Transition metal-based electrocatalysts for alkaline overall water splitting: advancements, challenges, and perspectives

Abstract

Water electrolysis has emerged as a promising method for efficiently producing hydrogen (H2) and oxygen (O2), crucial for renewable energy conversion and fuel cell technologies. The hydrogen evolution reaction (HER)...

Design strategy of encapsulated nanoplates and nanorods (ID-CoMo): enhanced catalytic activity and sustainability for overall & solar cell water splitting

“…10 Muhammad Nazim et al discussed TM-based (oxides, phosphides, nitrides, and borides) electrocatalysts for the HER and OER in alkaline media, revealing that more accessible surface active sites, specific electronic effects and string effects are essential for the development of efficient electrocatalysts towards electrochemical water splitting application. 11 Hence, rational design of highly active, robust, stable, cost-effective and earth-abundant element-based catalysts is imperative in large-scale hydrogen generation through water electrolysis. 12…”

Co@Ir core–shell nanochain aerogels for the hydrogen evolution reaction and the oxygen evolution reaction in alkaline media

“…, hence has been deemed as an effective and sustainable approach for hydrogen production. 6–10 Moreover, the entire process of water splitting is significantly impeded by the low energy conversion efficiency of the HER and OER catalysts. For both the HER and OER, some energy barrier needs to be overcome to drive the reactions.…”

Crystalline/amorphous nickel sulfide interface for high current density in alkaline HER: surface and volume confinement matters!

“…4,5 Supreme EWS catalysts, such as Pt, RuO 2 , IrO 2 , Rh, or Pd, effortlessly catalyse the reaction in an acidic medium, but in an alkaline medium, due to the lack of protons, these catalysts perform only moderately and their higher cost, non-durability and challenging large-scale production also provide room for a strategic exploration of earth-abundant transition-metals for alkaline EWS. 6 The sluggish 4e − OER process involves ‘3d transition metals’, which undergo surface reconstruction and create OER-active O–OH sites in the anodic potential at pH 14, and the kinetics of this whole reaction are dependent on the other half cell reaction, the HER. But in an alkaline medium, the 2e − HER process is difficult to carry out as the catalyst has to undergo an additional water-dissociation step.…”