1. 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: 1197; Downloads: 7 Full text (4,22 MB) This document has many files! More... |
2. Iron phosphide thin films for electrocatalytic H2 generation and water remediation studies : abstractTakwa Chouki, Manel Machreki, Jelena Topic, Lorena Butinar, Plamen Stefanov, Erika Jež, Jack S Summers, Matjaž Valant, Aaron Fait, Saim Emin, 2022, published scientific conference contribution abstract Keywords: Iron phosphide thin films
H2 generation
water remediation Published in RUNG: 10.02.2023; Views: 1213; Downloads: 0 This document has many files! More... |
3. 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: 1192; Downloads: 0 This document has many files! More... |
4. Growth of MoSe2 thin films and use in electrochemical hydrogen evolution : abstractTakwa Chouki, Borjana Donkova, Burhan can Aktarla, Plamen Stefanov, Saim Emin, 2020, published scientific conference contribution abstract Abstract: We present the chemical vapor deposition (CVD) approach to grow MoSe2 thin films using colloidal molybdenum nanoparticles (Mo NPs). The synthetic protocol of Mo NPs was achieved using a wet-chemical method. The obtained Mo NPs were spin-coated on graphite substrates and heat-treated in the presence of selenium vapors at several temperatures (≥750 °C). The electrocatalytic activities of heat-treated MoSe2 thin
films were studied for hydrogen evolution reaction (HER) in 0.5 M sulfuric acid (H2SO4). The lowest recorded
overpotential of 218 mV at 10 mA cm−2 vs. a reversible hydrogen electrode was achieved with MoSe2−800°C catalyst. In addition, electrochemical impedance spectroscopy (EIS) was performed to access the charge-transfer resistance of the MoSe2 films. The colloidal approach combined with CVD is a promising route to produce carbon supported MoSe2 electrocatalyst for HER. Keywords: MoSe2 thin films
CVD
HER Published in RUNG: 06.02.2023; Views: 1248; Downloads: 0 This document has many files! More... |
5. Iron phosphide precatalyst for electrocatalytic degradation of rhodamine B dye and removal of Escherichia coli from simulated wastewaterTakwa Chouki, Manel Machreki, Jelena Topić, Lorena Butinar, Plamen Stefanov, Erika Jež, Jack S. Summers, Matjaž Valant, Aaron Fait, Saim Emin, 2022, original scientific article Keywords: železov fosfat, elektrokataliza, rodamin Published in RUNG: 02.08.2022; Views: 1634; Downloads: 96 Link to full text This document has many files! More... |
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7. Tungsten carbide electrocatalysts prepared from metallic tungsten nanoparticles for efficient hydrogen evolutionSaim Emin, Cesur Altinkaya, Ali Semerci, Hasan Okuyucu, Abdullah Yildiz, Plamen Stefanov, 2018, original scientific article Keywords: Tungsten carbide, Colloid, Hydrogen evolution, Overpotential, Electrocatalyst Published in RUNG: 23.05.2018; Views: 4875; Downloads: 0 This document has many files! More... |