1
|
K H. A review on carbon quantum dot/semiconductor-based nanocomposites as hydrogen production photocatalysts. RSC Adv 2024; 14:23404-23422. [PMID: 39055266 PMCID: PMC11270004 DOI: 10.1039/d4ra04149f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2024] [Accepted: 07/10/2024] [Indexed: 07/27/2024] Open
Abstract
Carbon quantum dots (CQDs) are discrete, quasi-spherical carbon nanoparticles with sizes below 10 nm. The properties of CQDs can be further enhanced by doping with elements such as nitrogen, phosphorous, sulphur, and boron or co-doping with heteroatoms such as nitrogen-phosphorous, nitrogen-sulphur, and nitrogen-boron. These excellent properties of CQDs can be utilized to enhance the photocatalytic performance of semiconductors. Therefore, in this review, we summarize different types of bare CQD-scaffolded semiconductors, both doped and co-doped, used for photocatalytic hydrogen production. Moreover, the detailed photocatalytic mechanism of CQD/semiconductor-based hydrogen production is reviewed. Recent progress in the design and development of CQD-based photocatalysts, along with the challenges involved, is comprehensively reviewed.
Collapse
Affiliation(s)
- Hareesh K
- Department of Physics, Manipal Institute of Technology Bengaluru, Manipal Academy of Higher Education Manipal 576104 India
| |
Collapse
|
2
|
Nayana K, Sunitha AP. Amphi-Luminescent MoS 2 nanostructure for photocatalytic splitting of water and removal of Methylene Blue. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2024; 314:124190. [PMID: 38554694 DOI: 10.1016/j.saa.2024.124190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 02/24/2024] [Accepted: 03/25/2024] [Indexed: 04/02/2024]
Abstract
Chemical dyes used in the textile industries are one of the major pollutants in water. Methylene blue (MB) is a commonly seen dye that creates hazardous health problems. In this article the photocatalytic degradation of MB by the nanocatalyst MoS2 (Nano-MoS2) and carbon dot (C Dots) incorporated MoS2 (Nano-CD-MoS2) is reported. The photocatalytic degradation of MB is analyzed based on the electron-hole recombination rate of the catalyst. Photoluminescence emission exhibited by the catalyst is used as a key indicator to probe the electron-hole recombination rate. Nano-MoS2 was synthesized hydrothermally at 180 0C for 8 h from ammonium tetra thiomolybdate (ATTM). C Dot was prepared following a green root from ash guard extract which later mixed with Nano-MoS2 and kept in an autoclave at a temperature 140 °C for 4 h to get Nano-CD-MoS2. The photoluminescence (PL) and photocatalytic behavior of Nano-MoS2 and Nano-CD-MoS2 and their application for water splitting and water purification are reported. The incorporation of graphene and artificial C Dot into MoS2 nanostructures are reported to increase the conductivity and active edge sites of MoS2 that enhances the photocatalytic action. Since green C Dots are eco-friendly and easily synthesizable than artificial C Dots, as a novel study, this article investigated the influence of green C Dots on the PL and photocatalytic performance of nanosized MoS2. Nano-MoS2 and Nano-CD-MoS2 exhibited both upconversion and downconversion PL; accordingly the nanostructures were termed as amphi-luminescent. The amphi-luminescence property widens the photon absorption range and hence enhances the catalytic degradation of dyes. Nano-MoS2 which exhibited lesser intensity of amphi-luminescence emission compared to Nano-CD-MoS2 showed better results in degradation of MB. C Dots may bind with the valence band electrons of MoS2, resulting in the reduction of dangling bonds. Dangling bonds can trap photo-induced excitons to hinder the rate of electron-hole recombination. So, fast electron-hole recombination occurs in Nano-CD-MoS2 than Nano-MoS2. Fast electron-hole recombination supports radiative electron-hole recombination while suppresses the non-radiative energy transfer of electrons and causes high PL intensity. However, according to the energy level diagram, Nano-MoS2 with minimal electron-hole recombination rate is more favorable for O2/O2-,.OH/ OH- and.OH/H2O reactions that facilitate MB degradation. Photocatalytic activity of catalysts were confirmed by measuring the photocurrent from a simple custom-made two-electrode water photolysis cell where the nanocatalysts were dispersed in electrolyte. Lead and steel rods were used as electrodes. Multimeter was used to measure current. Nano-MoS2 exhibited better performance with a maximum photocurrent of 141 µA. Influence of green C Dots in energy levels, PL and photocatalysis of MoS2 and mechanisms of PL and degradation of MB are thoroughly investigated in this article.
