title: A facile approach for synthesizing Fe-based layered double hydroxides with high purity and its exfoliation.
abstract: Transition metal (e.g., Fe, Co, Ni)-based layered double hydroxides (LDHs) and their exfoliated nanosheets have great potential applications due to their redox and magnetic properties. Here we report a facile approach for the preparation of Co-Fe LDHs with good crystallinity and high purity. The proposed approach includes two steps: (1) The mixed divalent metal (e.g., Co(2+), Fe(2+)) hydroxides were first synthesized using a homogeneous precipitation without piping N2 into the system; hexamethylenetetramine (HMT) was the hydrolysis agent providing OH(-), and hydroxylamine hydrochloride (HAH) was used as both a reducing and a complexing reagent. (2) Then the as-prepared hydroxides were slowly oxidated by air and simultaneously intercalated by CO3(2-) to form CO3-intercalated LDHs. The Co-Fe LDHs were roundly characterized by XRD, SEM, EDX and FT-IR. The effect of HAH on the morphology and structure of the Co-Fe LDHs was also studied. The magnetism of Co-Fe LDHs at room temperature was investigated and the results showed that the LDHs displayed a low saturation magnetization value of 6.3emug(-1), suggesting that the purity of the products was very high. In addition, the intercalated CO3(2-) in the Co-Fe LDHs could be successfully exchanged with other anions such as Cl(-) and ClO4(-). Furthermore, the exchanged-LDHs could be exfoliated in formamide. This work establishes a new method for the synthesis of Fe-based LDHs with good crystallinity and high purity under mild conditions, and can accelerate the development of applications using these layered materials.
authors.affiliation: Anhui Key Laboratory of Chemo/Biosensing, Anhui Laboratory of Molecule-Based Materials, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, China.
authors.forename: Yinling
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Anhui Key Laboratory of Chemo/Biosensing, Anhui Laboratory of Molecule-Based Materials, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, China.
authors.forename: Fajun
authors.initials: F
authors.lastname: Li
authors.affiliation: Anhui Key Laboratory of Chemo/Biosensing, Anhui Laboratory of Molecule-Based Materials, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, China.
authors.forename: Shengye
authors.initials: S
authors.lastname: Dong
authors.affiliation: Anhui Key Laboratory of Chemo/Biosensing, Anhui Laboratory of Molecule-Based Materials, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, China.
authors.forename: Xiaowang
authors.initials: X
authors.lastname: Liu
authors.affiliation: Anhui Key Laboratory of Chemo/Biosensing, Anhui Laboratory of Molecule-Based Materials, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, China. Electronic address: limaoguo@mail.ahnu.edu.cn.
authors.forename: Maoguo
authors.initials: M
authors.lastname: Li
keywords: Exfoliation; Fe-based LDHs; Layered double hydroxides; Magnetic properties; Nanosheets