Electrochemical Controllable Synthesis of Bismuth Hexacyanoferrate(II) Nanoplates and Its Application in Electrocatalysis

A facile electrochemical approach was developed for the controllable synthesis of bismuth hexacyanoferrate(II) (BiHCF(II)) nanoplates. The composition, morphology, and structure of the as-prepared BiHCF(II) nanoplates were characterized by the techniques such as infrared spectrum, thermogravimetry, inductively coupled plasma mass spectroscopy, X-ray photoelectron spectroscopy, energy-dispersive X-ray spectrum, powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and selected area electron diffraction. The formula of the prepared BiHCF(II) nanoplates could be assigned to KBi[Fe(CN)6]·xH2O. It was observed that the nanoplates and their flowerlike aggregations could be obtained in the electrolytes containing different concentration of HNO3. The nanoplates were prepared at the potential for 0.2 V (versus SCE) and could be further grown to a good single-crystalline hexagonal microstructure at 0.6 V. To the best of our knowledge, the structures have not been reported before. The modified Au electrode by the BiHCF(II) nanoplates showed good electrochemical properties, especially with a stable anodic response over the pH range from 2.0 to 11.0. Also, the electrode possesses prominent electrocatalytic activity toward the reduction of hydrogen peroxide.