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Rega R, Fioravanti A, Hejazi SMH, Shahrezaei M, Kment Š, Maddalena P, Naldoni A, Lettieri S. Charge carrier recombination processes, intragap defect states, and photoluminescence mechanisms in stoichiometric and reduced TiO 2 brookite nanorods: an interpretation scheme through in situ photoluminescence excitation spectroscopy in controlled environment. NANOSCALE 2024; 16:11296-11309. [PMID: 38787737 DOI: 10.1039/d4nr00593g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2024]
Abstract
The study of titanium dioxide (TiO2) in the brookite phase is gaining popularity as evidence has shown the efficient photocatalytic performance of this less investigated polymorph. It has been recently reported that defective anisotropic brookite TiO2 nanorods display remarkable substrate-specific reactivity towards alcohol photoreforming, with rates of hydrogen production significantly (18-fold) higher than those exhibited by anatase TiO2 nanoparticles. To elucidate the basic photo-physical mechanisms and peculiarities leading to such an improvement in the photoactive efficiency, we investigated the recombination processes of photoexcited charge carriers in both stoichiometric and reduced brookite nanorods via photoluminescence excitation spectroscopy in controlled environment. Through an investigation procedure employing both supragap and subgap excitation during successive exposure to oxidizing and reducing gaseous agents, we firstly obtained an interpretation scheme describing the main photoluminescence and charge recombination pathways in stoichiometric and reduced brookite, which includes information about the spatial and energetic position of the intragap states involved in photoluminescence mechanisms, and secondly identified a specific photoluminescence enhancement process occurring in only reduced brookite nanorods, which indicates the injection of a conduction band electron during ethanol photo-oxidation. The latter finding may shed light on the empirical evidence about the exceptional reactivity of reduced brookite nanorods toward the photo-oxidation of alcohols and the concomitant efficiency of photocatalytic hydrogen generation.
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Affiliation(s)
- Romina Rega
- Institute of Applied Sciences and Intelligent Systems "Eduardo Caianiello", National Research Council (CNR-ISASI), Via Cintia 21, 80126 Napoli, Italy
| | - Ambra Fioravanti
- Institute of Sciences and Technologies for Sustainable Energy and Mobility, National Research Council (CNR-STEMS), Via Canal Bianco 28, 44124 Ferrara, Italy
| | - S M Hossein Hejazi
- Czech Advanced Technology and Research Institute, Regional Centre of Advanced Technologies and Materials, Palacký University Olomouc, Křížkovského 511/8, 77900 Olomouc, Czech Republic
- Nanotechnology Centre, Centre for Energy and Environmental Technologies, VŠB-Technical University of Ostrava, 17. listopadu 2172/15, Poruba, 708 00 Ostrava, Czech Republic
| | - Mahdi Shahrezaei
- Czech Advanced Technology and Research Institute, Regional Centre of Advanced Technologies and Materials, Palacký University Olomouc, Křížkovského 511/8, 77900 Olomouc, Czech Republic
| | - Štěpán Kment
- Czech Advanced Technology and Research Institute, Regional Centre of Advanced Technologies and Materials, Palacký University Olomouc, Křížkovského 511/8, 77900 Olomouc, Czech Republic
- Nanotechnology Centre, Centre for Energy and Environmental Technologies, VŠB-Technical University of Ostrava, 17. listopadu 2172/15, Poruba, 708 00 Ostrava, Czech Republic
| | - Pasqualino Maddalena
- Department of Physics "E. Pancini", University of Naples Federico II, Complesso Universitario di Monte S. Angelo, Via Cintia 21, 80126 Napoli, Italy.
| | - Alberto Naldoni
- Department of Chemistry, University of Turin, Via Pietro Giuria, 7, 10125 Torino, Italy.
| | - Stefano Lettieri
- Department of Physics "E. Pancini", University of Naples Federico II, Complesso Universitario di Monte S. Angelo, Via Cintia 21, 80126 Napoli, Italy.
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Chin JY, Ahmad AL, Low SC. Antibiotics oxytetracycline removal by photocatalyst titanium dioxide and graphitic carbon nitride in aquaculture wastewater. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 343:118231. [PMID: 37247545 DOI: 10.1016/j.jenvman.2023.118231] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 05/18/2023] [Accepted: 05/20/2023] [Indexed: 05/31/2023]
Abstract
The surge in the use of antibiotics, especially in aquaculture, has led to development of antibiotic resistance genes, which will harm environmental and public health. One of the most commonly used antibiotics in aquaculture is oxytetracycline (OTC). Employing photocatalysis, this study compared OTC degradation efficiency of two different types of common photocatalysts, TiO2 and graphitic carbon nitride (GCN) in terms of their photochemical properties and underlying photocatalytic mechanism. For reference purpose, self-synthesized GCN from urea precursor (GCN-Urea) and commercial GCN (GCN-Commercial) were both examined. OTC adsorption-photocatalysis removal rates in pure OTC solution by TiO2, GCN-Urea and GCN-Commercial were attained at 95%, 60% and 40% respectively. Photochemical properties evaluated included light absorption, band gap, valence and conduction band positions, photoluminescence, cyclic voltammetry, BET surface area and adsorption capability of the photocatalysts. Through the evaluations, this study provides novel insights towards current state-of-the-art heterogeneous photocatalytic processes. The electron-hole recombination examined by photoluminescence is not the key factor influencing the photocatalytic efficacies as commonly discussed. On the contrary, the dominating factors governing the higher OTC degradation efficiency of TiO2 compared to GCN are the high mobility of electrons that leads to high redox capability and the high pollutant-photocatalyst affinity. These claims are proven by 86% and 40% more intense anodic and cathodic cyclic voltammetry curve peaks of TiO2 as compared to both GCNs. OTC also demonstrated 1.7 and 2.3 times higher affinity towards TiO2 than GCN-Urea and GCN-Commercial. OTC removal by TiO2 in real aquaculture wastewater only achieved 50%, due to significant inhibition effect by dissolved solids, dissolved organic matters and high ionic contents in the wastewater.
