Sunlight-Driven (Eu, Pd, Fe, Bi) Modified-TiO2 Photocatalysts and Their Catalytic Activity Using Scavengers Molecules

Abstract

In this work, it is reported the physicochemical characterization and photocatalytic activity evaluation of TiO2 thin films modified with Eu, Pd, Fe and Bi. Several characterization techniques were used to investigate thin film properties. The chemical composition as well as the chemical environment of the elements present were determined by X-ray photoelectron spectroscopy (XPS). The crystalline structure was characterized by X-ray diffraction (XRD) and micro-Raman spectroscopy (RS) whereas the optical band gap was determined using UV-Vis spectroscopy. The photocatalytic activity was evaluated in the degradation of the Malachite Green (MG) dye using simulated sunlight. It was found that films modified with Fe and Pd reached MG degradations close to 64.7 and 58.1% after 180 min of reaction. Additionally, thin films were photocatalytically evaluated under UV light (λ=254 nm) using wastewater containing diclofenac (DCF). The best catalytic performance (44% was reached by the film modified with Fe followed by the films modified with Pd (39%) and Bi (38%). To identify the role of reactive species for degradation of MG and DCF, triethanolamine (TEOA), isopropyl alcohol (IPA), ascorbic acid (AA) and benzoquinone (BZQ) were employed as scavenger’s molecules. The results obtained revealed that the O2• radical is the reactive specie that mainly contributes to the MG and DCF degradation.