Effective and Rational Design of Metal Doped Transition Metal Phosphides for Bifunctional Electrolysis
Creators: Tahsin, Maysha
Publisher: name: University of Alberta Library
Year: 2024

<p>An attractive alternative for energy conversion and storage to avoid dependence on finite fossil fuel supplies and stop the severe deterioration of the climate is the electrochemical splitting of water. Electrocatalytic water splitting has proved to be an efficient and clean technique for achieving sustainable energy production, as it does not emit any carbon and only produces water as a byproduct. To implement water-splitting reactions to produce hydrogen fuel for large-scale industrial applications, it is crucial to develop highly efficient and cost-effective electrocatalysts. However, designing electrocatalysts for water splitting reactions presents several challenges, related to material selection, synthesis methods, stability, efficiency, and cost. Therefore, it is imperative that these concerns be addressed, given the increase in demand for sophisticated energy storage systems.<br>
To address the concerns of the electrocatalyst, it is crucial to study the reaction mechanisms that they are catalyzing. The two half-cell reactions of water splitting that have gained a lot of research interest are the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). Hence, herein we have studied the mechanism of these reactions.<br><br>
In the following section, we have also conducted a comprehensive study on the key performance parameters of electrocatalysts. These parameters, which can influence the water splitting reactions significantly and streamline the water electrolysis process, are the focus of countless researchers across the globe. The study conducted on them reveals how they affect reaction processes and how the merits and demerits of these factors can be considered when designing electrocatalysts. <br>
Noble metals like platinum and ruthenium/iridium are the state-of-art electrocatalysts for HER and OER, respectively. However, these metals are expensive as well as rare. Currently, researchers are focusing on feasible alternatives, such as non-noble metal catalysts, to replace the expensive and rare noble metal catalysts. Transition metal phosphides exhibit promising potential as effective electrocatalysts for HER. However, their proficiency in the OER remains inadequate. Hence, rational design and synthesis of stable bifunctional electrocatalysts are crucial. Herein, we have conducted experimental studies to in-situ grow Fe-doped NiCoP on nickel foam with different amounts of iron. Needle-like structures with nanoflakes are uniformly grown on nickel foam through this fabrication process. Doping Fe not only modified the surface electronic structure of the electrocatalyst but also enhanced the electrochemical surface area (ECSA) to expose more accessible active sites and increase the intrinsic activity for HER and OER. Owing to the numerous active sites, large surface area, and optimized doping amount, Fe-NiCoP/NF with a cobalt-to-iron molar ratio of 5:1, shows low overpotentials of 41 mV and 100 mV for HER and OER, respectively. Moreover, the electrocatalyst assembled for a water-splitting cell shows a cell voltage of 1.55 V, excellent durability, and comparative performance compared to other reported transition metal-based bifunctional electrocatalysts.</p>