NiAl-layered Double Hydroxide/Reduced Graphene Oxide Composite: Microwave-assisted Synthesis and Supercapacitive Properties

Pure NiAl-layered double hydroxides (LDHs) and graphene oxide (GO)/NiAl-LDHs composites are both fabricated by refluxing solution with the assistance of microwave irradiation within 2 hours. The structural characterization and morphological observation of the composites suggest that small NiAl-LDHs crystals are in situ grown on the surface of GO nanosheets, preventing the compact stacking of GO as an intercalated spacer. The electrochemical performances of pure LDHs and GO/NiAl-LDHs composites with different content of GO are investigated and compared. The GO/NiAl-LDHs composite containing 23 wt% GO exhibits a higher specific capacitance of 1630 Fg(-1) at 1 Ag-1 in 6 M KOH solution and more stable rate capability than others. When GO is substituted by microwave reduced graphene oxide (rGO) or the GO in the GO/NiAl-LDHs composite is thermally reduced at a rational temperature, rGO/NiAl-LDHs composites are obtained with enhanced electrochemical behavior in rate capability and cycle life. Critical comparisons indicate that rGO/NiAl-LDHs composite prepared by thermal reducing GO/NiAl-LDHs has better cycling performance and rate capability than the counterpart directly prepared with rGO. (C) 2014 Elsevier Ltd. All rights reserved.