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Nguyen Tan T, Babel S, Bora T, Sreearunothai P, Laohhasurayotin K. Preparation of heterogeneous cation exchange membrane and its contributions in enhancing the removal of Ni 2+ by capacitive deionization system. Chemosphere 2024; 350:141115. [PMID: 38182085 DOI: 10.1016/j.chemosphere.2024.141115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 12/24/2023] [Accepted: 01/02/2024] [Indexed: 01/07/2024]
Abstract
Capacitive deionization (CDI), an emerging method to eliminate ions from water at a low cost, has garnered significant interest in recent years. This study evaluates the implication of cation exchange resin loading on the membrane via the nonsolvent-induced phase inversion method. After determining the quantity of resins efficiently loaded on the membrane, it was subsequently utilized as a cation exchange membrane in the membrane capacitive deionization (MCDI) unit to examine the performance removal of Ni2+. The results show that the amount of resins influenced the membrane structure and significantly improved the efficiency of Ni2+ removal. The sulfonic acid group show a strong intensity directly proportional to the quantity of resins based on the FTIR measurement. In conjunction with the enhanced resin amount, ion exchange capacity and water content were increased. Simultaneously, there was an observed elevation in the water contact angle and the roughness of the membrane surface with increased resin amount. In the MCDI unit, membrane M20 (20% by weight resin) was employed to elucidate its roles in the CDI unit, encompassing an examination of various concentrations and flow rates, with Ni2+ utilized as a test contaminant. The results demonstrated that using membrane M20 in the MCDI (MCDI-M20) unit consistently exhibited higher adsorption levels than the CDI unit, reaching 19.80 mg g-1 ACC in the MCDI-M20 unit, while CDI unit achieved 10.27 mg g-1 ACC at 200 mg L-1 Ni2+ concentration and a flow rate of 10 mL min-1 at 1.2 V. Additionally, Ni2+ concentrations and flow rates in CDI system had an evident impact on the duration of adsorption due to the mechanisms of ions transport on the membrane. This study suggests that employing the prepared membrane in the MCDI unit enhanced the removal of Ni2+ from the solution, contributing to sustainable development goals.
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Affiliation(s)
- Thong Nguyen Tan
- School of Biochemical Engineering and Technology, Sirindhorn International Institute of Technology, Thammasat University, P.O. Box 22, Pathum Thani, 12121, Thailand
| | - Sandhya Babel
- School of Biochemical Engineering and Technology, Sirindhorn International Institute of Technology, Thammasat University, P.O. Box 22, Pathum Thani, 12121, Thailand.
| | - Tanujjal Bora
- Center of Excellence in Nanotechnology, School of Engineering and Technology, Asian Institute of Technology, P.O. Box 4, Klong Luang, Pathum Thani, 12121, Thailand
| | - Paiboon Sreearunothai
- School of Biochemical Engineering and Technology, Sirindhorn International Institute of Technology, Thammasat University, P.O. Box 22, Pathum Thani, 12121, Thailand
| | - Kritapas Laohhasurayotin
- National Nanotechnology Center, National Science and Technology Development Agency 111 Thailand Science Park, Khlong 1, Khlong Luang, Pathum Thani, 12120, Thailand
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Swargiary K, Metem P, Kulatumyotin C, Thaneerat S, Ajchareeyasoontorn N, Jitpratak P, Bora T, Mohammed WS, Dutta J, Viphavakit C. ZnO Nanorods Coated Single-Mode-Multimode-Single-Mode Optical Fiber Sensor for VOC Biomarker Detection. Sensors (Basel) 2022; 22:6273. [PMID: 36016038 PMCID: PMC9415095 DOI: 10.3390/s22166273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 08/15/2022] [Accepted: 08/18/2022] [Indexed: 06/15/2023]
Abstract
This work demonstrated a ZnO-coated optical fiber sensor for the detection of a volatile organic compound (VOC) biomarker for diabetes for detecting isopropanol (IPA) markers. A coreless silica fiber (CSF) was connected to a single-mode fiber (SMF) at both ends to achieve a SMF-CSF-SMF structure. CSF is the sensing region where multimode interference (MMI) generates higher light interaction at the interface between the fiber and sensing medium, leading to enhanced sensitivity. Optimization of the CSF length was conducted numerically to attain the highest possible coupling efficiency at the output. Surface functionalization was achieved via hydrothermal growth of ZnO nanorods directly onto the CSF at low temperatures. The optical fiber-based sensor was successfully fabricated and tested with 20%, 40%, 60%, 80%, and 100% of IPA. The sensor response was recorded using an optical spectrometer and analyzed for sensor sensitivity. The fabricated sensor shows the potential to detect isopropanol with the sensitivity of 0.053 nm/%IPA vapor. Further improvement of the sensor sensitivity and selectivity is also proposed for future work.
