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Chandra A, Ghosh S, Sarkar R, Sarkar S, Chattopadhyay KK. TiO 2 nanorods decorated Si nanowire hierarchical structures for UV light activated photocatalytic application. CHEMOSPHERE 2024; 352:141249. [PMID: 38266878 DOI: 10.1016/j.chemosphere.2024.141249] [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: 08/31/2023] [Revised: 01/09/2024] [Accepted: 01/16/2024] [Indexed: 01/26/2024]
Abstract
Water remediation techniques like photolysis have recently piqued the interest of many researchers due to water contamination resulting from heavy industrialization and urbanization. In the current work, as-synthesized TiO2 nanorod decorated vertically aligned silicon nanowire (SiNW) leads to a hierarchical morphological structure formation. The photocatalytic nature of the fabricated SiNW/TiO2 nanoheterojunction is examined by the dye degradation of textile pollutants like methylene blue (MB), rhodamine B (RhB), and eosin B (EB). The catalytic dye degradation investigations revealed that 4 h hydrothermal synthesis of TiO2 on the surface of SiNW (ST4) exhibited excellent catalytic behaviour. In the presence of H2O2 and UV irradiation, the ST4 nanoheterostructure can degrade 98.89% of the model pollutant methylene blue (MB) in 15 min, demonstrating remarkable photocatalytic performance. The direct Z-scheme heterojunction exhibited by the SiNW/TiO2 structure facilitates a more efficient charge transfer mechanism with higher reducing and oxidizing ability leading to enhanced photocatalytic behaviour. The degradation pathway examined by LC-MS studies demonstrated the complete breakdown of the organic MB dye molecules ultimately mineralizing into CO2, H2O, and other inorganic substances. The photocatalyst ST4 exhibited excellent reusability and stability after multiple cycles of dye degradation enabling its use in practical water purification purposes.
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Affiliation(s)
- Ankita Chandra
- School of Materials Science and Nanotechnology, Jadavpur University, Kolkata, 700032, India
| | - Shrabani Ghosh
- School of Materials Science and Nanotechnology, Jadavpur University, Kolkata, 700032, India
| | - Ratna Sarkar
- Thin film and Nano Science Laboratory, Department of Physics, Jadavpur University, Kolkata, 700032, India
| | - Sourav Sarkar
- School of Materials Science and Nanotechnology, Jadavpur University, Kolkata, 700032, India
| | - K K Chattopadhyay
- School of Materials Science and Nanotechnology, Jadavpur University, Kolkata, 700032, India; Thin film and Nano Science Laboratory, Department of Physics, Jadavpur University, Kolkata, 700032, India.
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In Situ Growth and UV Photocatalytic Effect of ZnO Nanostructures on a Zn Plate Immersed in Methylene Blue. Catalysts 2022. [DOI: 10.3390/catal12121657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Nanostructures of zinc oxide (ZnO) are considered promising photocatalysts for the degradation of organic pollutants in water. This work discusses an in situ growth and UV photocatalytic effect of ZnO nanostructures on a Zn plate immersed in methylene blue (MB) at room temperature. First, the Zn surfaces were pretreated via sandblasting to introduce a micro-scale roughness. Then, the Zn plates were immersed in MB and exposed to UV light, to observe ZnO nanostructure growth and photocatalytic degradation of MB. Scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and UV-Vis diffuse reflectance spectroscopy were used to characterize the Zn surfaces. We observed the growth of stoichiometric and crystalline ZnO with a nano-leaf morphology and an estimated bandgap of 3.08 eV. The photocatalytic degradation of MB was also observed in the presence of the ZnO nanostructures and UV light. The average percentage degradation was 76% in 4 h, and the degradation rate constant was 0.3535 h−1. The experimental results suggest that room temperature growth of ZnO nanostructures (on Zn surfaces) in organic dye solutions is possible. Furthermore, the nanostructured surface can be used simultaneously for the photocatalytic degradation of the organic dye.
