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Samy M, Tang S, Zhang Y, Leung DYC. Understanding the variations in degradation pathways and generated by-products of antibiotics in modified TiO 2 and ZnO photodegradation systems: A comprehensive review. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 370:122402. [PMID: 39243651 DOI: 10.1016/j.jenvman.2024.122402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2024] [Revised: 08/05/2024] [Accepted: 08/31/2024] [Indexed: 09/09/2024]
Abstract
This review examines various modification techniques, including metal doping, non-metal doping, multi doping, mixed doping, and the construction of heterojunction photocatalysts, for enhancing the performance of pure TiO2 and ZnO in the photodegradation of antibiotics. The study finds that mixed and multi doping approaches are more effective in improving photodegradation performance compared to single doping. Furthermore, the selection of suitable semiconductors for constructing heterojunction photocatalysts is crucial for achieving an efficient charge carrier separation. The environmental impacts, recent research, and real application of photocatalysis process have been discussed. The review also investigates the impact of operating parameters on the degradation pathways and the generation of by-products for different antibiotics. Additionally, the toxicity of the by-products resulting from the photodegradation of antibiotics using modified ZnO and TiO2 photocatalysts is explored, revealing that these by-products may exhibit higher toxicity than the original antibiotics. Consequently, to enable the widespread implementation of photodegradation systems, researchers should focus on optimizing degradation systems to control the conversion pathways of by-products, developing innovative photoreactors, and evaluating toxicity in real wastewater matrices.
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Affiliation(s)
- Mahmoud Samy
- Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China; Public Works Engineering Department, Faculty of Engineering, Mansoura University, Mansoura, 35516, Egypt
| | - Shaoru Tang
- Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Yingguang Zhang
- Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Dennis Y C Leung
- Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China.
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2
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Sahoo S, Mahamallik P, Das R, Panigrahi S. A critical review on non-metal doped g-C 3N 4 based photocatalyst for organic pollutant remediation with sustainability assessment by life cycle analysis. ENVIRONMENTAL RESEARCH 2024; 258:119390. [PMID: 38879105 DOI: 10.1016/j.envres.2024.119390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 05/14/2024] [Accepted: 06/07/2024] [Indexed: 06/22/2024]
Abstract
Photocatalysis is recognized to be one of the most promising ways to address energy and environmental issues by utilizing visible light. Graphitic carbon nitride (g-C3N4), with a moderate band gap (∼2.7 eV) has been the flashpoint in environmental photocatalysis as it can work better under visible light, can be synthesized by a facile synthesis process using low-cost materials, thermally and chemically stable. Still the photocatalytic performance of g-C3N4 is not satisfactory because of certain limitations such as insufficient visible light absorption capacity, low electron-hole separation efficiency, high recombination rate, poor surface area. Introduction of doping, band structure engineering, defecting and designing of heterojunction, composites etc. were investigated to amplify its applications. Among all these modifications, elemental doping is a suitable and successful alternative for the enhancement of the photocatalytic activity by changing the optical and electronic properties. This review emphasizes on advancement and trends of elemental doping and its application on photocatalytic organic pollutant remediation in aqueous medium. The fundamental photocatalytic activity of heterogeneous photocatalysis and specifically g-C3N4-based photocatalysis have been discussed. The benfits of non-metal doping, enhanced photocatalytic performance by doping element, mechanism invloved in doping, advantages of co-doping has been explained. Mono, bi, and tri non-metal doped g-C3N4 and their application for the removal of organic pollutants from water medium by visible light photocatalysis has been summerized. Life cycle assessment (LCA) of photocatalytic system has been highlighted. Future research should focus on the large-scale application of the photocatalysis process considering the economic aspects. A rigorous life cycle assessment for deploying the non-metal doped g-C3N4-based photocatalysis technology for successful commercial application is recommended.
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Affiliation(s)
- Subhalaxmi Sahoo
- Water and Wastewater Research Laboratory, Department of Civil Engineering, National Institute of Technology (NIT), Rourkela, 769008, Odisha, India
| | - Prateeksha Mahamallik
- Water and Wastewater Research Laboratory, Department of Civil Engineering, National Institute of Technology (NIT), Rourkela, 769008, Odisha, India.