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Affiliation(s)
- Jing Yi Chin
- School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, Seri Ampangan, 14300, Nibong Tebal, Pulau Pinang, Malaysia.
| | - Abdul Latif Ahmad
- School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, Seri Ampangan, 14300, Nibong Tebal, Pulau Pinang, Malaysia.
| | - Siew Chun Low
- School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, Seri Ampangan, 14300, Nibong Tebal, Pulau Pinang, Malaysia.
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3
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Hegyi A, Lăzărescu AV, Ciobanu AA, Ionescu BA, Grebenişan E, Chira M, Florean C, Vermeşan H, Stoian V. Study on the Possibilities of Developing Cementitious or Geopolymer Composite Materials with Specific Performances by Exploiting the Photocatalytic Properties of TiO 2 Nanoparticles. MATERIALS (BASEL, SWITZERLAND) 2023; 16:ma16103741. [PMID: 37241366 DOI: 10.3390/ma16103741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 05/06/2023] [Accepted: 05/11/2023] [Indexed: 05/28/2023]
Abstract
Starting from the context of the principles of Sustainable Development and Circular Economy concepts, the paper presents a synthesis of research in the field of the development of materials of interest, such as cementitious composites or alkali-activated geopolymers. Based on the reviewed literature, the influence of compositional or technological factors on the physical-mechanical performance, self-healing capacity and biocidal capacity obtained was analyzed. The inclusion of TiO2 nanoparticles in the matrix increase the performances of cementitious composites, producing a self-cleaning capacity and an anti-microbial biocidal mechanism. As an alternative, the self-cleaning capacity can be achieved through geopolymerization, which provides a similar biocidal mechanism. The results of the research carried out indicate the real and growing interest for the development of these materials but also the existence of some elements still controversial or insufficiently analyzed, therefore concluding the need for further research in these areas. The scientific contribution of this study consists of bringing together two apparently distinct research directions in order to identify convergent points, to create a favorable framework for the development of an area of research little addressed so far, namely, the development of innovative building materials by combining improved performance with the possibility of reducing environmental impact, awareness and implementation of the concept of a Circular Economy.
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Affiliation(s)
- Andreea Hegyi
- NIRD URBAN-INCERC Cluj-Napoca Branch, 117 Calea Floresti, 400524 Cluj-Napoca, Romania
| | | | | | | | - Elvira Grebenişan
- NIRD URBAN-INCERC Cluj-Napoca Branch, 117 Calea Floresti, 400524 Cluj-Napoca, Romania
| | - Mihail Chira
- NIRD URBAN-INCERC Cluj-Napoca Branch, 117 Calea Floresti, 400524 Cluj-Napoca, Romania
| | - Carmen Florean
- NIRD URBAN-INCERC Cluj-Napoca Branch, 117 Calea Floresti, 400524 Cluj-Napoca, Romania
- NIRD URBAN-INCERC Iaşi Branch, 6 Anton Şesan Street, 700048 Iaşi, Romania
| | - Horaţiu Vermeşan
- Faculty of Materials and Environmental Engineering, Technical University of Cluj-Napoca, 103-105 Muncii Boulevard, 400641 Cluj-Napoca, Romania
| | - Vlad Stoian
- Department of Microbiology, Facutly of Agriculture, University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca, 3-5 Calea Mănăştur, 400372 Cluj-Napoca, Romania
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4
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Kaur M, Charak A, Sandhu S, Toor AP, Singh V. Biomass-derived graphene modified γ-Fe 2O 3/N,Fe–TiO 2@GO: a prolific photoactive material with extended visible to near IR harvesting. Catal Sci Technol 2023. [DOI: 10.1039/d2cy01502a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
This study reports the development of a novel ternary self-assembled γ-Fe2O3/N,Fe–TiO2@GO nanocomposite as a visible to near IR (NIR) active photocatalyst prepared by ultrasonic activation followed by hydrothermal treatment.
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Affiliation(s)
- Manpreet Kaur
- Department of Applied Sciences, Punjab Engineering College, Deemed to be University, Sector-12, Chandigarh, India
| | - Abhishek Charak
- Department of Production and Industrial Engineering, Punjab Engineering College, Deemed to be University, Sector-12, Chandigarh, India
| | - Sofia Sandhu
- Department of Applied Sciences, Punjab Engineering College, Deemed to be University, Sector-12, Chandigarh, India
| | - Amrit Pal Toor
- Dr. SSB, University Institute of Chemical Engineering & Technology, Panjab University, Chandigarh, India
- Energy Research Centre, Panjab University, Chandigarh, India
| | - Vasundhara Singh
- Department of Applied Sciences, Punjab Engineering College, Deemed to be University, Sector-12, Chandigarh, India
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Zhang N, Zheng Y, Li J, Du Z, Cheng F. Enhanced photocatalytic and settling performance of a mesoporous graphene/titanium oxide composite for wastewater treatment. REACTION KINETICS MECHANISMS AND CATALYSIS 2022. [DOI: 10.1007/s11144-022-02323-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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6
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Materials for Chemical Sensing: A Comprehensive Review on the Recent Advances and Outlook Using Ionic Liquids, Metal–Organic Frameworks (MOFs), and MOF-Based Composites. CHEMOSENSORS 2022. [DOI: 10.3390/chemosensors10080290] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The ability to measure and monitor the concentration of specific chemical and/or gaseous species (i.e., “analytes”) is the main requirement in many fields, including industrial processes, medical applications, and workplace safety management. As a consequence, several kinds of sensors have been developed in the modern era according to some practical guidelines that regard the characteristics of the active (sensing) materials on which the sensor devices are based. These characteristics include the cost-effectiveness of the materials’ manufacturing, the sensitivity to analytes, the material stability, and the possibility of exploiting them for low-cost and portable devices. Consequently, many gas sensors employ well-defined transduction methods, the most popular being the oxidation (or reduction) of the analyte in an electrochemical reactor, optical techniques, and chemiresistive responses to gas adsorption. In recent years, many of the efforts devoted to improving these methods have been directed towards the use of certain classes of specific materials. In particular, ionic liquids have been employed as electrolytes of exceptional properties for the preparation of amperometric gas sensors, while metal–organic frameworks (MOFs) are used as highly porous and reactive materials which can be employed, in pure form or as a component of MOF-based functional composites, as active materials of chemiresistive or optical sensors. Here, we report on the most recent developments relative to the use of these classes of materials in chemical sensing. We discuss the main features of these materials and the reasons why they are considered interesting in the field of chemical sensors. Subsequently, we review some of the technological and scientific results published in the span of the last six years that we consider among the most interesting and useful ones for expanding the awareness on future trends in chemical sensing. Finally, we discuss the prospects for the use of these materials and the factors involved in their possible use for new generations of sensor devices.
