materials-logo

Journal Browser

Journal Browser

Photocatalytic Properties and Kinetics of Materials

A special issue of Materials (ISSN 1996-1944). This special issue belongs to the section "Catalytic Materials".

Deadline for manuscript submissions: closed (10 July 2023) | Viewed by 13177

Special Issue Editor


E-Mail Website
Guest Editor
Department of Industrial Engineering, University of Salerno, 84084 Fisciano, Italy
Interests: catalysis; environmental depollution; characterization of materials; nanomaterials
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Photocatalytic materials have been the subject of extensive studies in the last decade due to their unique properties such as promoted catalysis, adsorption surface, and high reactivity in mild conditions. This Special Issue is devoted to exploring and highlighting the relationships between the structure, morphological and optical properties, and the features of photocatalysts and photoactivity.

The synthetic procedures, including doping, semiconductor coupling, and surface coating, can noticeably affect the physicochemical properties of semiconductors. Innovative photocatalysts implemented as layered materials; nanostructures; size- or shape-tuned nanoparticles; micro-, meso-, and macro-structured catalysts; as well as composites with other functional materials are included. Chemical, physical, electrical, magnetic, and optical characterization will help identify correlations with the photocatalytic performance of the advanced materials.

Photocatalytic materials are able to promote photoreactions and their performance depends on the kind of molecules, level of concentration, temperature, solution pH, photocatalyst dosage, presence of other organic and inorganic compounds, and kind and intensity of light. Understanding and modeling kinetics are essential for the optimization and implementation of photocatalytic processes. Fundamental investigation on photocatalytic kinetics of semiconductors photocatalysts may validate the proposed reaction mechanism and can offer a mathematical law as function of operative parameters.

In this Special Issue, frontier researchers and colleagues are invited to present original papers and review articles involving (without being limited to) the topics listed below:

  • materials for photocatalytic water and wastewater treatment
  • materials for sustainable photocatalytic synthesis
  • materials for photocatalysis under visible light
  • materials for CO2 photoreduction
  • materials for air purification
  • materials for bacterial photoinactivation
Prof. Diana Sannino
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Materials is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Photocatalysis
  • Innovative semiconducting materials
  • Environmental photocatalysis
  • Photocatalytic syntheses
  • Kinetics evaluation
  • Advanced photocatalytic materials
  • Structured materials

Published Papers (6 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

18 pages, 5154 KiB  
Article
The Kinetics of the Redox Reaction of Platinum(IV) Ions with Ascorbic Acid in the Presence of Oxygen
by Magdalena Luty-Błocho, Aleksandra Szot, Volker Hessel and Krzysztof Fitzner
Materials 2023, 16(13), 4630; https://doi.org/10.3390/ma16134630 - 27 Jun 2023
Cited by 1 | Viewed by 977
Abstract
In this work, the kinetics of the redox reaction between platinum(IV) chloride complex ions and ascorbic acid is studied. The reduction process of Pt(IV) to Pt(II) ions was carried out at different reagent concentrations and environmental conditions, i.e., pH (2.2–5.1), temperature (20–40 °C), [...] Read more.
In this work, the kinetics of the redox reaction between platinum(IV) chloride complex ions and ascorbic acid is studied. The reduction process of Pt(IV) to Pt(II) ions was carried out at different reagent concentrations and environmental conditions, i.e., pH (2.2–5.1), temperature (20–40 °C), ionic strength (I = 0.00–0.40 M) and concentrations of chloride ions (0.00–0.40 M). The kinetic traces during the reduction process were registered using stopped-flow spectrophotometry. Based on the kinetic traces, the rate constants were determined, and the kinetic equations were proposed. It was shown that in the mild acidic medium (pH = 2.5), the reduction process of Pt(IV) to Pt(II) ions is more complex in the presence of oxygen dissolved in the aqueous solutions. For these processes, the values of the enthalpy and entropy of activation were determined. Moreover, the mechanism of the reduction of Pt(IV) to Pt(II) ions was proposed. The presented results give an overview of the process of the synthesis of platinum nanoparticles in the solution containing oxygen, in which the reduction process of Pt(IV) to Pt(II) ions is the first step. Full article
(This article belongs to the Special Issue Photocatalytic Properties and Kinetics of Materials)
Show Figures