| | - Rahul Das
- Department of Civil Engineering, National Institute of Technology (NIT), 799046, Agartala, India
| | - Sagarika Panigrahi
- Department of Civil Engineering, National Institute of Technology (NIT), 799046, Agartala, India
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3
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Kanmani S, Dileepan AGB. Treatment of landfill leachate using photocatalytic based advanced oxidation process - a critical review. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 345:118794. [PMID: 37619385 DOI: 10.1016/j.jenvman.2023.118794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 06/30/2023] [Accepted: 08/09/2023] [Indexed: 08/26/2023]
Abstract
Landfill leachate is a discrete volumetric component of municipal solid waste; hence, researchers and professionals are more concerned about it because of its obscurity. Innovative treatment and emerging technologies are being scrutinized to address the treatment of landfill leachate challenges. The leading target of this review was to examine the possibility of removing recalcitrant organic pollutants from landfill leachate by photocatalytic-based advanced oxidation processes. A summary of the systematic applicability of conventional treatment for landfill leachate is provided, with a focus on physico-chemical and biological processes. The biological treatment, such as aerobic and anaerobic digestion, is an excellent technique for treating highly concentrated organic pollutants in the wastewater. However, Leachate can scarcely be treated using conventional techniques since it is enriched with refractory organics and inorganic ions. It is clear from the literature review that none of the available combinations of physico-chemical and biological treatments are entirely relevant for the removal of recalcitrant organic pollutants from leachate. Recently, the photo-assisted TiO2/ZnO oxidation has shown an excessively potential and feasible way to treat landfill leachate. TiO2/ZnO photocatalysis is currently developing to treat recalcitrant organic pollutants from landfill leachate. The effect of operating parameters reveals that pH and temperature affect the reaction rate. The addition of oxidant H2O2 to the TiO2/ZnO suspension suggests that TiO2 leads to an increase in the rate of reaction when compared to ZnO. Photocatalytic remediation technique of landfill leachate would support the goal of environmental sustainability by greatly enhancing the effectiveness of treated leachate reutilization. In this review, the selection of the best photocatalytic treatment for leachate based on its systematic relevance and potential conditions, characteristics, cost-effectiveness, essential controlling, discharge limit, long-term environmental effects, and its future study perspectives are emphasized and discussed.
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Affiliation(s)
- S Kanmani
- Centre for Environmental Studies, College of Engineering Guindy, Anna University, Chennai, 600 025, Tamil Nadu, India.
| | - A G Bharathi Dileepan
- Centre for Environmental Studies, College of Engineering Guindy, Anna University, Chennai, 600 025, Tamil Nadu, India
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4
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Environmental Footprint Assessment of Methylene Blue Photodegradation using Graphene-based Titanium Dioxide. BULLETIN OF CHEMICAL REACTION ENGINEERING & CATALYSIS 2023. [DOI: 10.9767/bcrec.17450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/14/2023]
Abstract
To date, photocatalysis has received much attention in terms of the degradation of organic pollutants in wastewater. Various studies have shown that graphene-based photocatalysts are one of the impressive options owing to their intriguing features, including high surface area, good conductivity, low recombination rate of electron-hole pair, and fast charge separation and transfer. However, the environmental impacts of the photocatalysts synthesis and their photodegradation activity remain unclear. Thus, this report aims to identify the environmental impacts associated with the photodegradation of methylene blue (MB) over reduced graphene oxide/titanium oxide photocatalyst (TiO2/rGO) using Life Cycle Assessment (LCA). The life cycle impacts were assessed using ReCiPe 2016 v1.1 midpoint method, Hierachist version in Gabi software. A cradle-to-gate approach and a functional unit of 1 kg TiO2/rGOwere adopted in the study. Several important parameters, such as the solvent type (ultrapure water, ethanol, and isopropanol), with/without silver ion doping, and visible light power consumption (150, 300, and 500 W) were evaluated in this study. In terms of the selection of solvent, ultrapure water is certainly a better choice since it contributed the least negative impact on the environment. Furthermore, it is not advisable to dope the photocatalyst with silver ions since the increment in performance is insufficient to offset the environmental impact that it caused. The results of different power of visible light for MB degradation showed that the minimum power level, 150 W, could give a comparable photodegradation efficiency and better environmental impacts compared to higher power light sources. Copyright © 2023 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
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5
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Porcu S, Secci F, Ricci PC. Advances in Hybrid Composites for Photocatalytic Applications: A Review. Molecules 2022; 27:molecules27206828. [PMID: 36296421 PMCID: PMC9607189 DOI: 10.3390/molecules27206828] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 10/07/2022] [Accepted: 10/09/2022] [Indexed: 11/16/2022] Open
Abstract
Heterogeneous photocatalysts have garnered extensive attention as a sustainable way for environmental remediation and energy storage process. Water splitting, solar energy conversion, and pollutant degradation are examples of nowadays applications where semiconductor-based photocatalysts represent a potentially disruptive technology. The exploitation of solar radiation for photocatalysis could generate a strong impact by decreasing the energy demand and simultaneously mitigating the impact of anthropogenic pollutants. However, most of the actual photocatalysts work only on energy radiation in the Near-UV region (<400 nm), and the studies and development of new photocatalysts with high efficiency in the visible range of the spectrum are required. In this regard, hybrid organic/inorganic photocatalysts have emerged as highly potential materials to drastically improve visible photocatalytic efficiency. In this review, we will analyze the state-of-art and the developments of hybrid photocatalysts for energy storage and energy conversion process as well as their application in pollutant degradation and water treatments.
