Controllable synthesis of self-assembly Co₃O₄nanoflake microspheres for electrochemical performance

Abstract

Tuning the ratios of ethanol to water, self-assembling microspheres composed of Co3O4 nanoflakes are synthesized by the hydrothermal method. The scanning electron microscopy (SEM) images of as-grown samples obviously show that the dispersive multilayered structures gradually change into micro/nanobelts and cubic blocks structures, and then into the desired self-assembled microspheres with increasing ratios of ethanol to water. Also, all the x-ray diffraction (XRD) patterns evidently demonstrate that all obtained Co3O4 has cubic crystal structure. The corresponding synthesis mechanism is discussed in detail. More importantly, the unique self-assembling Co3O4 nanoflake microspheres have excellent electrochemical performance with large specific capacitance, good rate capability and excellent cycling performance, evidently presenting a potential capability of Co3O4 nanoflake microspheres to act as electrode materials for supercapacitors in sustainable power sources.

Modulating the Hydrothermal Synthesis of Co3O4 and CoOOH Nanoparticles by H2O2 Concentration

“…To exploit the potential applications of cobalt-based oxide (Co 3 O 4 ), hydroxide (Co­(OH) 2 ), and oxyhydroxide (CoOOH) in electrochemistry, , sensors, − and energy storage, − the nanoparticle synthesis of these cobalt oxide, hydroxide, and oxyhydroxide has attracted wide interest. In the past decade, cobalt oxides with different morphologies, for example, nanocubes, , hexagonal microplate, microspheres, , hollow nanoboxes, porous nanorods, − ultrathin nanosheet arrays, and crystalline films of Co 3 O 4 , have been successfully prepared.…”

Self-Assembly of Hierarchically Structured Cellulose@ZnO Composite in Solid–Liquid Homogeneous Phase: Synthesis, DFT Calculations, and Enhanced Antibacterial Activities

“…Over the past few decades, self-assembly has been used to guide the synthesis of certain structural materials such as ZnO, Co 3 O 4 , SiO 2 , TiO 2 , fullerenes, and silk. − Diverse morphologies including mesopores, hollow spheres, and nanotubes have been achieved. Interestingly, some of these morphologies have endowed materials with enhanced properties of catalytic activities, antibacterial activities, or electrochemical performance. − A challenging issue that has been posed for chemical and materials scientists is how to properly utilize self-assembly to induce special structures of materials with excellent properties. In this respect, self-assembly mechanisms must be clarified.…”

Effect of the synthesis conditions on the properties of Co embedded porous Si nanostructures

“…When the deposition time increases to 15 min and 30 min, the resulting cobalt clusters of spherical particles become much denser and bigger. It is also found that the largest clusters of spherical Co nanoparticles are observed for 60 min and these clusters consist of Co nanoflakes [14]. As can be seen in the SEM images, the nanoflakes have formed along the radial direction expanding from the center to the edges of a nanoparticles cluster.…”