Figure 1

13 pages, 1971 KiB  
Article
TiO2/Karaya Composite for Photoinactivation of Bacteria
by Anderson C. B. Lopes, Francisca P. Araújo, Alan I. S. Morais, Idglan S. de Lima, Luzia M. Castro Honório, Luciano C. Almeida, Ramón Peña Garcia, Edson C. Silva-Filho, Marcelo B. Furtini and Josy A. Osajima
Materials 2022, 15(13), 4559; https://doi.org/10.3390/ma15134559 - 28 Jun 2022
Cited by 7 | Viewed by 1697
Abstract
TiO2/Karaya composite was synthesized by the sol-gel method for the photoinactivation of pathogens. This is the first time that we have reported this composite for an antimicrobial approach. The structure, morphology, and optical properties were characterized by X-ray diffraction (XRD), scanning [...] Read more.
TiO2/Karaya composite was synthesized by the sol-gel method for the photoinactivation of pathogens. This is the first time that we have reported this composite for an antimicrobial approach. The structure, morphology, and optical properties were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-rays (EDS), Fourier transform infrared spectroscopy (FTIR), and diffuse reflectance, and the surface area was characterized by the BET method. The XRD and EDS results showed that the TiO2/Karaya composite was successfully stabilized by the crystal structure and pore diameter distribution, indicating a composite of mesoporous nature. Furthermore, antibacterial experiments showed that the TiO2/Karaya composite under light was able to photoinactivate bacteria. Therefore, the composite is a promising candidate for inhibiting the growth of bacteria. Full article
(This article belongs to the Special Issue Photocatalytic Properties and Kinetics of Materials)
Show Figures

Figure 1

14 pages, 3746 KiB  
Article
Natural Volcanic Material as a Sustainable Photocatalytic Material for Pollutant Degradation under Solar Irradiation
by María Emma Borges, Silvia Navarro, Héctor de Paz Carmona and Pedro Esparza
Materials 2022, 15(11), 3996; https://doi.org/10.3390/ma15113996 - 03 Jun 2022
Cited by 1 | Viewed by 1416
Abstract
Recently, photocatalysis has been demonstrated as a solid approach for efficient wastewater cleaning. Using natural materials as photocatalysts means a promising solution to develop green catalysts for environmental purposes. This work aimed to study the suitability of a natural volcanic material (La Gomera, [...] Read more.
Recently, photocatalysis has been demonstrated as a solid approach for efficient wastewater cleaning. Using natural materials as photocatalysts means a promising solution to develop green catalysts for environmental purposes. This work aimed to study the suitability of a natural volcanic material (La Gomera, Canary Islands, Spain) as a photocatalytic material for the degradation of pollutants in wastewater with solar energy. After analysing the properties of the natural material (BET surface 0.188 m2/g and band-gap of 3 eV), the photocatalytic activity was evaluated at laboratory and pilot plant scale for the degradation of methylene blue (MB) in water (50 mg L−1), at 20 °C, during a period of 4 h, under UV/Vis light and solar irradiation. Photolytic and adsorption studies were developed to distinguish the photocatalytic contribution to the wastewater decontamination process by photocatalysis. Our results enable us to determine the viability of black sand as a photocatalytic material activated by solar irradiation (photodegradation of MB up to 100% by using solar energy), developing a natural and green photocatalytic system with significantly high potential for application in a sustainable wastewater cleaning process. Full article
(This article belongs to the Special Issue Photocatalytic Properties and Kinetics of Materials)
Show Figures

Figure 1

22 pages, 4490 KiB  
Article
Visible Light-Driven Photocatalytic Activity and Kinetics of Fe-Doped TiO2 Prepared by a Three-Block Copolymer Templating Approach
by Antonietta Mancuso, Olga Sacco, Vincenzo Vaiano, Barbara Bonelli, Serena Esposito, Francesca Stefania Freyria, Nicola Blangetti and Diana Sannino
Materials 2021, 14(11), 3105; https://doi.org/10.3390/ma14113105 - 05 Jun 2021
Cited by 17 | Viewed by 2771
Abstract
Fe-doped titania photocatalysts (with 1, 2.5, and 3.5 wt. % Fe nominal content), showing photocatalytic activity under visible light, were prepared by a soft-template assisted sol–gel approach in the presence of the triblock copolymer Pluronic P123. An undoped TiO2 photocatalyst was also [...] Read more.
Fe-doped titania photocatalysts (with 1, 2.5, and 3.5 wt. % Fe nominal content), showing photocatalytic activity under visible light, were prepared by a soft-template assisted sol–gel approach in the presence of the triblock copolymer Pluronic P123. An undoped TiO2 photocatalyst was also prepared for comparison. The photocatalysts were characterized by means of X-ray powder Diffraction (XRPD), Quantitative Phase Analysis as obtained by Rietveld refinement, Diffuse Reflectance (DR) UV−Vis spectroscopy, N2 adsorption/desorption at −196 °C, electrophoretic mobility in water (ζ-potential), and X-ray photoelectron spectroscopy (XPS). The physico-chemical characterization showed that all the samples were 100% anatase phase and that iron was present both in the bulk and at the surface of the Fe-doped TiO2. Indeed, the band gap energy (Eg) decreases with the Fe content, with Tauc’s plot determined values ranging from 3.35 (undoped TiO2) to 2.70 eV (3.5 wt. % Fe). Notwithstanding the obtained Eg values, the photocatalytic activity results under visible light highlighted that the optimal Fe content was equal to 2.5 wt. % (Tauc’s plot determined Eg = 2.74 eV). With the optimized photocatalyst and in selected operating conditions, under visible light it was possible to achieve 90% AO7 discoloration together with a TOC removal of 40% after 180 min. The kinetic behavior of the photocatalyst was also analyzed. Moreover, the tests in the presence of three different scavengers revealed that the main reactive species are (positive) holes and superoxide species. Finally, the optimized photocatalyst was also able to degrade phenol under visible light. Full article
(This article belongs to the Special Issue Photocatalytic Properties and Kinetics of Materials)
Show Figures

