Surface reconstruction establishing Mott-Schottky heterojunction and built-in space-charging effect accelerating oxygen evolution reaction

Abstract

Structural reconstruction of nanomaterials offers a fantastic way to regulate the electronic structure of active sites and promote their catalytic activities. However, how to properly facilitate surface reconstruction to overcome large overpotential that stimulate the surface reconstruction has remained elusive. Herein, we adopt a facile approach to activate surface reconstruction on Ni(OH)2 by incorporating F anions to achieve electro-derived structural oxidation process and further boost its oxygen evolution reaction (OER) activity. Ex situ Raman and X-ray photoemission spectroscopy studies indicate that F ions incorporation facilitated surface reconstruction and promotes the original Ni(OH)2 transformed into a mesoporous and amorphous F-NiOOH layer during the electrochemical process. Density functional theory (DFT) calculation reveals that this self-reconstructed NiOOH induces a space-charge effect on the p-n junction interface, which not only promotes the absorption of intermediates species (*OH, *O, and *OOH) and charge-transfer process during catalysis, but also leads to a strong interaction of the p-n junction interface to stabilize the materials. This work opens up a new possibility to regulate the electronic structure of active sites and promote their catalytic activities.