The development of a competent (pre)catalyst for the oxygen evolution reaction (OER) to produce green hydrogen is critical for a carbon‐neutral economy. In this aspect, the low‐temperature, single‐source precursor (SSP) method allows the formation of highly efficient OER electrocatalysts, with better control over their structural and electronic properties. Herein, a transition metal (TM) based chalcogenide material, nickel sulfide (NiS), is prepared from a novel molecular complex [NiII(PyHS)4][OTf]2 (1) and utilized as a (pre)catalyst for OER. The NiS (pre)catalyst requires an overpotential of only 255 mV to reach the benchmark current density of 10 mA cm−2 and shows 63 h of chronopotentiometry (CP) stability along with over 95% Faradaic efficiency in 1 m KOH. Several ex situ measurements and quasi in situ Raman spectroscopy uncover that NiS irreversibly transformed to a carbonate‐intercalated γ−NiOOH phase under the alkaline OER conditions, which serves as the actual active structure for the OER. Additionally, this in situ formed active phase successfully catalyzes the selective oxidation of alcohol, aldehyde, and amine‐based organic substrates to value‐added chemicals, with high efficiencies.

Epoxides to cyclic carbonates conversion utilizing CO2 is one of the efficient approaches for CO2 fixation. Atmospheric fixation of CO2 generally required the use of halogen containing catalysts or additionally...

The quest toward finding an efficient oxygen evolution reaction (OER) catalyst utilizing a sustainable and facile synthetic strategy is still underway. Low overpotential, better stability, and rapid kinetics are the key features to be considered while designing a competent OER catalyst. Herein, we have developed a rapid and efficient wet chemical route for the synthesis of a cobalt-and silver-based precatalytic oxalate (CoC 2 O 4 /Ag 2 C 2 O 4 ) framework via a rapid precipitation method at room temperature. The optimized catalyst required an overpotential of 260 mV to reach the benchmark current density of 10 mA/cm 2 geo , with a Tafel slope value of 47 mV/dec. It has also shown 72 h of chronopotentiometry stability as well as 1000 cycles of potentiodynamic stability along with 90% Faradaic efficiency in 1(M) KOH for OER. Addition of a minimal amount of silver component assists in the reduction of overpotential up to 120 mV compared to CoC 2 O 4 . Furthermore, the minimal amount of silver inclusion improved the charge migration property via lowering the charge-transfer resistance besides tuning the charge storage mechanism (b value). The paradigm shift in catalytic efficiency can be manifested by calculating both intrinsic (persite activity) and geometric (based on the effective area of electrode materials) activities. Interestingly, significant improvement in C dl (double-layer capacitance) from 10.25 to 19.59 mF/cm 2 is achieved upon silver component inclusion, indicating a higher number of accessible catalytic sites for alkaline OER. The turnover frequency value further authenticates the importance of silver component in the precatalytic oxalate network for intrinsic catalytic activity under alkaline conditions. The mechanistic trajectory is also investigated from the proton reaction order (ρRHE), revealing the occurrence of the proton-decoupled electron transfer process for the optimized catalyst. The results reveal the efficient electrochemical surface reconstruction in the cobalt-and silver-based precatalytic oxalate framework for improved alkaline water oxidation through exposing the surface as well as bulk active centers for easy electrolyte diffusion in alkaline medium.

The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/smsc.202200115.