The development of earth-friendly efficient electrocatalysts for the oxygen evolution reaction (OER) becomes crucial for renewable energy production. In this work, green synthesized reduced cobalt ferrocyanide at different time intervals (RCFC-t) was demonstrated as an effective and long-lasting electrocatalyst for the OER process. The RCFC-10 loaded glassy carbon electrode runs at an overpotential of 321 mV (1.55 V) at 10 mA cm–2, and a lower overpotential of 291 mV exhibited by the optimal RCFC-10/nickel foam was almost comparable to the benchmark catalyst, such as IrO2. This newborn RCFC-10 shows excellent OER performance and durability over 250 h with 4.1% potential loss in alkaline medium. At 1.58 V, the solar-driven water electrolysis demonstration supports the efficiency of a newborn electrocatalyst in solar-to-hydrogen conversion. These research findings confirm that low-cost greener synthesized RCFC-10/NF can be used for large-scale hydrogen generation.

The development of high-performance catalysts for oxygen-evolution reaction (OER) is paramount for cost-effective conversion of renewable electricity to fuels and chemicals.

Fe3O4-implanted ZnO and pristine ZnO nanosheets have been synthesized hydrothermally. High-resolution scanning electron microscopy, high-resolution transmission electron microscopy, energy dispersive X-ray spectroscopy, elemental mapping, selected area electron diffractometry, powder X-ray diffractometry, Raman spectroscopy, vibrating sample magnetometry, solid state impedance spectroscopy, UV-visible diffuse reflectance spectroscopy, and photoluminescence spectroscopy show implantation of Fe3O4 in ZnO nanosheets. Fe3O4 core with ZnO shell is of type I core/shell heterostructure which is to quench charge carriers and suppress photocatalysis. But the photocatalytic activity is not suppressed on implantation of Fe3O4 in ZnO nanosheets, and time controlled single photon counting lifetime spectroscopy shows that the photogenerated charge carriers are not quenched by the Fe3O4 core in the ZnO nanosheets. The composite nanosheets are photostable, reusable, and magnetically recoverable, revealing potential application in mineralization of organic pollutants.