Synthesis of NiFeAl LDHs from electroplating sludge and Their excellent supercapacitor performance
Tianbao Liu1, Hanfeng Zhou2, Guoxiong Zhong3
1School of Chemical and Environmental Science, Yili Normal University, Xingjiang 835000, PR China; School of Environment and Energy, Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters (Ministry of Education), South China University of Technology, Guangzhou 510006, PR China; Guangdong Key Laboratory of Solid Waste Pollution Control and Resource Recycling, Guangdong Engineering and Technology Research Center for Environmental Nanomaterials, South China University of Technology, Guangzhou, Guangdong 510006, PR China.
Abstract:
This work demonstrated that electroplating sludges (EPS) of specific composition may be used for the synthesis of layered double hydroxide (LDH) materials for energy applications after appropriate treatment. The unique composition and structure of EPS render it with good electrochemical energy storage performance. The EPS containing Ni, Fe, and Al was dissolved by acid and added with urea precipitator. The LDH material was prepared by a facile hydrothermal method. The increase of urea in a certain range is conducive to the formation of intact LDH. However excessive urea levels promoted the transformation from LDH to Ni(HCO3)2. Various active Ni bridged by N in ‒O‒CN promoted electron transfer, ‒O‒CN content in LDHs was proportional to the urea amount. The prepared LDHs exhibited a specific capacitance of 1652.20 F g-1 at 0.5 A g-1, and the value remained at 766.69 F g-1 after 1000 cycles. The prepared LDH has excellent supercapacitor performance, which is closely related to its structure. Therefore, the proposed recycling strategy of EPS resources can be used to prepare LDH supercapacitors, paving the way for new applications of EPS in the field of energy storage.
