Special Issue "Sustainable and Safe Nano-Enabled Water Treatment Applications"

A special issue of Nanomaterials (ISSN 2079-4991).

Deadline for manuscript submissions: closed (1 June 2019).

Special Issue Editors

Prof. Navid B. Saleh
Website
Guest Editor
Department of Civil, Architectural and Environmental Engineering, University of Texas at Austin, Austin, TX, USA
Interests: Professor Saleh’s laboratory focuses on design and development of novel and human-centered water treatment technologies. The primary goal is to enhance economically challenged communities' access to potable water via innovative nanomaterial-enabled treatment processes. By integrating state-of-the-art experimentation and modeling under a 'safer by design' umbrella, his lab aims to lead in appropriate technology innovation that is safe and sustainable. This design approach extracts favorable electronic and chemical properties at the nano-scale, while tests for environmental and health safety through fate, transport, and toxicity analyses. Material choice and technology design are human-centered and are guided by 'sustainability principles', i.e., minimization of energy, resources, and cost. Using similar approaches, nano-enabled structural material development is pursued, which complements his lab's mission of access to sustainable civil infrastructure.
Prof. Onur G. Apul
Website
Guest Editor
Department of Civil and Environmental Engineering, University of Massachusetts Lowell, Lowell, MA, USA
Interests: The central theme of Professor Apul’s laboratory is experimental investigation of nanomaterials for water treatment applications. The specific focus of his research program is exploring molecular level interactions between pollutants and nanomaterials in aquatic environment. His lab employs a mechanistic, hypothesis driven, experimentalist approach to investigate fundamental level research questions with a vision of advancing in engineering applications. His current projects focus on overcoming application barriers (such as high cost and potential risks associated with unintended release) in front of nano-enabled water treatment technologies. Therefore, his lab investigates nanomaterials that are: (i) infinitely recyclable and (ii) immobilized in a macrostructure sustaining superior functionalities.

Special Issue Information

Dear Colleagues,

Discovery of emergent pollutants and continued presence of legacy contaminants in our water bodies necessitate the development of novel technologies that are cost- and energy-efficient, as well as are appropriate for water treatment and remediation. Nanomaterials with exceptional properties are utilized to enable treatment solutions for achieving these goals. However, ensuring safe and sustainable use of nanomaterials are key considerations in any treatment applications. This Special Issue invites papers on nano-scale materials, devices, and nano-enabled processes for water treatment in a safe and sustainable manner. We welcome perspectives, review articles, and technical papers that include, but are not limited to, nano-enabled approaches for removal of recalcitrant compounds (e.g., perfluorinated compounds, contaminants released through fracking fluids, emerging synthetic organics, etc.); nano-enhanced antimicrobial techniques to reduce risks from water-borne bacteria and viruses; sensor development for water management, detection of pathogens and toxicants, and detection of macro- and micro-nutrients; low-energy footprint technologies for water treatment; nano-enabled membranes for desalination and oil-water separation; development of nano-enabled and multifunctional materials for nutrient and energy recovery from water; and nano-enabled water treatment testbeds and pilot studies.

Prof. Navid B. Saleh
Prof. Onur G. Apul
Guest Editors

Manuscript Submission Information

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Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2000 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

  • Photo- and electro-catalysts
  • Advanced oxidation
  • Biodegradation
  • Desalination
  • Disinfection
  • Adsorption
  • Recalcitrant compounds
  • Perfluorinated compounds
  • Fracking
  • Sustainable

Published Papers (12 papers)

