Experimental and theoretical investigations of the influence of carbon on a Ho3+-TiO2 photocatalyst with Vis response

Patrycja Parnicka , Tomasz Grzyb , Alicja Mikołajczyk , Kunlei Wang , Ewa Kowalska , Norbert Steinfeldt , Marek Klein , Paweł Mazierski , Adriana Zaleska-Medynska , Joanna Nadolna

Abstract

Due to their photon up-converting capability, lanthanide ions are ideal candidates dopants for semiconductors for developing visible light-driven photocatalytic activity. Of particular relevance, the low luminescence efficiency of Ln-based nanoparticles is one of the main factors that limits their further applications. Carbon, which is present on the surface of all TiO2 photocatalysts, can be responsible for luminescence quenching processes and, thus, decreasing the photocatalytic activity of TiO2. This article presents a systematic experimental and theoretical study of the effects of carbon on the photocatalytic performance of Ho3+-modified TiO2. Ho3+-TiO2 photocatalysts modified with various carbon contents (from 0.5 to 20 mol.%) were successfully prepared using a simple hydrothermal method. As-obtained samples were characterized by UV–Vis diffuse reflectance spectroscopy (DRS/UV–Vis), X-ray diffraction (XRD), X-ray photoelectron emission spectroscopy (XPS), N2 adsorption measurements, photoluminescent spectroscopy (PL), field-emission scanning electron microscopy (FE-SEM) and scanning transmission microscopy (STEM). The photodegradation efficiency of phenol was estimated for visible light (λ > 420 nm and λ > 455 nm). The XPS and XRD analyses and theoretical calculations revealed that the substitutional doping of holmium and carbon in the TiO2 anatase structure resulted in the appearance of a new sub-band-gap. Changes in the material texture, BET surface area and pore volume can be easily controlled via carbon content in samples. Doping of the Ho3+-TiO2 photocatalysts with carbon resulted in quenching of the emission of Ho3+ and, thus, the photodegradation of phenol, was observed in samples containing smaller amounts of carbon. Sixty minutes of irradiation resulted in 89% of phenol degradation under visible light (λ > 420 nm).
Author Patrycja Parnicka (FCh / DET / LPh)
Patrycja Parnicka,,
- Laboratory of Photocatalysis
, Tomasz Grzyb
Tomasz Grzyb,,
-
, Alicja Mikołajczyk (FCh / DET / LPh)
Alicja Mikołajczyk,,
- Laboratory of Photocatalysis
, Kunlei Wang
Kunlei Wang,,
-
, Ewa Kowalska
Ewa Kowalska,,
-
, Norbert Steinfeldt
Norbert Steinfeldt,,
-
, Marek Klein
Marek Klein,,
-
, Paweł Mazierski (FCh / DET / LPh)
Paweł Mazierski ,,
- Laboratory of Photocatalysis
, Adriana Zaleska-Medynska (FCh / DET / LPh)
Adriana Zaleska-Medynska,,
- Laboratory of Photocatalysis
, Joanna Nadolna (FCh / DET / LPh)
Joanna Nadolna,,
- Laboratory of Photocatalysis
Journal seriesJournal of Colloid and Interface Science, ISSN 0021-9797, (A 30 pkt)
Issue year2019
Vol549
Pages212-224
Publication size in sheets0.6
ASJC Classification1505 Colloid and Surface Chemistry; 2508 Surfaces, Coatings and Films; 2502 Biomaterials; 2504 Electronic, Optical and Magnetic Materials
DOIDOI:10.1016/j.jcis.2019.04.074
Languageen angielski
Score (nominal)30
ScoreMinisterial score = 30.0, 24-07-2019, ArticleFromJournal
Publication indicators Scopus SNIP (Source Normalised Impact per Paper): 2017 = 1.289; WoS Impact Factor: 2017 = 5.091 (2) - 2017=4.281 (5)
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