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Chen F, Tian L, Liu B, Sun Y, Ge S, Hou J. Investigation on the gaseous benzene removed by photocatalysis employing TiO 2 modified with cobalt and iodine as photocatalysts under visible light. Environ Technol 2022; 43:2990-2999. [PMID: 33820487 DOI: 10.1080/09593330.2021.1912833] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Accepted: 03/25/2021] [Indexed: 06/12/2023]
Abstract
A new type of photocatalysts, nanocrystalline titanium dioxide (TiO2) doped with Co and I, were synthesized and modified via the sol-gel method to enhance the utilization of visible light. Herein, mono- and co-doped TiO2 (i.e. Co-TiO2, I-TiO2, Co-I-TiO2) were employed as the photocatalysts to investigate the photocatalytic performance on gaseous benzene removal. The prepared photocatalysts were characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET)-specific surface areas, Raman spectroscopy, UV-visible diffuse reflectance spectroscopy (UV-vis-DRS), X-ray photoelectron spectroscopy (XPS), photoluminescence (PL), and electrochemical impedance spectroscopy (EIS). Results indicated that both particle sizes and band gaps of TiO2 were significantly reduced by doping with Co/I. Also, the lattice defects and the specific surface areas of TiO2 were substantially augmented by adding Co/I because of the increase of oxygen vacancies, especially for Co-I-TiO2. Meanwhile, Co and I were distributed on the titanium base with the existence of multivalent states. The benzene treatment capacity of Co-I-TiO2, Co-TiO2, I-TiO2 and Pure TiO2 is 441.46, 424.36, 388.06, and 51.25 μgC6H6/(g·h), respectively. To sum up, photocatalytic degradation of gaseous benzene could be improved by doping with Co/I because of the extension of catalyst lifetime and light response range covering visible light.
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Affiliation(s)
- Fulong Chen
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou, People's Republic of China
| | - Lijiang Tian
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou, People's Republic of China
| | - Bingkun Liu
- Sinoma International Engineering Co., Ltd., Nanjing, People's Republic of China
| | - Yue Sun
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou, People's Republic of China
| | - Sijie Ge
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou, People's Republic of China
| | - Jing Hou
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou, People's Republic of China
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Salvadores F, Reli M, Alfano OM, Kočí K, Ballari MDLM. Efficiencies Evaluation of Photocatalytic Paints Under Indoor and Outdoor Air Conditions. Front Chem 2020; 8:551710. [PMID: 33195045 PMCID: PMC7650231 DOI: 10.3389/fchem.2020.551710] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 09/09/2020] [Indexed: 11/24/2022] Open
Abstract
The removal of indoor and outdoor air pollutants is crucial to prevent environmental and health issues. Photocatalytic building materials are an energy-sustainable technology that can completely oxidize pollutants, improving in situ the air quality of contaminated sites. In this work, different photoactive TiO2 catalysts (anatase or modified anatase) and amounts were used to formulate photocatalytic paints in replacement of the normally used TiO2 (rutile) pigment. These paints were tested in two different experimental systems simulating indoor and outdoor environments. In one, indoor illumination conditions were used in the photoreactor for the oxidation of acetaldehyde achieving conversions between 37 and 55%. The other sets of experiments were performed under simulated outdoor radiation for the degradation of nitric oxide, resulting in conversions between 13 and 35%. This wide range of conversions made it difficult to directly compare the paints. Thus, absorption, photonic, and quantum efficiencies were calculated to account for the paints photocatalytic performance. It was found that the formulations containing carbon-doped TiO2 presented the best efficiencies. The paint with the maximum amount of this photocatalyst showed the highest absorption and photonic efficiencies. On the other hand, the paint with the lowest amount of carbon-doped TiO2 presented the highest value of quantum efficiency, thus becoming the optimal formulation in terms of energy use.
