Special Issue "Photoactive Nanomaterials"

A special issue of Nanomaterials (ISSN 2079-4991). This special issue belongs to the section "Synthesis, Interfaces and Nanostructures".

Deadline for manuscript submissions: closed (1 January 2021).

Printed Edition Available!
A printed edition of this Special Issue is available here.

Special Issue Editor

Dr. Nurxat Nuraje
E-Mail Website
Guest Editor
1. Department of Chemical Engineering, Texas Tech University, 2500 Broadway, Lubbock, TX 79409, USA
2. Department of Chemical and Materials Engineering, School of engineering and Digital Science, Nazarbayev University, 53 Kabanbay Batyr Ave, Nursultan, Kazakhstan
Interests: nanomaterials; photocatalyst; solar energy conversion; zwitterionic polymers

Special Issue Information

Dear Colleagues,

The aim of this Special Issue is to deliver recent research progress in the field of photoactive nanomaterials to the scientific community. This Special Issue focuses on photoactive nanomaterials from fundamental research to their applications. Included are the fundamental study of photoactive nanomaterials in solar energy conversion starting with light harnessing, charge separation/recombination, and catalytic reaction kinetics, as well as their various applications including energy, environmental, and catalytic. Applications in the energy field include photovoltaic use, as well as fuel generation from watersplitting, biomass, carbon dioxide, nitrogen conversion, etc. Environmental applications include photo degradation of organic and inorganic pollutants. Some examples of catalytic applications include photocatalytic conversion of biomass-derived platform molecules, carbon dioxide, and nitrogen. The application of the photoactive nanomaterials is not limited to the above three fields. The fundamental study of photoactive nanomaterials can experimental and theoretical investigations of solar energy conversion, including photovoltaic and photocatalytic mechanisms using different simulation software from material design to reaction kinetics. The scope of this Special Issue can have photoactive nanomaterial synthesis, a basic study of the solar energy conversion process with simulations, and applications including environmental, catalytic, photovoltaic, and solar fuel generation. Other research areas of photoactive nanomaterials are also welcomed. Manuscripts can be review, research and communications.

Dr. Nurxat Nuraje
Guest Editor

Manuscript Submission Information

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Keywords

  • photocatalyst
  • photoelectrochemical cell
  • charge separation
  • light harnessing
  • cocatalyst
  • solar to hydrogen efficiency
  • hydrogen generation

Published Papers (10 papers)

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Editorial

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Editorial
Photoactive Nanomaterials
Nanomaterials 2021, 11(1), 77; https://doi.org/10.3390/nano11010077 - 01 Jan 2021
Viewed by 588
Abstract
With the depletion of carbon-based energy resources and the consideration of global warming, renewable energy is considered a promising energy source for future energy [...] Full article
(This article belongs to the Special Issue Photoactive Nanomaterials)