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Research

Open AccessArticle
New Poly(β-Cyclodextrin)/Poly(Vinyl Alcohol) Electrospun Sub-Micrometric Fibers and Their Potential Application for Wastewater Treatments
Nanomaterials 2020, 10(3), 482; https://doi.org/10.3390/nano10030482 - 07 Mar 2020
Abstract
Cyclodextrin (CD)-based polymers are known to efficiently form molecular inclusion complexes with various organic and inorganic guest compounds. In addition, they also have a great potential as metal complexes because deprotonated hydroxyls can strongly bind metal ions under alkaline conditions. The range of [...] Read more.
Cyclodextrin (CD)-based polymers are known to efficiently form molecular inclusion complexes with various organic and inorganic guest compounds. In addition, they also have a great potential as metal complexes because deprotonated hydroxyls can strongly bind metal ions under alkaline conditions. The range of environmental conditions for polycyclodextrin/metal ion complexation can be extended by the polymerization of CDs with polyacids. This article describes the preparation and characterization of a new type of poly(β-cyclodextrin) (Poly-βCD) sub-micrometric fibers and explores their potential as metal ion sorbents. A water-soluble hyper-branched β-cyclodextrin polymer was blended with poly(vinyl alcohol) (PVA) and here used to improve the mechanical and morphological features of the fibers. Solutions with a different Poly-βCD/PVA ratio were electrospun, and the fibers were cross-linked by a post-spinning thermal treatment at 160 °C to ensure non-solubility in water. The fiber morphology was analyzed by scanning electron microscopy (SEM) before and after the curing process, and physical-chemical properties were studied by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The capability of the insoluble cyclodextrin-based fibers to remove heavy metals from wastewaters was investigated by testing the adsorption of Cu2+ and Cd2+ using inductively coupled plasma-optical emission spectroscopy (ICP-OES). The results suggest that the poly(β-cyclodextrin)/poly(vinyl alcohol) sub-micrometric fibers can complex metal ions and are especially effective Cu2+ sorbents, thus opening new perspectives to the development of fibers and membranes capable of removing both metal ions and organic pollutants. Full article
(This article belongs to the Special Issue Sustainable and Safe Nano-Enabled Water Treatment Applications)
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Open AccessArticle
Carbamazepine Degradation Mediated by Light in the Presence of Humic Substances-Coated Magnetite Nanoparticles
Nanomaterials 2019, 9(10), 1379; https://doi.org/10.3390/nano9101379 - 26 Sep 2019
Cited by 3
Abstract
The use of iron-based nanomaterials for environmental remediation processes has recently received considerable attention. Here, we employed core-shell magnetite-humic acids nanoparticles as a heterogeneous photosensitizer and iron source in photo-Fenton reaction for the degradation of the psychiatric drug carbamazepine (CBZ). CBZ showed low [...] Read more.
The use of iron-based nanomaterials for environmental remediation processes has recently received considerable attention. Here, we employed core-shell magnetite-humic acids nanoparticles as a heterogeneous photosensitizer and iron source in photo-Fenton reaction for the degradation of the psychiatric drug carbamazepine (CBZ). CBZ showed low photodegradation rates in the presence of the magnetic nanoparticles, whereas the addition of hydrogen peroxide at pH = 3 to the system drastically increased the abatement of the contaminant. The measured Fe2+ and Fe3+ profiles point to the generation of Fe3+ at the surface of the nanoparticles, indicating a heterogeneous oxidation of the contaminant mediated by hydroxyl radicals. Products with a higher transformation degree were observed in the photo-Fenton procedure and support the attack of the HO radical on the CBZ molecule. Promising results encourage the use of the nanoparticles as efficient iron sources with enhanced magnet-sensitive properties, suitable for applications in photo-Fenton treatments for the purification of wastewater. Full article
(This article belongs to the Special Issue Sustainable and Safe Nano-Enabled Water Treatment Applications)
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Open AccessArticle
Fabrication and Surface Interactions of Super-Hydrophobic Silicon Carbide for Membrane Distillation
Nanomaterials 2019, 9(8), 1159; https://doi.org/10.3390/nano9081159 - 13 Aug 2019
Cited by 1
Abstract
Hydrophilic silicon carbide was modified by surface deposition of a super-hydrophobic coating that is based on perfluorosilanes. The modification was proven to yield membrane surfaces with contact angles that were higher than 145° and to be stable under hydrothermal conditions. The measurement of [...] Read more.
