(639g) Construction of Heterojunction in2S3/NH2-MIL-68(In) for Effcient Visible-Light-Induced Hydrogen Production

Construction of heterojunction In₂S₃/NH₂-MIL-68(In)
for effcient visible-light-induced hydrogen production

Yunhong
Pi, Xiyi Li, Jing Xiao, Zhong Li *

Efficient
spatial separation of photo-induced charges is critical to utilize solar energy
over photocatalysts. Delicate formation of a heterojunction with intimate
contact between kinds of semiconductors can be used to limit the recombination
of electrons and holes by an internal electric field. Herein, we rationally
construct In₂S₃/NH₂-MIL-68(In) heterojunction
by precise control the sulfuration process of NH₂-MIL-68(In) as an
effective photocatalyst for hydrogen production. Through sulfuration process,
the phase belongs to In₂S₃ appear indicated by the peak
at approximately 27¡ã, 33¡ã and 48¡ã, respectively, while the framework of MOF
also stays intact in a large extent, as shown in Figure 1. The incorporation of
In₂S₃ significantly enhances the optical absorption
compared with the pristine MOF, which displays an obvious red-shift toward the
pure In₂S₃, as shown in Figure 2. Due to the band bending
induced by homologous metal sources and intimate interface, the photo-induced
electrons can be efficiently transferred between NH₂-MIL-68(In) and
In₂S₃, which is shown by the quenching of steady-state PL
spectra in Figure 3. Compared to the poor activity (1.85
µmol g^-1 h^-1)
of NH₂-MIL-68(In)
and (4.35 µmol g^-1
h^-1) of In₂S₃, the In₂S₃/NH₂-MIL-68(In)
heterojunction exhibits around 10 times and 5 times
higher photocatalytic efficiency (23.93 µmol
g^-1 h^-1), revealing that the charge spatial separation
within this heterostructure. This work may provide guidelines for design and
fabrication of MOFs-based heterojunction for improvement of photocatalytic
process.

Keywords: In₂S₃/NH₂-MIL-68(In);
heterojunction;
photocatalytic hydrogen production