Assessment of Density Functional Theory Methods on Bulk and Electronic Properties of β-NiOOH Structural Models

The development of novel oxygen evolution reaction (OER) electrocatalyst for electrochemical water splitting has been an active field of research for sustainable energy future. Transition metal (oxy)hydroxides such as nickel oxyhydroxide (NiOOH) has been heavily studied as electrocatalyst for OER due to its stability in alkaline environment. Past studies also showed that catalytic activity can be further enhanced upon doping with other transition metals such as iron (Fe). However, the development of Ni-based (oxy)hydroxide electrocatalyst has been hindered by the uncertainty in structure-activity relationships. First-principles calculations based on DFT have been critical to help develop structural models and structure-activity relationships. However, understanding the structure has been challenging due to discrepancies in the level of theory used across the literature, namely the choice of appropriate exchange-correlation functional, Hubbard U correction, dispersion correction and ultimately the NiOOH model proposed. In this work, we systematically analyze the performance of three popular exchange-correlation functional (PBE, r2SCAN and HSE06) with Hubbard U and dispersion correction on the structural and electronic properties of three widely used NiOOH bulk models. Our result indicates that PBE and r2SCAN level calculations are sufficient for evaluating the structural properties and energetic pathway for OER while computationally intensive HSE06 functional is required to describe the electronic properties of NiOOH.