Collapse
Affiliation(s)
- K Nayana
- Department of Physics, Government Victoria College, Affiliated to University of Calicut, Palakkad, Kerala 678001, India; Department of Physics, N. S. S. College, Affiliated to University of Calicut, Ottapalam, Kerala 679103, India
| | - A P Sunitha
- Department of Physics, Government Victoria College, Affiliated to University of Calicut, Palakkad, Kerala 678001, India.
| |
Collapse
|
3
|
Jose J, Mohanraj R, G K S, K P G, Jacob JM. Turn-Off Fluorescence Sensor for the Detection of Ferric Ion in Water Using Green Synthesized Wrightia coccinea Carbon Quantum Dot. J Fluoresc 2024:10.1007/s10895-024-03760-3. [PMID: 38767724 DOI: 10.1007/s10895-024-03760-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Accepted: 05/05/2024] [Indexed: 05/22/2024]
Abstract
The current study report that the production of carbon quantum dots from Wrightia coccinea (WC) leaves using an eco-friendly, one-pot process. The structural, morphological, and optical characteristics of the CDs made from W. coccinea leaves by hydrothermal treatment at 200 °C for six hours were assessed using a variety of spectroscopic and electron microscopy techniques. The average size of CD was found to be approximately 5 nm using transmission electron microscopy (TEM) and the quantum yield of the produced CD was 15.6%. The synthesized CDs demonstrated extraordinary sensing capacity with a detection limit of 0.511 µM for ferric ion detection. The impact of varying pH levels on the fluorescence behavior of CD was thoroughly investigated. The maximum fluorescence intensity was examined at pH 3. Therefore, to detect Fe3+ ions as best as possible, the pH of the entire solution was adjusted to a value of 3. Furthermore, the pH-dependent fluorescence feature of CDs can be exploited by pH-sensitive fluorescence sensors. In the future, this might provide an added advantage for pH-based fluorescence sensor applications.
Collapse
Affiliation(s)
- Jincy Jose
- Department of Environmental Science and Management, Bharathidasan University, Tiruchirappalli, 620024, Tamil Nadu, India.
| | - Rangaswamy Mohanraj
- Department of Environmental Science and Management, Bharathidasan University, Tiruchirappalli, 620024, Tamil Nadu, India.
| | - Shamnamol G K
- Department of Biotechnology & Biochemical Engineering, Sree Buddha College of Engineering, Pattoor, APJ Abdulkalam Technological University, Thiruvananthapuram, Kerala, 690 529, India
| | - Greeshma K P
- Department of Chemistry, Sri Ramakrishna College of Arts and Science, Coimbatore, 641006, Tamilnadu, India
| | - Jaya Mary Jacob
- Scientist-B, Kerala State Council for Science Technology and Environment (KSCSTE), Pattom, 695004, Thiruvananthapuram, Kerala, India
| |
Collapse
|
4
|
K N, A P S. Unveiling the Radiative Electron-Hole Recombination of MoS 2 Nanostructures at Extreme pH Conditions. J Fluoresc 2024:10.1007/s10895-024-03616-w. [PMID: 38381234 DOI: 10.1007/s10895-024-03616-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 02/12/2024] [Indexed: 02/22/2024]
Abstract
Nanostructures of MoS2 are in wide research for optoelectronic, energy and biological applications. Opto-electronic and biological applications requires the tuning of photoluminescence properties of MoS2 nanostructures. In this article, nanosized MoS2 is hydrothermally synthesized, and photoluminescence at extreme pH conditions (pH 1 and 13) is examined. As the photoluminescence gives a key to probe the radiative electron-hole recombination, here, photoluminescence emissions are used as an indicator to suggest the pattern of electron-hole recombination in the material at extreme pH conditions. Raman spectroscopy, dynamic light scattering, Scanning electron microscopic image and energy dispersive x-ray analysis are done for material confirmation. At pH 1 and 13 as-synthesized nanostructured MoS2 exhibited both upconversion and downconversion photoluminescence. The intensity of photoluminescence is varied with respect to pH. Excitation-dependent photoluminescence mechanisms and preliminary understanding on the ratio of quantum yields and life span of excited state of as-synthesized nanostructured MoS2 are unveiled here.
Collapse
Affiliation(s)
- Nayana K
- Department of Physics, Government Victoria College, Affiliated to University of Calicut, Palakkad, 678001, Kerala, India
- Department of Physics, N. S. S. College, Affiliated to University of Calicut, Ottapalam, Palakkad, 679103, Kerala, India
| | - Sunitha A P
- Department of Physics, Government Victoria College, Affiliated to University of Calicut, Palakkad, 678001, Kerala, India.
