A novel surface modification of silicon nanowires by polydopamine to prepare SiNWs/NC@NiO electrode for high-performance supercapacitor

Abstract In this article, we synthesized a ternary silicon nanowire arrays (SiNWs)-based composite electrode by a novel wet-chemical technique for the application in high-performance supercapacitors. Initially, the polydopamine (PDOP) was loaded as the modifier to enhance the surface hydrophilicity properties of the SiNWs. Meanwhile, PDOP serves as the nitrogen-doped carbon source. Subsequently, the conformal PDOP layer was used as the template to guide the preferential deposition of the nickel oxide (NiO) precursor. Finally, the SiNWs/NC@NiO composite electrode was obtained by a one-step calcination process. The existence of the N-doped carbon was characterized by the XPS and element analysis characterizations. The FE-SEM characterizations revealed the formation processes of NiO nanoflakes precursor on PDOP layer. The N-doped carbon and nickel oxide play a synergistic role in enhancing the electrochemical performance in aqueous electrolytes. The as-prepared SiNWs/NC@NiO composite electrode shows an areal specific capacitance as high as 110 mF/cm2 at the current density of 1.0 mA/cm2.