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Gao X, Song M, Sun D, Guan R, Zhai H, Zhao Z, Zhang Q, Li X. A Facile In Situ Hydrothermal Etching Method to CaTiO3/TiO2 Heterostructure for Efficient Photocatalytic N2 Reduction. Catal Letters 2022. [DOI: 10.1007/s10562-021-03813-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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8
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Praxedes F, Moreno H, Simões A, Teixeira V, Nunes R, Amoresi R, Ramirez M. Interface matters: Design of an efficient CaCu3Ti4O12-rGO photocatalyst. POWDER TECHNOL 2022. [DOI: 10.1016/j.powtec.2022.117478] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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9
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Magnetic Resonance Studies of Hybrid Nanocomposites Containing Nanocrystalline TiO2 and Graphene-Related Materials. MATERIALS 2022; 15:ma15062244. [PMID: 35329696 PMCID: PMC8949220 DOI: 10.3390/ma15062244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 03/09/2022] [Accepted: 03/16/2022] [Indexed: 02/01/2023]
Abstract
Nanocomposites based on nanocrystalline titania modified with graphene-related materials (reduced and oxidized form of graphene) showed the existence of magnetic agglomerates. All parameters of magnetic resonance spectra strongly depended on the materials’ modification processes. The reduction of graphene oxide significantly increased the number of magnetic moments, which caused crucial changes in the reorientation and relaxation processes. At room temperature, a wide resonance line dominated for all nanocomposites studied and in some cases, a narrow resonance line derived from the conduction electrons. Some nanocomposites (samples of titania modified with graphene oxide, prepared with the addition of water or butan-1-ol) showed a single domain magnetic (ferromagnetic) arrangement, and others (samples of titania modified with reduced graphene oxide) exhibited magnetic anisotropy. In addition, the spectra of EPR from free radicals were observed for all samples at the temperature of 4 K. The magnetic resonance imaging methods enable the capturing of even a small number of localized magnetic moments, which significantly affects the physicochemical properties of the materials.
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10
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Santamaria L, Maddalena P, Lettieri S. An Instantaneous Recombination Rate Method for the Analysis of Interband Recombination Processes in ZnO Crystals. MATERIALS 2022; 15:ma15041515. [PMID: 35208053 PMCID: PMC8878150 DOI: 10.3390/ma15041515] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 02/03/2022] [Accepted: 02/16/2022] [Indexed: 02/06/2023]
Abstract
Time-resolved photoluminescence (TRPL) analysis is often performed to assess the qualitative features of semiconductor crystals using predetermined functions (e.g., double- or multi-exponentials) to fit the decays of PL intensity. However, in many cases—including the notable case of interband PL in direct gap semiconductors—this approach just provides phenomenological parameters and not fundamental physical quantities. In the present work, we highlight that within a properly chosen range of laser excitation, the TRPL of zinc oxide (ZnO) bulk crystals can be described with excellent precision with second-order kinetics for the total recombination rate. We show that this allows us to define an original method for data analysis, based on evaluating the “instantaneous” recombination rate that drives the initial slope of the decay curves, acquired as a function of the excitation laser fluence. The method is used to fit experimental data, determining useful information on fundamental quantities that appear in the second-order recombination rate, namely the PL (unimolecular) lifetime, the bimolecular recombination coefficient, the non-radiative lifetime and the equilibrium free-carrier concentration. Results reasonably close to those typically obtained in direct gap semiconductors are extracted. The method may represent a useful tool for gaining insight into the recombination processes of a charge carrier in ZnO, and for obtaining quantitative information on ZnO excitonic dynamics.
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Affiliation(s)
- Luigi Santamaria
- Italian Space Agency (ASI), Space Geodesy Center “G. Colombo”, 75100 Matera, Italy;
| | - Pasqualino Maddalena
- Dipartimento di Fisica “E. Pancini”, Università degli Studi di Napoli “Federico II“, Complesso Universitario di Monte S. Angelo, Via Cupa Cintia 21, 80126 Napoli, Italy;
| | - Stefano Lettieri
- Istituto di Scienze Applicate e Sistemi Intelligenti “E. Caianiello”, Consiglio Nazionale delle Ricerche (CNR-ISASI), Complesso Universitario di Monte S. Angelo, Via Cupa Cintia 21, 80126 Napoli, Italy
- Correspondence: ; Tel.: +39-081-676809
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11
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Lettieri S, Pavone M. TiO 2-Based Nanostructures, Composites and Hybrid Photocatalysts. MATERIALS (BASEL, SWITZERLAND) 2022; 15:1271. [PMID: 35207813 PMCID: PMC8879892 DOI: 10.3390/ma15041271] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 02/07/2022] [Indexed: 02/01/2023]
Abstract
The field of materials sciences has always been strongly interconnected with the most significant technological developments in the modern era, and such an interconnection is absolutely evident at least since the 1950s revolution of electronics and microelectronics, driven by advances in the science of semiconductors [...].