| |
Collapse
|
5
|
Nocito G, Zribi R, Chelly M, Pulvirenti L, Nicotra G, Bongiorno C, Arrigo A, Fazio B, Neri G, Nastasi F, Conoci S. Photochemical synthesis, characterization, and electrochemical sensing properties of CD-AuNP nanohybrids. NANOSCALE 2024; 16:3571-3582. [PMID: 38293870 DOI: 10.1039/d3nr05897b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Among the existing nanosystems used in electrochemical sensing, gold nanoparticles (AuNPs) have attracted considerable attention owing to their intriguing chemical and physical properties such as good electrical conductivity, high electrocatalytic activity, and high surface-to-volume ratio. However, despite these useful characteristics, there are some issues due to their instability in solution that can give rise to aggregation phenomena and the use of hazardous chemicals in the most common synthetic procedures. With an aim to find a solution to these issues, recently, we prepared and characterized carbon dots (CDs), from olive solid wastes, and employed them as reducing and capping agents in photo-activated AuNP synthesis, thus creating CD-Au nanohybrids. These nanomaterials appear extremely stable in aqueous solutions at room temperature, are contemporary, and have been obtained using CDs, which are exclusively based on non-toxic elements, with an additional advantage of being generated from an otherwise waste material. In this paper, the synthesis and characterization of CD-Au nanohybrids are described, and the electrochemical experiments for hydroquinone detection are discussed. The results indicate that CD-Au acts as an efficient material for sensing hydroquinone, matching a wide range of interests in science from industrial processes to environmental pollution.
Collapse
Affiliation(s)
- Giuseppe Nocito
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno d'Alcontres, 31, 98166 Messina, Italy.
| | - Rayhane Zribi
- Department of Engineering, University of Messina, Contrada Di Dio, 98166 Messina, Italy
| | - Meryam Chelly
- Department of Engineering, University of Messina, Contrada Di Dio, 98166 Messina, Italy
| | - Luca Pulvirenti
- Department of Chemical Sciences, University of Catania, Viale Andrea Doria, 6, 95125 Catania, Italy
| | - Giuseppe Nicotra
- Consiglio Nazionale delle Ricerche, Istituto per la Microelettronica e Microsistemi (CNR-IMM), Strada VIII, n. 5, Zona Industriale, Catania, 1-95121 Italy
| | - Corrado Bongiorno
- Consiglio Nazionale delle Ricerche, Istituto per la Microelettronica e Microsistemi (CNR-IMM), Strada VIII, n. 5, Zona Industriale, Catania, 1-95121 Italy
| | - Antonino Arrigo
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno d'Alcontres, 31, 98166 Messina, Italy.
- Interuniversitary Research Center for Artificial Photosynthesis (Solar Chem, Messina Node), Viale Ferdinando Stagno d'Alcontres, 31, 98166 Messina, Italy
| | - Barbara Fazio
- Consiglio Nazionale delle Ricerche, URT Lab-Sens Beyond Nano - Department of Physical Science and Technologies of Matter, Viale Ferdinando Stagno d'Alcontres, 31, 98166 Messina, Italy
- Consiglio Nazionale delle Ricerche, Istituto per i Processi Chimico Fisici (CNR-IPCF), Viale Ferdinando Stagno d'Alcontres, 37, 98158 Messina, Italy
| | - Giovanni Neri
- Department of Engineering, University of Messina, Contrada Di Dio, 98166 Messina, Italy
| | - Francesco Nastasi
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno d'Alcontres, 31, 98166 Messina, Italy.
- Interuniversitary Research Center for Artificial Photosynthesis (Solar Chem, Messina Node), Viale Ferdinando Stagno d'Alcontres, 31, 98166 Messina, Italy
- Consiglio Nazionale delle Ricerche, URT Lab-Sens Beyond Nano - Department of Physical Science and Technologies of Matter, Viale Ferdinando Stagno d'Alcontres, 31, 98166 Messina, Italy
| | - Sabrina Conoci
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno d'Alcontres, 31, 98166 Messina, Italy.
- Consiglio Nazionale delle Ricerche, URT Lab-Sens Beyond Nano - Department of Physical Science and Technologies of Matter, Viale Ferdinando Stagno d'Alcontres, 31, 98166 Messina, Italy
- Department of Chemistry "Giacomo Ciamician", University of Bologna, Via Selmi, 2, 40126 Bologna, Italy
| |
Collapse
|
6
|
Hameed R, Li G, Son Y, Fang H, Kim T, Zhu C, Feng Y, Zhang L, Abbas A, Zhao X, Wang J, Li J, Dai Z, Du D. Structural characteristics of dissolved black carbon and its interactions with organic and inorganic contaminants: A critical review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 872:162210. [PMID: 36791863 DOI: 10.1016/j.scitotenv.2023.162210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 01/15/2023] [Accepted: 02/09/2023] [Indexed: 06/18/2023]
Abstract
Biochar (BC) is a sustainable and renewable carbonaceous material, and its soluble component, dissolved black carbon (DBC), is the key to understanding BC's geological and environmental processes. Although the relationship between the changes in DBC structure and its properties, functions, and associated environmental risks has been explored, a gap remains in our understanding of DBC's fate and behavior in the natural environment. Thus, in this review, we have highlighted the molecular and chemical compositions and the structural evolution of DBC during pyrolysis, the influence of DBC's physicochemical properties on its fate and transport, DBC's interaction with soil and its contaminants, and DBC stability in soil and water environments along with potential risks. Based on our in-depth assessment of DBC and its biogeochemical roles, we believe that future studies should focus on the following: (1) using advanced techniques to understand the chemical and molecular structure of DBC deeply and concisely and, thus, determine its fundamental role in the natural environment; (2) investigating the multi-functional properties of DBC and its interaction mechanisms; and (3) evaluating the environmental behaviors of and risks associated with DBC after BC application. In future, it is necessary to gain a deeper insight into the fate and transport of DBC with contaminants and study its associated risks under BC application in the environment.
