Study of adsorption and degradation of dimethylphthalate on TiO2-based photocatalysts

•DMP has been degraded and mineralized by heterogeneous photocatalysis.•SG750, a synthesized photocatalyst, offers the best results.•Surface Pt and Au particles do not improve degradation.•The kinetic pattern fits the Langmuir-Hinshelwood model.•FTIR observations correlate to adsorption constants from the Freundlich model.

This work studied the degradation and adsorption of dimethylphthalate (DMP) using various TiO2-based photocatalysts: TiO2 Aeroxide P25, Kronos vlp7000, Hombikat UV-100, Kemira 650 and a synthesized photocatalyst named SG750. As the photocatalysts with mixed anatase and rutile phases, P25 and SG750, showed greater activity than those of pure phase, an in-depth study was undertaken of these two catalysts in the adsorption and degradation of DMP. The degradation results were fitted with a high degree of correlation to the Langmuir-Hinshelwood model and those for adsorption to the Freundlich model. The Freundlich constants showed good correlation with FTIR observations of the DMP-P25 and DMP-SG750 interactions. These two photocatalysts were additionally modified by photodeposition with Pt and Au (0.5-1.5 wt%) to study the effect of these metals on degradation and mineralization kinetics.

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