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Affiliation(s)
- Stefano Lettieri
- Institute of Applied Sciences and Intelligent Systems “E. Caianiello”, Consiglio Nazionale delle Ricerche (CNR-ISASI), Complesso Universitario di Monte S. Angelo, Via Cupa Cintia 21, 80126 Napoli, Italy
| | - Michele Pavone
- Department of Chemical Sciences, University of Naples “Federico II”, Complesso Universitario di Monte Sant’Angelo, Via Cupa Cintia 21, 80126 Napoli, Italy;
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Zhu D, Cai L, Sun Z, Zhang A, Héroux P, Kim H, Yu W, Liu Y. Efficient degradation of tetracycline by RGO@black titanium dioxide nanofluid via enhanced catalysis and photothermal conversion. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 787:147536. [PMID: 33992942 DOI: 10.1016/j.scitotenv.2021.147536] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 04/26/2021] [Accepted: 04/30/2021] [Indexed: 06/12/2023]
Abstract
The applications of photocatalytic pollutant degradation have remained limited due to the low efficiency of solar energy utilization. In this study, a photothermal catalyst consisting of reduced graphene oxide @ black TiO2 (RGO@BT) nanofluid with effective full-spectrum (from ultraviolet to infrared light) absorption was synthesized by a typical two-step method of high temperature calcination and hydrothermal method. Moreover, the photothermal catalytic performance of the RGO@BT nanofluid on tetracycline was verified. Compared with individual processes (i.e, photocatalysis and thermocatalysis), the photothermal catalytic process significantly enhanced tetracycline degradation under simulated global standard spectrum sunlight (AM 1.5G, 1000 W m-2). The maximum photothermal conversion efficiency reached 91.8%, which resulted in 94.7% tetracycline degradation (40 mg L-1) after 120 min of treatment with 200 mg L-1 RGO@BT nanofluid. Holes, OH, and O2- were found to be the main active species during the photothermal catalytic process. Moreover, heat was spontaneously converted from light energy without the use of any external energy source. The elevated system temperature facilitated the tetracycline degradation based on the Arrhenius behavior. These findings provide insights into the improvement of photocatalytic efficiency in organic contaminant degradation via solar energy-efficient photothermal conversion materials.
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Affiliation(s)
- Dahai Zhu
- College of Environmental Science and Engineering, Donghua University, Shanghai 201620, PR China
| | - Li Cai
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, PR China
| | - Zhuyu Sun
- College of Environmental Science and Engineering, Donghua University, Shanghai 201620, PR China
| | - Ai Zhang
- College of Environmental Science and Engineering, Donghua University, Shanghai 201620, PR China
| | - Paul Héroux
- Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Canada
| | - Hyunjung Kim
- Department of Mineral Resources and Energy Engineering & Department of Environment and Energy, Jeonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju, 54896, Jeonbuk, Republic of Korea
| | - Wei Yu
- School of Environmental and Materials Engineering, College of Engineering, Shanghai Polytechnic University, Shanghai 201209, PR China
| | - Yanan Liu
- College of Environmental Science and Engineering, Donghua University, Shanghai 201620, PR China.
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13
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Mesoporous TiO2 from Metal-Organic Frameworks for Photoluminescence-Based Optical Sensing of Oxygen. Catalysts 2021. [DOI: 10.3390/catal11070795] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Metal−organic frameworks (MOFs) are a class of porous coordination networks extraordinarily varied in physicochemical characteristics such as porosity, morphologies, and compositions. These peculiarities make MOFs widely exploited in a large array of applications, such as catalysis, chemicals and gas sensing, drug delivery, energy storage, and energy conversion. MOFs can also serve as nanostructured precursors of metal oxides with peculiar characteristics and controlled shapes. In this work, starting from MIL125-(Ti), a 1,4-benzenedicarboxylate (BDC)-based MOF with Ti as metallic center, mesoporous TiO2 powders containing both anatase and rutile crystalline phases were produced. A challenging utilization of these porous MOF-derived Ti-based oxides is the optically-based quantitative detection of molecular oxygen (O2) in gaseous and/or aqueous media. In this study, the photoluminescence (PL) intensity changes during O2 exposure of two MOF-derived mixed-phase TiO2 powders were probed by exploiting the opposite response of rutile and anatase in VIS-PL and NIR-PL wavelength intervals. This result highlights promising future possibilities for the realization of MOF-derived doubly-parametric TiO2-based optical sensors.
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14
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Nwahara N, Adeniyi O, Mashazi P, Nyokong T. Visible light responsive TiO2 - graphene oxide nanosheets - Zn phthalocyanine ternary heterojunction assisted photoelectrocatalytic degradation of Orange G. J Photochem Photobiol A Chem 2021. [DOI: 10.1016/j.jphotochem.2021.113291] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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15
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Photocatalytic Degradation of Sulfolane Using a LED-Based Photocatalytic Treatment System. Catalysts 2021. [DOI: 10.3390/catal11050624] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Sulfolane is an emerging industrial pollutant detected in the environments near many oil and gas plants in North America. So far, numerous advanced oxidation processes have been investigated to treat sulfolane in aqueous media. However, there is only a few papers that discuss the degradation of sulfolane using photocatalysis. In this study, photocatalytic degradation of sulfolane using titanium dioxide (TiO2) and reduced graphene oxide TiO2 composite (RGO-TiO2) in a light-emitting diode (LED) photoreactor was investigated. The impact of different waters (ultrapure water, tap water, and groundwater) and type of irradiation (UVA-LED and mercury lamp) on photocatalytic degradation of sulfolane were also studied. In addition, a reusability test was conducted for the photocatalyst to examine the degradation of sulfolane in three consecutive cycles with new batches of sulfolane-contaminated water. The results show that LED-based photocatalysis was effective in degrading sulfolane in waters even after three photocatalytic cycles. UVA-LEDs displayed more efficient use of photon energy when compared with the mercury lamps as they have a narrow emission spectrum coinciding with the absorption of TiO2. The combination of UVA-LED and TiO2 yielded better performance than UVA-LED and RGO-TiO2 for the degradation of sulfolane. Much lower sulfolane degradation rates were observed in tap water and groundwater than ultrapure water.
