Abstracts Book - IMRC 2018

• SF3-P008
AN IMPROVED ADSORPTION AND PHOTOCATALYTIC REMOVAL
OF METHYLENE BLUE BY MoO3: ROLE OF SPUTTERING POWER,
FILM THICKNESS, AND SPUTTERING WORKING PRESSURE
Mario Pérez González 1 , Michael Morales Luna 1,2 , Jaime Santoyo 1 , Horacio Crotte Ledesma 1 ,
Pedro Emmanuel Garcia Tinoco 1 , Sergio Armando Tomás Velázquez 1
1 Centro de Investigación y de Estudios Avanzados del IPN - CINVESTAV, Fisica, Mexico.
2 Universidad Autónoma de Querétaro, Facultad de Quimica, Mexico.
The role of the sputtering power, film thickness, and sputtering working
pressure on the adsorption and photocatalytic removal of methylene blue (MB)
by MoO 3 thin films was studied. MoO 3 thin films were deposited at room
temperature by rf reactive magnetron sputtering and, subsequently, postannealed
in air at 500 °C. Films were immersed in 10 ppm MB aqueous
solutions. XRD analysis revealed the presence of the alpha- and beta-MoO 3
crystalline phases. Photoacoustic and Raman spectroscopy showed a strong MB
adsorption on the film surface as a function of the film thickness. A strong
hypsochromic shift of the absorption bands was observed, indicating that MB
forms aggregates on the MoO 3 surface. The MB adsorption on the film was
evaluated the MB removal an aqueous solution under dark conditions. In
addition, the photocatalytic activity for the most adsorbent films was evaluated
the degradation of a MB aqueous solution under UV-irradiation. The maximum
adsorption and photocatalytic performance were observed for samples
deposited at 60 W, 400 nm, and 12.0 mTorr. These results are explained in terms
of the MoO 3 stoichiometry, structural, optical, and morphological properties of
the films.
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