Electrochemical Construction of Low-Crystalline CoOOH Nanosheets with Short-Range Ordered Grains to Improve Oxygen Evolution Activity

In this study, low-crystalline CoOOH nanosheet arrays that are grown on carbon fiber cloth (LC-CoOOH NAs/CFC) were prepared using a facile electrochemical strategy for the oxygen evolution reaction (OER). The low-crystalline CoOOH nanosheets were assembled randomly by numerous short-range (1-5 nm) ordered grains with different orientations, inducing abundant grain boundaries (edge sites of CoOOH). Moreover, a certain number of structural defects (oxygen vacancies) were also engineered on the low-crystalline CoOOH nanosheets. Benefiting from these abundant edge sites of CoOOH and oxygen vacancies, LC-CoOOH NAs/CFC exhibit much improved OER activity compared to the high-crystallinity CoOOH NAs/CFC with a perfect structure. This research provides a new way to synthesize the defective materials with a short-range ordered structure and lays a valuable theoretical foundation for the structure and property of OER catalysts.

Automated summary

In this study, low-crystalline CoOOH nanosheet arrays were prepared on carbon fiber cloth for the oxygen evolution reaction using an electrochemical strategy. The nanosheets had abundant edge sites of CoOOH and oxygen vacancies, leading to improved OER activity compared to high-crystallinity samples. This research presents a new approach for synthesizing defective materials with a short-range ordered structure and contributes to the understanding of OER catalysts.