In order to explore
a new electrocatalyst (or its precursor) for
oxygen evolution reaction (OER), much attention has recently been
given to the alternative engineering strategy for fabricating a novel
nanofilm electrode with high efficiency and long duration. We herein
use a two-step electrodeposition method to prepare a series of nanofilm
electrodes containing Ni, Co, P, and Se on carbon cloth. After a suitable
electrochemical activation process through cyclic voltammetry, the
resultant binder-free NiCoP–NiCoSe2 nano-bilayer
films are transformed from compact layer(s) to porous nanoparticle
ones composed by NiCo hydroxides and a small amount of NiCo oxyhydroxides
and thus exhibit a striking electrocatalytic activity (lower to 243
mV overpotential for 10 mA cm–2) and excellent stability
(80 h) for OER. The rougher surface, well-suited electronic structure
originated from the Ni/Co codoping and the rational integration of
NiCoP and NiCoSe2 are important factors for the excellent
OER performance of the NiCoP–NiCoSe2 film after
the electrochemical activation process. In addition, the results on
overall water splitting reveal that the NiCoP–NiCoSe2 film is also promising in the practical application of energy conversion
and storage.