V-Shaped RuO<sub>2</sub> Nanotwin Complex Defect Facilitation of OER Reaction
Jingjing Wu, Huining Zhao, Xin Tang
Abstract
RuO 2 is one of the most active catalysts for the acidic oxygen evolution reaction (OER). As a first step in understanding the mechanism for V-shaped RuO 2 nanotwin facilitation of the OER reaction, the relaxed atomic configuration and detailed partial density of states are determined using density-functional theory and are shown to dictate an upward shift of d- and p-band centers. The RuO 2 101-nanotwin grain boundary (101-TGB), as the first ∑101 V-shaped structure constructed, reduces the distance between kinked Ru and its surrounding O atoms, which enhances p–d hybridization. The special structure properly regulates the value of Δ G *O –Δ G *OH and charge-transfer energy. In addition, with the introduction of transition-metal and oxygen vacancies, the degree of nanotwin dislocation increases, exhibiting positive effects on the improvement of surface catalytic activity. Regulating the synergistic effect of nanotwins and transition metals can thus be crucial in assisting the exploration of new, multiple, and excellent RuO 2 -based nanocatalyst materials.