Photocatalytic Hydrogen Evolution by Flexible Graphene Composites Decorated with Ni(OH)2 Nanoparticles


Antonia Martínez Luévanos

ABSTRACT: This work presents the hydrogen evolution
produced by flexible graphene composites (FGCs) fabricated by
a casting method. Ni(OH)2 nanoparticles were also grown on the
FGCs by using a wet chemical method. Those nanoparticles
present spherical shapes and are uniformly distributed on the
surface of the FGCs. The hydrogen generation activity in water
for the FGCs with and without Ni(OH)2 nanoparticles was
produced by UV light excitation. The FGCs decorated with
Ni(OH)2 nanoparticles had a hydrogen generation rate 2.66 times
higher than the FGCs without nanoparticles. It was also observed
that the surface of the FGCs is oxidized during the photocatalytic
process (formation of graphene oxide); this in turn helped to
create actives sites for the generation of the electron−hole pairs
during the irradiation under UV light and to transfer of charge
from the FGCs’ surface to the electron trapping centers (Ni(OH)2 nanoparticles). Further, reuse experiments of the FGCs
demonstrated that their stability for the hydrogen generation improved due to the presence of Ni(OH)2 nanoparticles, since the
hydrogen generation rate after three cycles of use decreased by 46% and by 84% in the FGCs with and without Ni(OH)2
nanoparticles, respectively. The flexibility of the graphene composites facilitated their introduction and removal from the water
container where the photocatalytic generation of H2 occurred. Hence, our results suggest that the FGCs could be a feasible
option for water splitting in industrial reactors.

Artículo- AML 3 2018