TiO2-Based Nanostructures and Photocatalysts

A special issue of Catalysts (ISSN 2073-4344). This special issue belongs to the section "Photocatalysis".

Deadline for manuscript submissions: closed (31 December 2020) | Viewed by 7741

Special Issue Editor

Institute of Sciences and Technologies for Sustainable Energy and Mobility-CNR, P.le V. Tecchio 80, 80125 Naples, Italy
Interests: photocatalytic materials; carbon-based hybrid nanostructures; metal–organic frameworks; end-of-life materials valorization; graphene-related materials
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

TiO2 is one of the most studied semiconductor photoactive materials for a wide array of applications, ranging from heterogeneous photocatalysis, gas sensing to biological applications. Not surprisingly, this research topic is continually fostered by efforts to tune TiO2 for specific applications.

A wide array of approaches have been proposed and developed for enhancing the TiO2 photocatalytic activity, including TiO2 morphology tuning at a nanoscale level, improving its intrinsic charge mobility, and hindering or decreasing the electron–hole recombination via charge separation through a hetero-interface (combining TiO2 with graphene-related materials, small molecules, or metal oxides).

This Special Issue will be focused on the recent advances in the development of TiO2-based materials, covering both innovative synthesis and specific applications. Contributions elucidating peculiar electron transport mechanisms are also invited for submission. Submissions framed, especially in these following areas, are welcome:

  • TiO2 nanostructures: synthesis, doping, and modelling
  • Hybrid TiO2/two-dimensional materials (transition metal dichalcogenides and graphene-related materials): synthesis, characterizations, and photocatalytic applications
  • Application of TiO2-based materials and composites for photocatalysis, water remediation, gas sensing, fine chemical production, self-cleaning surfaces, antibacterial activity, and biomedical applications.

Dr. Michela Alfè
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. Catalysts is an international peer-reviewed open access monthly 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 2700 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

  • titanium dioxide
  • photocatalysis
  • multifunctional TiO2-based oxides
  • TiO2 doping
  • environmental remediation
  • gas sensing
  • TiO2 hybrids and composites
  • TiO2-based 2D materials

Published Papers (3 papers)

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

Research

18 pages, 6412 KiB  
Article
Mesoporous TiO2 from Metal-Organic Frameworks for Photoluminescence-Based Optical Sensing of Oxygen
Catalysts 2021, 11(7), 795; https://doi.org/10.3390/catal11070795 - 29 Jun 2021
Cited by 12 | Viewed by 2039
Abstract
Metal−organic frameworks (MOFs) are a class of porous coordination networks extraordinarily varied in physicochemical characteristics such as porosity, morphologies, and compositions. These peculiarities make MOFs widely exploited in a large array of applications, such as catalysis, chemicals and gas sensing, drug delivery, energy [...] Read more.
Metal−organic frameworks (MOFs) are a class of porous coordination networks extraordinarily varied in physicochemical characteristics such as porosity, morphologies, and compositions. These peculiarities make MOFs widely exploited in a large array of applications, such as catalysis, chemicals and gas sensing, drug delivery, energy storage, and energy conversion. MOFs can also serve as nanostructured precursors of metal oxides with peculiar characteristics and controlled shapes. In this work, starting from MIL125-(Ti), a 1,4-benzenedicarboxylate (BDC)-based MOF with Ti as metallic center, mesoporous TiO2 powders containing both anatase and rutile crystalline phases were produced. A challenging utilization of these porous MOF-derived Ti-based oxides is the optically-based quantitative detection of molecular oxygen (O2) in gaseous and/or aqueous media. In this study, the photoluminescence (PL) intensity changes during O2 exposure of two MOF-derived mixed-phase TiO2 powders were probed by exploiting the opposite response of rutile and anatase in VIS-PL and NIR-PL wavelength intervals. This result highlights promising future possibilities for the realization of MOF-derived doubly-parametric TiO2-based optical sensors. Full article
(This article belongs to the Special Issue TiO2-Based Nanostructures and Photocatalysts)
Show Figures