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Affiliation(s)
- Kankan Swargiary
- International School of Engineering (ISE), Intelligent Control Automation of Process Systems Research Unit, Chulalongkorn University, Bangkok 10330, Thailand
| | - Prattakorn Metem
- International School of Engineering (ISE), Intelligent Control Automation of Process Systems Research Unit, Chulalongkorn University, Bangkok 10330, Thailand
- Functional NanoMaterials Group, Department of Applied Physics, KTH Royal Institute of Technology, Hannes Alfvéns väg 12, 11419 Stockholm, Sweden
| | - Chayapol Kulatumyotin
- International School of Engineering (ISE), Intelligent Control Automation of Process Systems Research Unit, Chulalongkorn University, Bangkok 10330, Thailand
| | - Suphavit Thaneerat
- International School of Engineering (ISE), Intelligent Control Automation of Process Systems Research Unit, Chulalongkorn University, Bangkok 10330, Thailand
| | - Noppasin Ajchareeyasoontorn
- International School of Engineering (ISE), Intelligent Control Automation of Process Systems Research Unit, Chulalongkorn University, Bangkok 10330, Thailand
| | - Pannathorn Jitpratak
- Biomedical Engineering Program, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand
| | - Tanujjal Bora
- Center of Excellence in Nanotechnology, Asian Institute of Technology, Pathumthani 12120, Thailand
| | - Waleed S. Mohammed
- Center of Research in Optoelectronics, Communication and Control Systems (BU-CROCCS), School of Engineering, Bangkok University, Pathumthani 12120, Thailand
| | - Joydeep Dutta
- Functional NanoMaterials Group, Department of Applied Physics, KTH Royal Institute of Technology, Hannes Alfvéns väg 12, 11419 Stockholm, Sweden
| | - Charusluk Viphavakit
- International School of Engineering (ISE), Intelligent Control Automation of Process Systems Research Unit, Chulalongkorn University, Bangkok 10330, Thailand
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Rico-Yuson CA, Hornyak GL, Bora T. Cyanide-free environment-friendly alternative to copper electroplating for zinc die-cast alloys. Environ Sci Pollut Res Int 2021; 28:38065-38073. [PMID: 33725308 DOI: 10.1007/s11356-021-13398-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 03/08/2021] [Indexed: 06/12/2023]
Abstract
In this paper, a cyanide-free electroplating bath containing glutamate as a complexing agent is investigated as an environment-friendly alternative for copper plating on zinc die-cast alloys. Glutamate reacts with copper in an aqueous solution that exhibits similar copper cyanide properties by forming complexes. The electroplating bath pH is chosen from equilibrium diagrams to avoid the formation of insoluble complexes and oxides at varying copper-to-glutamate molar ratio. The plating bath's electrochemical response on a stationary electrode confirms that a 1:3 molar ratio between copper and glutamate at pH 8 exhibits better copper deposition onto the substrate, with its morphology characterized using SEM. The results suggest that the copper glutamate electroplating bath can be suitable for copper cyanide bath replacement without additives, allowing a one-step electroplating process. Moreover, the polarization and electrochemical impedance measurements suggest inhibition of the substrate's corrosion when copper was electroplated at a 1:3 copper-to-glutamate molar ratio. With the careful control of the concentration ratio, the process can provide adequate copper deposition and anti-corrosion capability suitable for green nanocoating applications.
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Affiliation(s)
- Christine Adelle Rico-Yuson
- Center of Excellence in Nanotechnology, School of Engineering and Technology, Asian Institute of Technology, PO Box 4, Klong Luang, Pathumthani, 12120, Thailand
- Department of Physics, College of Arts and Sciences, Central Mindanao University, Musuan, 8710, Maramag, Bukidnon, Philippines
| | - G Louis Hornyak
- Center of Excellence in Nanotechnology, School of Engineering and Technology, Asian Institute of Technology, PO Box 4, Klong Luang, Pathumthani, 12120, Thailand
| | - Tanujjal Bora
- Center of Excellence in Nanotechnology, School of Engineering and Technology, Asian Institute of Technology, PO Box 4, Klong Luang, Pathumthani, 12120, Thailand.
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Dobretsov S, Sathe P, Bora T, Barry M, Myint MTZ, Abri MA. Toxicity of Different Zinc Oxide Nanomaterials at 3 Trophic Levels: Implications for Development of Low-Toxicity Antifouling Agents. Environ Toxicol Chem 2020; 39:1343-1354. [PMID: 32274816 DOI: 10.1002/etc.4720] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 11/27/2019] [Accepted: 03/30/2020] [Indexed: 06/11/2023]
Abstract
Because zinc oxide (ZnO) nanomaterials are used in antifouling and antibacterial solutions, understanding their toxic effects on different aquatic organisms is essential. In the present study, we evaluated the toxicity of ZnO nanoparticles of 10 to 30 nm (ZnONPI) and 80 to 200 nm (ZnONPII), ZnO nanorods (width 80 nm, height 1.7 µm) attached to the support substrate (glass, ZnONRG) and not attached (ZnONRS), as well as Zn2+ ions at concentrations ranging from 0.5 to 100 mg/L. Toxicity was evaluated using the microalga Dunaliella salina, the brine shrimp Artemia salina, and the marine bacterium Bacillus cereus. The highest toxicity was observed for ZnONPs (median lethal concentration [LC50] ~15 mg/L) and Zn2+ ions (LC50 ~13 mg/L), whereas the lowest toxicity found for ZnO nanorods (ZnONRG LC50 ~60 mg/L; ZnONRS LC50 ~42 mg/L). The presence of the support substrate in case of ZnO nanorods reduced the associated toxicity to aquatic organisms. Smaller ZnONPs resulted in the highest Zn2+ ion dissolution among tested nanostructures. Different aquatic organisms responded differently to ZnO nanomaterials, with D. salina and B. cereus being more sensitive than A. salina. Toxicity of nanostructures increased with an increase of the dose and the time of exposure. Supported ZnO nanorods can be used as a low-toxicity alternative for future antimicrobial and antifouling applications. Environ Toxicol Chem 2020;39:1343-1354. © 2020 SETAC.
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Affiliation(s)
- Sergey Dobretsov
- Department of Marine Science & Fisheries, College of Agricultural & Marine Sciences, Sultan Qaboos University, Muscat, Sultanate of Oman
- Center of Excellence in Marine Biotechnology, Sultan Qaboos University, Muscat, Sultanate of Oman
| | - Priyanka Sathe
- Department of Marine Science & Fisheries, College of Agricultural & Marine Sciences, Sultan Qaboos University, Muscat, Sultanate of Oman
- Center of Nanotechnology, Sultan Qaboos University, Muscat, Sultanate of Oman
| | - Tanujjal Bora
- Nanotechnology Industrial System Engineering, School of Engineering and Technology, Asian Institute of Technology, Klong Luang, Pathumthani, Thailand
| | - Michael Barry
- Department of Biology, College of Science, Sultan Qaboos University, Muscat, Sultanate of Oman
| | - Myo Tay Zar Myint
- Department of Physics, College of Science, Sultan Qaboos University, Muscat, Sultanate of Oman
| | - Mohammed Al Abri
- Center of Nanotechnology, Sultan Qaboos University, Muscat, Sultanate of Oman
- Petroleum and Chemical Engineering Department, College of Engineering, Sultan Qaboos University, Muscat, Sultanate of Oman
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Agarwal A, Manna S, Nath S, Sharma K, Chaudhury P, Bora T, Solomon I, Sarma A. Controlling oil/water separation using oleophillic and hydrophobic coatings based on plasma technology. Mater Res Express 2020; 7:036411. [DOI: 10.1088/2053-1591/ab8097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/19/2023]
Abstract
Abstract
Disposable and highly efficient device that can separate oil from water is in high demand. This work reveals the concept of oil/water separation using plasma technology. Copper coated, oxygen plasma-treated mesh has been used to separate oil and water from its mixture. At some critical conditions, the prepared coated mesh showed hydrophobic and oleophilic behavior. The coated mesh was used to separate the oil-water mixture, which allowed the oil to pass through, while it repelled water completely. The designed coated mesh maintained separation efficiency as high as 99 percent. Properties of coated and uncoated mesh were examined using various techniques and analyzed to understand the physical changes.
