Aims: In the present study, we investigate the photocatalytic properties of α-Ag2WO4 nanocrystals-
modified Palygorskite (PAL) clay synthesized by the impregnation method. The PAL clay
was chemically purified and heat-treated (500 ºC for 2 h), which served as an excellent supporting
matrix for loading α-Ag2WO4 (α-AWO) nanocrystals.
Background: Water contamination is one of the most serious problems affecting human health, ecosystem
survival, and the economic growth of societies. Industrial effluents, such as textile dyes, when
not treated and improperly discharged into water resources are considered the main cause of water
pollution. Thus the scientific community has been developing effective remediation technologies
based on advanced oxidative processes to reduce the harmful effects of these organic pollutants.
Objective: This study aimed to improve the photocatalytic activity of PAL clay with α-AWO nanocrystals
to degradation of Rhodamine B (RhB) dye.
Methods: We purified and heat-treated the PAL clay, synthesized nanocrystals of α-AWO nanocrystals
and modified PAL clay with 30% α-AWO nanocrystals by the impregnation method. The modified
PAL clay was able to improve RhB dye degradation. The materials were characterized by XRD,
RAMAN, FE-SEM, FT-IR, XRF, etc. The samples were used as photocatalysts under UV-C lamps for
the degradation of RhB dye in order to analyze their catalytic performances.
Results: The PAL clay modified with 30% α-AWO nanocrystals showed a catalytic efficiency of
79%, and degradation kinetics about 16 times higher when compared to PAL-500 only purified and
heat-treated at 500 ºC. In this way, this PAL-modified is an alternative as a low-cost photocatalyst for
the degradation of RhB dye.
Conclusion: Ultraviolet-visible spectra revealed that our materials have optical band gap energies
controlled by indirect and direct electronic transitions and suitable to be activated under ultraviolet illumination.
The adequate amount (30 wt.%) of α-Ag2WO4 nanocrystals added to PAL brought significant
improvement in the photocatalytic activity for the degradation of rhodamine B. Finally, a photocatalytic
mechanism was proposed in detail.