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Padmanabhan NT, Thomas N, Louis J, Mathew DT, Ganguly P, John H, Pillai SC. Graphene coupled TiO 2 photocatalysts for environmental applications: A review. CHEMOSPHERE 2021; 271:129506. [PMID: 33445017 DOI: 10.1016/j.chemosphere.2020.129506] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 12/28/2020] [Accepted: 12/29/2020] [Indexed: 05/28/2023]
Abstract
Nanostructured photocatalysts have always offered opportunities to solve issues concerned with the environmental challenges caused by rapid urbanization and industrialization. These materials, due to their tunable physicochemical characteristics, are capable of providing a clean and sustainable ecosystem to humanity. One of the current thriving research focuses of visible-light-driven photocatalysts is on the nanocomposites of titanium dioxide (TiO2) with carbon nanostructures, especially graphene. Coupling TiO2 with graphene has proven more active by photocatalysis than TiO2 alone. It is generally considered that graphene sheets act as an electron acceptor facilitating the transfer and separation of photogenerated electrons during TiO2 excitation, thereby reducing electron-hole recombination. This study briefly reviews the fundamental mechanism and interfacial charge-transfer dynamics in TiO2/graphene nanocomposites. Design strategies of various graphene-based hybrids are highlighted along with some specialized synthetic routes adopted to attain preferred properties. Importantly, the enhancing interfacial charge transfer of photogenerated e¯CB through the graphene layers by morphology orientation of TiO2, predominated exposure of their high energy crystal facets, defect engineering, enhancing catalytic sites in graphene, constructing dedicated architectures, tuning the nanomaterial dimensionality at the interface, and employing the synergism adopted through various modifications, are systematically compiled. Portraying the significance of these photocatalytic hybrids in environmental remediation, important applications including air and water purification, self-cleaning surfaces, H2 production, and CO2 reduction to desired fuels, are addressed.
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Affiliation(s)
- Nisha T Padmanabhan
- Department of Polymer Science and Rubber Technology, Cochin University of Science and Technology, Kerala, India
| | - Nishanth Thomas
- Nanotechnology and Bio-engineering Research Group, Department of Environmental Science, Institute of Technology Sligo, Sligo, Ireland; Centre for Precision Engineering, Materials and Manufacturing Research (PEM), Institute of Technology Sligo, Sligo, Ireland
| | - Jesna Louis
- Department of Polymer Science and Rubber Technology, Cochin University of Science and Technology, Kerala, India; Inter University Centre for Nanomaterials and Devices, Cochin University of Science and Technology, Kerala, India
| | - Dhanu Treasa Mathew
- Department of Polymer Science and Rubber Technology, Cochin University of Science and Technology, Kerala, India
| | - Priyanka Ganguly
- Nanotechnology and Bio-engineering Research Group, Department of Environmental Science, Institute of Technology Sligo, Sligo, Ireland; Centre for Precision Engineering, Materials and Manufacturing Research (PEM), Institute of Technology Sligo, Sligo, Ireland
| | - Honey John
- Department of Polymer Science and Rubber Technology, Cochin University of Science and Technology, Kerala, India; Inter University Centre for Nanomaterials and Devices, Cochin University of Science and Technology, Kerala, India
| | - Suresh C Pillai
- Nanotechnology and Bio-engineering Research Group, Department of Environmental Science, Institute of Technology Sligo, Sligo, Ireland; Centre for Precision Engineering, Materials and Manufacturing Research (PEM), Institute of Technology Sligo, Sligo, Ireland.
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Lettieri S, Pavone M, Fioravanti A, Santamaria Amato L, Maddalena P. Charge Carrier Processes and Optical Properties in TiO 2 and TiO 2-Based Heterojunction Photocatalysts: A Review. MATERIALS 2021; 14:ma14071645. [PMID: 33801646 PMCID: PMC8036967 DOI: 10.3390/ma14071645] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 03/19/2021] [Accepted: 03/23/2021] [Indexed: 02/07/2023]
Abstract
Photocatalysis based technologies have a key role in addressing important challenges of the ecological transition, such as environment remediation and conversion of renewable energies. Photocatalysts can in fact be used in hydrogen (H2) production (e.g., via water splitting or photo-reforming of organic substrates), CO2 reduction, pollution mitigation and water or air remediation via oxidation (photodegradation) of pollutants. Titanium dioxide (TiO2) is a “benchmark” photocatalyst, thanks to many favorable characteristics. We here review the basic knowledge on the charge carrier processes that define the optical and photophysical properties of intrinsic TiO2. We describe the main characteristics and advantages of TiO2 as photocatalyst, followed by a summary of historical facts about its application. Next, the dynamics of photogenerated electrons and holes is reviewed, including energy levels and trapping states, charge separation and charge recombination. A section on optical absorption and optical properties follows, including a discussion on TiO2 photoluminescence and on the effect of molecular oxygen (O2) on radiative recombination. We next summarize the elementary photocatalytic processes in aqueous solution, including the photogeneration of reactive oxygen species (ROS) and the hydrogen evolution reaction. We pinpoint the TiO2 limitations and possible ways to overcome them by discussing some of the “hottest” research trends toward solar hydrogen production, which are classified in two categories: (1) approaches based on the use of engineered TiO2 without any cocatalysts. Discussed topics are highly-reduced “black TiO2”, grey and colored TiO2, surface-engineered anatase nanocrystals; (2) strategies based on heterojunction photocatalysts, where TiO2 is electronically coupled with a different material acting as cocatalyst or as sensitizer. Examples discussed include TiO2 composites or heterostructures with metals (e.g., Pt-TiO2, Au-TiO2), with other metal oxides (e.g., Cu2O, NiO, etc.), direct Z-scheme heterojunctions with g-C3N4 (graphitic carbon nitride) and dye-sensitized TiO2.
