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 X-ray Detector (EDX) were used to characterize h-MHCFs nanoparticles. The CV results indicated that the nanoparticle 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. [Display omitted] •The water-dispersed hybrid-metal hexacyanoferrates (h-MHCFs) nanoparticle inks prepared firstly by wet chemical precipitation•The h-MHCF nanoparticle film is feasible for large-scale applications.•The nanoparticle film holds higher current response and surface active concentration.•The prepared h-MHCFs have a hybrid vigor in crosses of single-metal hexacyanoferrates.