As the energy shortage and environmental
problem become the worldwide
concern, the green synthesis of catalysts and their green applications
have long been pursued. Here we proposed a facile catalyst synthesis
approach in which Ag–TiO2 composites were prepared
through an in situ reduction at room temperature without severe conditions
or hydrogen atmosphere. Porous glass (PG) was chosen as the support,
and the as-prepared Ag–TiO2/PG was equipped with
the remarkable merits of intense visible light absorbance, effective
separation of electron–hole pairs, high surface areas for adsorption,
and abundant reactive sites for the photocatalytic oxidation. Conversions
of 95.2% and 92.1% for dibenzothiophene (DBT) and benzothiophene (BT),
respectively, were realized under irradiation of energy-saving visible
light emitting diodes (LEDs), complying with the principles of “green
chemistry”. Moreover, none of the external oxidants, such as
H2O2 or O2, was introduced, greatly
increasing the viability of industrial applications. Ag–TiO2/PG also showed remarkable activity for removing rhodamine
B (RhB), methylene blue (MB), and methylene orange (MO) with the rate
constants of 0.14, 0.18, and 0.055 min–1, respectively.
The mechanism study revealed that the immobilized Ag acted as the
role of “killing two birds with one stone”: enhancing
the absorption of visible light, suppressing the recombination of
photoinduced electron–hole pairs via trapping electrons, and
contributing to the generation of •O2
–. In addition, oxygen vacancies, •OH, and h+ also took part in the photocatalytic oxidation.
This work explored the green synthesis of Ag–TiO2/PG and characterized their excellent photocatalytic activity for
photocatalytic desulfurization and degradation of organic dyes, opening
up new possibilities for low-energy-consumption photocatalysis and
sustainable chemistry.