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Ponlamuangdee K, Hornyak GL, Bora T, Bamrungsap S. Graphene oxide/gold nanorod plasmonic paper – a simple and cost-effective SERS substrate for anticancer drug analysis. NEW J CHEM 2020. [DOI: 10.1039/d0nj02448a] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A simple and cost-effective plasmonic paper as a SERS substrate based on a combination of graphene oxide (GO) and gold nanorods (AuNRs).
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Affiliation(s)
- Kanyawan Ponlamuangdee
- National Nanotechnology Center (NANOTEC)
- National Science and Technology Development Agency (NSTDA)
- Pathum Thani
- Thailand
- Center of Excellence in Nanotechnology
| | - Gabor L. Hornyak
- Center of Excellence in Nanotechnology
- Department of Industrial Systems Engineering
- School of Engineering and Technology
- Asian Institute of Technology (AIT)
- Pathum Thani 12120
| | - Tanujjal Bora
- Center of Excellence in Nanotechnology
- Department of Industrial Systems Engineering
- School of Engineering and Technology
- Asian Institute of Technology (AIT)
- Pathum Thani 12120
| | - Suwussa Bamrungsap
- National Nanotechnology Center (NANOTEC)
- National Science and Technology Development Agency (NSTDA)
- Pathum Thani
- Thailand
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Bora T, Dutta J. Plasmonic Photocatalyst Design: Metal-Semiconductor Junction Affecting Photocatalytic Efficiency. J Nanosci Nanotechnol 2019; 19:383-388. [PMID: 30327045 DOI: 10.1166/jnn.2019.15785] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Silver-zinc oxide nanorods (Ag-ZnO NRs) and gold-zinc oxide nanorods (Au-ZnO NRs) plasmonic photocatalysts were fabricated by the deposition of Ag and Au nanoparticles on ZnO NRs. The photocatalysts were studied with electron microscopy, energy dispersive spectroscopy (EDS), UVvis optical absorption and photoluminescence spectroscopy. The effect of type of metals on the ZnO surface on its photocatalytic activity under ultra violet (UV) as well as visible light excitation are investigated and their contribution towards enhanced photo-generated charge separation in terms of the type of junction (Ohmic or Schottky) the metal forms with the semiconductor are explained.
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Affiliation(s)
- Tanujjal Bora
- Nanotechnology, Industrial System Engineering, School of Engineering and Technology, Asian Institute of Technology, P.O. Box 4, Klong Luang, Pathumthani-12120, Thailand
| | - Joydeep Dutta
- Functional Materials, Applied Physics Department, School of Engineering Sciences School, Kungliga Tekniska Högskolan Royal Institute of Technology, Isafjordsgatan 22, SE-16440 Kista-Stockholm, Sweden
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Loiko P, Bora T, Serres JM, Yu H, Aguiló M, Díaz F, Griebner U, Petrov V, Mateos X, Dutta J. Oriented zinc oxide nanorods: A novel saturable absorber for lasers in the near-infrared. Beilstein J Nanotechnol 2018; 9:2730-2740. [PMID: 30416924 PMCID: PMC6204775 DOI: 10.3762/bjnano.9.255] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 09/28/2018] [Indexed: 06/09/2023]
Abstract
Zinc oxide (ZnO) nanorods (NRs) oriented along the crystallographic [001] axis are grown by the hydrothermal method on glass substrates. The ZnO NRs exhibit a broadband (1-2 µm) near-IR absorption ascribed to the singly charged zinc vacancy VZn -1. The saturable absorption of the ZnO NRs is studied at ≈1 µm under picosecond excitation, revealing a low saturation intensity, ≈10 kW/cm2, and high fraction of the saturable losses. The ZnO NRs are applied as saturable absorbers in diode-pumped Yb (≈1.03 µm) and Tm (≈1.94 µm) lasers generating nanosecond pulses. The ZnO NRs grown on various optical surfaces are promising broadband saturable absorbers for nanosecond near-IR lasers in bulk and waveguide geometries.
