A facile approach for synthesizing Fe-based layered double hydroxides with high purity and its exfoliation

作者：Wang, Yinling^*; Li, Fajun; Dong, Shengye; Liu, Xiaowang; Li, Maoguo^*

来源：Journal of Colloid and Interface Science, 2016, 467: 28-34.

DOI：10.1016/j.jcis.2015.12.058

• Layered double hydroxides
• Fe-based LDHs
• Exfoliation
• Nanosheets
• Magnetic properties

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., Co2+, Fe2+) hydroxides were first synthesized using a homogeneous precipitation without piping N-2 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 CO32- 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 6.3 emu g(-1), suggesting that the purity of the products was very high. In addition, the intercalated CO32- 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.

• 出版日期2016-4-1
• 单位安徽师范大学