Research

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Article
Protonation-Induced Enhanced Optical-Light Photochromic Properties of an Inorganic-Organic Phosphomolybdic Acid/Polyaniline Hybrid Thin Film
Nanomaterials 2020, 10(9), 1839; https://doi.org/10.3390/nano10091839 - 15 Sep 2020
Cited by 2 | Viewed by 721
Abstract
A phosphomolybdic acid/polyaniline (PMoA/PANI) optical-light photochromic inorganic/organic hybrid thin film was successfully synthesized by protonation between the the multiprotonic acid phosphomolybdic acid (H3PO4·12MoO3) and the conductive polymer polyaniline. The stable Keggin-type structure of PMoA was maintained throughout [...] Read more.
A phosphomolybdic acid/polyaniline (PMoA/PANI) optical-light photochromic inorganic/organic hybrid thin film was successfully synthesized by protonation between the the multiprotonic acid phosphomolybdic acid (H3PO4·12MoO3) and the conductive polymer polyaniline. The stable Keggin-type structure of PMoA was maintained throughout the process. Protonation and proton transfer successfully transformed the quinone structure of eigenstate PANI into the benzene structure of single-polarized PANI in the PMoA/PANI hybridized thin film, and proton transfer transformed the benzene structure of single-polarized PANI back to the quinone structure of eigenstate PANI in the PMoA/PANI hybrid thin film, as verified by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The average distribution of PMoA/PANI was observed by atom force microscopy (AFM). Interestingly, protonation of PMoA caused PANI to trigger transformation of the quinone structure into the single-polarized benzene structure, which enhanced the electron delocalization ability and vastly enhanced the maximum light absorption of the PMoA/PANI hybrid thin film as confirmed by density functional theory (DFT), electrochemistry, and ultraviolet-visible spectroscopy (UV-Vis) studies. Under optical-light illumination, the pale-yellow PMoA/PANI hybrid thin film gradually turned deep blue, thus demonstrating a photochromic response, and reversible photochromism was also observed in the presence of hydrogen peroxide (H2O2) or oxygen (O2). After 40 min of optical-light illumination, 36% of the Mo5+ species in PMoA was photoreduced via a protonation-induced proton transfer mechanism, and this proton transfer resulted in a structural change of PANI, as observed by XPS, generating a dominant structure with high maximum light absorption of 3.46, when compared with the literature reports. Full article
(This article belongs to the Special Issue Photoactive Nanomaterials)
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Article
Influence of Metal Oxide Particles on Bandgap of 1D Photocatalysts Based on SrTiO3/PAN Fibers
Nanomaterials 2020, 10(9), 1734; https://doi.org/10.3390/nano10091734 - 01 Sep 2020
Cited by 3 | Viewed by 935
Abstract
This paper deals with the study of the optical properties of one-dimensional SrTiO3/PAN-based photocatalysts with the addition of metal oxide particles and the determination of their bandgaps. One-dimensional photocatalysts were obtained by the electrospinning method. Particles of metals such as iron, [...] Read more.
This paper deals with the study of the optical properties of one-dimensional SrTiO3/PAN-based photocatalysts with the addition of metal oxide particles and the determination of their bandgaps. One-dimensional photocatalysts were obtained by the electrospinning method. Particles of metals such as iron, chromium, and copper were used as additives that are capable of improving the fibers’ photocatalytic properties based on SrTiO3/PAN. The optimal ratios of the solutions for the electrospinning of fibers based on SrTiO3/PAN with the addition of metal oxide particles were determined. The transmission and reflection of composite photocatalysts with metal oxide particles were measured in a wide range of spectra, from the ultraviolet region (185 nm) to near-infrared radiation (3600 nm), to determine the values of their bandgaps. Thus, the introduction of metal oxide particles resulted in a decrease in the bandgaps of the obtained composite photocatalysts compared to the initial SrTiO3/PAN (3.57 eV), with the following values: −3.11 eV for SrTiO3/PAN/Fe2O3, −2.84 eV for SrTiO3/PAN/CuO, and −2.89 eV for SrTiO3/PAN/Cr2O3. The obtained composite photocatalysts were tested for the production of hydrogen by the splitting of water–methanol mixtures under UV irradiation, and the following rates of hydrogen evolution were determined: 344.67 µmol h−1 g−1 for SrTiO3/PAN/Fe2O3, 398.93 µmol h−1 g−1 for SrTiO3/PAN/Cr2O3, and 420.82 µmol h−1 g−1 for SrTiO3/PAN/CuO. Full article
(This article belongs to the Special Issue Photoactive Nanomaterials)
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Article
2D Bi2Se3 van der Waals Epitaxy on Mica for Optoelectronics Applications
Nanomaterials 2020, 10(9), 1653; https://doi.org/10.3390/nano10091653 - 22 Aug 2020
Cited by 4 | Viewed by 1010
Abstract
Bi2Se3 possesses a two-dimensional layered rhombohedral crystal structure, where the quintuple layers (QLs) are covalently bonded within the layers but weakly held together by van der Waals forces between the adjacent QLs. It is also pointed out that Bi2 [...] Read more.