Hydrophilic silicon carbide was modified by surface deposition of a super-hydrophobic coating that is based on perfluorosilanes. The modification was proven to yield membrane surfaces with contact angles that were higher than 145° and to be stable under hydrothermal conditions. The measurement of the isosteric heat of adsorption of water and toluene by microgravimetry showed that, after modification, the membrane material was fully covered by a low-energy surface, which is consistent with the fluorocarbon moieties that were introduced by the modification. The same modification method was applied to a commercial multichannel SiC membrane tube (nominal pore size = 0.04 µm), which was tested in a direct contact membrane distillation apparatus. The membrane was permeable to water vapour and volatiles, but it showed full rejection for salt ions and organic pollutants with low vapour pressure (such as ibuprofen and caffeine). Moreover, the membrane was reusable, and its performances were stable with no sign of pore wetting over 8 h of filtration. Full article
(This article belongs to the Special Issue Sustainable and Safe Nano-Enabled Water Treatment Applications)
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Open AccessArticle
Photo-Fenton Degradation of Pentachlorophenol: Competition between Additives and Photolysis
Nanomaterials 2019, 9(8), 1157; https://doi.org/10.3390/nano9081157 - 13 Aug 2019
Cited by 1
Abstract
In the present work, the photo-Fenton degradation of pentachlorophenol (PCP, 1 mg/L) has been studied under simulated and natural solar irradiation; moreover, the effect on the process efficiency of urban waste-derived soluble bio-based substances (SBO), structurally comparable to humic acids, has been investigated. [...] Read more.
In the present work, the photo-Fenton degradation of pentachlorophenol (PCP, 1 mg/L) has been studied under simulated and natural solar irradiation; moreover, the effect on the process efficiency of urban waste-derived soluble bio-based substances (SBO), structurally comparable to humic acids, has been investigated. Experiments showed a crucial role of PCP photolysis, present in the solar pilot plant and hindered by the Pyrex® filter present in the solar simulator. Indeed, the SBO screen negatively affects PCP degradation when working under natural solar light, where the photolysis of PCP is relevant. In contrast, in the absence of PCP photolysis, a significant improvement of the photo-Fenton process was observed when added to SBO. Furthermore, SBO were able to extend the application of the photo-Fenton process at circumneutral pH values, due to their ability to complex iron, avoiding its precipitation as oxides or hydroxides. This positive effect has been observed at higher concentration of Fe(II) (4 mg/L), whereas at 1 mg/L, the degradation rates of PCP were comparable in the presence and absence of SBO. Full article
(This article belongs to the Special Issue Sustainable and Safe Nano-Enabled Water Treatment Applications)
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Open AccessArticle
Sustainable Magnetic Materials (from Chitosan and Municipal Biowaste) for the Removal of Diclofenac from Water
Nanomaterials 2019, 9(8), 1091; https://doi.org/10.3390/nano9081091 - 30 Jul 2019
Cited by 5
Abstract
The photodegradation of an aqueous solution of diclofenac (DCF) has been attempted in the presence of hydrogen peroxide and organic/inorganic hybrid magnetic materials under simulated and real solar light. The hybrid magnetic materials have been prepared via coprecipitation synthesis starting from iron(II) and [...] Read more.
The photodegradation of an aqueous solution of diclofenac (DCF) has been attempted in the presence of hydrogen peroxide and organic/inorganic hybrid magnetic materials under simulated and real solar light. The hybrid magnetic materials have been prepared via coprecipitation synthesis starting from iron(II) and iron(III) inorganic salts in the presence of bioderived organic products (i.e., chitosan or bio-based substances isolated from commercially available composted urban biowastes) acting as stabilizers of the iron-containing phase. In addition to the as prepared hybrid materials, the corresponding materials obtained after a pyrolytic step at low temperature (550 °C) have been tested. The obtained results evidenced the capability of the materials to activate hydrogen peroxide at mild pH promoting DCF (photo) degradation. All the materials feature also as adsorbents since a decrease of DCF is observed also when working in the dark and in the absence of hydrogen peroxide. Full article
(This article belongs to the Special Issue Sustainable and Safe Nano-Enabled Water Treatment Applications)
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Open AccessArticle
Phenol Abatement by Titanium Dioxide Photocatalysts: Effect of The Graphene Oxide Loading
Nanomaterials 2019, 9(7), 947; https://doi.org/10.3390/nano9070947 - 29 Jun 2019
Cited by 1
Abstract
