Graphene oxide (GO), GO reduced by
hydrazine hydrate (rGO-HH),
GO reduced by ethylene glycol (rGO-EG), Pt-decorated rGO-HH composite
(Pt/rGO-HH), and Pt-decorated rGO-EG composite (Pt/rGO-EG), are fabricated
for the heterogeneous catalytic decomposition of HI in a sulfur–iodine
thermochemical cycle. Corresponding material characterization on various
catalysts are performed to gain insight into the catalytic mechanism.
rGO-HH presents better catalytic activity than the GO and rGO-EG counterparts,
due to the increase of active sites (unsaturated carbon atoms) with
the reduction of oxygen-containing groups and the formation of edge
planes. Homogeneously dispersed fine Pt nanoparticles are obtained
with employing rGO-EG as the support. The corrugation morphology and
graphene edges benefit the nucleation, dispersion, and immobilization
of Pt nanoparticles. As a consequence, Pt/rGO-EG presents better catalytic
activity and stability than the convenient Pt/activated-carbon (Pt/AC)
counterpart. Results indicate that the graphene-based catalysts hold
a great promise for the catalytic decomposition of HI.