Electrochemical synthesis of Co-, Ni- and NiCo-based hexacyanocobaltates as efficient electrocatalysts for water oxidation studies

The performance of electrocatalysts for the oxidation of water is a crucial factor in the advancement of future technologies for energy conversion such as nonsegregated solar water-splitting systems and water electrolyzers. Previous research demonstrates indisputably that PBAs' catalytic activity can vary significantly depending on their altered structural makeup and fabrication techniques. In the current study electrodeposition, a binder-free perspective has been applied to synthesize Co-, Ni-, and a rare example of trimetallic NiCo-hexacyanocobaltates as electrocatalysts on the surface of fluorine-doped tin oxide (FTO) substrates. The synthesized materials have been characterized by Fourier transform infrared (FTIR) spectroscopy, powder X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, and X-ray photoelectron spec-troscopy (XPS). The water oxidation activity of synthesized materials has been examined in 1 M KOH by measuring their overpotential, Tafel slope, electrochemical active surface area (ECSA), and charge transfer resistance (Rct) values. Results have shown that trimetallic NiCo-hexacyanocobaltate exhibited good electro-catalytic activity for water oxidation reaction with an overpotential of 331 mV versus RHE at 10 mA cm-2 current density, 48 mV/dec Tafel slope, and 75 cm2 ECSA.

Automated summary

In this study, binder-free electrodeposition was used to synthesize Co-, Ni-, and trimetallic NiCo-hexacyanocobaltates as electrocatalysts on fluorine-doped tin oxide (FTO) substrates. The synthesized materials were characterized using various analytical techniques including FTIR spectroscopy, XRD analysis, SEM, EDX analysis, and XPS. The catalytic performance of the synthesized materials for the oxidation of water was evaluated in 1 M KOH, and the results showed that the trimetallic NiCo-hexacyanocobaltate exhibited good electrocatalytic activity.