Scaling up photoelectrocatalytic reactors: A TiO2 nanotube-coated disc compound reactor effectively degrades acetaminophen

• Autores: Montenegro-Ayo R., Morales-Gomero J.C., Alarcon H., Cotillas S., Westerhoff P., Garcia-Segura S.
• Formato: artículo
• Fecha de Publicación: 2019
• Institución: Consejo Nacional de Ciencia Tecnología e Innovación
• Repositorio: CONCYTEC-Institucional
• Lenguaje: inglés
• OAI Identifier: oai:repositorio.concytec.gob.pe:20.500.12390/2752
• Enlace del recurso: https://hdl.handle.net/20.500.12390/2752; https://doi.org/10.3390/w11122522
• Nivel de acceso: acceso abierto
• Materia: Water treatment; Electrochemical advanced oxidation processes; Hydroxyl radical; Persistent organic pollutant; Titanium dioxide nanotubes; http://purl.org/pe-repo/ocde/ford#2.07.05

Multiple discs coated with hierarchically-organized TiO2 anatase nanotubes served as photoelectrodes in a novel annular photoelectrocatalytic reactor. Electrochemical characterization showed light irradiation enhanced the current response due to photogeneration of charge carriers. The pharmaceutical acetaminophen was used as a representative water micropollutant. The photoelectrocatalysis pseudo-first-order rate constant for acetaminophen was seven orders of magnitude greater than electrocatalytic treatment. Compared against photocatalysis alone, our photoelectrocatalytic reactor at <8 V reduced by two fold, the electric energy per order (EEO; kWh m-3 order-1 for 90% pollutant degradation). Applying a cell potential higher than 8 V detrimentally increased EEO. Acetaminophen was degraded across a range of initial concentrations, but absorbance at higher concentration diminished photon transport, resulting in higher EEO. Extended photoelectrocatalytic reactor operation degraded acetaminophen, which was accompanied by 53% mineralization based upon total organic carbon measurements. This proof of concept for our photoelectrocatalytic reactor demonstrated a strategy to increase photo-active surface area in annular reactors. © 2020 by the authors.