Bi2Se3 possesses a two-dimensional layered rhombohedral crystal structure, where the quintuple layers (QLs) are covalently bonded within the layers but weakly held together by van der Waals forces between the adjacent QLs. It is also pointed out that Bi2Se3 is a topological insulator, making it a promising candidate for a wide range of electronic and optoelectronic applications. In this study, we investigate the growth of high-quality Bi2Se3 thin films on mica by the molecular beam epitaxy technique. The films exhibited a layered structure and highly c-axis-preferred growth orientation with an XRD rocking curve full-width at half-maximum (FWHM) of 0.088°, clearly demonstrating excellent crystallinity for the Bi2Se3 deposited on the mica substrate. The growth mechanism was studied by using an interface model associated with the coincidence site lattice unit (CSLU) developed for van der Waals epitaxies. This high (001) texture favors electron transport in the material. Hall measurements revealed a mobility of 726 cm2/(Vs) at room temperature and up to 1469 cm2/(Vs) at 12 K. The results illustrate excellent electron mobility arising from the superior crystallinity of the films with significant implications for applications in conducting electrodes in optoelectronic devices on flexible substrates. Full article
(This article belongs to the Special Issue Photoactive Nanomaterials)
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Article
Kinetics of Hydrogen Generation from Oxidation of Hydrogenated Silicon Nanocrystals in Aqueous Solutions
Nanomaterials 2020, 10(7), 1413; https://doi.org/10.3390/nano10071413 - 20 Jul 2020
Cited by 5 | Viewed by 1155
Abstract
Hydrogen generation rate is one of the most important parameters which must be considered for the development of engineering solutions in the field of hydrogen energy applications. In this paper, the kinetics of hydrogen generation from oxidation of hydrogenated porous silicon nanopowders in [...] Read more.
Hydrogen generation rate is one of the most important parameters which must be considered for the development of engineering solutions in the field of hydrogen energy applications. In this paper, the kinetics of hydrogen generation from oxidation of hydrogenated porous silicon nanopowders in water are analyzed in detail. The splitting of the Si-H bonds of the nanopowders and water molecules during the oxidation reaction results in powerful hydrogen generation. The described technology is shown to be perfectly tunable and allows us to manage the kinetics by: (i) varying size distribution and porosity of silicon nanoparticles; (ii) chemical composition of oxidizing solutions; (iii) ambient temperature. In particular, hydrogen release below 0 °C is one of the significant advantages of such a technological way of performing hydrogen generation. Full article
(This article belongs to the Special Issue Photoactive Nanomaterials)
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Article
White Light Emission by Simultaneous One Pot Encapsulation of Dyes into One-Dimensional Channelled Aluminophosphate
Nanomaterials 2020, 10(6), 1173; https://doi.org/10.3390/nano10061173 - 16 Jun 2020
Cited by 1 | Viewed by 930
Abstract
By simultaneous occlusion of rationally chosen dyes, emitting in the blue, green and red region of the electromagnetic spectrum, into the one-dimensional channels of a magnesium-aluminophosphate with AEL-zeolitic type structure, MgAPO-11, a solid-state system with efficient white light emission under UV excitation, was [...] Read more.
By simultaneous occlusion of rationally chosen dyes, emitting in the blue, green and red region of the electromagnetic spectrum, into the one-dimensional channels of a magnesium-aluminophosphate with AEL-zeolitic type structure, MgAPO-11, a solid-state system with efficient white light emission under UV excitation, was achieved. The dyes herein selected—acridine (AC), pyronin Y (PY), and hemicyanine LDS722—ensure overall a good match between their molecular sizes and the MgAPO-11 channel dimensions. The occlusion was carried out via the crystallization inclusion method, in a suitable proportion of the three dyes to render efficient white fluorescence systems by means of fine-tuned FRET (fluorescence resonance energy transfer) energy transfer processes. The FRET processes are thoroughly examined by the analysis of fluorescence decay traces using the femtosecond fluorescence up-conversion technique. Full article
(This article belongs to the Special Issue Photoactive Nanomaterials)
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Article
PMMA Thin Film with Embedded Carbon Quantum Dots for Post-Fabrication Improvement of Light Harvesting in Perovskite Solar Cells
Nanomaterials 2020, 10(2), 291; https://doi.org/10.3390/nano10020291 - 09 Feb 2020
Cited by 16 | Viewed by 2053
Abstract
Perovskite solar cells (PSCs) with a standard sandwich structure suffer from optical transmission losses due to the substrate and its active layers. Developing strategies for compensating for the losses in light harvesting is of significant importance to achieving a further enhancement in device [...] Read more.
Perovskite solar cells (PSCs) with a standard sandwich structure suffer from optical transmission losses due to the substrate and its active layers. Developing strategies for compensating for the losses in light harvesting is of significant importance to achieving a further enhancement in device efficiencies. In this work, the down-conversion effect of carbon quantum dots (CQDs) was employed to convert the UV fraction of the incident light into visible light. For this, thin films of poly(methyl methacrylate) with embedded carbon quantum dots ([email protected]) were deposited on the illumination side of PSCs. Analysis of the device performances before and after application of [email protected] photoactive functional film on PSCs revealed that the devices with the coating showed an improved photocurrent and fill factor, resulting in higher device efficiency. Full article
(This article belongs to the Special Issue Photoactive Nanomaterials)
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Review