Collapse
Affiliation(s)
- Rashida Hameed
- School of Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Guanlin Li
- School of Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China; Department of Environmental Science and Ecological Engineering, Korea University, Seoul 02841, Republic of Korea.
| | - Yowhan Son
- Department of Environmental Science and Ecological Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Huajun Fang
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Taewan Kim
- Institute of Ecological Phytochemistry, Hankyong National University, Anseong 17579, Republic of Korea
| | - Chaodong Zhu
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; College of Biological Sciences, University of Chinese Academy of Sciences, Beijing 100049, China; State Key Laboratory of Integrated Pest Management, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yanfang Feng
- Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Lihua Zhang
- College of Life and Environmental Science, Minzu University of China, Beijing 100081, China
| | - Adeel Abbas
- School of Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Xin Zhao
- Department of Civil and Environmental Engineering, College of Engineering, Seoul National University, Seoul 08826, Republic of Korea
| | - Jiaqian Wang
- School of Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Jian Li
- School of Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Zhicong Dai
- School of Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Daolin Du
- School of Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China
| |
Collapse
|
7
|
Thakur A, Maitra S, Sinha RK, Devi P. Plasmonic Copper-activated ZnO Microarrays for Efficient Photoelectrocatalytic Applications. Chem Asian J 2023; 18:e202201155. [PMID: 36519348 DOI: 10.1002/asia.202201155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/15/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022]
Abstract
In the present work, green synthesized plasmonic copper nanostructures derived from carbon quantum dots (PCQDs) activated ZnO microarrays (MAs) based catalyst system is developed and studied for photocatalytic activity and photoelectrocatalytic water splitting. CQDs are synthesized from pharmaceutical waste and used as a reducing agent to synthesize PCQDs of an average size of 10±2 nm. PCQDs decorated ZnO (PCQDs/ZnO) MAs exhibited enhanced photocurrent density of ∼7.1 mA/cm2 at 1.23 V (vs. RHE), which is ∼11 fold to ZnO MAs alone (0.65 mA/cm2 ). The catalyst exhibits an ABPE of 1.07% at 0.7 V (vs. RHE), IPEC of 8.8% for 450 nm, and hydrogen production rate of 435 μmol/h. The enhanced PEC characteristics are assigned to the improved photons collection and better charge transfer for their participation in oxidation/reduction reaction. The same is well supported with DFT studies for the PCQDs/ZnO MAs catalyst for the first time.
Collapse
Affiliation(s)
- Anupma Thakur
- Academy of Scientific and Innovative Research (AcSIR), 201002, Ghaziabad, India.,CSIR-Central Scientific Instruments Organization, Sector-30C, 160030, Chandigarh, India
| | - Soumyajit Maitra
- CSIR-Central Scientific Instruments Organization, Sector-30C, 160030, Chandigarh, India
| | - R K Sinha
- Academy of Scientific and Innovative Research (AcSIR), 201002, Ghaziabad, India.,CSIR-Central Scientific Instruments Organization, Sector-30C, 160030, Chandigarh, India
| | - Pooja Devi
- Academy of Scientific and Innovative Research (AcSIR), 201002, Ghaziabad, India.,CSIR-Central Scientific Instruments Organization, Sector-30C, 160030, Chandigarh, India
| |
Collapse
|
8
|
Zhao Z, Pieber B, Delbianco M. Modulating the Surface and Photophysical Properties of Carbon Dots to Access Colloidal Photocatalysts for Cross-Couplings. ACS Catal 2022. [DOI: 10.1021/acscatal.2c04025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Zhouxiang Zhao
- Department of Biomolecular Systems, Max-Planck-Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476 Potsdam, Germany
- Department of Chemistry and Biochemistry, Freie Universität Berlin, Arnimallee 22, 14195 Berlin, Germany
| | - Bartholomäus Pieber
- Department of Biomolecular Systems, Max-Planck-Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Martina Delbianco
- Department of Biomolecular Systems, Max-Planck-Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476 Potsdam, Germany
| |
Collapse
|
9
|
Bio-Inspired Synthesis of Carbon-Based Nanomaterials and Their Potential Environmental Applications: A State-of-the-Art Review. INORGANICS 2022. [DOI: 10.3390/inorganics10100169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2022] Open
Abstract
Providing safe drinking water and clean water is becoming a more challenging task all around the world. Although some critical issues and limits remain unsolved, implementing ecologically sustainable nanomaterials (NMs) with unique features, e.g., highly efficient and selective, earth-abundance, renewability, low-cost manufacturing procedures, and stability, has become a priority. Carbon nanoparticles (NPs) offer tremendous promise in the sectors of energy and the environment. However, a series of far more ecologically friendly synthesis techniques based on natural, renewable, and less expensive waste resources must be explored. This will reduce greenhouse gas emissions and harmful material extraction and assist the development of green technologies. The progress achieved in the previous 10 years in the fabrication of novel carbon-based NMs utilizing waste materials as well as natural precursors is reviewed in this article. Research on carbon-based NPs and their production using naturally occurring precursors and waste materials focuses on this review research. Water treatment and purification using carbon NMs, notably for industrial and pharmaceutical wastes, has shown significant potential. Research in this area focuses on enhanced carbonaceous NMs, methods, and novel nano-sorbents for wastewater, drinking water, groundwater treatment, as well as ionic metal removal from aqueous environments. Discussed are the latest developments and challenges in environmentally friendly carbon and graphene quantum dot NMs.
