posted on 2022-02-07, 15:03authored byRan Duan, Yejun Li, Shu Wang, Jun Gong, Yonggang Tong, Weihong Qi
Although
there is a general consensus that the electrocatalysts
will undergo reconstruction to generate (oxy)hydroxides as real active
sites during the electrochemical oxygen evolution reaction (OER),
the understanding of this process is still far from satisfactory.
In particular, the reconstruction process of most of these electrocatalysts
is either slow or occurs only on the surface, which thus restrains
the OER performance of the electrocatalysts. Herein, we reveal a fast
and deep reconstruction of the coprecipitated Fe phosphates on nickel
foam, via in situ Raman spectroscopy together with electron microscopy,
X-ray photoelectron spectroscopy, and electrochemical tests. The generated
NiFe (oxy)hydroxide nanosheets after reconstruction behave as the
real active sites for the OER in the alkaline condition, with a low
overpotential and excellent durability. The present work provides
deep insights on the reconstruction dynamics of OER electrocatalysts.