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Affiliation(s)
- Federico Salvadores
- Instituto de Desarrollo Tecnológico para la Industria Química (Universidad Nacional del Litoral and Consejo Nacional de Investigaciones Científicas y Técnicas), Santa Fe, Argentina
| | - Martin Reli
- Institute of Environmental Technology, Vysoká Škola Báňská-Technical University of Ostrava, Ostrava, Czechia
| | - Orlando M Alfano
- Instituto de Desarrollo Tecnológico para la Industria Química (Universidad Nacional del Litoral and Consejo Nacional de Investigaciones Científicas y Técnicas), Santa Fe, Argentina
| | - Kamila Kočí
- Institute of Environmental Technology, Vysoká Škola Báňská-Technical University of Ostrava, Ostrava, Czechia
| | - María de Los Milagros Ballari
- Instituto de Desarrollo Tecnológico para la Industria Química (Universidad Nacional del Litoral and Consejo Nacional de Investigaciones Científicas y Técnicas), Santa Fe, Argentina
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Janus M, Kusiak-Nejman E, Rokicka-Konieczna P, Markowska-Szczupak A, Zając K, Morawski AW. Bacterial Inactivation on Concrete Plates Loaded with Modified TiO 2 Photocatalysts under Visible Light Irradiation. Molecules 2019; 24:E3026. [PMID: 31438511 DOI: 10.3390/molecules24173026] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 08/18/2019] [Accepted: 08/20/2019] [Indexed: 11/16/2022] Open
Abstract
The antibacterial activity of concrete plates loaded with various titania photocatalysts was investigated. The target in bacteria testing was Escherichia coli K12. The presence of photocatalysts in the concrete matrix at a dose of 10 wt.% improved the antibacterial properties, which became significant depending on the type of the added photocatalyst. Total inactivation of E. coli irradiated under artificial solar light was observed on the concrete plates loaded with the following photocatalysts: TiO2/N,CMeOH-300, TiO2/N,CEtOH-100, TiO2/N,CisoPrOH-100 and TiO2/N-300. The modified Hom disinfection kinetic model was found as a best-fit model for the obtained results. The presence of nitrogen and carbon in the photocatalysts structure, as well as crystallite size, surface area and porosity, contributed to the increase of antibacterial properties of concrete plates.
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Le PH, Hieu LT, Lam TN, Hang NTN, Truong NV, Tuyen LTC, Phong PT, Leu J. Enhanced Photocatalytic Performance of Nitrogen-Doped TiO₂ Nanotube Arrays Using a Simple Annealing Process. Micromachines (Basel) 2018; 9:E618. [PMID: 30477205 DOI: 10.3390/mi9120618] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 11/08/2018] [Accepted: 11/20/2018] [Indexed: 11/29/2022]
Abstract
Nitrogen-doped TiO2 nanotube arrays (N-TNAs) were successfully fabricated by a simple thermal annealing process in ambient N2 gas at 450 °C for 3 h. TNAs with modified morphologies were prepared by a two-step anodization using an aqueous NH4F/ethylene glycol solution. The N-doping concentration (0–9.47 at %) can be varied by controlling N2 gas flow rates between 0 and 500 cc/min during the annealing process. Photocatalytic performance of as-prepared TNAs and N-TNAs was studied by monitoring the methylene blue degradation under visible light (λ ≥ 400 nm) illumination at 120 mW·cm−2. N-TNAs exhibited appreciably enhanced photocatalytic activity as compared to TNAs. The reaction rate constant for N-TNAs (9.47 at % N) reached 0.26 h−1, which was a 125% improvement over that of TNAs (0.115 h−1). The significant enhanced photocatalytic activity of N-TNAs over TNAs is attributed to the synergistic effects of (1) a reduced band gap associated with the introduction of N-doping states to serve as carrier reservoir, and (2) a reduced electron‒hole recombination rate.
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Acharya R, Naik B, Parida K. Cr(VI) remediation from aqueous environment through modified-TiO 2-mediated photocatalytic reduction. Beilstein J Nanotechnol 2018; 9:1448-1470. [PMID: 29977679 PMCID: PMC6009310 DOI: 10.3762/bjnano.9.137] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 04/19/2018] [Indexed: 05/21/2023]
Abstract
Cr(VI) exhibits cytotoxic, mutagenic and carcinogenic properties; hence, effluents containing Cr(VI) from various industrial processes pose threat to aquatic life and downstream users. Various treatment techniques, such as chemical reduction, ion exchange, bacterial degradation, adsorption and photocatalysis, have been exploited for remediation of Cr(VI) from wastewater. Among these, photocatalysis has recently gained considerable attention. The applications of photocatalysis, such as water splitting, CO2 reduction, pollutant degradation, organic transformation reactions, N2 fixation, etc., towards solving the energy crisis and environmental issues are briefly discussed in the Introduction of this review. The advantages of TiO2 as a photocatalyst and the importance of its modification for photocatalytic reduction of Cr(VI) has also been addressed. In this review, the photocatalytic activity of TiO2 after modification with carbon-based advanced materials, metal oxides, metal sulfides and noble metals towards reduction of Cr(VI) was evaluated and compared with that of bare TiO2. The photoactivity of dye-sensitized TiO2 for reduction of Cr(VI) was also discussed. The mechanism for enhanced photocatalytic activity was highlighted and attributed to the resultant properties, namely, effective separation of photoinduced charge carriers, extension of the light absorption range and intensity, increase of the surface active sites, and higher photostability. Advantages and limitations for photoreduction of Cr(VI) over modified TiO2 are depicted in the Conclusion. The various challenges that restrict the technology from practical applications in remediation of Cr(VI) from wastewater were addressed in the Conclusion section as well. The future perspectives of the field presented in this review are focused on the development of whole-solar-spectrum responsive, TiO2-coupled photocatalysts which provide efficient photocatalytic reduction of Cr(VI) along with their good recoverability and recyclability.