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Affiliation(s)
- Stefania Porcu
- Department of Physics, University of Cagliari, S.P. No. 8 Km 0.700, 09042 Monserrato, Italy
| | - Francesco Secci
- Department of Chemical and Geological Science, University of Cagliari, S.P. No. 8 Km 0.700, 09042 Monserrato, Italy
| | - Pier Carlo Ricci
- Department of Physics, University of Cagliari, S.P. No. 8 Km 0.700, 09042 Monserrato, Italy
- Correspondence: ; Tel.: +39-070675-4821
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Sendão RMS, Esteves da Silva JCG, Pinto da Silva L. Photocatalytic removal of pharmaceutical water pollutants by TiO 2 - Carbon dots nanocomposites: A review. CHEMOSPHERE 2022; 301:134731. [PMID: 35489458 DOI: 10.1016/j.chemosphere.2022.134731] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 04/06/2022] [Accepted: 04/22/2022] [Indexed: 06/14/2023]
Abstract
Pharmaceuticals are becoming increasingly more relevant water contaminants, with photocatalysts (such as TiO2) being a promising approach to remove these compounds from water. However, TiO2 has poor sunlight-harvesting capacity, low photonic efficiency, and poor adsorption towards organic pollutants. One of the emerging strategies to enhance the photocatalytic performance of TiO2 is by conjugating it with fluorescent carbon dots. Herein, we performed a critical review of the development of TiO2 - carbon dots nanocomposites for the photocatalytic removal of pharmaceuticals. We found that carbon dots can improve the photocatalytic efficiency of the resulting nanocomposites, mostly due to increasing the adsorption of organic pollutants and enhancing the absorption in the visible range. However, while this approach shows significant promise, we also identified and discussed several aspects that need to be addressed before this strategy could be more widely used. We hope that this review can guide future studies aiming to the development of enhanced photocatalytic TiO2 - carbon dots nanocomposites.
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Affiliation(s)
- Ricardo M S Sendão
- Chemistry Research Unit (CIQUP), Institute of Molecular Sciences (IMS), Faculty of Sciences of University of Porto (FCUP), Rua do Campo Alegre 687, 4169-007, Porto, Portugal
| | - Joaquim C G Esteves da Silva
- Chemistry Research Unit (CIQUP), Institute of Molecular Sciences (IMS), Faculty of Sciences of University of Porto (FCUP), Rua do Campo Alegre 687, 4169-007, Porto, Portugal; LACOMEPHI, GreenUPorto, Department of Geosciences, Environment and Territorial Planning, Faculty of Sciences of University of Porto (FCUP), Rua do Campo Alegre 687, 4169-007, Porto, Portugal
| | - Luís Pinto da Silva
- Chemistry Research Unit (CIQUP), Institute of Molecular Sciences (IMS), Faculty of Sciences of University of Porto (FCUP), Rua do Campo Alegre 687, 4169-007, Porto, Portugal; LACOMEPHI, GreenUPorto, Department of Geosciences, Environment and Territorial Planning, Faculty of Sciences of University of Porto (FCUP), Rua do Campo Alegre 687, 4169-007, Porto, Portugal.
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7
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Nanosafety: An Evolving Concept to Bring the Safest Possible Nanomaterials to Society and Environment. NANOMATERIALS 2022; 12:nano12111810. [PMID: 35683670 PMCID: PMC9181910 DOI: 10.3390/nano12111810] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 05/18/2022] [Accepted: 05/19/2022] [Indexed: 11/16/2022]
Abstract
The use of nanomaterials has been increasing in recent times, and they are widely used in industries such as cosmetics, drugs, food, water treatment, and agriculture. The rapid development of new nanomaterials demands a set of approaches to evaluate the potential toxicity and risks related to them. In this regard, nanosafety has been using and adapting already existing methods (toxicological approach), but the unique characteristics of nanomaterials demand new approaches (nanotoxicology) to fully understand the potential toxicity, immunotoxicity, and (epi)genotoxicity. In addition, new technologies, such as organs-on-chips and sophisticated sensors, are under development and/or adaptation. All the information generated is used to develop new in silico approaches trying to predict the potential effects of newly developed materials. The overall evaluation of nanomaterials from their production to their final disposal chain is completed using the life cycle assessment (LCA), which is becoming an important element of nanosafety considering sustainability and environmental impact. In this review, we give an overview of all these elements of nanosafety.