Figure 1

14 pages, 3090 KiB  
Article
Graphitic Carbon Nitride for Photocatalytic Air Treatment
by Michal Baudys, Šárka Paušová, Petr Praus, Vlasta Brezová, Dana Dvoranová, Zuzana Barbieriková and Josef Krýsa
Materials 2020, 13(13), 3038; https://doi.org/10.3390/ma13133038 - 07 Jul 2020
Cited by 14 | Viewed by 2607
Abstract
Graphitic carbon nitride (g-C3N4) is a conjugated polymer, which recently drew a lot of attention as a metal-free and UV and visible light responsive photocatalyst in the field of solar energy conversion and environmental remediation. This is due to [...] Read more.
Graphitic carbon nitride (g-C3N4) is a conjugated polymer, which recently drew a lot of attention as a metal-free and UV and visible light responsive photocatalyst in the field of solar energy conversion and environmental remediation. This is due to its appealing electronic band structure, high physicochemical stability and earth-abundant nature. In the present work, bulk g-C3N4 was synthesized by thermal decomposition of melamine. This material was further exfoliated by thermal treatment. S-doped samples were prepared from thiourea or further treatment of exfoliated g-C3N4 by mesylchloride. Synthesized materials were applied for photocatalytic removal of air pollutants (acetaldehyde and NOx) according to the ISO 22197 and ISO 22197-1 methodology. The efficiency of acetaldehyde removal under UV irradiation was negligible for all g-C3N4 samples. This can be explained by the fact that g-C3N4 under irradiation does not directly form hydroxyl radicals, which are the primary oxidation species in acetaldehyde oxidation. It was proved by electron paramagnetic resonance (EPR) spectroscopy that the dominant species formed on the irradiated surface of g-C3N4 was the superoxide radical. Its production was responsible for a very high NOx removal efficiency not only under UV irradiation (which was comparable with that of TiO2), but also under visible irradiation. Full article
(This article belongs to the Special Issue Photocatalytic Properties and Kinetics of Materials)
Show Figures

Figure 1

25 pages, 15754 KiB  
Article
Preparation and Characterization of Defective TiO2. The Effect of the Reaction Environment on Titanium Vacancies Formation
by Zuzanna Bielan, Szymon Dudziak, Agnieszka Sulowska, Daniel Pelczarski, Jacek Ryl and Anna Zielińska-Jurek
Materials 2020, 13(12), 2763; https://doi.org/10.3390/ma13122763 - 18 Jun 2020
Cited by 17 | Viewed by 2553
Abstract
Among various methods of improving visible light activity of titanium(IV) oxide, the formation of defects and vacancies (both oxygen and titanium) in the crystal structure of TiO2 is an easy and relatively cheap alternative to improve the photocatalytic activity. In the presented [...] Read more.
Among various methods of improving visible light activity of titanium(IV) oxide, the formation of defects and vacancies (both oxygen and titanium) in the crystal structure of TiO2 is an easy and relatively cheap alternative to improve the photocatalytic activity. In the presented work, visible light active defective TiO2 was obtained by the hydrothermal reaction in the presence of three different oxidizing agents: HIO3, H2O2, and HNO3. Further study on the effect of used oxidant and calcination temperature on the physicochemical and photocatalytic properties of defective TiO2 was performed. Obtained nanostructures were characterized by X-ray diffractometry (XRD), specific surface area (BET) measurements, UV-Vis diffuse reflectance spectroscopy (DR-UV/Vis), photoluminescence spectroscopy (PL), X-ray photoelectron spectroscopy (XPS), and electron paramagnetic resonance (EPR) spectroscopy. Degradation of phenol as a model pollutant was measured in the range of UV-Vis and Vis irradiation, demonstrating a significant increase of photocatalytic activity of defective TiO2 samples above 420 nm, comparing to non-defected TiO2. Correlation of EPR, UV-Vis, PL, and photodegradation results revealed that the optimum concentration of HIO3 to achieve high photocatalytic activity was in the range of 20–50 mol%. Above that dosage, titanium vacancies amount is too high, and the obtained materials’ photoactivity was significantly decreased. Studies on the photocatalytic mechanism using defective TiO2 have also shown that O2 radical is mainly responsible for pollutant degradation. Full article
(This article belongs to the Special Issue Photocatalytic Properties and Kinetics of Materials)
Show Figures

Graphical abstract

Back to TopTop