Computational and Experimental Investigations of the Au and NiOOH Interface in the Oxygen Evolution Reaction
Author: Ginzu Fung Guan
Faculty Supervisor: Jingjing Qiu
Department: Chemistry & Biochemistry
Transitioning to renewable energy sources, notably hydrogen (H2), is critical in combating climate change. Water electrolysis, particularly the oxygen evolution reaction (OER), is pivotal for H2 production. Prior experimental results have shown that gold (Au) could improve the apparent activities of the OER electrocatalysts such as nickel hydroxide (Ni(OH)2) in alkaline electrolytes.1- 3 However, the detailed interfacial atomic structure and mechanisms of the increased catalytic activity remain poorly understood. To understand the interfacial effect between Au and Ni(OH)2 in the OER process, our research uses the model system of Au nanoparticles (NPs) and nickel oxyhydroxide (NiOOH), the active phase of Ni(OH)2 layers in the OER, to investigate their interfacial interactions with both experimental and computational approaches. Our studies involve computational analysis using Density Functional Theory (DFT) calculations to obtain the local density of states (LDOS), which can help us better visualize the local electronic structure of the system. Additionally, Bader analysis is employed to examine the electron distribution at the AuNPs/NiOOH interface. Furthermore, the catalytic efficacy of AuNPs on NiOOH is assessed through electrodepositions followed by cyclic voltammetry(CV) measurements. This research is expected to contribute to the insights of substrate and catalyst interactions for design of more efficient electrocatalysts.