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Fernandes S, Esteves da Silva JCG, Pinto da Silva L. Life Cycle Assessment-Based Comparative Study between High-Yield and "Standard" Bottom-Up Procedures for the Fabrication of Carbon Dots. MATERIALS (BASEL, SWITZERLAND) 2022; 15:3446. [PMID: 35629474 PMCID: PMC9145381 DOI: 10.3390/ma15103446] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 05/04/2022] [Accepted: 05/05/2022] [Indexed: 02/01/2023]
Abstract
Carbon dots (CDs) are carbon-based nanomaterials with remarkable properties that can be produced from a wide variety of synthesis routes. Given that "standard" bottom-up procedures are typically associated with low synthesis yields, different authors have been trying to devise alternative high-yield fabrication strategies. However, there is a doubt if sustainability-wise, the latter should be really preferred to the former. Herein, we employed a Life Cycle Assessment (LCA) approach to compare and understand the environmental impacts of high-yield and "standard" bottom-up strategies, by applying different life cycle impact assessment (LCIA) methods. These routes were: (1) production of hydrochar, via the hydrothermal treatment of carbon precursors, and its alkaline peroxide treatment into high-yield CDs; (2) microwave treatment of carbon precursors doped with ethylenediamine; (3) and (6) thermal treatment of carbon precursor and urea; (4) hydrothermal treatment of carbon precursor and urea; (5) microwave treatment of carbon precursor and urea. For this LCA, four LCIA methods were used: ReCiPe, Greenhouse Gas Protocol, AWARE, and USEtox. Results identified CD-5 as the most sustainable synthesis in ReCiPe, Greenhouse Gas Protocol, and USEtox. On the other hand, in AWARE, the most sustainable synthesis was CD-1. It was possible to conclude that, in general, high-yield synthesis (CD-1) was not more sustainable than "standard" bottom-up synthesis, such as CD-5 and CD-6 (also with relatively high-yield). More importantly, high-yield synthesis (CD-1) did not generate much lower environmental impacts than "standard" approaches with low yields, which indicates that higher yields come with relevant environmental costs.
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Affiliation(s)
- Sónia Fernandes
- Chemistry Research Unit (CIQUP), Institute of Molecular Sciences (IMS), Faculty of Sciences of University of Porto, R. Campo Alegre 697, 4169-007 Porto, Portugal; (S.F.); (J.C.G.E.d.S.)
| | - Joaquim C. G. Esteves da Silva
- Chemistry Research Unit (CIQUP), Institute of Molecular Sciences (IMS), Faculty of Sciences of University of Porto, R. Campo Alegre 697, 4169-007 Porto, Portugal; (S.F.); (J.C.G.E.d.S.)
- LACOMEPHI, GreenUPorto, Department of Geosciences, Environmental and Territorial Planning, Faculty of Sciences of University of Porto, R. Campo Alegre 697, 4169-007 Porto, Portugal
| | - Luís Pinto da Silva
- Chemistry Research Unit (CIQUP), Institute of Molecular Sciences (IMS), Faculty of Sciences of University of Porto, R. Campo Alegre 697, 4169-007 Porto, Portugal; (S.F.); (J.C.G.E.d.S.)
- LACOMEPHI, GreenUPorto, Department of Geosciences, Environmental and Territorial Planning, Faculty of Sciences of University of Porto, R. Campo Alegre 697, 4169-007 Porto, Portugal
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A High-Performing Nanostructured Ir Doped-TiO2 for Efficient Photocatalytic Degradation of Gaseous Toluene. INORGANICS 2022. [DOI: 10.3390/inorganics10030029] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
TiO2-based photocatalysts still have some limitations such as large bandgap and low surface area, leading to low efficiency in the photocatalytic degradation of VOCs and limiting it to use in sunlight. Here we report that the nanostructured Ir-doped TiO2 as an efficient photocatalyst generates an excellent risk-reduction material of gaseous toluene. We have succeeded in developing a nanostructured Ir-doped TiO2 and initially found that excellent efficient photocatalytic VOC decomposition can be achieved in our materials The nanostructured Ir-doped TiO2 was synthesized by a one pot, low temperature hydrothermal process with different ratios of Ir doped into the TiO2. It exhibited a high surface area, uniformly spherical morphology of 10–15 nm. Its activity for the photocatalytic degradation of gaseous toluene exhibited up to 97.5% under UV light. This enhancement could be explained by iridium doping which created a high concentration oxygen vacancy and changed the recombination rate of the photogenerated charge carriers. More generally, our study indicates a strategic way to develop the novel nanostructured material for numerous applications.
