(222a) Fabrication of Homologous TiO2/NH2-MIL-125(Ti) Heterojunction for Effcient Visible-Light-Induced Aerobic Oxidation of Benzyl Alcohol and Degration of Degradation of Tetracycline

Fabrication of homologous TiO₂/NH₂-MIL-125(Ti) heterojunction for effcient visible-light-induced
aerobic oxidation of benzyl alcohol and degradation of tetracycline

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

Incorporation
of noble metal nanoparticles is one effective approach to limit the
recombination of photo-induced carriers in NH₂-MIL-125(Ti), although it suffers from the loss of active
intermediate Ti³⁺. In this work, TiO₂/NH₂-MIL-125(Ti) heterojunction is synthesis to facilitate the transfer
of photo-induced electrons/holes pairs, and preserve the Ti³⁺ during
the transfer process at the same time. The TiO₂/NH₂-MIL-125(Ti) shows higher photo-degradation efficiency of
tetracycline compared with the pristine NH₂-MIL-125(Ti), as shown in Figure 1. Moreover, in the
visible-light-induced aerobic oxidation of benzyl alcohol, TiO₂/NH₂-MIL-125(Ti) exhibits highest conversion among the pristine NH₂-MIL-125(Ti), Pt/NH₂-MIL-125(Ti),
P-25 and CdS, as shown in Figure 2. The
electron spin resonance (ESR) spectroscopy, photocurrent response measurements,
and electrochemical impedance spectroscopy (EIS) are used to illustrated the
photocatalytic mechanism. The higher photocurrent and smaller impedance
guarantee the efficient transfer of TiO₂/NH₂-MIL-125(Ti), and the signal of Ti³⁺ under visible light
confirmed the preservation of Ti³⁺ during photocatalysis
reaction. The presevation of Ti3+ facilitate the
generation of O₂^¡¤-, and
resulting in higher yield of benzaldehyde from benzyl alcohol, as shown in Figure
3. This work offers a facile route to promote the transfer of photo-induced
e-/h+ without the loss of the active species of Ti³⁺ in NH₂-titanium
terephthalate metal-organic framework.

Keywords:
TiO₂/NH₂-MIL-125(Ti); O₂^¡¤-;
photocatalytic oxidation