Collapse
|
10
|
Moustafa HM, Mahmoud MS, Nassar MM. Photon-induced water splitting experimental and kinetic studies with a hydrothermally prepared TiO2-doped rGO photocatalyst. INORG CHEM COMMUN 2022. [DOI: 10.1016/j.inoche.2022.109546] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
11
|
Guo Y, Guo Y, Hua S, Xu G, Xu Z, Yan C. Coupling band structure and oxidation-reduction potential to expound photodegradation performance difference of biochar-derived dissolved black carbon for organic pollutants under light irradiation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 820:153300. [PMID: 35074367 DOI: 10.1016/j.scitotenv.2022.153300] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 01/07/2022] [Accepted: 01/17/2022] [Indexed: 06/14/2023]
Abstract
Herein, the photodegradation performances difference of rice straw biochar-derived dissolved black carbon (DBC) for Tetracycline and Methylene Blue under visible light irradiation have been investigated. Tetracycline is easier degraded (degradation rate: 68%), followed by Methylene Blue (degradation rate: 14%). Singlet oxygen (1O2), superoxide radicals (O2-), holes (h+) and triplet DBC (3DBC*) are all make contribution for Tetracycline degradation by DBC, whereas just singlet oxygen (1O2), superoxide radicals (O2-) and 3DBC* are involved in the MB degradation by DBC. Singlet oxygen (1O2) maybe from the fulvic acid-like structure of DBC, while band structure of DBC can explain why superoxide radicals (O2-) and holes (h+) can be formed, whereas hydroxyl radicals (OH) cannot be formed. The oxidation-reduction potential results of Tetracycline and Methylene Blue suggests that Tetracycline is easier to be oxidized than Methylene Blue as well as Methylene Blue is easier to be reduced than Tetracycline. Furthermore, experimental and theoretical results support that DBC has good interaction with Tetracycline, but the interaction between DBC and Methylene Blue is very weak. This likely explain why holes (h+) is not detected for Methylene Blue degradation by DBC since Methylene Blue has not too much chance to meet holes (h+). TC photodegradation intermediates are less toxic than Tetracycline based on QSAR method. Two possible photodegradation path of Tetracycline by DBC are proposed according to HPLC-MS results.
Collapse
Affiliation(s)
- Ying Guo
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210093, PR China
| | - Yong Guo
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210093, PR China.
| | - Shugui Hua
- School of Life Science, Chemistry & Chemical Engineering, Jiangsu Second Normal University, Nanjing 210013, PR China.
| | - Guowei Xu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210093, PR China
| | - Zixuan Xu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210093, PR China
| | - Congcong Yan
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210093, PR China
| |
Collapse
|
12
|
Subedi S, Rella AK, Trung LG, Kumar V, Kang SW. Electrically Switchable Anisometric Carbon Quantum Dots Exhibiting Linearly Polarized Photoluminescence: Syntheses, Anisotropic Properties, and Facile Control of Uniaxial Orientation. ACS NANO 2022; 16:6480-6492. [PMID: 35343230 DOI: 10.1021/acsnano.2c00758] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Carbon quantum dots (CQDs) have been extensively explored in diverse fields because of their exceptional features. The nanometric particles with photoluminescence (PL) benefit various optical and photonic applications. However, the majority of previous reports have mainly focused on either unpolarized or circular-polarized (CP) PL. Linearly polarized (LP) emission of CQDs is limited mainly because of their isometric shape and difficulties in macroscopic orientation control. Herein, we report syntheses of anisometric CQDs and facile control of the uniaxial orientation on a macroscopic scale, which results in linearly polarized photoluminescence (LP-PL). The anisometric CQDs are synthesized from rigid-rod-shaped precursors and evenly dispersed in the rod-like liquid crystal (LC) host. As-synthesized CQDs exhibit a PL quantum yield as high as 35% in chloroform. In addition to uniform alignment, facile directional switching of the elongated CQD is established by employing the electrical responsiveness of the CQD and host LC. Therefore, the dichroic photophysical properties of anisometric CQDs have been beneficially adopted for fabrications of polarization-sensitive and electrically switchable PL devices. Also, anisometric CQDs are embedded in polymer films with molecular orientational patterns and clearly recognized by LP-PL.