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Singh V, Lousada CM, Jonsson M, Belova LM. Scalable InkJet‐Based Additive Fabrication of Photocatalytic TiO
2
Thin Films. CHEMPHOTOCHEM 2022. [DOI: 10.1002/cptc.202100212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Veena Singh
- Department of Materials Science and Engineering KTH Royal Institute of Technology 100 44 Stockholm Sweden
| | - Cláudio M. Lousada
- Department of Materials Science and Engineering KTH Royal Institute of Technology 100 44 Stockholm Sweden
| | - Mats Jonsson
- Department of Chemistry KTH Royal Institute of Technology SE-100 44 Stockholm Sweden
| | - Liubov M. Belova
- Department of Materials Science and Engineering KTH Royal Institute of Technology 100 44 Stockholm Sweden
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Lin S, Ng SF, Ong WJ. Life cycle assessment of environmental impacts associated with oxidative desulfurization of diesel fuels catalyzed by metal-free reduced graphene oxide. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 288:117677. [PMID: 34273765 DOI: 10.1016/j.envpol.2021.117677] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 06/11/2021] [Accepted: 06/27/2021] [Indexed: 06/13/2023]
Abstract
This study aimed to analyze the environmental impacts of the oxidative desulfurization (ODS) process catalyzed by metal-free reduced graphene oxide (rGO) through life cycle assessment (LCA). The environmental impacts study containing the rGO production process, the ODS process, the comparison of different oxidants and solvents was developed. This study was performed by using ReCiPe 2016 V1.03 Hierarchist midpoint as well as endpoint approach and SimaPro software. For the production of 1 kg rGO, the results showed that hydrochloric acid (washing), sulfuric acid (mixing), hydrazine (reduction) and electricity were four main contributors in this process, and this process showed a significant impact on human health 14.21 Pt followed by ecosystem 0.845 Pt and resources 0.164 Pt. For the production of 1 kg desulfurized oil (400 ppm), main environmental impacts were terrestrial ecotoxicity (43.256 kg 1,4-DCB), global warming (41.058 kg CO2), human non-carcinogenic toxicity (19.570 kg 1,4-DCB) and fossil resource scarcity (13.178 kg oil), and the main contributors were electricity, diesel oil and acetonitrile. The whole ODS process also showed a greatest effect on human health. For two common oxidants hydrogen peroxide and oxygen used in ODS, hydrogen peroxide showed a greater impact than oxygen. On the other hand, for three common solvents employed in ODS, N-methyl-2-pyrrolidone had a more serious impact on human health followed by acetonitrile and N,N-dimethylformamide. As such, LCA results demonstrated the detailed environmental impacts originated from the catalytic ODS, hence elucidating systematic guidance for its future development toward practicality.
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Affiliation(s)
- Shichun Lin
- School of Energy and Chemical Engineering, Xiamen University Malaysia, Selangor Darul Ehsan, 43900, Malaysia
| | - Sue-Faye Ng
- School of Energy and Chemical Engineering, Xiamen University Malaysia, Selangor Darul Ehsan, 43900, Malaysia; Center of Excellence for NaNo Energy & Catalysis Technology (CONNECT), Xiamen University Malaysia, Selangor Darul Ehsan, 43900, Malaysia
| | - Wee-Jun Ong
- School of Energy and Chemical Engineering, Xiamen University Malaysia, Selangor Darul Ehsan, 43900, Malaysia; Center of Excellence for NaNo Energy & Catalysis Technology (CONNECT), Xiamen University Malaysia, Selangor Darul Ehsan, 43900, Malaysia; College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.
