Enhanced Li+ adsorption by magnetically recyclable iron-doped lithium manganese oxide ion-sieve: Synthesis, characterization, adsorption kinetics and isotherm

• DOI: 10.1016/j.jmrt.2021.04.073
• Publication Date: 2021-05-03T18:05:46Z
• Authors: Jian-ming Gao; Zongyuan Du; Qian Zhao; Yanxia Guo; Fangqin Cheng
• Keywords: Langmuir adsorption model

Abstract The Li+ adsorption from aqueous solution by lithium-ion sieve has become one of the most promising methods due to high efficiency and selectivity towards lithium ion (Li+). However, industrial application manganese oxide ion-sieve is limited its difficult separation decrease capacity resulting dissolution loss. In this paper, magnetically recyclable Fe-doped ion-sieves with spinel-structure were proposed prepared LiMn2-xFexO4 synthesized solid state reaction method. effects calcination temperature, time Fe doping amounts on phase compositions, loss performance precursors systematically studied, influences pH value, initial concentration temperature investigated. mechanism was further discovered through kinetics thermodynamics. results show that could reach 34.8 mg·g–1 when content controlled at 450 °C, 6 h, 0.05, respectively. Mn reduced 0.51%, much lower than undoped (2.48%), which attributed inhibition disproportionation increasing proportion Mn4+ in skeleton. process conformed pseudo-second-order equation Langmuir isothermal model. Furthermore, recycling showed remain 22.5 mg·g–1 (about 70%) after five cycles, greater 50%), recovery can be realized magnetic an applying field.