Collapse
Affiliation(s)
- Subhangi Subedi
- Department of Nano Convergence Engineering, Jeonbuk National University, Jeonju, 54896, Republic of Korea
- Department of Chemistry, Tri-Chandra Multiple Campus, Tribhuvan University, Kathmandu, 44613, Nepal
| | - Avinash K Rella
- Department of Nano Convergence Engineering, Jeonbuk National University, Jeonju, 54896, Republic of Korea
| | - Le Gia Trung
- Department of Nano Convergence Engineering, Jeonbuk National University, Jeonju, 54896, Republic of Korea
| | - Vineet Kumar
- Department of Nano Convergence Engineering, Jeonbuk National University, Jeonju, 54896, Republic of Korea
| | - Shin-Woong Kang
- Department of Nano Convergence Engineering, Jeonbuk National University, Jeonju, 54896, Republic of Korea
| |
Collapse
|
13
|
Plastic Waste Precursor-Derived Fluorescent Carbon and Construction of Ternary FCs@CuO@TiO2 Hybrid Photocatalyst for Hydrogen Production and Sensing Application. ENERGIES 2022. [DOI: 10.3390/en15051734] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A sustainable nexus between renewable energy production and plastic abatement is imperative for overall sustainable development. In this regard, this study aims to develop a cheaper and environmentally friendly nexus between plastic waste management, wastewater treatment, and renewable hydrogen production. Fluorescent carbon (FCs) were synthesized from commonly used LDPE (low-density polyethylene) by a facile hydrothermal approach. Optical absorption study revealed an absorption edge around 300 nm and two emission bands at 430 and 470 nm. The morphological analysis showed two different patterns of FCs, a thin sheet with 2D morphology and elongated particles. The sheet-shaped particles are 0.5 μm in size, while as for elongated structures, the size varies from 0.5 to 1 μm. The as-synthesized FCs were used for the detection of metal ions (reference as Cu2+ ions) in water. The fluorescence intensity of FCs versus Cu2+ ions depicts its upright analytical ability with a limit of detection (LOD) reaching 86.5 nM, which is considerably lesser than earlier reported fluorescence probes derived from waste. After the sensing of Cu2+, the as-obtained FCs@Cu2+ was mixed with TiO2 to form a ternary FCs@CuO@TiO2 composite. This ternary composite was utilized for photocatalytic hydrogen production from water under 1.5 AM solar light irradiation. The H2 evolution rate was found to be ~1800 μmolg−1, which is many folds compared to the bare FCs. Moreover, the optimized FCs@CuO@TiO2 ternary composite showed a photocurrent density of ~2.40 mA/cm2 at 1 V vs. Ag/AgCl, in 1 M Na2SO4 solution under the illumination of simulated solar light. The achieved photocurrent density corresponds to the solar-to-hydrogen (STH) efficiency of ~0.95%. The efficiency is due to the fluorescence nature of FCs and the synergistic effect of CuO embedded in TiO2, which enhances the optical absorption of the composite by reaching the bandgap of 2.44 eV, apparently reducing the recombination rate, which was confirmed by optoelectronic, structural, and spectroscopic characterizations.
Collapse
|
14
|
Liccardo L, Lushaj E, Dal Compare L, Moretti E, Vomiero A. Nanoscale ZnO/α‐Fe
2
O
3
Heterostructures: Toward Efficient and Low‐Cost Photoanodes for Water Splitting. SMALL SCIENCE 2021. [DOI: 10.1002/smsc.202100104] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Affiliation(s)
- Letizia Liccardo
- Department of Molecular Sciences and Nanosystems Ca’ Foscari University of Venice Via Torino 155 30172 Venezia Mestre Italy
| | - Edlind Lushaj
- Department of Molecular Sciences and Nanosystems Ca’ Foscari University of Venice Via Torino 155 30172 Venezia Mestre Italy
| | - Laura Dal Compare
- Department of Molecular Sciences and Nanosystems Ca’ Foscari University of Venice Via Torino 155 30172 Venezia Mestre Italy
| | - Elisa Moretti
- Department of Molecular Sciences and Nanosystems Ca’ Foscari University of Venice Via Torino 155 30172 Venezia Mestre Italy
| | - Alberto Vomiero
- Department of Molecular Sciences and Nanosystems Ca’ Foscari University of Venice Via Torino 155 30172 Venezia Mestre Italy
- Division of Materials Science Department of Engineering Sciences and Mathematics Luleå University of Technology 97187 Luleå Sweden
| |
Collapse
|
15
|
Tsai IH, Li JT, Chang CW. Effects of Sonication and Hydrothermal Treatments on the Optical and Chemical Properties of Carbon Dots. ACS OMEGA 2021; 6:14174-14181. [PMID: 34124440 PMCID: PMC8190798 DOI: 10.1021/acsomega.1c00765] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 05/12/2021] [Indexed: 06/12/2023]
Abstract
In our study, we have tested the effects of sonication and hydrothermal treatments on the properties of carbon dots synthesized from a microwave-assisted method (C-dotsMW). When the carbon dots are sonicated in an aerobic environment, the fluorescence quantum yield decreases drastically because the molecular fluorophores attached to the surface of the carbon dots are oxidized during the sonication process. Meanwhile, the sonicated C-dotsMW also lose their Hg2+ ion sensing and photoreduction activity due to the oxidization of surface functional groups. After the hydrothermal treatment, the fluorescence quantum yield of C-dotsMW increases due to the formation of new fluorophores; however, the Hg2+ ion sensitivity and photoreduction activity of C-dotsMW decrease significantly due to the oxidization of surface functional groups. By autoclaving the C-dotsMW at 100 °C, we have demonstrated that we can enhance the fluorescence quantum yield of C-dotsMW without losing their Hg2+ ion sensitivity. This finding can be used to improve the fluorescence quantum yield of the fluorescent ion sensor based on C-dots.
