Ni3S2/Ball-milled Silicon Flour as a Bi-Functional Electrocatalyst, Hydrogen and Oxygen Evolution Reaction, Ali A. Ensafi, Mehdi Jafari-Asl, Afshin Nabiyan, B. Rezaei, Energy, 2016, 116, 392-401.
Elaborate design of highly efﬁcient and durable electrocatalysts from earth-abundant elements is a
milestone in the ﬁeld of electrochemistry. In this study, heazlewoodite (Ni3S2) was successfully grafted
on the silicon ﬂour (Ni3S2 @ SiF) and ball-milled silicon ﬂour (Ni3S2 @ BeSiF) through a simple hydrothermal
process. The products were then etched using the HF solution to prepare the modiﬁed porous silicon
(PSi) compounds of Ni3S2 @ PSi and Ni3S2 @ BePSiF. Electrochemical studies showed that Ni3S2 @
BeSiF and Ni3S2 @ BePSiF were not only durable but also exhibited electrocatalytic activity toward both alkaline and
acidic hydrogen evolution reactions (HER) with appropriate Tafel slopes of 74 and 52 mV dec1,
respectively. Moreover, they recorded an electrocatalytic activity for the oxygen evolution reaction (OER)
with an overpotential of 164 mV dec 1 . Based on the electrocatalytic studies, the Ni3S2 @BePSiF electro-
catalyst was found to have the best electrocatalytic behavior toward HER and OER. The isolated island
architecture of the bi-functional (i.e., HER and OER) electrocatalyst could act as promising electrode
materials for water splitting using electrochemical methods.