Synergetic Effect of MoS<sub>2</sub> and Graphene
as Cocatalysts for Enhanced Photocatalytic H<sub>2</sub> Production
Activity of TiO<sub>2</sub> Nanoparticles
- Publication date
- Publisher
Abstract
The production of H<sub>2</sub> by photocatalytic water
splitting
has attracted a lot attention as a clean and renewable solar H<sub>2</sub> generation system. Despite tremendous efforts, the present
great challenge in materials science is to develop highly active photocatalysts
for splitting of water at low cost. Here we report a new composite
material consisting of TiO<sub>2</sub> nanocrystals grown in the presence
of a layered MoS<sub>2</sub>/graphene hybrid as a high-performance
photocatalyst for H<sub>2</sub> evolution. This composite material
was prepared by a two-step simple hydrothermal process using sodium
molybdate, thiourea, and graphene oxide as precursors of the MoS<sub>2</sub>/graphene hybrid and tetrabutylorthotitanate as the titanium
precursor. Even without a noble-metal cocatalyst, the TiO<sub>2</sub>/MoS<sub>2</sub>/graphene composite reaches a high H<sub>2</sub> production
rate of 165.3 μmol h<sup>–1</sup> when the content of
the MoS<sub>2</sub>/graphene cocatalyst is 0.5 wt % and the content
of graphene in this cocatalyst is 5.0 wt %, and the apparent quantum
efficiency reaches 9.7% at 365 nm. This unusual photocatalytic activity
arises from the positive synergetic effect between the MoS<sub>2</sub> and graphene components in this hybrid cocatalyst, which serve as
an electron collector and a source of active adsorption sites, respectively.
This study presents an inexpensive photocatalyst for energy conversion
to achieve highly efficient H<sub>2</sub> evolution without noble
metals