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HAMDI D, MANSOURI L, SRIVASTAVA V, SILLANPAA M, BOUSSELMI L. Cerium and europium doped TiO 2 thin films deposited by a sol-gel dip-coating process: characterization and photocatalytic activity toward dye degradation. Turk J Chem 2021; 46:415-433. [PMID: 38143462 PMCID: PMC10734741 DOI: 10.3906/kim-2106-55] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 04/27/2022] [Accepted: 12/01/2021] [Indexed: 12/26/2023] Open
Abstract
Cerium (Ce) and europium (Eu)-doped TiO2 thin films were obtained by sol-gel dip-coating technique. SEM micrographs showed that the surfaces are covered by agglomerated particles due to the repeating coating process. XRD patterns showed the presence of TiO2 anatase phase. Raman spectra revealed that the peaks recorded at 146 cm-1(Eg) and 397 cm-1(B1g) were related to the anatase phase. EIS measurements proved that Ce-TiO2 (1wt%) and Eu-TiO2 (0.1wt%) photocatalysts possessed a lower electron transfer resistance than pure TiO2, which can lead to effective separation of electron/ hole pairs during the photoreactions. The photoactivity of Ce and Eu-doped TiO2 was investigated by the degradation of amido black10B dye (AB) under UV excitation and varying the initial pH and concentrations. It was found that Eu-TiO2 (0.1wt%) exhibited higher photocatalytic activity, reaching a first-order reaction rate of kapp (0.036min-1), t1/2 was around 12 min and AB removal was 98.94%, under optimal pH of 3.5 and AB concentration of 10ppm compared to (t1/2= 45 min, t1/2=30 min), (kapp= 0.022 min-1, kapp=0.026min-1) and AB removal (94.78%, 96.44%), respectively for pure TiO2 and Ce-TiO2 (1wt%). Further increase in Eu/Ce amount up to optimal concentration (1wt% Ce and 0.1wt% Eu) led to a decrease in the AB removal. The mineralization of AB using Eu-TiO2 photocatalyst was confirmed by HPLC analysis.
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Affiliation(s)
- Dalanda HAMDI
- Laboratory of Wastewater and Environment, Center for Water Research and Technologies of BorjCedria
Tunisia (CERTE), Technopark Borj Cedria, Soliman,
Tunisia
- University of Gabes, National school of engineers of Gabes, Gabes,
Tunisia
| | - Lobna MANSOURI
- Laboratory of Wastewater and Environment, Center for Water Research and Technologies of BorjCedria
Tunisia (CERTE), Technopark Borj Cedria, Soliman,
Tunisia
| | - Varsha SRIVASTAVA
- Research Unit of Sustainable Chemistry, Faculty of Technology, University of Oulu, Oulu,
Finland
| | - Mika SILLANPAA
- Environmental Engineering and Management Research Group, Ton Duc Thang University, Ho Chi Minh City,
Vietnam
- Faculty of Environment and Labour Safety, Ton Duc Thang University, Ho Chi Minh City,
Vietnam
| | - Latifa BOUSSELMI
- Laboratory of Wastewater and Environment, Center for Water Research and Technologies of BorjCedria
Tunisia (CERTE), Technopark Borj Cedria, Soliman,
Tunisia
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Auto-combustion Fabrication and Optical Properties of Zinc Oxide Nanoparticles for Degradation of Reactive Red 195 and Methyl Orange Dyes. J Inorg Organomet Polym Mater 2021. [DOI: 10.1007/s10904-021-01975-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Cherukupally P, Sun W, Williams DR, Ozin GA, Bilton AM. Wax-wetting sponges for oil droplets recovery from frigid waters. SCIENCE ADVANCES 2021; 7:7/11/eabc7926. [PMID: 33692099 PMCID: PMC7946373 DOI: 10.1126/sciadv.abc7926] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 01/26/2021] [Indexed: 06/12/2023]
Abstract
Energy-efficient recovery of oil droplets from ice-cold water, such as oil sands tailings, marine, and arctic oil spills, is challenging. In particular, due to paraffin wax crystallization at low temperatures, the crude oil exhibits high viscosity, making it difficult to collect using simple solutions like sponges. Here, we report a wax-wetting sponge designed by conforming to the thermoresponsive microstructure of crude oil droplets. To address paraffin wax crystallization, we designed the sponge by coating a polyester polyurethane substrate with nanosilicon functionalized with paraffin-like octadecyl ligands. The wax-wetting sponge can adsorb oil droplets from wastewater between 5° and 40°C with 90 to 99% removal efficacy for 10 cycles. Also, upon rinsing with heptol, the adsorbed oil is released within seconds. The proposed approach of sponges designed to conform with the temperature-dependent microstructure of the crude oils could enable cold water technologies and improve circular economy metrics in the oil industry.
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Affiliation(s)
- P Cherukupally
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Canada.
- Department of Chemical Engineering, Imperial College London, London, UK
| | - W Sun
- Department of Chemistry, University of Toronto, Toronto, Canada
| | - D R Williams
- Department of Chemical Engineering, Imperial College London, London, UK
| | - G A Ozin
- Department of Chemistry, University of Toronto, Toronto, Canada.
| | - A M Bilton
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Canada.
