Alessandro Di Michele, Elisa Boccalon, Ferdinando Costantino, Maria Bastianini, Riccardo Vivani, Morena Nocchetti
{"title":"尿素法合成 LDH 的启示:形态和插层阴离子控制","authors":"Alessandro Di Michele, Elisa Boccalon, Ferdinando Costantino, Maria Bastianini, Riccardo Vivani, Morena Nocchetti","doi":"10.1039/d4dt01529k","DOIUrl":null,"url":null,"abstract":"Layered double hydroxides (LDH) are a class of layered solids applied in many application fields. The study on synthetic methods able to control the interlayer composition and morphology of LDH is an open issue. The urea method, that exploits the thermal decomposition of urea, is known for yielding highly crystalline LDH in carbonate form. This form is highly stable and, to replace carbonate ions with more easily exchangeable anions, a second step is required. In this work, we modified the urea method to obtain MgAl and ZnAl LDH in chloride or nitrate form through a one-step synthesis. The effect of the urea/(Al+M(II)) molar ratio (R), reaction time and metal salt concentrations were deeply investigated. We found that LDH in chloride and nitrate forms can be prepared from solutions of metal salts not exceeding 1M by adjusting R and maintaining the reaction time at 48 hours. The morphology of these products was found to depend on the R value and on the metal salts used in the synthesis. High R value and nitrate salts favoured the formation of sand-rose crystals, while chloride salts induced the formation of plate-like crystals. The crystal growth mechanism and the parameters influencing the morphology are discussed with reference to ZnAl LDH by monitoring the synthesis over time.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":null,"pages":null},"PeriodicalIF":3.5000,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Insight on the synthesis of LDH with urea method: morphology and intercalated anion control\",\"authors\":\"Alessandro Di Michele, Elisa Boccalon, Ferdinando Costantino, Maria Bastianini, Riccardo Vivani, Morena Nocchetti\",\"doi\":\"10.1039/d4dt01529k\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Layered double hydroxides (LDH) are a class of layered solids applied in many application fields. The study on synthetic methods able to control the interlayer composition and morphology of LDH is an open issue. The urea method, that exploits the thermal decomposition of urea, is known for yielding highly crystalline LDH in carbonate form. This form is highly stable and, to replace carbonate ions with more easily exchangeable anions, a second step is required. In this work, we modified the urea method to obtain MgAl and ZnAl LDH in chloride or nitrate form through a one-step synthesis. The effect of the urea/(Al+M(II)) molar ratio (R), reaction time and metal salt concentrations were deeply investigated. We found that LDH in chloride and nitrate forms can be prepared from solutions of metal salts not exceeding 1M by adjusting R and maintaining the reaction time at 48 hours. The morphology of these products was found to depend on the R value and on the metal salts used in the synthesis. High R value and nitrate salts favoured the formation of sand-rose crystals, while chloride salts induced the formation of plate-like crystals. The crystal growth mechanism and the parameters influencing the morphology are discussed with reference to ZnAl LDH by monitoring the synthesis over time.\",\"PeriodicalId\":71,\"journal\":{\"name\":\"Dalton Transactions\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":3.5000,\"publicationDate\":\"2024-07-03\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Dalton Transactions\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://doi.org/10.1039/d4dt01529k\",\"RegionNum\":3,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"CHEMISTRY, INORGANIC & NUCLEAR\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Dalton Transactions","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1039/d4dt01529k","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, INORGANIC & NUCLEAR","Score":null,"Total":0}
引用次数: 0
摘要
层状双氢氧化物(LDH)是应用于许多领域的一类层状固体。研究能够控制 LDH 层间成分和形态的合成方法是一个未决问题。众所周知,利用尿素热分解的尿素法可以生成碳酸盐形式的高结晶 LDH。这种形态高度稳定,要想用更易交换的阴离子取代碳酸根离子,还需要第二步。在这项工作中,我们对尿素法进行了改进,通过一步合成法获得了氯化物或硝酸盐形式的 MgAl 和 ZnAl LDH。我们深入研究了尿素/(Al+M(II))摩尔比(R)、反应时间和金属盐浓度的影响。我们发现,通过调节 R 并将反应时间保持在 48 小时,可以从不超过 1M 的金属盐溶液中制备出氯化物和硝酸盐形式的 LDH。我们发现这些产物的形态取决于 R 值和合成中使用的金属盐。高 R 值和硝酸盐有利于沙玫瑰晶体的形成,而氯化物盐则会诱导板状晶体的形成。通过监测合成过程的时间,以 ZnAl LDH 为例讨论了晶体生长机制和影响形态的参数。
Insight on the synthesis of LDH with urea method: morphology and intercalated anion control
Layered double hydroxides (LDH) are a class of layered solids applied in many application fields. The study on synthetic methods able to control the interlayer composition and morphology of LDH is an open issue. The urea method, that exploits the thermal decomposition of urea, is known for yielding highly crystalline LDH in carbonate form. This form is highly stable and, to replace carbonate ions with more easily exchangeable anions, a second step is required. In this work, we modified the urea method to obtain MgAl and ZnAl LDH in chloride or nitrate form through a one-step synthesis. The effect of the urea/(Al+M(II)) molar ratio (R), reaction time and metal salt concentrations were deeply investigated. We found that LDH in chloride and nitrate forms can be prepared from solutions of metal salts not exceeding 1M by adjusting R and maintaining the reaction time at 48 hours. The morphology of these products was found to depend on the R value and on the metal salts used in the synthesis. High R value and nitrate salts favoured the formation of sand-rose crystals, while chloride salts induced the formation of plate-like crystals. The crystal growth mechanism and the parameters influencing the morphology are discussed with reference to ZnAl LDH by monitoring the synthesis over time.
期刊介绍:
Dalton Transactions is a journal for all areas of inorganic chemistry, which encompasses the organometallic, bioinorganic and materials chemistry of the elements, with applications including synthesis, catalysis, energy conversion/storage, electrical devices and medicine. Dalton Transactions welcomes high-quality, original submissions in all of these areas and more, where the advancement of knowledge in inorganic chemistry is significant.