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

Authors: 
Pi, Y., South China University of Technology
Li, X., South China University of Technology
Xiao, J., South China University of Technology
Li, Z., South China University of Technology

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

Figure 1 XRD images of NH2-MIL-68(In), In2S3/NH2-MIL-68(In) and In2S3.

Figure 2 UV-vis DRS of NH2-MIL-68(In), In2S3/NH2-MIL-68(In) and In2S3

Figure 3 PL image of In2S3/NH2-MIL-68(In) and In2S3

Figure 4 Hydrogen production of NH2-MIL-68(In), In2S3/NH2-MIL-68(In) and In2S3 (Reaction condition: 10 mg photocatalyst, 27 mL CH3CN, 3 mL TEOA, 1 atm Ar, and 2.5 W LED)