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12
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Fernandes S, Esteves da Silva JCG, Pinto da Silva L. Comparative life cycle assessment of high-yield synthesis routes for carbon dots. NANOIMPACT 2021; 23:100332. [PMID: 35559833 DOI: 10.1016/j.impact.2021.100332] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 06/02/2021] [Accepted: 06/03/2021] [Indexed: 05/25/2023]
Abstract
Carbon dots (CDs) are carbon-based nanomaterials with advantageous luminescent properties, making them promising alternatives to other molecular and nanosized fluorophores. However, the development of CDs is impaired by the low synthesis yield of standard fabrication strategies, making high-yield strategies essential. To help future studies to focus on cleaner production strategies, we have employed a Life Cycle Assessment (LCA) to compare and understand the environmental impacts of available routes for the high-yield synthesis of carbon dots. These routes were: (1) production of hydrochar, via hydrothermal treatment of carbon precursors, and its alkaline-peroxide treatment into high-yield carbon dots; (2) thermal treatment of carbon precursors mixed in a eutectic mixture of salts. Results show that the first synthesis route is associated with the lowest environmental impacts. This is attributed to the absence of the mixture of salts in the first synthesis route, which offsets its higher electricity consumption. Sensitivity analysis showed that the most critical parameter in the different synthetic strategies is the identity of the carbon precursor, with electricity being also relevant for the first synthesis route. Nevertheless, the use of some carbon precursors (as citric acid) with higher associated environmental impacts may be justified by their beneficial role in increasing the luminescent performance of carbon dots. Thus, the first synthesis route is indicated to be the most environmental benign and should be used as a basis in future studies aimed to the cleaner and high-yield production of carbon dots.
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Affiliation(s)
- Sónia Fernandes
- Chemistry Research Unit (CIQUP), Faculty of Sciences of University of Porto, R. Campo Alegre 697, 4169-007 Porto, Portugal
| | - Joaquim C G Esteves da Silva
- Chemistry Research Unit (CIQUP), Faculty of Sciences of University of Porto, R. Campo Alegre 697, 4169-007 Porto, Portugal; LACOMEPHI, GreenUPorto, Department of Geosciences, Environmental and Territorial Planning, Faculty of Sciences of University of Porto, R. Campo Alegre 697, 4169-007 Porto, Portugal
| | - Luís Pinto da Silva
- Chemistry Research Unit (CIQUP), Faculty of Sciences of University of Porto, R. Campo Alegre 697, 4169-007 Porto, Portugal; LACOMEPHI, GreenUPorto, Department of Geosciences, Environmental and Territorial Planning, Faculty of Sciences of University of Porto, R. Campo Alegre 697, 4169-007 Porto, Portugal.
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13
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Pinto da Silva L. Editorial Materials: Special Issue on Advances in Luminescent Engineered Nanomaterials. MATERIALS 2021; 14:ma14113121. [PMID: 34200120 PMCID: PMC8201253 DOI: 10.3390/ma14113121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 06/03/2021] [Indexed: 11/28/2022]
Affiliation(s)
- Luís Pinto da Silva
- Chemistry Research Unit (CIQUP), Faculty of Sciences of University of Porto, R. Campo Alegre 687, 4169-007 Porto, Portugal;
- LACOMEPHI, GreenUPorto, Department of Geosciences, Environment and Territorial Planning, Faculty of Sciences of University of Porto, R. Campo Alegre 687, 4169-007 Porto, Portugal
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14
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Temizel-Sekeryan S, Hicks AL. Cradle-to-grave environmental impact assessment of silver enabled t-shirts: Do nano-specific impacts exceed non nano-specific emissions? NANOIMPACT 2021; 22:100319. [PMID: 35559976 DOI: 10.1016/j.impact.2021.100319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 04/16/2021] [Accepted: 04/21/2021] [Indexed: 06/15/2023]
Abstract
Consumption of silver nanoparticles (nAg) is increasing due to their use in various industries. A comprehensive analysis is needed to elucidate the potential environmental and human health benefits and costs of the silver-enabled consumer products. For this purpose, four commercially available silver/nanosilver enabled polyester textiles with different initial silver/nanosilver loadings (1.07-4030 μg Ag/g textile) are included in the current research and cradle-to-grave life cycle assessments (LCA) are conducted to identify hotspots associated with production and use of these products throughout their lifetimes (100 cycles). Both non nano-specific and nano-specific impacts are calculated using nano-specific ecotoxicity characterization factors for nAg, instead of the commonly utilized ionic silver (Ag+) surrogate. Additionally, four different laundering scenarios were modeled to analyze the impacts resulting from using conventional and high efficiency machines. In the majority of environmental impact categories, either polyester textile manufacturing (regardless of Ag/nAg enabling) or laundering were identified as hotspots. Non nano-specific ecotoxicity impacts ranged from 1.58 × 101-2.91 × 101 CTUe/textile (CTUe: comparative toxic units for ecosystems) and nano-specific ecotoxicity impacts ranged from 2.01 × 10-4-3.10 × 10-3 CTUe/textile for the lowest and the highest Ag/nAg containing textiles, respectively. It is also found that unless the initial silver loading per textile is significantly high (in this case 4030 μg Ag/g textile comparing to the lowest load of 1.07 μg Ag/g textile), ecotoxicity and human health impacts of released silver species would be lower than ecotoxicity and human health impacts resulting from raw materials acquisition and manufacturing of the antibacterial textiles.
