Synthesis and electrochemical properties of NiO nanospindles

•NiO nanospindles were synthesized without the addition of any surfactant.•The agglomeration–dissolution–recrystallization growth process was used to explain the precursors’ formation process of the spindle-like NiO.•As-obtained spindle-like NiO showed a different electrochemical activity as compared to those previous reports.

NiO nanospindles were successfully synthesized via a hydrothermal and post-treatment method. The as-synthesized nanospindles were about several hundred nanometers in width and about one micrometer in length. X-ray diffraction (XRD) analysis revealed that the spindle-like structure was cubic NiO phase crystalline. Scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) analysis indicated that these NiO nanospindles were of single crystal nature. On the basis of time-dependent experiments, a possible agglomeration–dissolution–recrystallization growth process was proposed to explain the formation process of the spindle-like precursors. The cyclic voltammetry (CV) measurement showed that the as-prepared spindle-like NiO exhibited a pseudo-capacitance behavior.

Graphical abstractNiO nanospindles with a different electrochemical activity as compared to those previous reports were synthesized via an agglomeration–dissolution–recrystallization growth process without the addition of any surfactant.Figure optionsDownload full-size imageDownload as PowerPoint slide