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Li Y, Liao C, Tjong SC. Recent Advances in Zinc Oxide Nanostructures with Antimicrobial Activities. Int J Mol Sci 2020; 21:E8836. [PMID: 33266476 PMCID: PMC7700383 DOI: 10.3390/ijms21228836] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 11/18/2020] [Accepted: 11/19/2020] [Indexed: 12/18/2022] Open
Abstract
This article reviews the recent developments in the synthesis, antibacterial activity, and visible-light photocatalytic bacterial inactivation of nano-zinc oxide. Polycrystalline wurtzite ZnO nanostructures with a hexagonal lattice having different shapes can be synthesized by means of vapor-, liquid-, and solid-phase processing techniques. Among these, ZnO hierarchical nanostructures prepared from the liquid phase route are commonly used for antimicrobial activity. In particular, plant extract-mediated biosynthesis is a single step process for preparing nano-ZnO without using surfactants and toxic chemicals. The phytochemical molecules of natural plant extracts are attractive agents for reducing and stabilizing zinc ions of zinc salt precursors to form green ZnO nanostructures. The peel extracts of certain citrus fruits like grapefruits, lemons and oranges, acting as excellent chelating agents for zinc ions. Furthermore, phytochemicals of the plant extracts capped on ZnO nanomaterials are very effective for killing various bacterial strains, leading to low minimum inhibitory concentration (MIC) values. Bioactive phytocompounds from green ZnO also inhibit hemolysis of Staphylococcus aureus infected red blood cells and inflammatory activity of mammalian immune system. In general, three mechanisms have been adopted to explain bactericidal activity of ZnO nanomaterials, including direct contact killing, reactive oxygen species (ROS) production, and released zinc ion inactivation. These toxic effects lead to the destruction of bacterial membrane, denaturation of enzyme, inhibition of cellular respiration and deoxyribonucleic acid replication, causing leakage of the cytoplasmic content and eventual cell death. Meanwhile, antimicrobial activity of doped and modified ZnO nanomaterials under visible light can be attributed to photogeneration of ROS on their surfaces. Thus particular attention is paid to the design and synthesis of visible light-activated ZnO photocatalysts with antibacterial properties.
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Affiliation(s)
- Yuchao Li
- Department of Materials Science and Engineering, Liaocheng University, Liaocheng 252000, China;
| | - Chengzhu Liao
- Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Sie Chin Tjong
- Department of Physics, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China
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Li Y, Zhang L, Shi Y, Huang J, Yang Y, Ming D. Poly( N-Isopropylacrylamide)-Functional Silicon Nanocrystals for Thermosensitive Fluorescence Cellar Imaging. Polymers (Basel) 2020; 12:polym12112565. [PMID: 33139603 PMCID: PMC7693885 DOI: 10.3390/polym12112565] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 10/30/2020] [Accepted: 10/30/2020] [Indexed: 02/06/2023] Open
Abstract
Silicon nanocrystals (Si NCs) have received surging interest as a type of quantum dot (QD) due to the availability of silicon in nature, tunable fluorescence emission properties and excellent biocompatibility. More importantly, compared with many group II-VI and III-V based QDs, they have low toxicity. Here, thermoresponsive poly(N-isopropylacrylamide) (PNIPAAm)-functional Si NCs were firstly prepared for thermoresponsive detection of cancer cells. Si NCs were prepared under normal pressure with excellent water solubility. Then folic acid was bonded to the silicon nanocrystals through the reaction of amino and carboxyl groups for specific recognition of cancer cells. The folic-acid-modified silicon crystals (Si NCs-FA) could be modified by a one-pot copolymerization process into PNIPAAm nanospheres during the monomer polymerization process (i.e., Si NCs-FA-PNIPAAm) just by controlling the temperature below the lower critical solution temperature (LCST) and above the LCST. The results showed that the Si-FA-PNIAAm nanospheres exhibited not only reversible temperature-responsive on-off fluorescence properties, but also can be used as temperature indicators in cancer cells.
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Affiliation(s)
- Yiting Li
- College of Food and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210023, China; (Y.L.); (L.Z.)
- College of Biological and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Lihui Zhang
- College of Food and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210023, China; (Y.L.); (L.Z.)
| | - Youhong Shi
- College of Pharmacy, Nanjing Tech University, Nanjing 211816, China; (Y.S.); (J.H.)
| | - Jialing Huang
- College of Pharmacy, Nanjing Tech University, Nanjing 211816, China; (Y.S.); (J.H.)
| | - Yaqiong Yang
- College of Food and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210023, China; (Y.L.); (L.Z.)
- Correspondence: (Y.Y.); (D.M.)
| | - Dengming Ming
- College of Biological and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, China
- Correspondence: (Y.Y.); (D.M.)
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