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Affiliation(s)
- Pavel Loiko
- ITMO University, Kronverkskiy pr., 49, 197101 Saint-Petersburg, Russia
| | - Tanujjal Bora
- Chair in Nanotechnology, Water Research Center, Sultan Qaboos University, P.O. Box 17, Al-Khoudh, 123 Muscat, Oman
- Nanotechnology, School of Engineering and Technology, Asian Institute of Technology, P.O. Box 4, Klong Luang, Pathumthani – 12120, Thailand
| | - Josep Maria Serres
- Física i Cristallografia de Materials i Nanomaterials (FiCMA-FiCNA)-EMaS, Dept. Química Física i Inòrganica, Universitat Rovira i Virgili (URV), Campus Sescelades, 43007 Tarragona, Spain
| | - Haohai Yu
- State Key Laboratory of Crystal Materials and Institute of Crystal Materials, Shandong University, Jinan 250100, China
| | - Magdalena Aguiló
- Física i Cristallografia de Materials i Nanomaterials (FiCMA-FiCNA)-EMaS, Dept. Química Física i Inòrganica, Universitat Rovira i Virgili (URV), Campus Sescelades, 43007 Tarragona, Spain
| | - Francesc Díaz
- Física i Cristallografia de Materials i Nanomaterials (FiCMA-FiCNA)-EMaS, Dept. Química Física i Inòrganica, Universitat Rovira i Virgili (URV), Campus Sescelades, 43007 Tarragona, Spain
| | - Uwe Griebner
- Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, Max-Born-Str. 2a, 12489 Berlin, Germany
| | - Valentin Petrov
- Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, Max-Born-Str. 2a, 12489 Berlin, Germany
| | - Xavier Mateos
- Física i Cristallografia de Materials i Nanomaterials (FiCMA-FiCNA)-EMaS, Dept. Química Física i Inòrganica, Universitat Rovira i Virgili (URV), Campus Sescelades, 43007 Tarragona, Spain
| | - Joydeep Dutta
- Functional Materials, Applied Physics Department, School of Engineering Sciences, KTH Royal Institute of Technology, Isafjordsgatan 22, SE-164 40 Kista Stockholm, Sweden
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Khalid M, Bora T, Ghaithi AA, Thukral S, Dutta J. Raman Spectroscopy detects changes in Bone Mineral Quality and Collagen Cross-linkage in Staphylococcus Infected Human Bone. Sci Rep 2018; 8:9417. [PMID: 29925892 PMCID: PMC6010429 DOI: 10.1038/s41598-018-27752-z] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 06/04/2018] [Indexed: 01/01/2023] Open
Abstract
Diagnosis of osteomyelitis presents a formidable challenge. Lack of pathognomonic clinical sign(s) and diagnostic tests that can diagnose osteomyelitis at an early stage contribute to this difficulty. If the diagnosis is not made early, the disease becomes very difficult to eradicate and can lead to limb threatening and potentially life-threatening complications. Staphylococcus aureus is the most common organism causing osteomyelitis. Raman Spectroscopy provides information about molecular vibration that could potentially be harnessed as a spectral signature for cellular changes in specific pathologic conditions. In this study we describe a technique using Raman spectroscopy that could potentially be used to diagnose staphylococcal osteomyelitis. Human bone samples were co-cultured with Staphylococcus aureus (S. aureus) and the effects of bacterial growth on bone quality were then monitored using Raman spectroscopy. A major drop in the bone mineral quality and crystallinity was observed in the infected bones compared to the controls. S. aureus infection was also found to alter the collagen cross-linking. Our study shows that specific spectral signatures are present for the cause as well as the effect of staphylococcal osteomyelitis, opening the possibility of developing a useful diagnostic modality for early and rapid diagnosis of this condition.
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Affiliation(s)
- Mohamed Khalid
- Department of Orthopaedics, College of Medicine, Taibah University, Universities Road, Taibah, Madinah Al-Munawwarah, 42353, Saudi Arabia
| | - Tanujjal Bora
- Centre of Excellence in Nanotechnology, Asian Institute of Technology, PO Box 4, Klong Luang, Pathumthani, 12120, Thailand
| | - Ahmed Al Ghaithi
- Oman Medical Specialty Board, Orthopaedic Residency Program, Al-Khoud, Al-Athiba, Oman
| | - Sharanjit Thukral
- Microbiology Department, College of Medicine, Sultan Qaboos University, Al-Khoud, 123, Oman
| | - Joydeep Dutta
- Functional Materials, Department of Applied Physics, SCI School, KTH Royal Institute of Technology, SE-164 40, Kista, Stockholm, Sweden.
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Sulaiman SAJ, Bora T, Abou-Zied OK. Spectroscopic characterization of the warfarin drug-binding site of folded and unfolded human serum albumin anchored on gold nanoparticles: effect of bioconjugation on the loading capacity. RSC Adv 2018; 8:7523-7532. [PMID: 35539131 PMCID: PMC9078392 DOI: 10.1039/c8ra00006a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Accepted: 02/09/2018] [Indexed: 12/02/2022] Open
Abstract
Protein-conjugated gold nanoparticles (AuNPs) have recently shown promising applications in medicine, owing to their inertness and biocompatibility. Herein, we studied the spectroscopy of 25 nm diameter AuNPs, coated with human serum albumin (HSA) as a model drug carrier. The morphology and coating of the AuNPs were examined using transmission electron microscopy and dynamic light scattering. Resonance energy transfer from the sole tryptophan of HSA (Trp214) to the AuNPs indicates a single layer of protein coverage. Using fluorescein (FL) to probe the warfarin drug-binding site in HSA revealed an increase in the HSA–FL binding by ∼4.5 times when HSA is anchored on the nanoparticle surface, indicating a rise in the loading capacity. Femtosecond transient absorption measurements of the surface plasmonic resonance band of the AuNPs show three ultrafast dynamics that are involved in the relaxation process. The three decay components were assigned to the electron–electron (∼400 fs), electron–phonon (∼2.0 ps) and phonon–phonon (200–250 ps) interactions. These dynamics were not changed upon coating the AuNPs with HSA which indicates the chemical and physical stability of the AuNPs upon bioconjugation. Chemical unfolding of the warfarin binding site with guanidine hydrochloride (GdnHCl) was studied by measuring the