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Affiliation(s)
- Sila Temizel-Sekeryan
- Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Andrea L Hicks
- Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA.
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Majrik K, Pászti Z, Korecz L, Mihály J, May Z, Németh P, Cannilla C, Bonura G, Frusteri F, Tompos A, Tálas E. Effect of the Microstructure of the Semiconductor Support on the Photocatalytic Performance of the Pt-PtO x/TiO 2 Catalyst System. MATERIALS (BASEL, SWITZERLAND) 2021; 14:943. [PMID: 33671227 PMCID: PMC7921961 DOI: 10.3390/ma14040943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 02/08/2021] [Accepted: 02/14/2021] [Indexed: 11/16/2022]
Abstract
The influence of the semiconductor microstructure on the photocatalytic behavior of Pt-PtOx/TiO2 catalysts was studied by comparing the methanol-reforming performance of systems based on commercial P25 or TiO2 from sol-gel synthesis calcined at different temperatures. The Pt co-catalyst was deposited by incipient wetness and formed either by calcination or high-temperature H2 treatment. Structural features of the photocatalysts were established by X-ray powder diffraction (XRD), electron spin resonance (ESR), X-ray photoelectron spectroscopy (XPS), optical absorption, Raman spectroscopy and TEM measurements. In situ reduction of Pt during the photocatalytic reaction was generally observed. The P25-based samples showed the best H2 production, while the activity of all sol-gel-based samples was similar in spite of the varying microstructures resulting from the different preparation conditions. Accordingly, the sol-gel-based TiO2 has a fundamental structural feature interfering with its photocatalytic performance, which could not be improved by annealing in the 400-500 °C range even by scarifying specific surface area at higher temperatures.
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Affiliation(s)
- Katalin Majrik
- Research Centre for Natural Sciences, Institute of Materials and Environmental Chemistry, Eötvös Loránd Research Network (ELKH), H-1117 Budapest, Magyar Tudósok Körútja 2, Hungary; (K.M.); (L.K.); (J.M.); (Z.M.); (P.N.); (A.T.); (E.T.)
| | - Zoltán Pászti
- Research Centre for Natural Sciences, Institute of Materials and Environmental Chemistry, Eötvös Loránd Research Network (ELKH), H-1117 Budapest, Magyar Tudósok Körútja 2, Hungary; (K.M.); (L.K.); (J.M.); (Z.M.); (P.N.); (A.T.); (E.T.)
| | - László Korecz
- Research Centre for Natural Sciences, Institute of Materials and Environmental Chemistry, Eötvös Loránd Research Network (ELKH), H-1117 Budapest, Magyar Tudósok Körútja 2, Hungary; (K.M.); (L.K.); (J.M.); (Z.M.); (P.N.); (A.T.); (E.T.)
| | - Judith Mihály
- Research Centre for Natural Sciences, Institute of Materials and Environmental Chemistry, Eötvös Loránd Research Network (ELKH), H-1117 Budapest, Magyar Tudósok Körútja 2, Hungary; (K.M.); (L.K.); (J.M.); (Z.M.); (P.N.); (A.T.); (E.T.)
| | - Zoltán May
- Research Centre for Natural Sciences, Institute of Materials and Environmental Chemistry, Eötvös Loránd Research Network (ELKH), H-1117 Budapest, Magyar Tudósok Körútja 2, Hungary; (K.M.); (L.K.); (J.M.); (Z.M.); (P.N.); (A.T.); (E.T.)
| | - Péter Németh
- Research Centre for Natural Sciences, Institute of Materials and Environmental Chemistry, Eötvös Loránd Research Network (ELKH), H-1117 Budapest, Magyar Tudósok Körútja 2, Hungary; (K.M.); (L.K.); (J.M.); (Z.M.); (P.N.); (A.T.); (E.T.)