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Affiliation(s)
- Stefano Lettieri
- Institute of Applied Sciences and Intelligent Systems “E. Caianiello”, Consiglio Nazionale delle Ricerche (CNR-ISASI), Complesso Universitario di Monte S. Angelo, Via Cupa Cintia 21, 80126 Napoli, Italy
- Correspondence: ; Tel.: +39-081676809
| | - Michele Pavone
- Department of Chemical Sciences, University of Naples “Federico II”, Complesso Universitario di Monte S. Angelo, Via Cupa Cintia 21, 80126 Napoli, Italy;
| | - Ambra Fioravanti
- Institute of Science and Technology for Sustainable Energy and Mobility, Consiglio Nazionale delle Ricerche (CNR-STEMS), Via Canal Bianco 28, 44124 Ferrara, Italy;
| | | | - Pasqualino Maddalena
- Department of Physics “E. Pancini”, University of Naples “Federico II”, Complesso Universitario di Monte S. Angelo, Via Cupa Cintia 21, 80126 Napoli, Italy;
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Azeez NA, Dash SS, Gummadi SN, Deepa VS. Nano-remediation of toxic heavy metal contamination: Hexavalent chromium [Cr(VI)]. CHEMOSPHERE 2021; 266:129204. [PMID: 33310359 DOI: 10.1016/j.chemosphere.2020.129204] [Citation(s) in RCA: 65] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 12/02/2020] [Accepted: 12/02/2020] [Indexed: 05/04/2023]
Abstract
The inexorable industrialization and modern agricultural practices to meet the needs of the increasing population have polluted the environment with toxic heavy metals such as Cr(VI), Cu2+, Cd2+, Pb2+, and Zn2+. Among the hazardous heavy metal(loid)s contamination in agricultural soil, water, and air, hexavalent chromium [Cr(VI)] is the most virulent carcinogen. The metallurgic industries, tanneries, paint manufacturing, petroleum refineries are among various such human activities that discharge Cr(VI) into the environment. Various methods have been employed to reduce the concentration of Cr(VI) contamination with nano and bioremediation being the recent advancement to achieve recovery at low cost and higher efficiency. Bioremediation is the process of using biological sources such as plant extracts, microorganisms, and algae to reduce the heavy metals while the nano-remediation uses nanoparticles to adsorb heavy metals. In this review, we discuss the various activities that liberate Cr(VI). We then discuss the various conventional, nano-remediation, and bioremediation methods to keep Cr(VI) concentration in check and further discuss their efficiencies. We also discuss the mechanism of nano-remediation techniques for better insight into the process.
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Affiliation(s)
- Nazeer Abdul Azeez
- Department of Biotechnology, Bannari Amman Institute of Technology, Erode, Tamil Nadu, 638401, India.
| | - Swati Sucharita Dash
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Applied and Industrial Microbiology Laboratory, Indian Institute of Technology Madras, Chennai, 600036, India.
| | - Sathyanarayana Naidu Gummadi
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Applied and Industrial Microbiology Laboratory, Indian Institute of Technology Madras, Chennai, 600036, India.
| | - Vijaykumar Sudarshana Deepa
- Department of Biotechnology, National Institute of Technology, Tadepalligudem, Andhra Pradesh, 534 101, India.
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(Ti,Sn) Solid Solution Based Gas Sensors for New Monitoring of Hydraulic Oil Degradation. MATERIALS 2021; 14:ma14030605. [PMID: 33525544 PMCID: PMC7865283 DOI: 10.3390/ma14030605] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/21/2021] [Accepted: 01/25/2021] [Indexed: 01/28/2023]
Abstract
The proper operation of a fluid power system in terms of efficiency and reliability is directly related to the fluid state; therefore, the monitoring of fluid ageing in real time is fundamental to prevent machine failures. For this aim, an innovative methodology based on fluid vapor analysis through metal oxide (shortened: MOX) gas sensors has been developed. Two apparatuses were designed and realized: (i) a dedicated test bench to fast-age the fluid under controlled conditions; (ii) a laboratory MOX sensor system to test the headspace of the aged fluid samples. To prepare the set of MOX gas sensors suitable to detect the analytes’ concentrations in the fluid headspace, different functional materials were synthesized in the form of nanopowders, characterizing them by electron microscopy and X-ray diffraction. The powders were deposited through screen-printing technology, realizing thick-film gas sensors on which dynamical responses in the presence of the fluid headspace were obtained. It resulted that gas sensors based on solid solution TixSn1–xO2 with x = 0.9 and 0.5 offered the best responses toward the fluid headspace with lower response and recovery times. Furthermore, a decrease in the responses (for all sensors) with fluid ageing was observed.