Collapse
Affiliation(s)
- I-Hua Tsai
- Department of Chemistry, National Changhua University of Education, No. 1 Jin-De Road, Changhua City 50058, Taiwan
| | - Jyun-Ting Li
- Department of Chemistry, National Changhua University of Education, No. 1 Jin-De Road, Changhua City 50058, Taiwan
| | - Chih-Wei Chang
- Department of Chemistry, National Changhua University of Education, No. 1 Jin-De Road, Changhua City 50058, Taiwan
| |
Collapse
|
16
|
Singh J, Kaur S, Lee J, Mehta A, Kumar S, Kim KH, Basu S, Rawat M. Highly fluorescent carbon dots derived from Mangifera indica leaves for selective detection of metal ions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 720:137604. [PMID: 32143054 DOI: 10.1016/j.scitotenv.2020.137604] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Revised: 02/19/2020] [Accepted: 02/26/2020] [Indexed: 06/10/2023]
Abstract
In this study, we report an inexpensive, green, and one-pot synthesis method for highly fluorescent carbon quantum dots (CQDs) using mango (Mangifera indica: M. indica) leaves to develop an efficient sensing platform for metal ions. The CQDs synthesized from M. indica leaves via pyrolysis treatment at 300 °C for 3 h were characterized by various spectroscopic and electron microscopy techniques for their structural, morphological, and optical properties. Accordingly, the synthesized CQDs showed an absorption peak at 213 nm to confirm the p-p* transition of the carbon core state, while the CQD particles were spherical with a size less than 10 nm. The prepared CQDs showed excellent fluorescent properties with blue emission spectra (around 525 nm) upon excitation at 435 nm. The synthesized CQDs had the prodigious sensing potential to detect Fe2+ ions in water with a limit of detection of 0.62 ppm. Additionally, their sensing capability was tested using a real sample (e.g., Livogen tablet). Moreover, the synthesized CQDs showed substantial stability over a long period (three months). Thus, this study provides an inexpensive and facile method for CQD-based sensing of Fe2+ ions with a photoluminescence quenching mechanism.
Collapse
Affiliation(s)
- Jagpreet Singh
- Department of Nanotechnology, Sri Guru Granth Sahib World University, Fatehgarh Sahib 140406, India
| | - Sukhmeen Kaur
- Department of Nanotechnology, Sri Guru Granth Sahib World University, Fatehgarh Sahib 140406, India
| | - Jechan Lee
- Department of Environmental and Safety Engineering, Ajou University, Suwon 16499, Republic of Korea
| | - Akansha Mehta
- School of Chemistry and Biochemistry, Thapar Institute of Engineering and Technology, Patiala, India
| | - Sanjeev Kumar
- Deptartment of Physics, Sri Guru Granth Sahib World University, Fatehgarh Sahib 140406, India
| | - Ki-Hyun Kim
- Department of Civil & Environmental Engineering, Hanyang University, Seoul 04763, Republic of Korea.
| | - Soumen Basu
- Department of Environmental and Safety Engineering, Ajou University, Suwon 16499, Republic of Korea.
| | - Mohit Rawat
- Department of Nanotechnology, Sri Guru Granth Sahib World University, Fatehgarh Sahib 140406, India.