- Department of Earth and Environmental Sciences, University of Pannonia, H-8200 Veszprém, Egyetem út 10, Hungary
| | - Catia Cannilla
- National Council of Research–CNR-ITAE, ‘‘Nicola Giordano’’, Via S. Lucia 5, 98126 Messina, Italy; (C.C.); (G.B.); (F.F.)
| | - Giuseppe Bonura
- National Council of Research–CNR-ITAE, ‘‘Nicola Giordano’’, Via S. Lucia 5, 98126 Messina, Italy; (C.C.); (G.B.); (F.F.)
| | - Francesco Frusteri
- National Council of Research–CNR-ITAE, ‘‘Nicola Giordano’’, Via S. Lucia 5, 98126 Messina, Italy; (C.C.); (G.B.); (F.F.)
| | - András Tompos
- Research Centre for Natural Sciences, Institute of Materials and Environmental Chemistry, Eötvös Loránd Research Network (ELKH), H-1117 Budapest, Magyar Tudósok Körútja 2, Hungary; (K.M.); (L.K.); (J.M.); (Z.M.); (P.N.); (A.T.); (E.T.)
| | - Emília Tálas
- Research Centre for Natural Sciences, Institute of Materials and Environmental Chemistry, Eötvös Loránd Research Network (ELKH), H-1117 Budapest, Magyar Tudósok Körútja 2, Hungary; (K.M.); (L.K.); (J.M.); (Z.M.); (P.N.); (A.T.); (E.T.)
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Evaluation of Different Bottom-up Routes for the Fabrication of Carbon Dots. NANOMATERIALS 2020; 10:nano10071316. [PMID: 32635483 PMCID: PMC7407658 DOI: 10.3390/nano10071316] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 06/26/2020] [Accepted: 07/02/2020] [Indexed: 02/07/2023]
Abstract
Carbon dots (CDs) are carbon-based nanoparticles with very attractive luminescence features. Furthermore, their synthesis by bottom-up strategies is quite flexible, as tuning the reaction precursors and synthesis procedures can lead to an endless number of CDs with distinct properties and applications. However, this complex variability has made the characterization of the structural and optical properties of the nanomaterials difficult. Herein, we performed a systematic evaluation of the effect of three representative bottom-up strategies (hydrothermal, microwave-assisted, and calcination) on the properties of CDs prepared from the same precursors (citric acid and urea). Our results revealed that these synthesis routes led to nanoparticles with similar sizes, identical excitation-dependent blue-to-green emission, and similar surface-functionalization. However, we have also found that microwave and calcination strategies are more efficient towards nitrogen-doping than hydrothermal synthesis, and thus, the former routes are able to generate CDs with significantly higher fluorescence quantum yields than the latter. Furthermore, the different synthesis strategies appear to have a role in the origin of the photoluminescence of the CDs, as hydrothermal-based nanoparticles present an emission more dependent on surface states, while microwave- and calcination-based CDs present an emission with more contributions from core states. Furthermore, calcination and microwave routes are more suitable for high-yield synthesis (~27-29%), while hydrothermal synthesis present almost negligible synthesis yields (~2%). Finally, life cycle assessment (LCA) was performed to investigate the sustainability of these processes and indicated microwave synthesis as the best choice for future studies.
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Ma D, Li J, Liu A, Chen C. Carbon Gels-Modified TiO 2: Promising Materials for Photocatalysis Applications. MATERIALS 2020; 13:ma13071734. [PMID: 32276332 PMCID: PMC7178632 DOI: 10.3390/ma13071734] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 04/02/2020] [Accepted: 04/02/2020] [Indexed: 11/20/2022]
Abstract
Carbon gels are a kind of porous organic polymer, which play pivotal roles in electrode, supercapacitor, hydrogen storage, and catalysis. Carbon gels are commonly prepared by the condensation of resorcinol and formaldehyde. The as-prepared polymers are further aged and sintered at a high temperature in an inert atmosphere to form cross-linked and intertwined porous structures. Owing to its large specific area and narrow pore size distribution, this kind of material is very appropriate for mass transfer, substrate absorption, and product desorption from the pores. In recent years, carbon gels have been discovered to function as effective hybrid materials with TiO2 for photocatalytic applications. They could act as efficient deep-traps for photo-induced holes, which decreases the recombination probability of photo-induced carriers and lengthens their lifetime. In this mini-review, we will discuss the state-of-the-art paragon examples of carbon gels/TiO2 composite materials applied in photo(electro)catalysis. The major challenges and gaps of its application in this field will also be emphasized.
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Affiliation(s)
- Dongge Ma
- School of Science, Beijing Technology and Business University, Beijing 100048, China;
- Correspondence: ; Tel.: +86-010-68985573
| | - Jundan Li
- School of Science, Beijing Technology and Business University, Beijing 100048, China;
| | - Anan Liu
- Basic Experimental Center for Natural Science, University of Science and Technology Beijing, Beijing 100083, China;
| | - Chuncheng Chen
- Key Laboratory of Photochemistry, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China;
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