1. Photoelectrochemical activation of peroxymonosulfate using Sn-doped ▫$α-Fe_2O_3$▫ thin film for degradation of anti-inflammatory pharmaceutical drugManel Machreki, Georgi Tyuliev, Dušan Žigon, Qian Guo, Takwa Chouki, Ana Belén Jorge Sobrido, Stoichko Dimitrov, Saim Emin, 2024, original scientific article Abstract: Introduction of oxygen vacancies (OVs) has been investigated as a promising way to improve the electrical and catalytic characteristics of a hematite (α-Fe2O3) based photoelectrode. In this work, we develop a novel method for preparing porous Sn-doped α-Fe2O3 (Sn:Fe2O3) thin films with intrinsic OVs. The procedure included spin- coating an iron precursor onto a fluorine-doped tin oxide (FTO) substrate, followed by thermal treatment at elevated temperatures. The influence of Sn dopant on the optoelectronic properties of α-Fe2O3 was demonstrated by X-ray photoelectron spectroscopy and photoelectrochemical (PEC) measurements. The combined effect of OVs and Sn doping was found to play a synergistic role in reducing the charge recombination’s. The Sn:Fe2O3 photoanodes were used as a dual catalyst to oxidise water and break down an anti-inflammatory drug called 2-(4- isobutylphenyl)propanoic acid (IBPA). The Sn:Fe2O3 thin film with a 30-minute heat treatment time displayed the highest incident photon-to-current efficiency. For the first time, Sn:Fe2O3 thin films were utilised in the effective PEC degradation of IBPA employing peroxymonosulfate (PMS) under visible light illumination. The hydroxyl radicals (•OH), singlet oxygen (1O2), photogenerated holes (h+), and sulfate radicals (SO4 • ) were discovered to be the main reactive species during PEC degradation. IBPA degradation and the formation of new compounds were verified using liquid chromatography-mass spectrometry. The Lepidium sativum L phytotoxicity test reveals that PEC-treated wastewater with IBPA exhibits decreased toxicity. Keywords: Sn-doped Fe2O3, oxygen vacancies, photoelectrochemical degradation, 2-(4-isobutylphenyl)propanoic acid, peroxymonosulfate Published in RUNG: 10.01.2024; Views: 1643; Downloads: 42 Full text (2,44 MB) This document has many files! More... |
2. Defective ▫$TiO_2$▫ nanotube arrays for efficient photoelectrochemical degradation of organic pollutantsManel Machreki, Takwa Chouki, Georgi Tyuliev, Dušan Žigon, Bunsho Ohtani, Alexandre Loukanov, Plamen Stefanov, Saim Emin, 2023, original scientific article Abstract: Oxygen vacancies (OVs) are one of the most critical factors that enhance the electrical and catalytic characteristics of metal oxide-based photo-electrodes. In this work, a simple procedure was applied to prepare reduced TiO 2 nanotube arrays (NTAs) (TiO 2−x) via a one-step reduction method using NaBH 4. A series of characterization techniques were used to study the structural, optical, and electronic properties of TiO 2−x NTAs. X-ray photoelectron spectroscopy confirmed the presence of defects in TiO 2−x NTAs. Photoacoustic measurements were used to estimate the electron-trap density in the NTAs. Photoelectrochemical studies show that the photocurrent density of TiO 2−x NTAs was nearly 3 times higher than that of pristine TiO 2. It was found that increasing OVs in TiO 2 affects the surface recombination centers, enhances electrical conductivity, and improves charge transport. For the first time, a TiO 2−x photoanode was used in the photo-electrochemical (PEC) degradation of a textile dye (basic blue 41, B41) and ibuprofen (IBF) pharmaceutical using in situ generated reactive chlorine species (RCS). Liquid chromatography coupled with mass spectrometry was used to study the mechanisms for the degradation of B41 and IBF. Phytotoxicity tests of B41 and IBF solutions were performed using Lepidium sativum L. to evaluate the potential acute toxicity before and after the PEC treatment. The present work provides efficient PEC degradation of the B41 dye and IBF in the presence of RCS without generating harmful products. Keywords: TiO2, nanotube arrays, photoelectrochemical degradation, organic pollutants Published in RUNG: 12.06.2023; Views: 1907; Downloads: 12 Full text (4,22 MB) This document has many files! More... |
3. Oxygen vacancies engineering in metal oxide nanomaterials for efficient photo-electrocatalytic degradation of organic pollutants and chemical transformations : dissertationManel Machreki, 2022, doctoral dissertation Keywords: titanium dioxide nanotubes, hematite, oxygen vacancies, photoelectrochemical degradation of dye, ibuprofen, chemical transformation, glycerol, vanillyl alcohol, dissertations Published in RUNG: 01.03.2023; Views: 2778; Downloads: 57 Full text (5,71 MB) |
4. Reduced TiO2 nanotube arrays for photoelectrochemical degradation of pharmaceuticalManel Machreki, Takwa Chouki, Georgi Tyuliev, Dušan Žigon, Bunsho Ohtani, Alexandre Loukanov, Plamen Stefanov, Saim Emin, 2022, published scientific conference contribution abstract Keywords: TiO2, nanotube arrays, photoelectrochemical degradation, pharmaceuticals Published in RUNG: 10.02.2023; Views: 1938; Downloads: 0 This document has many files! More... |