2 research outputs found
Solution Synthesis of Thiospinel CuCo<sub>2</sub>S<sub>4</sub> Nanoparticles
CuCo<sub>2</sub>S<sub>4</sub> is an important mixed-metal spinel-type sulfide
that is typically synthesized using high-temperature solid-state reactions,
which produce agglomerated particles with low surface areas that are
not optimal for applications such as heterogeneous catalysis. Here,
we show that highly crystalline and nonagglomerated colloidal CuCo<sub>2</sub>S<sub>4</sub> nanoparticles can be synthesized in solution
at 200 °C, which is significantly lower than previously reported
methods. The CuCo<sub>2</sub>S<sub>4</sub> nanoparticles were found
to be highly active electrocatalysts for the oxygen evolution reaction
(OER) under strongly alkaline conditions (1.0 M KOH, pH 14), requiring
an OER overpotential of 395 mV to produce a current density of 10
mA cm<sup>–2</sup>. X-ray photoelectron spectroscopy (XPS)
studies showed evidence of oxide formation, suggesting, in conjunction
with the observed electrocatalytic properties, that the mixed-metal
sulfides may serve as precursors to oxides and/or hydroxides, which
are likely to be the catalytically active species