Nitrogen-incorporation activates NiFeO<sub>x</sub> catalysts for efficiently boosting oxygen evolution activity and stability of BiVO<sub>4</sub> photoanodes.

Zhang, Beibei; Yu, Shiqiang; Dai, Ying; Huang, Xiaojuan; Chou, Lingjun; Lu, Gongxuan; Dong, Guojun; Bi, Yingpu · Nat Commun · 2021

basic_science · Level V

Where this comes from

Abstract

Developing low-cost and highly efficient catalysts toward the efficient oxygen evolution reaction (OER) is highly desirable for photoelectrochemical (PEC) water splitting. Herein, we demonstrated that N-incorporation could efficiently activate NiFeO<sub>x</sub> catalysts for significantly enhancing the oxygen evolution activity and stability of BiVO<sub>4</sub> photoanodes, and the photocurrent density has been achieved up to 6.4 mA cm<sup>-2</sup> at 1.23 V (vs. reversible hydrogen electrode (RHE), AM 1.5 G). Systematic studies indicate that the partial substitution of O sites in NiFeO<sub>x</sub> catalysts by low electronegative N atoms enriched the electron densities in both Fe and Ni sites. The electron-enriched Ni sites conversely donated electrons to V sites of BiVO<sub>4</sub> for restraining V<sup>5+</sup> dissolution and improving the PEC stability, while the enhanced hole-attracting ability of Fe sites significantly promotes the oxygen-evolution activity. This work provides a promising strategy for optimizing OER catalysts to construct highly efficient and stable PEC water splitting devices.