Synthesis of hybrid-metal hexacyanoferrates nanoparticle films and investigation of its hybrid vigor

Water-dispersed hybrid-metal hexacyanoferrates (h-MHCFs) nanoparticle inks containing different ratios of copper, cobalt and nickel, were prepared by wet chemical precipitation. These inks can be simply spin-coated on plate electrode to form nanoparticle films. Cyclic voltammetry (CV), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM) and Energy Dispersive Xray Detector (EDX) were used to characterize h-MHCFs nanoparticles. The CV results indicated that the nano particle films held higher current responses and mass density of reactive sites in comparison with electrodeposited films. The nanoparticle structure of the h-MHCF film was determined by XRD patterns and FE-SEM images. The prepared h-MHCF existing within the film as a new phase not a simple mixture of corresponding single-metal hexacyanoferrates (s-MHCFs) was demonstrated by characteristic CV curves, distinct vibrational bands, no splitting diffraction peaks etc. Long-term potential cycling in various electrolytes illustrated long cycle life and strong stability of h-MHCFs nanoparticle films modified electrodes, especially for the hybrid-cobalt/nickel hexacyanoferrate showing 99% capacitance retention after 300 cycles. On comparing properties of s-MHCFs, it can be revealed that the h-MHCF films inherited corresponding s-MHCFs' physical/chemical characteristics and have a hybrid vigor in crosses of them.