新型Fe(Ⅱ)Fe(Ⅲ)-SO_(4)^(2-)水滑石的制备及结构研究

Preparation of Fe(Ⅱ)Fe(Ⅲ)-SO_(4)^(2-) Hydrotalcites and Investigation of Its Structure

采用共沉淀法进行了Fe?Fe?-SO42-型水滑石(FeFe-LDH)的制备研究,并利用X射线衍射、红外光谱、穆斯堡尔谱和热分析等手段对其晶体结构和稳定性进行了分析。研究结果表明:当反应投料物质的量之比Fe2+/Fe3+介于2～5之间,共沉淀pH值控制在6.5～7.5之间,反应温度为40℃,反应时间为2h时,可得到晶体结构规整的层状结构产物,所得产物的层板组成并不随投料比的改变而改变,基本保持恒定;且在FeFe-LDH层间形成了SO42-离子与H2O分子的双层排列方式,从而使层间距增大。

Fe?Fe? SO42- hydrotalcites(FeFe LDH) have been synthesized by the method of coprecipitation at low supersaturation. Such techniques have been usedas X ray diffraction, Infrared spectra, Thermal analysis and Mssbauer spectroscopy to describe its crystal structure and thermal property. The effects of varying reaction conditions on the crystal structure were also investigated. Theresult shows that well crystallized hydrotalcites were obtained, when Fe2+/Fe3+ mole ratio is from 3 to 5 in the stock solution, final value of pH, temperature and aging time are 7, 40℃ and 2h separately. And the constitute of Fe?Fe? SO42- hydrotalcites is constant with the change of Fe2+/Fe3+ mole ratio in stock solution. A double arranged structure are formed for SO42- ions and H2O molecular in interlayer of hydrotalcites, and this result leads to theincrease of lattice parameter c.