STUDY OF TEMPRETURE CHANGES IN HYDROTHERMAL ANDCOPORECIPITATION METODES ON PROPERTES OF NAVAL LAYERED DOUBLE HYDROXDES (LDH)

In this study we worked on Ni/Al nitrate layered double hydroxides, Ni/Al LDHs were prepared with Nickle(II) nitrate hexahydriate (N2NiO6.6H2O 99%) and Aluminium nitrate nonahydrate (Al(NO3)3. 9H2O 95%) with molar ratios of 2:1 and 3:1 by both coprecipitation and hydrothermal methods with nitrogen gas purged into the solutions at time ranges of 90-120°C (pH=9.5) for 24h and 180°C(pH= 6 and pH=9.5) for 24h. Samples obtained were characterized by XRD; FT-IR and SEM. These datasshow thatthetemperature increase in both methods enhanced the crystality and size of product and the better crystalinities were gained at hydrothermal conditions (180°C) at pH=6.00. This study offers a simple methodto produce Ni/All nitrate form LDHs under conitions of deionized water without surfactant. However when the reaction is conducted at 220°C another phase with boehemit structure emerges. At higher temperatureand in alkali conditions (pH> 10) there is possibility to form metal oxides;

کلیدواژه ها:

Ni/Al LDH:Layered double hydroxide ، Co-precipitation ، Hydrothermal