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

• Published in: Inorganic chemistry communications 2023-08, Vol.154, p.110916, Article 110916
• Main Authors: Tauseef Ashfaq, Hafiza, Adeel Asghar, Muhammad, Nisar, Talha, Wagner, Veit, Adil Mansoor, Muhammad, Haider, Ali, Ali, Saqib
• Format: Article
• Language: English
• Subjects: Electrocatalysis; Electrodeposition; Oxygen evolution reaction; Prussian blue analogs; Water oxidation
• ISSN: 1387-7003; 1879-0259
• DOI: 10.1016/j.inoche.2023.110916

In the current study electrodeposition, a binder-free approach has been applied to synthesize Co-, Ni-, and a rare example of ternary NiCo-hexacyanocobaltate as electrocatalysts on the surface of fluorine-doped tin oxide (FTO) substrates. The electrocatalytic water oxidation activity of synthesized Prussian blue analogs has been examined in 1 M KOH by measuring their overpotential, Tafel slope, electrochemical surface area (ECSA) and charge transfer resistance values. Results have shown that the ternary NiCo-hexacyanocobaltate exhibited good electrocatalytic 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. [Display omitted] •Co-, Ni-, and a rare example of trimetallic NiCo-hexacyanocobaltates was synthesized by a facile electrodeposition method.•Trimetallic NiCo-hexacyanocobaltate exhibited good electrocatalytic activity for water oxidation reaction.•It displayed the overpotential of 331 mV versus RHE at 10 mA cm−2 current density, with a Tafel slope of 48 mV/dec. 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 spectroscopy (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 electrocatalytic 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.