Reaching Visible Light Photocatalysts with Pt Nanoparticles Supported in TiO<sub>2</sub>-CeO<sub>2</sub>

Nanostructured catalysts of platinum (Pt) supported on commercial TiO<sub>2</sub>, as well as TiO<sub>2</sub>-CeO<sub>2</sub> (1, 5 and 10 wt% CeO<sub>2</sub>), were synthesized through the Sol-Gel and impregnation method doped to 1 wt% of Platinum, in...

Full description

Bibliographic Details
Main Authors: Ixchel Alejandra Mejia-Estrella, Alejandro Pérez Larios, Belkis Sulbarán-Rangel, Carlos Alberto Guzmán González
Format: Article
Language:English
Published: MDPI AG 2022-09-01
Series:Materials
Subjects:
Online Access:https://www.mdpi.com/1996-1944/15/19/6784
Description
Summary:Nanostructured catalysts of platinum (Pt) supported on commercial TiO<sub>2</sub>, as well as TiO<sub>2</sub>-CeO<sub>2</sub> (1, 5 and 10 wt% CeO<sub>2</sub>), were synthesized through the Sol-Gel and impregnation method doped to 1 wt% of Platinum, in order to obtain a viable photocatalytic material able to oxidate organic pollutants under the visible light spectrum. The materials were characterized by different spectroscopy and surface techniques such as Specific surface area (BET), X-ray photoelectron spectroscopy (XPS), XRD, and TEM. The results showed an increase in the diameter of the pore as well as the superficial area of the supports as a function of the CeO<sub>2</sub> content. TEM images showed Pt nanoparticles ranking from 2–7 nm, a decrease in the particle size due to the increase of CeO<sub>2</sub>. The XPS showed oxidized Pt<sup>2+</sup> and reduced Pt<sup>0</sup> species; also, the relative abundance of the elements Ce<sup>3+</sup>/Ce<sup>4−</sup> and Ti<sup>4+</sup> on the catalysts. Additionally, a shift in the Eg band gap energy (3.02–2.82 eV) was observed by UV–vis, proving the facticity of applying these materials in a photocatalytic reaction using visible light. Finally, all the synthesized materials were tested on their photocatalytic oxidation activity on a herbicide used worldwide; 2,4-Dichlorophenoxyacetic acid, frequently use in the agriculture in the state of Jalisco. The kinetics activity of each material was measured during 6 h of reaction at UV–Vis 190–400 nm, reaching a removal efficiency of 98% of the initial concentration of the pollutant in 6 h, compared to 32% using unmodified TiO<sub>2</sub> in 6 h.
ISSN:1996-1944