Synthesis Of Carbonate Pillared Hydrotalcite And Electrochemical Behavior Of Their Modified Electrode

Hydrotalcite is a sort of layered anionic clays with basic properties, micropore structure, memory effect and interlayer anionic exchangeability and adjustability. For their important catalytic and functional material. They intrest a lot of people working on electrochemistry to study them.The main objective of this work is to find out electroactive hydrotalcite and research their charge transport mechanism.Three series of carbonate pillared MgAl, CoAl and NiAl hydrotalcite which M²⁺/M³⁺ molar rations are 3 are synthesized by coprecipitation. XRD and IR are used in search of the composition and structure of the products. The results of t he XRD measurement certify that the hydrotalcites have nice crystal forms and hi gh purity. And the structure of 3NiAlCO₃-HT is the same as a-Ni(OH)₂'s. The re suits of IR analysis tell us it is CO₃^2- that has been intercalated between the double layers of hydrotalcite-structure. They both show that the synthesis of hydrotalc ites is successful.To find out electroactive hydrotalcites, we focused on the electrochemical behaviors of the three hydrotalcites in blank KC1 electrolyte and in electrolyte containing electroactive ions. The results indicate that the three hydrotalcites remain their layered structures after electrochemical cycling. The enhanced cathartic amperometry are ascribed to electron transfer between the intercalated anions and the oxidized centres in the hydrotalcites.In order to find the optimal experimental conditions for monitoring the signal relative to the electroxidation of the Ni-containing hydrotalcite, cyclic voltammograms using electrodes modified with 3NiAlCO₃-HT were recorded in different aqueous media. The result is that 0.1M NaOH is the best experimental condition, cyclic voltammograms using electrodes modified with 3NiAlCO₃-HT were recorded at different potential scan rate in 0.1M NaOH. The results indicate that electrochemical reaction always occurs under semi-infinite linear diffusion conditionsandthat, in the explored range of potential scan rate, the system never reaches a thin layer like behaviour, typical for an electrochemical reaction confined in the layers close to the electrode surface.