Figure 1

15 pages, 8145 KiB  
Article
Strong Activity Enhancement of the Photocatalytic Degradation of an Azo Dye on Au/TiO2 Doped with FeOx
Catalysts 2020, 10(8), 933; https://doi.org/10.3390/catal10080933 - 13 Aug 2020
Cited by 15 | Viewed by 2883
Abstract
The doping of Au/TiO2 with FeOx is shown to result in a strong enhancement of its photocatalytic activity in the degradation of the azo dye Orange II. In order to examine the source of this enhancement, Au-FeOx/TiO2 nanocomposites [...] Read more.
The doping of Au/TiO2 with FeOx is shown to result in a strong enhancement of its photocatalytic activity in the degradation of the azo dye Orange II. In order to examine the source of this enhancement, Au-FeOx/TiO2 nanocomposites containing different molar ratios of Au:Fe were synthesized, and X-ray diffraction (XRD), X-ray photoemission spectroscopy (XPS), and high-resolution transmission electron microscope (HRTEM) analyses indicated that the TiO2-supported Au nanoparticles were partially covered with an amorphous layer of FeOx species, in which the iron was present as Fe2+ and Fe3+. The metal-semiconductor system, i.e., Au/TiO2, showed only a moderate degradation rate, whereas doping with FeOx strongly enhanced the degradation activity. The bandgap energy decreased gradually from Au/TiO2 (3.13 eV) to the catalyst with the highest FeOx loading Au-FeOx (1:2)/TiO2 (2.23 eV), and this decrease was accompanied by a steady increase in the degradation activity of the catalysts. XPS analyses revealed that compared to Au/TiO2, on Au-FeOx/TiO2 a much higher population density of chemisorbed and/or dissociated oxygen species was generated, which together with the decreased bandgap resulted in the highest photocatalytic activity observed with Au-FeOx (1:2)/TiO2. The processes occurring during reaction on the catalyst surface and in the bulk liquid phase were investigated using operando attenuated total reflection IR spectroscopy (ATR-IR) combined with modulation excitation spectroscopy (MES), which showed that the doping of Au/TiO2 with FeOx weakens the interaction of the dye with the catalyst surface and strongly enhances the cleavage of the azo bond. Full article
(This article belongs to the Special Issue TiO2-Based Nanostructures and Photocatalysts)
Show Figures

Graphical abstract

13 pages, 4186 KiB  
Article
Correlation of the Photocatalytic Activities of Cu, Ce and/or Pt-Modified Titania Particles with their Bulk and Surface Structures Studied by Reversed Double-Beam Photoacoustic Spectroscopy
Catalysts 2019, 9(12), 1010; https://doi.org/10.3390/catal9121010 - 01 Dec 2019
Cited by 7 | Viewed by 2097
Abstract
Modified titania photocatalyst powder samples were prepared using the sol-gel method for copper (Cu) and cerium (Ce) doping and impregnation for platinum (Pt) loading. Their bulk crystalline structures were investigated using X-ray diffractometry (XRD) with the Rietveld analysis. The surface/bulk structure, surface properties, [...] Read more.
Modified titania photocatalyst powder samples were prepared using the sol-gel method for copper (Cu) and cerium (Ce) doping and impregnation for platinum (Pt) loading. Their bulk crystalline structures were investigated using X-ray diffractometry (XRD) with the Rietveld analysis. The surface/bulk structure, surface properties, and morphologies were observed using reversed double-beam photoacoustic spectroscopy (RDB-PAS), nitrogen adsorption, and scanning electron microscopy, respectively. The results from the XRD revealed that all samples were mainly anatase (ca. 80% or higher) with small amounts of rutile and non-crystalline components. The specific surface areas of all samples were in the range of 115–155 m2 g−1. Ce and Cu species were mainly distributed, while Pt was potentially loaded as a partially oxidized form on the titania surface. The results from the RDB-PAS indicated the changing of the energy-resolved distribution of electron traps (ERDT) from the original titania surface upon doping of the metals (Cu, Ce, and Pt), which altered their catalytic activities. The metals photocatalytic activities with UV irradiation were measured in two representative reactions; (a) CO2 evolution from acetic acid under the aerobic condition and (b) H2 evolution from deaerated aqueous methanol. In reaction (a), the Cu and/or Ce modification gave almost the same or slightly lower activity compared to the non-modified titania samples, while platinum loading yielded ca. 5–6 times higher activity. For reaction (b), the photocatalytic tests were divided into two sets; without (b1) and with (b2) Pt deposition during the reaction. Similar enhancements of activity from the Pt loading sample (and by Cu modification) were observed in reaction (b1) without in-situ platinum deposition, while the unmodified and Ce-doped samples were almost inactive. For the activities of reaction (b2) with in-situ platinum deposition, the unmodified samples showed the highest activity while the Cu-modified samples showed significantly lower activity. Full article
(This article belongs to the Special Issue TiO2-Based Nanostructures and Photocatalysts)
Show Figures

Figure 1

Back to TopTop