spectral shift in the Trp214 fluorescence and the appearance of the Tyr fluorescence. Unfolding was shown to start at [GdnHCl] ≥ 2.0 M and is complete at [GdnHCl] = 6.0 M. HSA anchored onto the nanoparticle surface shows more resistance to the unfolding effect which is attributed to the stability of the native form of HSA on the nanoparticle surface. On the other hand, upon complete unfolding, a larger red shift in the Trp214 fluorescence was observed for the HSA–AuNP complex. This observation indicates that, upon unfolding, the HSA molecule is still anchored on the AuNP surface in which subdomain IIA is facing the outer water molecules in the bulk solution as well as the hydration shell rather than the core of the nanoparticle. The current study is important for a better understanding of the physical and dynamical properties of protein-coated metal nanoparticles, which is expected to help in optimizing their properties for critical applications in nanomedicine. This work investigates the steady-state and ultrafast spectroscopy of bioconjugated gold nanoparticles and the implications on the protein binding activity and drug-loading capacity.![]()
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Affiliation(s)
- Saba A. J. Sulaiman
- Department of Chemistry
- Faculty of Science
- Sultan Qaboos University
- Muscat
- Sultanate of Oman
| | - Tanujjal Bora
- Nanotechnology Research Center
- Sultan Qaboos University
- Muscat
- Sultanate of Oman
| | - Osama K. Abou-Zied
- Department of Chemistry
- Faculty of Science
- Sultan Qaboos University
- Muscat
- Sultanate of Oman
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Al-Sabahi J, Bora T, Al-Abri M, Dutta J. Efficient visible light photocatalysis of benzene, toluene, ethylbenzene and xylene (BTEX) in aqueous solutions using supported zinc oxide nanorods. PLoS One 2017; 12:e0189276. [PMID: 29261711 PMCID: PMC5738043 DOI: 10.1371/journal.pone.0189276] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 11/22/2017] [Indexed: 12/01/2022] Open
Abstract
Benzene, toluene, ethylbenzene and xylenes (BTEX) are some of the common environmental pollutants originating mainly from oil and gas industries, which are toxic to human as well as other living organisms in the ecosystem. Here we investigate photocatalytic degradation of BTEX under visible light irradiation using supported zinc oxide (ZnO) nanorods grown on glass substrates using a microwave assisted hydrothermal method. ZnO nanorods were characterized by electron microscopy, X-ray diffraction (XRD), specific surface area, UV/visible absorption and photoluminescence spectroscopy. Visible light photocatalytic degradation products of BTEX are studied for individual components using gas chromatograph/mass spectrometer (GC/MS). ZnO nanorods with significant amount of electronic defect states, due to the fast crystallization of the nanorods under microwave irradiation, exhibited efficient degradation of BTEX under visible light, degrading more than 80% of the individual BTEX components in 180 minutes. Effect of initial concentration of BTEX as individual components is also probed and the photocatalytic activity of the ZnO nanorods in different conditions is explored. Formation of intermediate byproducts such as phenol, benzyl alcohol, benzaldehyde and benzoic acid were confirmed by our HPLC analysis which could be due to the photocatalytic degradation of BTEX. Carbon dioxide was evaluated and showed an increasing pattern over time indicating the mineralization process confirming the conversion of toxic organic compounds into benign products.
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Affiliation(s)
- Jamal Al-Sabahi
- Department of Petroleum and Chemical Engineering, College of Engineering, Sultan Qaboos University, Al-Khoudh, Oman
- Chair in Nanotechnology for Water Desalination, Water Research Center, Sultan Qaboos University, Al-Khoudh, Oman
| | - Tanujjal Bora
- Center of Excellence in Nanotechnology, Asian Institute of Technology, Klong Luang, Pathumthani, Thailand
| | - Mohammed Al-Abri
- Department of Petroleum and Chemical Engineering, College of Engineering, Sultan Qaboos University, Al-Khoudh, Oman
- Chair in Nanotechnology for Water Desalination, Water Research Center, Sultan Qaboos University, Al-Khoudh, Oman
- * E-mail: (MA); (JD)
| | - Joydeep Dutta
- Functional Materials, Department of Applied Physics, School of Engineering Sciences, KTH Royal Institute of Technology, Kista, Stockholm, Sweden
- * E-mail: (MA); (JD)
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Al-Saadi MJ, Al-Harthi SH, Kyaw HH, Myint MT, Bora T, Laxman K, Al-Hinai A, Dutta J. Influence of Atomic Hydrogen, Band Bending, and Defects in the Top Few Nanometers of Hydrothermally Prepared Zinc Oxide Nanorods. Nanoscale Res Lett 2017; 12:22. [PMID: 28063141 PMCID: PMC5218952 DOI: 10.1186/s11671-016-1800-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2016] [Accepted: 11/28/2016] [Indexed: 05/22/2023]
Abstract
We report on the surface, sub-surface (top few nanometers) and bulk properties of hydrothermally grown zinc oxide (ZnO) nanorods (NRs) prior to and after hydrogen treatment. Upon treating with atomic hydrogen (H*), upward and downward band bending is observed depending on the availability of molecular H2O within the structure of the NRs. In the absence of H2O, the H* treatment demonstrated a cleaning effect of the nanorods, leading to a 0.51 eV upward band bending. In addition, enhancement in the intensity of room temperature photoluminescence (PL) signals due to the creation of new surface defects could be observed. The defects enhanced the visible light activity of the ZnO NRs which were subsequently used to photocatalytically degrade aqueous phenol under simulated sunlight. On the contrary, in the presence of H2O, H* treatment created an electronic accumulation layer inducing downward band bending of 0.45 eV (~1/7th of the bulk ZnO band gap) along with the weakening of the defect signals as observed from room temperature photoluminescence spectra. The results suggest a plausible way of tailoring the band bending and defects of the ZnO NRs through control of H2O/H* species.