Hetero-photocatalytic graphene-TiO2 materials have, in the literature, been found to possess better photocatalytic activity for environmental applications compared to pure TiO2. These types of materials can be prepared in different ways; however, their photocatalytic performance and quality are not easily [...] Read more.
Hetero-photocatalytic graphene-TiO2 materials have, in the literature, been found to possess better photocatalytic activity for environmental applications compared to pure TiO2. These types of materials can be prepared in different ways; however, their photocatalytic performance and quality are not easily controlled and reproduced. Therefore, we synthetized graphene oxide-TiO2 nanoparticles by sol-gel reaction from TiCl4, as precursor, with two different methods of synthesis and with a graphene oxide (GO) loading ranging from 0 to 1.0. This approach led to a good adhesion of GO to TiO2 through the Ti-O-C bonding, which could enhance the photocatalytic performances of the materials. Overall, 0.05 wt % GO loading gave the highest rate in the photodegradation of phenol under visible light, while higher GO loadings had a negative impact on the photocatalytic performances of the composites. The 0.05 wt % GO-TiO2 composite material was confirmed to be a promising photocatalyst for water pollutant abatement. The designed synthetic approach could easily be implemented in large-scale production of the GO-TiO2 coupling materials. Full article
(This article belongs to the Special Issue Sustainable and Safe Nano-Enabled Water Treatment Applications)
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Open AccessArticle
An Easy Synthesis for Preparing Bio-Based Hybrid Adsorbent Useful for Fast Adsorption of Polar Pollutants
Nanomaterials 2019, 9(5), 731; https://doi.org/10.3390/nano9050731 - 11 May 2019
Cited by 7
Abstract
For the first time, γ-Al2O3 and Bio-Based Substances (BBS) hybrids (A-BBS) were prepared through a simple electrostatic interaction occurring between alumina, used as a support, and BBS (Bio-Based Substance from composted biowastes) carrying positive and negative charges, respectively. [...] Read more.
For the first time, γ-Al2O3 and Bio-Based Substances (BBS) hybrids (A-BBS) were prepared through a simple electrostatic interaction occurring between alumina, used as a support, and BBS (Bio-Based Substance from composted biowastes) carrying positive and negative charges, respectively. We evaluated the optimal amount of BBS to be immobilized on the support and the stability of the resulting A-BBS in order to use this novel hybrid material as an adsorbent for the removal of polar pollutants. Characterization was carried out by X-Ray Diffraction (XRD) for evaluating the crystal structure of the support, Fourier transform infrared spectroscopy (FT-IR) to evidence the presence of BBS on the hybrid material, thermogravimetric analysis (TGA) to measure the thermal stability of the hybrid materials and quantify the BBS amount immobilized on the support, N2 adsorption at 77 K for the evaluation of the surface area and porosity of the systems, Zeta potential measurements to evaluate the effect of BBS immobilization on the surface charge of the particles and choose the substrates possibly interacting with them. Firstly, we tested the adsorption capability of three samples differently coated with BBS toward cationic species considering various adsorbate/adsorbent ratio. Crystal Violet (CV) was chosen as model pollutant to compare the performance of the hybrid materials with those of other materials described in the literature. The adsorption data were modeled by Langmuir and Freundlich adsorption isotherms. Then, we studied the adsorption capability of the developed material towards molecules with different structures; for this purpose, two contaminants of emerging concerns (carbamazepine and atenolol) were tested. The results indicate that A-BBS could be applied in wastewater treatment for the removal of a significant amount of polar species. In addition, a comparison with literature data concerning CV adsorption was carried out in order to evaluate the environmental impact of synthetic routes used to prepare different adsorbents. Full article
(This article belongs to the Special Issue Sustainable and Safe Nano-Enabled Water Treatment Applications)
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Open AccessArticle
Yttrium Residues in MWCNT Enable Assessment of MWCNT Removal during Wastewater Treatment
Nanomaterials 2019, 9(5), 670; https://doi.org/10.3390/nano9050670 - 01 May 2019
Cited by 1
Abstract
Many analytical techniques have limited sensitivity to quantify multi-walled carbon nanotubes (MWCNTs) at environmentally relevant exposure concentrations in wastewaters. We found that trace metals (e.g., Y, Co, Fe) used in MWCNT synthesis correlated with MWCNT concentrations. Because of low background yttrium (Y) concentrations [...] Read more.
