摘要
以二氧化钛为钛源,氢氧化锂为锂源,氟化铵为改性剂,采用水热法制备氟改性钛酸锂(F-Li_(2)TiO_(3)),经盐酸洗脱得到氟化钛锂离子筛(F-H_(2)TiO_(3))。研究氟化铵用量和煅烧温度对Li_(2)TiO_(3)前驱体形貌、晶体结构的影响以及F-Li_(2)TiO_(3)洗脱和F-H_(2)TiO_(3)吸附性能。采用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、比表面积分析仪(BET)、X射线光电子能谱仪(XPS)分别对样品的表面形貌、晶相组成、比表面积和孔结构、元素含量和价态进行了表征分析。结果表明,氟钛比为0.15时,可以得到颗粒分散且具有多孔结构的F-Li_(2)TiO_(3),经过700℃热处理的样品各晶面结晶度最完整,洗脱率达到96.98%,显著高于未改性样品(90.55%)。F-H_(2)TiO_(3)最大吸附容量达到46.52 mg/g,与未改性样品(35.51 mg/g)相比有较大提升,对Li+的吸附速率明显加快,吸附平衡时间从12 h缩短到10 h。F-H_(2)TiO_(3)吸附等温线符合Langmuir模型,吸附动力学符合伪二级动力学模型,吸附方式为化学单层吸附。
Fluoride modified lithium titanate(F-Li_(2)TiO_(3))was prepared by hydrothermal method with titanium dioxide as titanium source,lithium hydroxide as lithium source and ammonium fluoride as modifier,followed by picking with hydrochloric acid to obtain fluoride modified titanium fluoride lithium ion sieve(F-H_(2)TiO_(3)).The effects of ammonium fluoride content and calcination temperature on the surface morphology and crystal structure of Li_(2)TiO_(3)precursor were studied.The elution performance of F-Li_(2)TiO_(3)and the adsorption performance of F-H_(2)TiO_(3)were investigated.The surface morphology,crystal phase,specific surface area and pore structure,element content and valence state of the samples were characte-rized using scanning electron microscopy(SEM),X-ray diffraction(XRD),specific surface area analyzer(BET),and X-ray photoelectron spectroscopy(XPS),respectively.The results showed that F-Li_(2)TiO_(3)with relatively dispersed particles and porous accumulation could be obtained when the fluorine titanium ratio was 0.15.The crystallinity of each crystal surface was the most complete with a calcination at 700℃,and the elution rate reached 96.98%,which was significantly higher than that of unmodified samples(90.55%).The maximum adsorption capacity of F-H_(2)TiO_(3)reached 46.52 mg/g,which was greatly improved compared with 35.51 mg/g of the unmodified sample.The Li+adsorption speed was significantly accelerated,and the adsorption equilibrium time was shortened from 12 h to 10 h.The adsorption isotherm conforms to the Langmuir model,the adsorption kinetics follows to pseudo second-order kinetic model,and the adsorption way is chemical monolayer adsorption.
作者
张理元
张菁菁
吴娜
沈如倩
ZHANG Liyuan;ZHANG Jingjing;WU Na;SHEN Ruqian(College of Chemistry and Chemical Engineering,Neijiang Normal University,Neijiang 641112,Sichuan,China;Key Laboratory of Fruit Waste Treatment and Resource Recycling of the Sichuan Provincial College,Neijiang 641112,Sichuan,China;Special Agricultural Resources in Tuojiang River Basin Sharing and Service Platform of Sichuan Province,Neijiang 641112,Sichuan,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2024年第18期54-61,共8页
Materials Reports
基金
四川省科技计划(2023YFG0247)
内江师范学院大学生创新项目(X2022001)。
关键词
钛锂离子筛
氟化
水热法
洗脱率
吸附容量
titanium-lithium ion sieve
fluorination
hydrothermal process
elution rate
adsorption capacity