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Affiliation(s)
- Mubarak J. Al-Saadi
- Department of Physics, Sultan Qaboos University, PO Box 36, Al Khoudh, 123, Muscat, Oman
| | - Salim H. Al-Harthi
- Department of Physics, Sultan Qaboos University, PO Box 36, Al Khoudh, 123, Muscat, Oman
| | - Htet H. Kyaw
- Department of Physics, Sultan Qaboos University, PO Box 36, Al Khoudh, 123, Muscat, Oman
| | - Myo T.Z. Myint
- Department of Physics, Sultan Qaboos University, PO Box 36, Al Khoudh, 123, Muscat, Oman
| | - Tanujjal Bora
- Chair in Nanotechnology, Water Research Center, Sultan Qaboos University, PO Box 17 Al Khoudh, 123, Muscat, Oman
| | - Karthik Laxman
- Chair in Nanotechnology, Water Research Center, Sultan Qaboos University, PO Box 17 Al Khoudh, 123, Muscat, Oman
| | - Ashraf Al-Hinai
- Department of Chemistry, Sultan Qaboos University, PO Box 36, Al Khoudh, 123, Muscat, Oman
| | - Joydeep Dutta
- Functional Materials Division, Materials and Nanophysics, ICT School, KTH Royal Institute of Technology, Isafjordsgatan 22, SE-164 40 Kista, Stockholm Sweden
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Karim F, Bora T, Chaudhari M, Habib K, Mohammed W, Dutta J. Measurement of aluminum oxide film by Fabry–Pérot interferometry and scanning electron microscopy. Journal of Saudi Chemical Society 2017. [DOI: 10.1016/j.jscs.2016.02.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Bora T, Sathe P, Laxman K, Dobretsov S, Dutta J. Defect engineered visible light active ZnO nanorods for photocatalytic treatment of water. Catal Today 2017. [DOI: 10.1016/j.cattod.2016.09.014] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Yüksel B, Bora T. Optimzation and validation of a GC-FID method for analysis of cocaine. Toxicol Lett 2016. [DOI: 10.1016/j.toxlet.2016.06.1694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Khan S, Bora T, Richards A, Chattopadhyay S, Jiang J, Laskar B, Dutta P. Molecular phylogenetics of Orientia tsutsugamushi strains circulating in Assam based on 56-kilodalton type-specific antigen gene. Int J Infect Dis 2016. [DOI: 10.1016/j.ijid.2016.02.421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Chowdhury P, Bora T, Khan S, Chakraborty B, Senapati K, Sengupta M, Borchetia S, Bandyopadhyay T. Inhibition of Japanese encephalitis virus infection by biogenic catechin silver nanoparticles: An in-vitro study. Int J Infect Dis 2016. [DOI: 10.1016/j.ijid.2016.02.611] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Bora T, Durmus I, Ertekin M, Fayda E, Tokdemir Ozturk S. EP-1615: Decreasing cone beam CT scan's doses and duration for breast cancer. Radiother Oncol 2016. [DOI: 10.1016/s0167-8140(16)32866-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
Visible light photocatalytic activity of the plasmonic gold–zinc oxide (Au–ZnO) nanorods (NRs) is investigated with respect to the surface defects of the ZnO NRs, controlled by annealing the NRs in ambient at different temperatures.
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Affiliation(s)
- T. Bora
- Chair in Nanotechnology
- Water Research Center
- Sultan Qaboos University
- Al Khoud – 123
- Oman
| | - M. T. Z. Myint
- Chair in Nanotechnology
- Water Research Center
- Sultan Qaboos University
- Al Khoud – 123
- Oman
| | - S. H. Al-Harthi
- Department of Physics
- College of Science
- Sultan Qaboos University
- Al Khoud – 123
- Oman
| | - J. Dutta
- Chair in Nanotechnology
- Water Research Center
- Sultan Qaboos University
- Al Khoud – 123
- Oman
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Abstract
Water on Earth is a precious and finite resource, which is endlessly recycled in the water cycle. Water, whose physical, chemical, or biological properties have been altered due to the addition of contaminants such as organic/inorganic materials, pathogens, heavy metals or other toxins making it unsafe for the ecosystem, can be termed as wastewater. Various schemes have been adopted by industries across the world to treat wastewater prior to its release to the ecosystem, and several new concepts and technologies are fast replacing the traditional methods. This article briefly reviews the recent advances and application of nanotechnology for wastewater treatment. Nanomaterials typically have high reactivity and a high degree of functionalization, large specific surface area, size-dependent properties etc., which makes them suitable for applications in wastewater treatment and for water purification. In this article, the application of various nanomaterials such as metal nanoparticles, metal oxides, carbon compounds, zeolite, filtration membranes, etc., in the field of wastewater treatment is discussed.
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Abstract
Water on Earth is a precious and finite resource, which is endlessly recycled in the water cycle. Water, whose physical, chemical, or biological properties have been altered due to the addition of contaminants such as organic/inorganic materials, pathogens, heavy metals or other toxins making it unsafe for the ecosystem, can be termed as wastewater. Various schemes have been adopted by industries across the world to treat wastewater prior to its release to the ecosystem, and several new concepts and technologies are fast replacing the traditional methods. This article briefly reviews the recent advances and application of nanotechnology for wastewater treatment. Nanomaterials typically have high reactivity and a high degree of functionalization, large specific surface area, size-dependent properties etc., which makes them suitable for applications in wastewater treatment and for water purification. In this article, the application of various nanomaterials such as metal nanoparticles, metal oxides, carbon compounds, zeolite, filtration membranes, etc., in the field of wastewater treatment is discussed.
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Karim F, Bora T, Chaudhari MB, Habib K, Mohammed WS, Dutta J. Optical fiber-based sensor for in situ monitoring of cadmium sulfide thin-film growth. Opt Lett 2013; 38:5385-5388. [PMID: 24322264 DOI: 10.1364/ol.38.005385] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
This work presents a scheme for in situ monitoring of thin-film growth. A fiber-optic sensor based on Fabry-Perot interferometric technique has been established for the first time to monitor in situ growth of thin films. This was applied for determining thickness of cadmium sulfide (CdS) thin films during growth. The fabrication process of CdS film was carried out in 30 mM cadmium acetate and thioacetamide solution at 60°C temperature. The estimated thickness determined during the growth was verified by scanning electron microscopy. This study shows that in situ measurement of the thickness of thin films is feasible by this new technique, and a close match of the estimated thickness was achieved.
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Bora T, Lakshman KK, Sarkar S, Makhal A, Sardar S, Pal SK, Dutta J. Modulation of defect-mediated energy transfer from ZnO nanoparticles for the photocatalytic degradation of bilirubin. Beilstein J Nanotechnol 2013; 4:714-25. [PMID: 24367739 PMCID: PMC3869374 DOI: 10.3762/bjnano.4.81] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Accepted: 10/22/2013] [Indexed: 05/26/2023]
Abstract
In recent years, nanotechnology has gained significant interest for applications in the medical field. In this regard, a utilization of the ZnO nanoparticles for the efficient degradation of bilirubin (BR) through photocatalysis was explored. BR is a water insoluble byproduct of the heme catabolism that can cause jaundice when its excretion is impaired. The photocatalytic degradation of BR activated by ZnO nanoparticles through a non-radiative energy transfer pathway can be influenced by the surface defect-states (mainly the oxygen vacancies) of the catalyst nanoparticles. These were modulated by applying a simple annealing in an oxygen-rich atmosphere. The mechanism of the energy transfer process between the ZnO nanoparticles and the BR molecules adsorbed at the surface was studied by using steady-state and picosecond-resolved fluorescence spectroscopy. A correlation of photocatalytic degradation and time-correlated single photon counting studies revealed that the defect-engineered ZnO nanoparticles that were obtained through post-annealing treatments led to an efficient decomposition of BR molecules that was enabled by Förster resonance energy transfer.
