Impact of Co Doping in MoS2 on Water Interaction Mechanisms for Sustainable Hydrogen Generation: Insights from in Situ Soft‐XAS

Renewable electricity-powered water-splitting offers a clean pathway to produce green hydrogen fuel, vital for energy security and emissions reduction. However, optimizing this process requires bifunctional electrocatalysts for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) under different conditions. Transition metal-based composites, such as Co-doped MoS2, are potentially suitable for this application but important questions regarding their mechanisms of water-splitting reaction remain unanswered. In this work, we employ in situ soft-X-ray absorption spectroscopy, combined with ex situ X-ray photoelectron spectroscopy and X-ray diffraction, to probe Co and Mo electronic states upon different environmental conditions (water exposure and applied voltage bias) shedding light on the role of cobalt in the catalytic mechanisms and advancing sustainable energy solutions.