Publication

Flower-like magnetized photocatalysts accelerating an emerging pollutant removal under indoor visible light and related phenomena

Résumé

This study presents the first evidence for FeOx intra-gap states on Bi2WO6- magnetized materials enhancing the Norfloxacin (NFX) degradation with respect to Bi2WO6 within acceptable times under indoor visible light (< 5 mW/cm(2)). The kinetically faster photocatalyst Bi2WO6-FeOx contained magnetite (Fe3O4). This material lead to NFX removal within one hour and was able to degrade NFX showing a stable performance over many cycles. Evidence for the Bi2WO6-FeOx photocatalyst behaving predomonantly as a semiconductor is described in this study. Evaluation of the magnetic field effect due to the FeOx intra-gap states and the applied light intensity are correlated with acceleration of the NFX-degradation kinetics. Bi2WO6-FeOx samples show a weak photoluminescence. The pH of the solution was monitored in situ and became more alkaline by 0.3 units within the time of NFX degradation. Reactive oxygen species (ROS) have been identified to account for this observation and a preliminary mechanistic scheme is suggested consistent with the experimental runs involving redox reactions. Several surface techniques have been used to characterize the nanoparticles (NPs) surfaces of the materials used during the course of this study. Magnetic photocatalysts are shown to have a potential for practical applications compared to more traditional methods currently used in the separation of dispersed catalysts at the end of environmental cleaning processes.

À propos de ce résultat
Cette page est générée automatiquement et peut contenir des informations qui ne sont pas correctes, complètes, à jour ou pertinentes par rapport à votre recherche. Il en va de même pour toutes les autres pages de ce site. Veillez à vérifier les informations auprès des sources officielles de l'EPFL.
Concepts associés (32)
Heterogeneous gold catalysis
Heterogeneous gold catalysis refers to the use of elemental gold as a heterogeneous catalyst. As in most heterogeneous catalysis, the metal is typically supported on metal oxide. Furthermore, as seen in other heterogeneous catalysts, activity increases with a decreasing diameter of supported gold clusters. Several industrially relevant processes are also observed such as H2 activation, Water-gas shift reaction, and hydrogenation. No gold-catalyzed reaction has been commercialized.
Champ magnétique
En physique, dans le domaine de l'électromagnétisme, le champ magnétique est une grandeur ayant le caractère d'un champ vectoriel, c'est-à-dire caractérisée par la donnée d'une norme, d’une direction et d’un sens, définie en tout point de l'espace et permettant de modéliser et quantifier les effets magnétiques du courant électrique ou des matériaux magnétiques comme les aimants permanents.
Champ magnétique terrestre
Le champ magnétique terrestre, aussi appelé bouclier terrestre, est un champ magnétique présent dans un vaste espace autour de la Terre (de manière non uniforme du fait de son interaction avec le vent solaire) ainsi que dans la croûte et le manteau. Il a son origine dans le noyau externe, par un mécanisme de dynamo auto-excitée. Dynamo terrestre Selon les études de John Tarduno de l'université de Rochester (États-Unis), la Terre possédait déjà un champ magnétique il y a 3,45 milliards d'années.
Afficher plus
Publications associées (33)

Understanding the role of surface oxygen-containing functional groups on carbon-supported cobalt catalysts for the oxygen evolution reaction

Andreas Züttel, Thi Ha My Pham, Kangning Zhao, Youngdon Ko, Liping Zhong, Manhui Wei

Supported Co-based catalysts exhibit promising catalytic activities in the oxygen evolution reaction (OER) during alkaline water electrolysis. Surface functionalization of the support modulates the dispersion of the catalysts and their interaction with the ...
ROYAL SOC CHEMISTRY2023

Insights into Electrocatalyst Transformations Studied in Real Time with Electrochemical Liquid-Phase Transmission Electron Microscopy

Vasiliki Tileli, Tzu-Hsien Shen, Robin Pierre Alain Girod

The value of operando and in situ characterization methodologies for understanding electrochemical systems under operation can be inferred from the upsurge of studies that have reported mechanistic insights into electrocatalytic processes based on such mea ...
Washington2023

Electron probing of oxygen-evolving oxide catalysts

Tzu-Hsien Shen

Water splitting is one of the cleanest ways to store energy. The production of hydrogen and oxygen gases can be utilized in fuel cells to generate electricity, power, and heat. In the water splitting process, the oxygen evolution reaction (OER), taking pla ...
EPFL2022
Afficher plus
MOOCs associés (25)
Plasma Physics: Introduction
Learn the basics of plasma, one of the fundamental states of matter, and the different types of models used to describe it, including fluid and kinetic.
Plasma Physics: Introduction
Learn the basics of plasma, one of the fundamental states of matter, and the different types of models used to describe it, including fluid and kinetic.
Plasma Physics: Applications
Learn about plasma applications from nuclear fusion powering the sun, to making integrated circuits, to generating electricity.
Afficher plus