量损失光谱(EELS)分析表明,碱金属原子的层间插层和表面缺陷的引入诱导了大量Fe^(2+)的存在,从而增强了其非谐波性和声子散射.此外,声子态密度(PDOS)分布也提供了确凿的证据,证明了散射概率的提高和声子模式整体的软化.所制得的层状无机材料Fe(III)_(1−n)Fe(II)_(n)O_(1−x)Cl[K^(+)]_(m)不仅结构稳定,而且在298 K时的热导率比原始FeOCl降低了近60%,低至0.29 W m^(−1) K^(−1),这在层状无机材料中是极低的.这项研究为低导热层状材料的设计提供了新的视角.
基金financially supported by the Chinese Academy of Sciences (CAS) Project for Young Scientists in Basic Research (YSBR-070)the National Natural Science Foundation of China (21925110, 21890750, U2032161, 12147105, 22201273, 22205226 and 21925302)+6 种基金the National Key Research and Development Program of China (2022YFA1203601, 2022YFA1203601 and 2022YFA1203602)the National Natural Science Fund for Young Scholars (22205226)the Open Foundation of the Key Laboratory Center of Engineering Research Center of Building Energy Efficiency Control and Evaluation, Ministry of Education (AHJZNX2023-04)the Fellowship of China Postdoctoral Science Foundation (2022M710141)the Fellowship of China National Postdoctoral Program for Innovative Talents (BX2021280)the University Synergy Innovation Program of Anhui Province (GXXT-2022-006)the Users with Excellence Project of Hefei Science Center CAS (2021HSC-UE004)。
文摘Layered inorganic materials provide an essential platform for constructing new structural configurations of materials with exceptional properties.However,precise control over the interlayer molecular arrangement remains a significant challenge,impeding in-depth exploration in physics and chemistry realm.Herein,we demonstrated a new layered organic-inorganic superlattice composed of a S-Ta-S inorganic lattice and bilayer linear molecules,providing superhigh heat insulation.A series of interlayer-confined intercalations of alkylamines with increasing chain length in the layered inorganic materials were achieved through precisely ordered molecule design(TaS_(2)-Cn,n=3,6,8,12).Systematic spectral analysis reveals that as the length of the intercalated alkyl chain increases,the alkyl chain between layers becomes more ordered and linear,and the gauche conformation decreases.Furthermore,the more linear and ordered alkyl chain conformation results in lower thermal conductivity.The thermal conductivity of TaS_(2)-C12 is 0.426 W m^(−1) K^(−1),which is only one-third that of the pristine TaS_(2) crystal.We anticipate that this layered organic-inorganic superlattice design will pave a new avenue for developing new organic-inorganic functional materials and probing the limits of ultralow thermal conductivity materials.