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Moztahida M, Lee DS. Photocatalytic degradation of methylene blue with P25/graphene/polyacrylamide hydrogels: Optimization using response surface methodology. JOURNAL OF HAZARDOUS MATERIALS 2020; 400:123314. [PMID: 32947714 DOI: 10.1016/j.jhazmat.2020.123314] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 05/01/2020] [Accepted: 06/23/2020] [Indexed: 05/23/2023]
Abstract
An environment-friendly hydrogel was synthesized by entrapping Degussa P25 on the surface of a reduced graphene oxide (rGO)-polyacrylamide (PAM) matrix.The PAM content of the P25-rGO-PAM (PGP) hydrogel considerably influenced the adsorption and photocatalytic degradation of methylene blue (MB), and the optimal PAM content was 10% (w/v). Furthermore, rGO not only enhanced the adsorption capacity of the hydrogel by increasing the surface area but also increased the photodegradation efficiency synergistically by separating electron-hole pairs. The reaction kinetic constant for MB degradation by the hydrogel was 0.0276 min-1, which was three and five times the reaction kinetic constants of P25-PAM and rGO-PAM hydrogels, respectively. The synthesized PGP showed high stability and its MB degradation efficiency was considerably high up to five consecutive cycles under UV-irradiation. The eco-friendly nature of the hydrogel was evaluated on the basis of bacterial inactivation, and the treated water was found to be safe for use. Three key operating parameters (initial MB concentration, temperature, and pH) were optimized for maximizing MB removal using a response surface methodology. The complete MB removal efficiency was obtained for the optimal conditions of pH 9.4, a temperature of 31.2 °C, and an initial MB concentration of 5.2 mg/L.
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Affiliation(s)
- Mokrema Moztahida
- Department of Environmental Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu, 41566, Republic of Korea
| | - Dae Sung Lee
- Department of Environmental Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu, 41566, Republic of Korea.
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Recent Developments of TiO 2-Based Photocatalysis in the Hydrogen Evolution and Photodegradation: A Review. NANOMATERIALS 2020; 10:nano10091790. [PMID: 32916899 PMCID: PMC7558756 DOI: 10.3390/nano10091790] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 08/28/2020] [Accepted: 08/29/2020] [Indexed: 01/01/2023]
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 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.
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Pirozzi D, Imparato C, D'Errico G, Vitiello G, Aronne A, Sannino F. Three-year lifetime and regeneration of superoxide radicals on the surface of hybrid TiO 2 materials exposed to air. JOURNAL OF HAZARDOUS MATERIALS 2020; 387:121716. [PMID: 31786026 DOI: 10.1016/j.jhazmat.2019.121716] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 11/12/2019] [Accepted: 11/18/2019] [Indexed: 05/08/2023]
Abstract
The generation and stabilization of reactive oxygen species (ROS), including the superoxide radical anion (O2-), have a huge potential in environmental remediation and industrial chemical processes, but they still remain a challenge. Here, we elucidate the formation, stability and reactivity of superoxide radicals spontaneously produced on the surface of a hybrid TiO2-acetylacetonate material exposed to air. EPR spectra reveal an exceptional lifetime (up to three years, in air at room temperature) of the adsorbed O2-, which can also be easily regenerated after its decay. The performances of this material in the degradation of organic pollutants in aqueous solution without any light irradiation indicate a heterogeneous catalytic mechanism, mediated by superoxide radicals, with a synergistic homogeneous action of hydroxyl radicals (OH), which are released in solution, as detected by the EPR spin trapping method. The regeneration ability of the adsorbed superoxide radicals by simple exposure to air counteracts the partial instability in aqueous environment of the organic component of the hybrid structure allowing the catalyst reuse. These structural and functional features joined to the simple preparation route open a new perspective in the field of advanced oxidation processes for hybrid TiO2 materials.
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Affiliation(s)
- Domenico Pirozzi
- Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale, Università di Napoli Federico II, P.le Tecchio 80, 80125, Napoli, Italy
| | - Claudio Imparato
- Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale, Università di Napoli Federico II, P.le Tecchio 80, 80125, Napoli, Italy
| | - Gerardino D'Errico
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario Monte S. Angelo, Via Cinthia, 80126, Napoli, Italy; CSGI, Center for Colloids and Surface Science, Via della Lastruccia 3, 50019, Sesto Fiorentino, Florence, Italy
| | - Giuseppe Vitiello
- Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale, Università di Napoli Federico II, P.le Tecchio 80, 80125, Napoli, Italy; CSGI, Center for Colloids and Surface Science, Via della Lastruccia 3, 50019, Sesto Fiorentino, Florence, Italy
| | - Antonio Aronne
- Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale, Università di Napoli Federico II, P.le Tecchio 80, 80125, Napoli, Italy
| | - Filomena Sannino
- Dipartimento di Agraria, Università di Napoli Federico II, Via Università 100, 80055, Portici, Napoli, Italy.
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Imparato C, Iervolino G, Fantauzzi M, Koral C, Macyk W, Kobielusz M, D'Errico G, Rea I, Di Girolamo R, De Stefano L, Andreone A, Vaiano V, Rossi A, Aronne A. Photocatalytic hydrogen evolution by co-catalyst-free TiO 2/C bulk heterostructures synthesized under mild conditions. RSC Adv 2020; 10:12519-12534. [PMID: 35497602 PMCID: PMC9051216 DOI: 10.1039/d0ra01322f] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 03/17/2020] [Indexed: 01/01/2023] Open
Abstract
Hydrogen production by photocatalytic water splitting is one of the most promising sustainable routes to store solar energy in the form of chemical bonds. To obtain significant H2 evolution rates (HERs) a variety of defective TiO2 catalysts were synthesized by means of procedures generally requiring highly energy-consuming treatments, e.g. hydrogenation. Even if a complete understanding of the relationship between defects, electronic structure and catalytic active sites is far from being achieved, the band gap narrowing and Ti3+-self-doping have been considered essential to date. In most reports a metal co-catalyst (commonly Pt) and a sacrificial electron donor (such as methanol) are used to improve HERs. Here we report the synthesis of TiO2/C bulk heterostructures, obtained from a hybrid TiO2-based gel by simple heat treatments at 400 °C under different atmospheres. The electronic structure and properties of the grey or black gel-derived powders are deeply inspected by a combination of classical and less conventional techniques, in order to identify the origin of their photoresponsivity. The defective sites of these heterostructures, namely oxygen vacancies, graphitic carbon and unpaired electrons localized on the C matrix, result in a remarkable visible light activity in spite of the lack of band gap narrowing or Ti3+-self doping. The materials provide HER values ranging from about 0.15 to 0.40 mmol h-1 gcat -1, under both UV- and visible-light irradiation, employing glycerol as sacrificial agent and without any co-catalyst.