Many analytical techniques have limited sensitivity to quantify multi-walled carbon nanotubes (MWCNTs) at environmentally relevant exposure concentrations in wastewaters. We found that trace metals (e.g., Y, Co, Fe) used in MWCNT synthesis correlated with MWCNT concentrations. Because of low background yttrium (Y) concentrations in wastewater, Y was used to track MWCNT removal by wastewater biomass. Transmission electron microscopy (TEM) imaging and dissolution studies indicated that the residual trace metals were strongly embedded within the MWCNTs. For our specific MWCNT, Y concentration in MWCNTs was 76 µg g−1, and single particle mode inductively coupled plasma mass spectrometry (spICP-MS) was shown viable to detect Y-associated MWCNTs. The detection limit of the specific MWCNTs was 0.82 µg L−1 using Y as a surrogate, compared with >100 µg L−1 for other techniques applied for MWCNT quantification in wastewater biomass. MWCNT removal at wastewater treatment plants (WWTPs) was assessed by dosing MWCNTs (100 µg L−1) in water containing a range of biomass concentrations obtained from wastewater return activated sludge (RAS) collected from a local WWTP. Using high volume to surface area reactors (to limit artifacts of MWCNT loss due to adsorption to vessel walls) and adding 5 g L−1 of total suspended solids (TSS) of RAS (3-h mixing) reduced the MWCNT concentrations from 100 µg L−1 to 2 µg L−1. The results provide an environmentally relevant insight into the fate of MWCNTs across their end of life cycle and aid in regulatory permits that require estimates of engineered nanomaterial removal at WWTPs upon accidental release into sewers from manufacturing facilities. Full article
(This article belongs to the Special Issue Sustainable and Safe Nano-Enabled Water Treatment Applications)
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Open AccessArticle
Control of Membrane Fouling in Organics Filtration Using Ce-Doped Zirconia and Visible Light
Nanomaterials 2019, 9(4), 534; https://doi.org/10.3390/nano9040534 - 03 Apr 2019
Cited by 1
Abstract
Membrane fouling has been a major issue in the development of more efficient water treatment processes. Specifically in surface waters filtration, organic matter, such as humic-like substances, can cause irreversible fouling. Therefore, this study evaluates the activity of a photocatalytic layer composed of [...] Read more.
Membrane fouling has been a major issue in the development of more efficient water treatment processes. Specifically in surface waters filtration, organic matter, such as humic-like substances, can cause irreversible fouling. Therefore, this study evaluates the activity of a photocatalytic layer composed of Ce-doped zirconia nanoparticles in improving the fouling resistance during filtration of an aqueous solution of humic acid (HA). These nanoparticles were prepared by hydrothermal and sol–gel processes and then characterized. Before the filtration experiments, the photodegradation of HA catalyzed by Ce-doped zirconia nanoparticles in dispersion was studied. It was observed that the sol–gel prepared Ce-ZrO2 exhibited higher HA removal in practically neutral pH, achieving 93% efficiency in 180 min of adsorption in the dark followed by 180 min under visible-light irradiation using light-emitting diodes (LEDs). Changes in spectral properties and in total organic carbon confirmed HA degradation and contributed to the proposal of a mechanism for HA photodegradation. Finally, in HA filtration tests, Ce-ZrO2 photocatalytic membranes were able to recover the flux in a fouled membrane using visible-light by degrading HA. The present findings point to the further development of anti-fouling membranes, in which solar light can be used to degrade fouling compounds and possibly contaminants of emerging concern, which will have important environmental implications. Full article
(This article belongs to the Special Issue Sustainable and Safe Nano-Enabled Water Treatment Applications)
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Open AccessArticle
A Novel Nanocomposite Membrane Combining BN Nanosheets and GO for Effective Removal of Antibiotic in Water
Nanomaterials 2019, 9(3), 386; https://doi.org/10.3390/nano9030386 - 06 Mar 2019
Cited by 2
Abstract
Residual antibiotics in water have become a primary source of water pollution due to their misuse. Recently, membranes, produced by layered nanomaterials such as graphene oxide (GO), boron nitride (BN) and transition metal dichalcogenides, have been used in water purification, desalination and molecule [...] Read more.