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Affiliation(s)
- Tanujjal Bora
- Center of Excellence in Nanotechnology, School of Engineering and Technology, Asian Institute of Technology, P. O. Box 4, Klong Luang, Pathumthani – 12120, Thailand
- Chair in Nanotechnology, Water Research Center, Sultan Qaboos University, P. O. Box 17, Al Khoud – 123, Sultanate of Oman
| | - Karthik Kunjali Lakshman
- Chair in Nanotechnology, Water Research Center, Sultan Qaboos University, P. O. Box 17, Al Khoud – 123, Sultanate of Oman
| | - Soumik Sarkar
- Department of Chemical, Biological & Macromolecular Sciences, Unit for Nanoscience & Technology, S. N. Bose National Centre for Basic Sciences, J D Block, Sector III, Salt Lake, Kolkata – 700 098, India
| | - Abhinandan Makhal
- Department of Chemical, Biological & Macromolecular Sciences, Unit for Nanoscience & Technology, S. N. Bose National Centre for Basic Sciences, J D Block, Sector III, Salt Lake, Kolkata – 700 098, India
| | - Samim Sardar
- Department of Chemical, Biological & Macromolecular Sciences, Unit for Nanoscience & Technology, S. N. Bose National Centre for Basic Sciences, J D Block, Sector III, Salt Lake, Kolkata – 700 098, India
| | - Samir Kumar Pal
- Department of Chemical, Biological & Macromolecular Sciences, Unit for Nanoscience & Technology, S. N. Bose National Centre for Basic Sciences, J D Block, Sector III, Salt Lake, Kolkata – 700 098, India
| | - Joydeep Dutta
- Center of Excellence in Nanotechnology, School of Engineering and Technology, Asian Institute of Technology, P. O. Box 4, Klong Luang, Pathumthani – 12120, Thailand
- Chair in Nanotechnology, Water Research Center, Sultan Qaboos University, P. O. Box 17, Al Khoud – 123, Sultanate of Oman
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Fallah H, Chaudhari M, Bora T, Harun SW, Mohammed WS, Dutta J. Demonstration of side coupling to cladding modes through zinc oxide nanorods grown on multimode optical fiber. Opt Lett 2013; 38:3620-3622. [PMID: 24104829 DOI: 10.1364/ol.38.003620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
A novel concept is introduced that utilizes the scattering properties of zinc oxide nanorods to control light guidance and leakage inside optical fibers coated with nanorods. The effect of the hydrothermal growth conditions of the nanorods on light scattering and coupling to optical fiber are experimentally investigated. At optimum conditions, 5% of the incident light is side coupled to the cladding modes. This coupling scheme could be used in different applications such as distributed sensors and light combing. Implementation of the nanorods on fiber provides low cost and controllable nonlithography-based solutions for free space to fiber coupling. Higher coupling efficiencies can be achieved with further optimization.
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Sarkar S, Makhal A, Bora T, Lakhsman K, Singha A, Dutta J, Pal SK. Hematoporphyrin-ZnO nanohybrids: twin applications in efficient visible-light photocatalysis and dye-sensitized solar cells. ACS Appl Mater Interfaces 2012. [PMID: 23186038 DOI: 10.1021/am302288m] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Light-harvesting nanohybrids (LHNs) are systems composed of an inorganic nanostructure associated with an organic pigment that have been exploited to improve the light-harvesting performance over individual components. The present study is focused on developing a potential LHN, attained by the functionalization of dense arrays of ZnO nanorods (NRs) with a biologically important organic pigment hematoporphyrin (HP), which is an integral part of red blood cells (hemoglobin). Application of spectroscopic techniques, namely, Fourier transform infrared spectroscopy (FTIR) and Raman scattering, confirm successful monodentate binding of HP carboxylic groups to Zn(2+) located at the surface of ZnO NRs. Picosecond-resolved fluorescence studies on the resulting HP-ZnO nanohybrid show efficient electron migration from photoexcited HP to the host ZnO NRs. This essential photoinduced event activates the LHN under sunlight, which ultimately leads to the realization of visible-light photocatalysis (VLP) of a model contaminant Methylene Blue (MB) in aqueous solution. A control experiment in an inert gas atmosphere clearly reveals that the photocatalytic activity is influenced by the formation of reactive oxygen species (ROS) in the media. Furthermore, the stable LHNs prepared by optimized dye loading have also been used as an active layer in dye-sensitized solar cells (DSSCs). We believe these promising LHNs to find their dual applications in organic electronics and for the treatment of contaminant wastewater.
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Affiliation(s)
- Soumik Sarkar
- Department of Chemical, Biological and Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700 098, India
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Bora T, Kyaw HH, Sarkar S, Pal SK, Dutta J. Highly efficient ZnO/Au Schottky barrier dye-sensitized solar cells: Role of gold nanoparticles on the charge-transfer process. Beilstein J Nanotechnol 2011; 2:681-90. [PMID: 22043457 PMCID: PMC3201621 DOI: 10.3762/bjnano.2.73] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Accepted: 09/21/2011] [Indexed: 05/03/2023]
Abstract
Zinc oxide (ZnO) nanorods decorated with gold (Au) nanoparticles have been synthesized and used to fabricate dye-sensitized solar cells (DSSC). The picosecond-resolved, time-correlated single-photon-count (TCSPC) spectroscopy technique was used to explore the charge-transfer mechanism in the ZnO/Au-nanocomposite DSSC. Due to the formation of the Schottky barrier at the ZnO/Au interface and the higher optical absorptions of the ZnO/Au photoelectrodes arising from the surface plasmon absorption of the Au nanoparticles, enhanced power-conversion efficiency (PCE) of 6.49% for small-area (0.1 cm(2)) ZnO/Au-nanocomposite DSSC was achieved compared to the 5.34% efficiency of the bare ZnO nanorod DSSC. The TCSPC studies revealed similar dynamics for the charge transfer from dye molecules to ZnO both in the presence and absence of Au nanoparticles. A slower fluorescence decay associated with the electron recombination process, observed in the presence of Au nanoparticles, confirmed the blocking of the electron transfer from ZnO back to the dye or electrolyte by the Schottky barrier formed at the ZnO/Au interface. For large area DSSC (1 cm(2)), ~130% enhancement in PCE (from 0.50% to 1.16%) was achieved after incorporation of the Au nanoparticles into the ZnO nanorods.