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Affiliation(s)
- Claudio Imparato
- Department of Chemical, Materials and Production Engineering, University of Naples Federico II P.le V. Tecchio 80 80125 Napoli Italy
| | - Giuseppina Iervolino
- Department of Industrial Engineering, University of Salerno Via Giovanni Paolo II 132 84084 Fisciano (Salerno) Italy
| | - Marzia Fantauzzi
- Department of Chemical and Geological Sciences, University of Cagliari S.S. 554 Bivio per Sestu 09042 Monserrato Cagliari Italy
| | - Can Koral
- Department of Physics, University of Naples Federico II, CNR-SPIN, UOS Napoli Via Cinthia 80126 Napoli Italy
| | - Wojciech Macyk
- Faculty of Chemistry, Jagiellonian University ul. Gronostajowa 2 30-387 Kraków Poland
| | - Marcin Kobielusz
- Faculty of Chemistry, Jagiellonian University ul. Gronostajowa 2 30-387 Kraków Poland
| | - Gerardino D'Errico
- Department of Chemical Sciences, University of Naples Federico II Via Cinthia 80126 Napoli Italy
| | - Ilaria Rea
- Institute for Microelectronics and Microsystems, National Research Council Via P. Castellino 111 80131 Napoli Italy
| | - Rocco Di Girolamo
- Department of Chemical Sciences, University of Naples Federico II Via Cinthia 80126 Napoli Italy
| | - Luca De Stefano
- Institute for Microelectronics and Microsystems, National Research Council Via P. Castellino 111 80131 Napoli Italy
| | - Antonello Andreone
- Department of Physics, University of Naples Federico II, CNR-SPIN, UOS Napoli Via Cinthia 80126 Napoli Italy
| | - Vincenzo Vaiano
- Department of Industrial Engineering, University of Salerno Via Giovanni Paolo II 132 84084 Fisciano (Salerno) Italy
| | - Antonella Rossi
- Department of Chemical and Geological Sciences, University of Cagliari S.S. 554 Bivio per Sestu 09042 Monserrato Cagliari Italy
| | - Antonio Aronne
- Department of Chemical, Materials and Production Engineering, University of Naples Federico II P.le V. Tecchio 80 80125 Napoli Italy
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Abstract
Solar radiation is becoming increasingly appreciated because of its influence on living matter and the feasibility of its application for a variety of purposes. It is an available and everlasting natural source of energy, rapidly gaining ground as a supplement and alternative to the nonrenewable energy feedstock. Actually, an increasing interest is involved in the development of efficient materials as the core of photocatalytic and photothermal processes, allowing solar energy harvesting and conversion for many technological applications, including hydrogen production, CO2 reduction, pollutants degradation, as well as organic syntheses. Particularly, photosensitive nanostructured hybrid materials synthesized coupling inorganic semiconductors with organic compounds, and polymers or carbon-based materials are attracting ever-growing research attention since their peculiar properties overcome several limitations of photocatalytic semiconductors through different approaches, including dye or charge transfer complex sensitization and heterostructures formation. The aim of this review was to describe the most promising recent advances in the field of hybrid nanostructured materials for sunlight capture and solar energy exploitation by photocatalytic processes. Beside diverse materials based on metal oxide semiconductors, emerging photoactive systems, such as metal-organic frameworks (MOFs) and hybrid perovskites, were discussed. Finally, future research opportunities and challenges associated with the design and development of highly efficient and cost-effective photosensitive nanomaterials for technological claims were outlined.
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25
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Controllable synthesis of TiO2 chemically bonded graphene for photocatalytic hydrogen evolution and dye degradation. Catal Today 2020. [DOI: 10.1016/j.cattod.2018.10.042] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Alfe M, Gargiulo V, Di Capua R. An Old but Lively Nanomaterial: Exploiting Carbon Black for the Synthesis of Advanced Materials. EURASIAN CHEMICO-TECHNOLOGICAL JOURNAL 2019. [DOI: 10.18321/ectj861] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Carbon black (CB) is an old-concept but versatile carbonaceous material prone to be structurally and chemically modified under quite mild wet conditions. Recently, we exploited the potentiality of CB for the production of a highly varied array of advanced materials with applications in energetics, water remediation and sensoristic. The proposed approaches are devised to meet specific needs: low production costs, scalable synthetic approaches, flexibility i.e. easy tuning of chemico-physical properties of the carbon-based advanced materials. Two main approaches have been exploited: modification of CB at the surface and highly CB de-structuration. The former approach allows obtaining highly homogenous CB-modified nanoparticles (around 160 nm) with tunable surface properties (hydrophilicity, typology of functional groups and surface charge density, pore size distribution), supports for ionic liquid (SILP) and composites (carbon-iron oxide). The latter approach exploiting a top-down demolition of CB produces a highly versatile graphene related material (GRM), made up by stacked short graphene-like layers (GL) particularly suitable for advanced composites synthesis and ultrathin carbon-based films production.
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Liu B, Zhao X, Yu J, Parkin IP, Fujishima A, Nakata K. Intrinsic intermediate gap states of TiO2 materials and their roles in charge carrier kinetics. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY C-PHOTOCHEMISTRY REVIEWS 2019. [DOI: 10.1016/j.jphotochemrev.2019.02.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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