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Review
Photoactive Tungsten-Oxide Nanomaterials for Water-Splitting
Nanomaterials 2020, 10(9), 1871; https://doi.org/10.3390/nano10091871 - 18 Sep 2020
Cited by 9 | Viewed by 1226
Abstract
This review focuses on tungsten oxide (WO3) and its nanocomposites as photoactive nanomaterials for photoelectrochemical cell (PEC) applications since it possesses exceptional properties such as photostability, high electron mobility (~12 cm2 V−1 s−1) and a long hole-diffusion [...] Read more.
This review focuses on tungsten oxide (WO3) and its nanocomposites as photoactive nanomaterials for photoelectrochemical cell (PEC) applications since it possesses exceptional properties such as photostability, high electron mobility (~12 cm2 V−1 s−1) and a long hole-diffusion length (~150 nm). Although WO3 has demonstrated oxygen-evolution capability in PEC, further increase of its PEC efficiency is limited by high recombination rate of photogenerated electron/hole carriers and slow charge transfer at the liquid–solid interface. To further increase the PEC efficiency of the WO3 photocatalyst, designing WO3 nanocomposites via surface–interface engineering and doping would be a great strategy to enhance the PEC performance via improving charge separation. This review starts with the basic principle of water-splitting and physical chemistry properties of WO3, that extends to various strategies to produce binary/ternary nanocomposites for PEC, particulate photocatalysts, Z-schemes and tandem-cell applications. The effect of PEC crystalline structure and nanomorphologies on efficiency are included. For both binary and ternary WO3 nanocomposite systems, the PEC performance under different conditions—including synthesis approaches, various electrolytes, morphologies and applied bias—are summarized. At the end of the review, a conclusion and outlook section concluded the WO3 photocatalyst-based system with an overview of WO3 and their nanocomposites for photocatalytic applications and provided the readers with potential research directions. Full article
(This article belongs to the Special Issue Photoactive Nanomaterials)
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Review
Recent Developments of TiO2-Based Photocatalysis in the Hydrogen Evolution and Photodegradation: A Review
Nanomaterials 2020, 10(9), 1790; https://doi.org/10.3390/nano10091790 - 09 Sep 2020
Cited by 18 | Viewed by 1687
Abstract
The growth of industrialization, which is forced to use non-renewable energy sources, leads to an increase in environmental pollution. Therefore, it is necessary not only to reduce the use of fossil fuels to meet energy needs but also to replace it with cleaner [...] Read more.
The growth of industrialization, which is forced to use non-renewable energy sources, leads to an increase in environmental pollution. Therefore, it is necessary not only to reduce the use of fossil fuels to meet energy needs but also to replace it with cleaner fuels. Production of hydrogen by splitting water is considered one of the most promising ways to use solar energy. TiO2 is an amphoteric oxide that occurs naturally in several modifications. This review summarizes recent advances of doped TiO2-based photocatalysts used in hydrogen production and the degradation of organic pollutants in water. An intense scientific and practical interest in these processes is aroused by the fact that they aim to solve global problems of energy conservation and ecology. Full article
(This article belongs to the Special Issue Photoactive Nanomaterials)
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Review
Metal/Semiconductor Nanocomposites for Photocatalysis: Fundamentals, Structures, Applications and Properties
Nanomaterials 2019, 9(3), 359; https://doi.org/10.3390/nano9030359 - 04 Mar 2019
Cited by 35 | Viewed by 2336
Abstract
Due to the capability of utilizing light energy to drive chemical reactions, photocatalysis has been widely accepted as a green technology to help us address the increasingly severe environment and energy issues facing human society. To date, a large amount of research has [...] Read more.
Due to the capability of utilizing light energy to drive chemical reactions, photocatalysis has been widely accepted as a green technology to help us address the increasingly severe environment and energy issues facing human society. To date, a large amount of research has been devoted to enhancing the properties of photocatalysts. As reported, coupling semiconductors with metals is one of the most effective methods to achieve high-performance photocatalysts. The excellent properties of metal/semiconductor (M/S) nanocomposite photocatalysts originate in two aspects: (a) improved charge separation at the metal-semiconductor interface; and (b) increased absorption of visible light due to the surface plasmon resonance of metals. So far, many M/S nanocomposite photocatalysts with different structures have been developed for the application in environmental remediation, selective organic transformation, hydrogen evolution, and disinfection. Herein, we will give a review on the M/S nanocomposite photocatalysts, regarding their fundamentals, structures (as well as their typical synthetic approaches), applications and properties. Finally, we will also present our perspective on the future development of M/S nanocomposite photocatalysts. Full article
(This article belongs to the Special Issue Photoactive Nanomaterials)
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