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Affiliation(s)
- Tanujjal Bora
- Center of Excellence in Nanotechnology, School of Engineering and Technology, Asian Institute of Technology, P. O. Box 4, Klong Luang, Pathumthani 12120, Thailand
| | - Htet H Kyaw
- Center of Excellence in Nanotechnology, School of Engineering and Technology, Asian Institute of Technology, P. O. Box 4, Klong Luang, Pathumthani 12120, Thailand
| | - Soumik Sarkar
- Unit for Nano Science and Technology, S. N. Bose National Centre for Basic Sciences, Sector - III, Block - JD, Salt Lake, Kolkata 700098, India
| | - Samir K Pal
- Unit for Nano Science and Technology, S. N. Bose National Centre for Basic Sciences, Sector - III, Block - JD, Salt Lake, Kolkata 700098, India
| | - Joydeep Dutta
- Center of Excellence in Nanotechnology, School of Engineering and Technology, Asian Institute of Technology, P. O. Box 4, Klong Luang, Pathumthani 12120, Thailand
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Sarkar S, Makhal A, Bora T, Baruah S, Dutta J, Pal SK. Photoselective excited state dynamics in ZnO–Au nanocomposites and their implications in photocatalysis and dye-sensitized solar cells. Phys Chem Chem Phys 2011; 13:12488-96. [DOI: 10.1039/c1cp20892f] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Abstract
We have explored light harvesting of the complex of ZnO nanoparticles with the biological probe Oxazine 1 in the near-infrared region using picosecond-time-resolved fluorescence decay studies. We have used ZnO nanoparticles and Oxazine 1 as a model donor and acceptor, respectively, to explore the efficacy of the Förster resonance energy transfer (FRET) in the nanoparticle-dye system. It has been shown that FRET from the states localized near the surface and those in the bulk of the ZnO nanoparticles can be resolved by measuring the resonance efficiency for various wavelengths of the emission spectrum. It has been observed that the states located near the surface for the nanoparticles (contributing to visible emission at lambda approximately 550 nm) can contribute to very high efficiency (>90%) FRET. The efficiency of light harvesting dynamics of the ZnO nanorods has also been explored in this study and they were found to have much less efficiency (approximately 40%) for energy transfer compared to the nanoparticles. The possibility of an electron transfer reaction has been ruled out from the picosecond-resolved fluorescence decay of the acceptor dye at the ZnO surface.
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Affiliation(s)
- Abhinandan Makhal
- Unit for Nano Science and Technology, S N Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700 098, India
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Baruah S, Mahmood MA, Myint MTZ, Bora T, Dutta J. Enhanced visible light photocatalysis through fast crystallization of zinc oxide nanorods. Beilstein J Nanotechnol 2010; 1:14-20. [PMID: 21977391 PMCID: PMC3045919 DOI: 10.3762/bjnano.1.3] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2010] [Accepted: 10/26/2010] [Indexed: 05/22/2023]
Abstract
Hydrothermally grown ZnO nanorods have inherent crystalline defects primarily due to oxygen vacancies that enhance optical absorption in the visible spectrum, opening up possibilities for visible light photocatalysis. Comparison of photocatalytic activity of ZnO nanorods and nanoparticle films on a test contaminant methylene blue with visible light irradiation at 72 kilolux (klx) showed that ZnO nanorods are 12-24% more active than ZnO nanoparticulate films. This can be directly attributed to the increased effective surface area for adsorption of target contaminant molecules. Defects, in the form of interstitials and vacancies, were intentionally created by faster growth of the nanorods by microwave activation. Visible light photocatalytic activity was observed to improve by ≈8% attributed to the availability of more electron deficient sites on the nanorod surfaces. Engineered defect creation in nanostructured photocatalysts could be an attractive solution for visible light photocatalysis.
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Affiliation(s)
- Sunandan Baruah
- Center of Excellence in Nanotechnology, School of Engineering and Technology, Asian Institute of Technology, Klong Luang, Pathumthani 12120, Thailand. Phone: +66 2 524 5680, Fax: +66 2 524 5617
| | - Mohammad Abbas Mahmood
- Center of Excellence in Nanotechnology, School of Engineering and Technology, Asian Institute of Technology, Klong Luang, Pathumthani 12120, Thailand. Phone: +66 2 524 5680, Fax: +66 2 524 5617
| | - Myo Tay Zar Myint
- Center of Excellence in Nanotechnology, School of Engineering and Technology, Asian Institute of Technology, Klong Luang, Pathumthani 12120, Thailand. Phone: +66 2 524 5680, Fax: +66 2 524 5617
| | - Tanujjal Bora
- Center of Excellence in Nanotechnology, School of Engineering and Technology, Asian Institute of Technology, Klong Luang, Pathumthani 12120, Thailand. Phone: +66 2 524 5680, Fax: +66 2 524 5617
| | - Joydeep Dutta
- Center of Excellence in Nanotechnology, School of Engineering and Technology, Asian Institute of Technology, Klong Luang, Pathumthani 12120, Thailand. Phone: +66 2 524 5680, Fax: +66 2 524 5617
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Özaktan H, Bora T, Sukan S, Sargin S, Vardar Sukan F. STUDIES ON DETERMINATION OF ANTAGONISTIC POTENTIAL AND BIOPREPARATION OF SOME BACTERIA AGAINST THE FIREBLIGHT PATHOGEN. ACTA ACUST UNITED AC 1999. [DOI: 10.17660/actahortic.1999.489.118] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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