固相法合成掺杂型锂钛系离子筛及其吸附性能

Solid-state Synthesis of Doped Lithium-Titanium Ion-sieve and Its Absorption Properties

以自制的氢氧化钛和乙酸锂为原料,掺入少量乙酸铈,用高温固相法焙烧得到掺杂型锂钛复合氧化物(LTCO),经0.1 mol·L^(-1)盐酸浸渍酸改型制备出锂离子筛(HTCO)。经X射线衍射仪(XRD)、扫描电子显微镜(SEM)及离子筛选择吸附性能测试,考察了离子筛的晶相、形貌及选择性。结果表明:在750℃下焙烧得到的离子筛为尖晶石结构,晶相较纯,颗粒大小均匀,盐酸浸渍后酸改率为86.60%,且酸改型前后晶型及表面颗粒形貌保持不变;离子筛的饱和吸附容量为4.4374 mmol·g^(-1),在单一离子溶液中以及混合离子溶液中均表现出对Li+较高的吸附性能,经过5次循环吸脱附试验后,离子筛对锂离子的吸附性能为4.3652 mmol·g^(-1),说明HTCO离子筛具有优良的稳定性及选择吸附性能。

High temperature solid state method was used to synthesize doped lithium titanium composite oxides(LTCO)by grinding self-preparation titanium hydroxide,lithium acetate and a few amount acetate and calcination process(HTCO).After pickling process by 0.1 mol·L^(-1)hydrochloric acid solution,LTCO transformed to the lithium ion sieve.We investigated the crystalline phase and morphology and the selection capacity of ion sieve by XRD,SEM techniques and the test of selective adsorption performance.The result showed that ion sieve calcined at 750℃had spinel structure,pure crystal phase and uniform particle sizes,and the acid-modification rate was up to 86.60%,besides the crystalline phase and morphology had still remained.Moreover,it had good adsorption performance for Li+in the single ion solution and the mixed ion solution,and the saturation adsorption capacity was up to 4.4374 mmol·g^(-1).Therefore,the ion sieve had excellent stability and selective adsorption capacity for Li+adsorption.After 5 cycles,the adsorption performance of ion sieve for lithium ions was 4.3652 mmol·g^(-1),which showed that HTCO ion sieve had excellent stability and selective adsorption performance.