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Affiliation(s)
- Rashmi Acharya
- Centre for Nano Science and Nano Technology, Siksha ‘O’ Anusandhan University, Bhubaneswar 751030, India
| | - Brundabana Naik
- Centre for Nano Science and Nano Technology, Siksha ‘O’ Anusandhan University, Bhubaneswar 751030, India
| | - Kulamani Parida
- Centre for Nano Science and Nano Technology, Siksha ‘O’ Anusandhan University, Bhubaneswar 751030, India
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Parnicka P, Mazierski P, Grzyb T, Lisowski W, Kowalska E, Ohtani B, Zaleska-Medynska A, Nadolna J. Influence of the preparation method on the photocatalytic activity of Nd-modified TiO 2. Beilstein J Nanotechnol 2018; 9:447-459. [PMID: 29515957 PMCID: PMC5815290 DOI: 10.3762/bjnano.9.43] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 01/08/2018] [Indexed: 06/15/2023]
Abstract
Nd-modified TiO2 photocatalysts have been obtained via hydrothermal (HT) and sol-hydrothermal (SHT) methods. The as-prepared samples were characterized by X-ray diffraction (XRD), BET surface area measurements, scanning electron microscopy (SEM), diffuse reflectance spectroscopy (DRS), luminescence spectroscopy and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity of the synthesized samples was evaluated by the degradation of phenol in aqueous solution under irradiation with UV-vis (λ > 350 nm) and vis (λ > 420 nm) light, as well as by the degradation of gaseous toluene under irradiation with vis (λmax = 415 nm) light. It was found that Nd-modified TiO2 is an efficient photocatalyst for the degradation of phenol and toluene under visible light. XPS analysis revealed that the photocatalyst prepared via HT method contains a three-times higher amount of hydroxy groups at the surface layer and a two-times higher amount of surface defects than that obtained by the SHT method. The photocatalytic efficiency of phenol and toluene degradation under vis irradiation in the presence of 0.25% Nd-TiO2(HT) reached 0.62 and 3.36 μmol·dm-1·min-1, respectively. Photocatalytic activity tests in the presence of Nd-TiO2 and scavenger confirm that superoxide radicals were responsible for the visible light-induced degradation of the model pollutant in aqueous solution.
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Affiliation(s)
- Patrycja Parnicka
- Department of Environmental Technology, University of Gdansk, 80-308 Gdansk, Poland
| | - Paweł Mazierski
- Department of Environmental Technology, University of Gdansk, 80-308 Gdansk, Poland
| | - Tomasz Grzyb
- Department of Rare Earths, Faculty of Chemistry, Adam Mickiewicz University in Poznan, 60-780 Poznan, Poland
| | - Wojciech Lisowski
- Institute of Physical Chemistry, Polish Academy of Sciences,01-224 Warsaw, Poland
| | - Ewa Kowalska
- Institute for Catalysis, Hokkaido University, Sapporo 001-0021, Japan
| | - Bunsho Ohtani
- Institute for Catalysis, Hokkaido University, Sapporo 001-0021, Japan
| | | | - Joanna Nadolna
- Department of Environmental Technology, University of Gdansk, 80-308 Gdansk, Poland
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Gotostos MJN, Su CC, De Luna MDG, Lu MC. Kinetic study of acetaminophen degradation by visible light photocatalysis. J Environ Sci Health A Tox Hazard Subst Environ Eng 2014; 49:892-9. [PMID: 24766590 DOI: 10.1080/10934529.2014.894310] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
In this work, a novel photocatalyst K3[Fe(CN)6]/TiO2 synthesized via a simple sol-gel method was utilized to degrade acetaminophen (ACT) under visible light with the use of blue and green LED lights. Parameters (medium pH, initial concentration of reactant, catalyst concentration, temperature, and number of blue LED lights) affecting photocatalytic degradation of ACT were also investigated. The experimental result showed that compared to commercially available Degussa P-25 (DP-25) photocatalyst, K3[Fe(CN)6]/TiO2 gave higher degradation efficiency and rate constant (kapp) of ACT. The degradation efficiency or kapp decreased with increasing initial ACT concentration and temperature, but increased with increased number of blue LED lamps. Additionally, kapp increased as initial pH was increased from 5.6 to 6.9, but decreased at a high alkaline condition (pH 8.3). Furthermore, the degradation efficiency and kapp of ACT increased as K3[Fe(CN)6]/TiO2 loading was increased to 1 g L(-1) but decreased and eventually leveled off at photocatalyst loading above this value. Photocatalytic degradation of ACT in K3[Fe(CN)6]/TiO2 catalyst system follows a pseudo-first-order kinetics. The Langmuir-Hinshelwood equation was also satisfactorily used to model the degradation of ACT in K3[Fe(CN)6]/TiO2 catalyst system indicated by a satisfactory linear correlation between 1/kapp and Co, with kini = 6.54 × 10(-4) mM/min and KACT = 17.27 mM(-1).
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Affiliation(s)
- Mary Jane N Gotostos
- a Department of Chemical Engineering , University of the Philippines , Diliman , Quezon City , Philippines
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