ISGS eSeminar, May 2024

 

 Layered Double Hydroxides: Sol-Gel Synthesis, 

Characterization and Application 

by
Aivaras Kareiva

Faculty of Chemistry and Geosciences, Vilnius University, Lithuania

 

 Layered double hydroxides (LDHs), hydrotalciten-type compounds or anionic clays are the names commonly used to describe a class of layered materials based upon the brucite (Mg(OH)2) crystal structure with general chemical formula of [MII1-xMIIIx(OH)2]x+ (Am-)x/m]·nH2O. The structure of LDH is formed by positively charged metal hydroxide layers [MII1-xMIIIx(OH)2]x+ and negatively charged anions in the interlayer space. As a rule, H2O molecules are also present in the interlayer space. 

A large number of LDHs can be synthesized by varying either the nature of the cati- ons or anions. Consequently, new materials can be obtained with specific properties. All LDHs having different chemical composition share typical common characteristics: layered structure and the formation of mixed-metal oxides after thermal treat- ment. Moreover, the possible reformation of mixed-metal oxides to layered structures (LDHs) using different aqueous media (“memory effect”) is also a common feature of LDHs. Usually, the surfaces of LDH samples are composed of the agglomerated small plate like particles.

LDHs could be used: as efficient adsorbents for liquidions and gas molecules for the removal of anionic toxins (arsenate, chromate, selenite and other) and also toxic metals ions for water purification; catalyst supports; as catalysts for oxidation, reduction and other reactions; hydrotalcite within inorganic membranes in sensor devices; incorporation of rare earth ions into LDH hosts; for anticorrosion protection of metal alloys; as bionanohybrids with ability to incorporate large molecules for drug and gens delivery, cosmetics, cancer therapy and biosensing; etc. In recent years, inorganic-organic hybrid luminescence materials have been widely investigated due to the novel properties to form stable compounds with lanthanides in the interlayer space of LDH.

It is our pleasure to invite you to join the ISGS eSeminar for May 2024, which will be delivered by Professor Aivaras Kareiva on Thursday 23 May. Aivaras joins us from the Faculty of Chemistry and Geosciences at Vilnius University in Litunaina, where he is the Dean of the Faculty. His research, contributions to our community and interesting career journey were profiled in the November 2021 issue of the ISGS Newsletter, which can be found here.

Date: Thursday 23 May 2024

Format:

  • ZOOM (eSeminar link), Meeting ID: 307 291 6432 Passcode: XoWH#863

Time:

  • 09:00 – USA (East Coast)
  • 10:00 – Chile, Brazil (São Paulo) and Argentina
  • 12:00 – UTC
  • 13:00 – UK, Portugal
  • 14:00 – Central Europe, Sweden, Norway, Switzerland
  • 15:00 – Romania, Israel, Eastern Europe, Ukraine
  • 15:00 – Russia (Moscow, St Petersburg)
  • 20:00 – China, Singapore, Malaysia
  • 21:00 – Japan, Korea
  • 22:00 – Australia (East Coast)