Synthesis and Lithium Adsorption Performance of NiFe2O4@AlLi-LDH

NiFe 2 O 4 -doped aluminum–lithium-layered double hydroxide (NiFe 2 O 4 @AlLi-LDH) was synthesized using the coprecipitation method. The main components of the samples are AlLi-LDH and Al(OH) 3 . The coprecipitation process of Li + and Al 3+ in alkaline solutions can be promoted by the addition of NiFe 2 O 4 , and hydroxide ions preferentially exist between the layers over chloride ions. The aging process of samples synthesized by the coprecipitation of Li + and Al 3+ is primarily a restructuring process of the Al-O layer, while the masses of samples just increase a little. The mass of the samples increases from 1.35 to 3.87 g because of the addition of NiFe 2 O 4 . The sample after the aging process presents a regular flower-like structure with a diameter of about 2–5 μm, and the thickness of the sheet is about 200 nm. The Li + adsorption amount of NiFe 2 O 4 @AlLi-LDH can reach 3.31 mg/g. Due to the metastable structure of AlLi-LDH, AlLi-LDH prefers to transform to Al(OH) 3 because of the higher stability of the Al-O octahedral structure in Al(OH) 3 during the Li + adsorption and desorption processes. Graphical Abstract