One-Step Electrophoretic Deposition of Reduced Graphene Oxide and Ni(OH)2 Composite Films for Controlled Syntheses Supercapacitor Electrodes

A facile, rapid, scalable, and environmentally friendly electrophoretic deposition (EPD) approach has been developed for the fabrication of reduced graphene oxide (RGO) and Ni(OH)2 syntheses based on EPD of graphene oxide (GO) and Ni(NO3)2 colloidal suspension. Nickel ion decoration made GO positively charged and further made cathodic EPD feasible. Direct assembly by one-step EPD facilitated transformation from GO to RGO and resulted in multilayer or flower-like RGO/Ni(OH)2 hybrid films on different substrates. X-ray diffraction analysis suggested that the crystal structures of Ni(OH)2 depended on the colloidal suspension and the substrate. Further transmission electron microscopy characterization indicated that Ni(OH)2 nanoclusters composed of 5–10 nm nanoparticles in grain size were homogeneously dispersed and anchored on the RGO. The resulting 100% binder-free RGO/Ni(OH)2 electrodes exhibited excellent pseudocapacitive behavior with high specific capacitance of 1404 F g–1 at 2 A g–1, high rate capabili...