Residual antibiotics in water have become a primary source of water pollution due to their misuse. Recently, membranes, produced by layered nanomaterials such as graphene oxide (GO), boron nitride (BN) and transition metal dichalcogenides, have been used in water purification, desalination and molecule separation as they are energy saving and simple to operate. The performance of membranes is closely related to their structure and the properties of the nanomaterials used. In this work, BN nanosheets (BNNSs) and GO were used to fabricate a two-dimensional nanocomposite membrane in order to improve the membrane’s permeance. It should be mentioned that the corresponding equal mass of the pure GO membrane was almost impermeable for the antibiotic solution. Multi-walled carbon nanotubes (MWCNTs) were inserted into the GO layers to increase the interlayer spacing and adsorb more antibiotics from the water. The resultant MWCNTs/BNNSs/GO membranes showed improved permeance and stable sieving capability for the antibiotic and small species. Specifically, permeance reached 30.2 L m−2 h−1 bar−1, which was much higher than pure GO membrane and the antibiotic rejection was 96.1%. Full article
(This article belongs to the Special Issue Sustainable and Safe Nano-Enabled Water Treatment Applications)
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Open AccessArticle
Green Waste-Derived Substances Immobilized on SBA-15 Silica: Surface Properties, Adsorbing and Photosensitizing Activities towards Organic and Inorganic Substrates
Nanomaterials 2019, 9(2), 162; https://doi.org/10.3390/nano9020162 - 29 Jan 2019
Cited by 3
Abstract
Urban wastes are a potential source of environment contamination, especially when they are not properly disposed. Nowadays, researchers are finding innovative solutions for recycling and reusing wastes in order to favour a sustainable development from the viewpoint of circular economy. In this context, [...] Read more.
Urban wastes are a potential source of environment contamination, especially when they are not properly disposed. Nowadays, researchers are finding innovative solutions for recycling and reusing wastes in order to favour a sustainable development from the viewpoint of circular economy. In this context, the lignin-like fraction of biomass derived from Green Compost is a cost-effective source of soluble Bio-Based Substances (BBS-GC), namely complex macromolecules/supramolecular aggregates characterized by adsorbing and photosensitizing properties. In this work BBS-GC were immobilized on a silica support (SBA-15) and the chemico-physical properties of the resulting hybrid material (BBS-SBA) were analysed by zeta-potential measurements, nitrogen adsorption at 77K and micro-calorimetric techniques. Successively, the BBS-SBA photosensitizing and adsorption abilities were tested. Adsorption in the dark of Rhodamine B and Orange II on BBS-SBA and their degradation upon irradiation under simulated solar light were shown, together with the formation of hydroxyl radicals detected by Electron Paramagnetic Resonance spectroscopy. Furthermore, the adsorption of six inorganic ions (Al, Ni, Mn, As, Hg, Cr) on BBS-SBA was studied in pure water at two different pH values and in a landfill leachate, showing the good potential of this kind of materials in the removal of wastewater contaminants. Full article
(This article belongs to the Special Issue Sustainable and Safe Nano-Enabled Water Treatment Applications)
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Open AccessArticle
Hierarchical Ta-Doped TiO2 Nanorod Arrays with Improved Charge Separation for Photoelectrochemical Water Oxidation under FTO Side Illumination
Nanomaterials 2018, 8(12), 983; https://doi.org/10.3390/nano8120983 - 28 Nov 2018
Cited by 3
Abstract
TiO2 is one of the most attractive semiconductors for use as a photoanode for photoelectrochemical (PEC) water oxidation. However, the large-scale application of TiO2 photoanodes is restricted due to a short hole diffusion length and low electron mobility, which can be [...] Read more.
TiO2 is one of the most attractive semiconductors for use as a photoanode for photoelectrochemical (PEC) water oxidation. However, the large-scale application of TiO2 photoanodes is restricted due to a short hole diffusion length and low electron mobility, which can be addressed by metal doping and surface decorating. In this paper we report the successful synthesis of hierarchical Ta doped TiO2 nanorod arrays, with nanoparticles on the top (Ta:TiO2), on F-doped tin oxide (FTO) glass by a hydrothermal method, and its application as photoanodes for photoelectrochemical water oxidation. It has been found that the incorporation of Ta5+ in the TiO2 lattice can decrease the diameter of surface TiO2 nanoparticles. Ta:TiO2-140, obtained with a moderate Ta concentration, yields a photocurrent of ∼1.36 mA cm−2 at 1.23 V vs. a reversible hydrogen electrode (RHE) under FTO side illumination. The large photocurrent is attributed to the large interface area of the surface TiO2 nanoparticles and the good electron conductivity due to Ta doping. Besides, the electron trap-free model illustrates that Ta:TiO2 affords higher transport speed and lower electron resistance when under FTO side illumination. Full article
(This article belongs to the Special Issue Sustainable and Safe Nano-Enabled Water Treatment Applications)
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