Controllable fabrication of flower-like Co–B microstructures

Abstract

Flower-like Co–B microstructures were synthesized by using a trace-level sodium citrate-assisted wet chemical route in which Co(OH)2 colloid, KBH4 and polyvinyl pyrrolidone (PVP) were used as Co source, B source, and protective agent, respectively. The Co–B microstructures were composed of numerous smooth nanoflakes that radiated from the center of the microstructure to form a floral pattern with a diameter of 2–3μm. The original Co(OH)2 colloid served as a hard template. The presence of trace concentrations of sodium citrate is indispensable for the preparation of Co–B flowers. Sodium citrate concentration directly influences the shape of the product. High sodium citrate concentration hinders the acquisition of high-quality Co–B flowers. The possible formation mechanism of flower-like Co–B microstructures was presented based on the experimental results.