IMPROVING NiOOH CATALYTIC ACTIVITY IN ELECTROCHEMICAL WATER SPLITTING USING TRANSITION METAL DOPANTS: A FIRST-PRINCIPLES CALCULATION BASED STUDY

Due to its massive industrialization, modern society is more and more concerned with energetic issues. While fossil resources have been so far the main source of energy, their availability is limited in the time and their utilization is responsible for various pollutants. Hence, it is necessary to look for alternative energies. Photoelectrochemical cells are an attractive solution.

Such devices aim at converting solar energy into chemical fuels. However, this technology suffers from a major limitation due to water oxidization (Oxygen Evolution Reaction – O.E.R) at the anode electrode. Indeed, this reaction requires highly active catalysts often based on noble metals, and thus economically non-viable for intensive industrial exploitation. Besides, they are not stable in operating conditions and thus have a short life span.

Various oxide and hydroxide of earth-abundant metals have already been proposed. Among them, nickel oxihydroxyde (NiOOH) exhibits outstanding properties, especially owing to its high chemical stability. However, its catalytic activity is extremely dependent on impurities and doping. Indeed, while Fe doped NiOOH is known to be remarkably active, pure NiOOH is only poorly efficient. Using density functional theory (DFT), we studied properties of doped and undoped NiOOH. For the first time in a theoretical work, we present here a systematic scan of various metallic dopants. According to bulk and slab calculations, we were able to show very different trends in catalytic activity between them. Owing to our results, we expect to give interesting guidelines for experimentalists and industrials in order to design more efficient photoelectrochemical cells.