Interactive oxidation of photoelectrocatalysis and electro-Fenton for azo dye degradation using TiO?¡VTi mesh and reticulated vitreous carbon electrodes

Author name used in this publication: Y. B. XieAuthor name used in this publication: X. Z. Li2005-2006 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe

Degradation of Diazinon based on photoelectrocatalytic technique using enhanced WO3 nanostructures: Mechanism and pathway

[EN] In this work, a resistant and toxic pesticide called diazinon was degraded through the photoelectrocatalysis (PEC) technique using tungsten oxide (WO3) nanostructures, applying an external bias of 1VAg/AgCl and simulated solar illumination. For this, WO3 nanostructures have been synthesized using electrochemical anodization in 0.05 M hydrogen peroxide and 1.5 M of different acidic electrolytes: H2SO4, CH4O3S or HNO3. Morphology, composition and crystallinity of the samples were evaluated through Field Emission Scanning Electron Microscopy (FE-SEM), Atomic Force Microscopy (AFM) and Raman Spectroscopy. Then, the photoelectrochemical properties of the samples were analyzed by Photo-Electrochemical Impedance Spectroscopy (PEIS). The conclusion obtained with these studies was that the nanostructures obtained in the CH4O3S-H2O2 electrolyte presented better photoelectrochemical behavior than the others. The degradation process was checked by UV-Visible, and through Ultra High-Performanc liquid Chromatography and Mass Spectrometry (UHPLC-Q-TOF/MS) the courses of the experiments have been controlled and five possible degradation intermediates have been identified. Finally, after 24 h of experiment, 90% degradation efficiency has been achieved, since it has been possible to decrease from 20 ppm to 2 ppm.Authors would like to show their gratitude for the financial support to the Ministerio de Ciencia e Innovacion (Project code: PID2019105844RB-I00) in the acquisition of Laser Raman Microscope (UPOV083E-012) and for the co-finance by the European Social Fund. Authors would also want to express thanks the Ministerio de Ciencia, Innovacion y Universidades (Project Code: CTQ2017-90659-REDT) and the Generalitat Valenciana for its support in the Atomic Force Microscope and UHPLC-Q-TOF/MS purchase (IDIFEDER/2018/044). Ramon M. Fernandez Domene also express gratitude to the Universitat Politecnica de Valencia (UPV) for the post-doctoral granting (PAID-10-17) and Gemma Rosello Marquez also thanks the Generalitat Valenciana for the pre-doctoral granting (ACIF/2018/159).Roselló-Márquez, G.; Fernández-Domene, RM.; Sánchez-Tovar, R.; Cifre-Herrando, M.; Garcia-Anton, J. (2021). Degradation of Diazinon based on photoelectrocatalytic technique using enhanced WO3 nanostructures: Mechanism and pathway. Journal of Environmental Chemical Engineering. 9(4):1-12. https://doi.org/10.1016/j.jece.2021.105371S1129

Photoelectrochemical reactors for CO2 utilization

The photoelectrochemical reduction of CO2 to renewable fuels and valuable chemicals using solar energy is a research topic that has attracted great attention recently due to its potential to provide value-added products under the Sun, solving the issues related to global warming at the same time. This review covers the main research efforts made on the photoelectrochemical reduction of CO2. Particularly, the study focuses in the configuration of the applied reactor, which is a topic scarcely explored in the literature. This includes the main materials used as photoelectrodes and their configuration in the photoelectrochemical reactor, which are discussed for technical uses. The review provides an overview of the state-of-the-art processes and aims to help in the development of enhanced photoelectroreactors for an efficient CO2 utilization.The authors acknowledge the financial support from the Spanish Ministry of Economy and Competitiveness (MINECO) under the project CTQ2016-76231-C2-1-R and Ramoń y Cajal programme (RYC-2015-17080)

Visible-light photoelectrodegradation of diuron on WO3 nanostructures

The degradation of pesticide diuron has been explored by photoelectrocatalysis (PEC) under visible light illumination using two different WO3 nanostructures, obtained by anodization of tungsten. The highest degradation efficiency (73%) was obtained for WO3 nanosheets synthesized in the presence of small amounts of hydrogen peroxide (0.05 M). For that nanostructure, the kinetic coefficient for diuron degradation was 133% higher than that for the other nanostructure (anodized in the presence of fluoride anions). These results have been explained by taking into account the different architecture and dimensions of the two WO3 nanostructures under study

Solar carbon fuel via photoelectrochemistry

A promising strategy to mitigate both energy shortage and global warming is the conversion of CO2 into chemicals that can be used as fuels (chemical fuels) by utilizing renewable energy sources. Up to date, solar-driven CO2 reduction has been achieved with photochemical (PC) and photoelectrochemical (PEC) systems or electrochemical cells combined with a photovoltaic system (PV-EC). This study is intended to compare and highlight the state-of-the-art PEC systems for CO2 reduction and show the limitation factors that still hinder their widespread utilization. The review starts with a description of semiconducting photocatalyst properties and fundamental understanding of PEC CO2 reduction process. Then, the most significant performance metrics used for evaluation of PEC systems are explained in details. In addition, recent progress in PEC CO2 reduction systems is summarized and classified in different categories according to the chemical product. Different strategies such as doping, combination of two or more semiconductors, synthesis of nanostructured materials, passivation layers and co-catalysts that enhance light absorption, chemical stability, charge transfer and reduce ohmic losses and overpotentials of photoactive materials are reviewed. Besides the improvement of photocatalysts, research progress on the front of PEC reactor design, combined with the development of advanced modelling tools and characterization techniques are expected to bring PEC CO2 reduction a step closer to commercialization