Highly efficient Cu-Fe containing prussian blue analogs (PBAs) for excellent electrocatalytic activity towards overall water splitting.

• Simple and affordable co-precipitation method for creating a potent and robust bifunctional electrocatalyst. • In situ , superficial oxidation studies have been conducted on the OER and HER processes. • Synthesized electrocatalyst has more active sites, which aids in the redox of FeII/III and CuI/II. • The Fe 8 Cu 2 CN/NF// Fe 8 Cu 2 CN/NF exhibits ultra-durability (over 180 h) with a negligible loss of 5.4 %. • During water electrolysis, 6.55 mmol h−1cm−2 of hydrogen was produced. Hydrogen generation by water electrolysis is considered a clean, green, and renewable approach for sustainable energy demands and environmental management. The efficient use of earth-abundant transition metal catalysts is cost-effective and limits the usage of noble metal catalysts like IrO 2 , RuO 2 , and Pt/C. The PBAs (Prussian Blue Analogs) are a class of transition metal hexacyanoferrates that can be tailored for specific electrochemical reactions. Both iron and copper are well-proven transition metals for catalytic activities owing to their aptitude to achieve much-pronounced reactant transformations under minor circumstances, as well as their environmental friendliness, cyclability, and long-term durability at 10 mA cm−2 in 1.0 M KOH, the greenly synthesized Fe 8 Cu 2 CN (PBAs) on NF (Nickel foam) displays a low overpotential of 150 mV (118 mV dec−1) for HER (Hydrogen Evolution Reaction) and 290 mV (112 mV dec−1) for OER (Oxygen Evolution Reaction). Fe 8 Cu 2 CN displays ultra-stable behavior (150 h) with a slight current loss of 4.2 % for OER and 3.4 % for HER, respectively. The interaction of Fe, Cu, and CN (cyanide) enhances the rate of reaction kinetics. The designing of a water electrolyzer that delivers 10 mA cm−2 at 1.60 V is made possible with the help of the improved bifunctional catalyst Fe 8 Cu 2 CN/NF. The Fe 8 Cu 2 CN/NF//Fe 8 Cu 2 CN/NF exhibits long-last durability (over 180 h) with a negligible current reduction of 5.4 %. The improved effectiveness of the synthesized catalyst is demonstrated by the solar water splitting at 1.66 V. These findings suggest that Fe 8 Cu 2 CN/NF//Fe 8 Cu 2 CN/NF can be used to produce large quantities of H 2 at very affordable prices. [Display omitted] [ABSTRACT FROM AUTHOR]