Regulation of Morphology and electronic structure of NiSe2 by Fe for high effective oxygen evolution reaction.

With the development of hydrogen-energy economy, it is urgent for researchers to explore high effective non-noble metal electrocatalysts for oxygen evolution reaction (OER). Nickel-based selenides have good conductivity and easy to regulate, which make them to be a promising OER electrocatalysts. Hence, many researchers engineering the structure of Nickel-based selenides to further improve the OER performance. In this paper, NixFe 1-x Se 2 porous-nano-microspheres with different size were synthesized. Interestingly, Fe not only affects the number of active sites in NiSe 2 , but also affects the intrinsic activity by forming lattice defects. The introduction of Fe can change the redox ability of Ni cation and Se anion, thus reduce the average valence state of Ni cation in NiOOH. As a result, the current density of OER is improved remarkably. When the current density reaches 10 mA cm -2 , the overpotential is only 285 mV.