In Situ Exfoliated,N‐Doped,and Edge‐Rich Ultrathin Layered Double Hydroxides Nanosheets for Oxygen Evolution Reaction

The number of catalytically reactive sites and their intrinsic electrocatalytic activity strongly affect the performance of electrocatalysts. Recently, there are growing concerns about layered double hydroxides (LDHs) for oxygen evolution reaction (OER). Exfoliating LDHs is an effective method to increase the reactive sites, however, a traditional liquid phase exfoliation method is usually very labor‐intensive and time‐consuming. On the other hand, proper heteroelement doping and edge engineering are helpful to tune the intrinsic activity of reactive sites. In this work, bulk CoFe LDHs are successfully exfoliated into ultrathin CoFe LDHs nanosheets by nitrogen plasma. Meanwhile, nitrogen doping and defects are introduced into exfoliated ultrathin CoFe LDHs nanosheets. The number of reactive sites can be increased efficiently by the formation of ultrathin CoFe LDHs nanosheets, the nitrogen dopant alters the surrounding electronic arrangement of reactive site facilitating the adsorption of OER intermediates, and the electrocatalytic activity of reactive sites can be further tuned efficiently by introducing defects which increase the number of dangling bonds neighboring reactive sites and decrease the coordination number of reactive sites. With these advantages, this electrocatalyst shows excellent OER activity with an ultralow overpotential of 233 mV at 10 mA cm^?2.     

合成条件对煤／ZnMgAl—LDHs纳米复合材料的影响

以超细神府煤为模板,采用原位共沉淀法制备了煤／水滑石类化合物（Coal／LDHs）纳米复合材料,并探讨了模板剂用量、沉淀反应pH及晶化时间对形成产物的物相及组成的影响,用X射线衍射（XRD）、傅里叶红外变换红外光谱（FTIR）及扫描电镜（SEM）对产物进行了表征,结果表明,所得复合材料具有典型的层状结构特征,煤模板剂对锌镁铝金属离子的选择性吸附使得产物中锌元素含量显著提高,煤酸性官能团如羧基等与水滑石层板羟基产生强烈的氢键相互作用,复合材料为纳米片状包覆表面;随着神府煤模板剂用量的增加,晶化时间延长,复合材料结晶度下降,煤与水滑石层板相互作用增强,材料表面的纳米片状团聚度降低;pH=10时,复合材料结晶度最好。     

催化领域中水滑石类层柱材料的技术现状及国内专利分析

文章简述了水滑石类层柱材料在催化领域的应用,从专利申请量年度分布情况、申请人类型统计和申请人排名情况三个方面进行统计分析,通过对数据的比较和分析,得出了我国水滑石类层柱材料在催化领域的研究现状、应用水平和研究趋势。     

Study on preparation of layered double hydroxides (LDHs) and properties of EPDM/LDHs composites

Abstract

The aim of this work was to study preparation and characterisation of layered double hydroxides (LDHs) and their effects on the mechanical and flame-retardant properties of ethylene propylene diene (EPDM) polymer. A series of Mg–Al, Ni–Al, and Cu–Al hydrotalcite-like compounds were prepared. The surface morphology, interlayer space, interlamellar structure, and thermal properties of these LDHs were investigated. Results showed that a best thermal stability could be obtained with Cu–Al–LDHs as the most effective components. EPDM/Cu–Al–LDHs composites were prepared by conventional compounding with EPDM and Cu–Al type of LDHs. The cure characteristics, tensile strength, wear resistant, and flame-retardant properties were investigated. The best properties were observed for 10 phr of Cu–Al–LDHs filled composite, which resulted in no obvious changes of tensile strength, increased thermal stability, 45% decrease in abrasion loss, and 53% increase in vertical burning time, respectively, compared to that of pure EPDM matrix.     

水滑石类材料的制备及在水污染治理中的应用

本文简要介绍了目前国内外水滑石类材料的各种制备方法,包括共沉淀法、焙烧还原法、离子交换法等。同时总结了其作为催化剂和离子交换剂在修复阴离子污染水体,印染废水脱色、重金属的去除等方面的应用。     

Corrosion inhibition of aluminum by coatings formulated with Al–Zn–vanadate hydrotalcite

The hydrotalcite structure is an ionic lamellar solid with positively charged layers incorporating two kinds of metallic cations and hydrated gallery anions. The ability of these compounds to retain aggressive ions and simultaneously release a corrosion inhibitor is the main reason for the development of hydrotalcite compounds to replace hexavalent chromium compounds (chromates) as inhibitive pigments.     

LDHs功能材料在建筑领域的应用研究进展

层状双（或复合）金属氢氧化物（Layered Double Hydroxides,LDHs）是一类具有特殊结构与功能的新型层状材料,因其独特的组成结构可调变性及记忆效应等特性使其在诸多领域获得广泛的研究和应用。综述了LDHs材料的组成、结构和性质以及近年来LDHs功能材料在混凝土、涂料、保温材料及其他建材中的应用进展。讨论了LDHs材料的特点和应用机理,并分析了当前LDHs材料存在的制备成本高、制备工艺条件苛刻、剥离困难及插层组装定位取向和机理分析不够成熟、用途较单一等问题。最后对LDHs在超分子功能材料及剥离重组等方面的开发使用进行了展望。     

基于LDHs阻燃剂阻燃纸的制备工艺

通过设计正交试验,讨论了复配阻燃剂的种类、复配阻燃剂的质量浓度、阻燃剂pH值、反应温度、反应时间和层状双羟基金属氧化物（LDHs）的质量浓度对120 g·m-2阻燃纸阻燃效果的影响。研究结果表明,当三聚氰胺（MA）的质量浓度为10 g/L、阻燃剂pH值为7.0、反应温度为50℃、反应时间为15 min、LDHs的质量浓度为30 g/L时,所制备的阻燃纸的氧指数（LOI）为31%,已经达到难燃级;与空白样原纸LOI的18%相比,阻燃纸的阻燃效果提高了72%。     

采用LDHs前驱体制备的甲醇水蒸气重整催化剂

对采用水滑石类层柱材料 (LDHs)前驱体制备的Cu/ZnAlO催化剂进行了研究 ,并探讨了Zr和Ce部分及完全取代Cu/ZnAlO催化剂中的Al时 ,对该类催化剂反应性能的影响。最后还对催化剂的稳定性进行了研究。