Photocatalytic activity of Ag/Al2O3–Gd2O3 photocatalysts prepared by the sol–gel method in the degradation of 4-chlorophenol. Issue 6 (15th January 2018)

• Record Type: Journal Article
• Authors: Barrera, A.; Tzompantzi, F.; Campa-Molina, J.; Casillas, J. E.; Pérez-Hernández, R.; Ulloa-Godinez, S.; Velásquez, C.; Arenas-Alatorre, J.
• Is Part Of: RSC advances. Volume 8:Issue 6(2018)
• Page Start: 3108
• Page End: 3119
• Publication Date: 2018-01-15
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c7ra12665d
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Ag/Al2 O3 –Gd2 O3 showed high efficacy to photodegradate 4-chlorophenol, the strong interaction between silver nano-particles and micro-particles and Al2 O3 –Gd2 O3 entities favors the decrease in the recombination rate. Abstract : The photocatalytic activity in the degradation of 4-chlorophenol (4-ClPh) in aqueous medium (80 ppm) using 2.0 wt% Ag/Al2 O3 –Gd2 O3 (Ag/Al–Gd- x ; where x = 2.0, 5.0, 15.0, 25.0 and 50.0 wt% of Gd2 O3 ) photocatalysts prepared by the sol–gel method was studied under UV light irradiation. The photocatalysts were characterized by N2 physisorption, X-ray diffraction, SEM, HRTEM, UV-Vis, XPS, FTIR and fluorescence spectroscopy. About 67.0% of 4-ClPh was photoconverted after 4 h of UV light irradiation using Ag/γ-–Al2 O3 . When Ag/Al–Gd- x photocatalysts were tested, the 4-ClPh photoconversion was improved and more than 90.0% of 4-ClPh was photoconverted after 3 h of UV light irradiation in the materials containing 15.0 and 25.0 wt% of Gd2 O3 . Ag/Al–Gd-25 was the material with the highest efficacy to mineralize dissolved organic carbon, mineralizing more than 85.0% after 4 h of UV light irradiation. Silver nanoparticles and micro-particles of irregular pentagonal shape intersected by plane nanobelts of Al2 O3 –Gd2 O3 composite oxide were detected in the Ag/Al–Gd-25 photocatalyst. This material is characterized by a lowest recombination rate of electron–hole pairs. The low recombination rate of photo-induced electron–hole pairs in the Ag/Al–Gd- x photocatalysts with high Gd2 O3 contents (≥15.0 wt%) confirmes that the presence of silver nanoparticles and microparticles interacting with Al2 O3 –Gd2 O3 composite oxide entities favors the separation of photo-induced charges (e − and h + ). These materials could be appropriate to be used as highly efficient photocatalysts to eliminate high concentrations of 4-ClPh in aqueous medium.