Serpentine Ni₃ Ge₂ O₅ (OH)₄ Nanosheets with Tailored Layers and Size for Efficient Oxygen Evolution Reactions

Layered serpentine Ni₃ Ge₂ O₅ (OH)₄ is compositionally active and structurally favorable for adsorption and diffusion of reactants in oxygen evolution reactions (OER). However, one of the major problems for these materials is limited active sites and low efficiency for OER. In this regard, a new catalyst consisting of layered serpentine Ni₃ Ge₂ O₅ (OH)₄ nanosheets is introduced via a controlled one-step synthetic process where the morphology, size, and layers are well tailored. The theoretical calculations indicate that decreased layers and increased exposure of (100) facets in serpentine Ni₃ Ge₂ O₅ (OH)₄ lead to much lower Gibbs free energy in adsorption of reactive intermediates. Experimentally, it is found that the reduction in number of layers with minimized particle size exhibits plenty of highly surface-active sites of (100) facets and demonstrates a much enhanced performance in OER than the corresponding multilayered nanosheets. Such a strategy of tailoring active sites of serpentine Ni₃ Ge₂ O₅ (OH)₄ nanosheets offers an effective method to design highly efficient electrocatalysts.