The effect of dopants and their concentration under strain on the efficiency of nickel oxyhydroxide (NiOOH) catalyst

07.02.2019
14:30
David Wang Auditorium, 3rd floor Dalia Maydan Bldg
Mrs. Ester Korkus Hamal

Mrs. Ester Korkus Hamal, M.Sc. Candidate

Department of Materials Science and Engineering,
Technion – Israel Institute of Technology
Haifa 3200003, Israel

Recently the research field of renewable energy is growing fast. There are several types of renewable energy sources and one of the significant routes among them is the hydrogen fuel that may be produced through water splitting. In my research I focused on the oxygen evolution reaction (OER) which is not favored kinetically and requires a catalyst. There are some suggestions for catalytic materials such as the first row transition metal oxides (containing, for example, Ni, Fe, Co, Mn). In the battery industry a common catalyst that is being used is Nickel oxyhydroxide (NiOOH). Pure NiOOH has poor efficiency. But doped NiOOH specifically with Fe dramatically improves efficiency. However, little is understood on the importance of the amount of doping. The goal of the research is to explore the influence of doping on the efficiency of NiOOH in the process of water oxidation. In addition, I investigate the effect of strain on catalytic efficiency of NiFeOOH alloy. I use Density Functional Theory +U (DFT+U) to check the dependence of the doping concentration on the efficiency of the catalyst in order to find the optimal concentration that provides the lowest OER overpotential. In this study I found that the overpotential for this process reduces upon Fe-doping at an ideal doping concentration for NiOOH. The best performance is achieved when applying 5% expansion strain to NiOOH with 33% Fe metallic content. Therefore, I found that applying strain is another useful control handle that can be used to understand and optimize catalytic efficiency.

Supervisor: Prof. Maytal Caspary Toroker