| |
Collapse
|
17
|
Mehta A, Mishra A, Basu S, Shetti NP, Reddy KR, Saleh TA, Aminabhavi TM. Band gap tuning and surface modification of carbon dots for sustainable environmental remediation and photocatalytic hydrogen production - A review. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2019; 250:109486. [PMID: 31518793 DOI: 10.1016/j.jenvman.2019.109486] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2019] [Revised: 08/27/2019] [Accepted: 08/27/2019] [Indexed: 05/06/2023]
Abstract
Energy and water are the two major issues facing the modern mankind. Providing freshwater requires energy and producing energy uses water. In the present-day scenario, both these routes face growing problems and limitations. Energy crisis has risen due to the depletion of fossil fuels that cause pollution to water bodies making the water unusable for human consumption. In this regard, semiconductor nanocrystals with luminescent properties or carbon quantum dots (CQDs) are the newly developed nanomaterials whose distinctive photo-physical characteristics are focusing to a new generation of robust materials and sensors for sustainable development. In this review, advances in surface and band gap modification of CQDs to improve the activity of nanomaterials will be discussed with special reference to some specific CQDs exhibiting special optical properties for water treatment/splitting applications. Recent advances on CQDs nanocomposites including their applications in photodegradation of organic pollutants, sensing of heavy metal ions in water and water splitting are discussed critically to narrate the future prospects in this field. Challenges and limitations for further improvement are covered to provide smart choices for creating sustainability of benign environment and economic benefits.
Collapse
Affiliation(s)
- Akansha Mehta
- School of Chemistry and Biochemistry, Thapar Institute of Engineering and Technology, Patiala, 147004, India
| | - Amit Mishra
- School of Chemistry and Biochemistry, Thapar Institute of Engineering and Technology, Patiala, 147004, India
| | - Soumen Basu
- School of Chemistry and Biochemistry, Thapar Institute of Engineering and Technology, Patiala, 147004, India.
| | - Nagaraj P Shetti
- Electrochemistry and Materials Group, Department of Chemistry, K.L.E. Institute of Technology, Hubballi, 580 030, Visvesvaraya Technological University, Karnataka, India
| | - Kakarla Raghava Reddy
- School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, NSW, 2006, Australia.
| | - Tawfik A Saleh
- Chemistry Department, King Fahd University of Petroleum & Minerals, B.O. Box: 346, Dhahran, 31261, Saudi Arabia
| | - Tejraj M Aminabhavi
- Pharmaceutical Engineering, Sonia College of Pharmacy, Dharwad, 580 002, Karnataka, India.
| |
Collapse
|
18
|
Tian XT, Yin XB. Carbon Dots, Unconventional Preparation Strategies, and Applications Beyond Photoluminescence. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2019; 15:e1901803. [PMID: 31240816 DOI: 10.1002/smll.201901803] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 05/23/2019] [Indexed: 05/24/2023]
Abstract
Carbon dots (C-dots) are generally separated into graphene quantum dots (GQDs) and carbon nanodots (CNDs) based on their respective top-down and bottom-up preparation processes. However, GQDs can be prepared by carbonization of small-molecule precursors as revealed with unconventional preparation strategies. Thus, it is their structures rather than their precursors and preparation strategy that govern whether C-dots are GQDs or CNDs. Here, the composites, structure, and electronic properties of C-dots are discussed. C-dots generally consist of a graphite-like core and amorphous oxygen-containing shell. When graphite becomes C-dots, its conduction and valence bands are separated, and the quantum confinement effect appears. Combined with the light-harvesting ability inherited from graphite, electrons in the core of C-dots are transferred from conduction to valence bands, leading to electron-hole pair formation upon light excitation. The photoexcitation activities, such as photovoltaic conversion, photocatalysis, and photodynamic therapy, are influenced by the electronic properties of the core. Different to the semiconductor properties of core, the C-dot shell is electrochemically active, leading to electrochemiluminescence (ECL). The oxygen-containing groups in shell can conjugate to functional species for use in imaging and therapy. The applications of C-dots beyond photoluminescence, including ECL, solar photovoltaics, photocatalysis, and theranostics, are reviewed.
Collapse
Affiliation(s)
- Xue-Tao Tian
- State Key Laboratory of Medicinal Chemical, Biology and Tianjin Key Laboratory of Biosensing and Molecular Recognition, College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Xue-Bo Yin
- State Key Laboratory of Medicinal Chemical, Biology and Tianjin Key Laboratory of Biosensing and Molecular Recognition, College of Chemistry, Nankai University, Tianjin, 300071, China
| |
Collapse
|
19
|
Almazroai LS, El-Mekawy RE. Synergetic effects of Cu/TiO 2 sensitized with different cyanine dyes on hydrogen evolution. RSC Adv 2019; 9:24670-24681. [PMID: 35528639 PMCID: PMC9069643 DOI: 10.1039/c9ra04696h] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Accepted: 07/24/2019] [Indexed: 11/21/2022] Open
Abstract
The production of hydrogen as an alternative fuel is a major challenge for developed countries. To achieve this, photocatalysis is a promising method, which depends mainly on a renewable energy source, namely, the sun. Many derivatives of cyanine-sensitized Cu/TiO2 were prepared and characterized by XRD, SEM-EDS, TEM, BET surface area and UV-vis spectrophotometry and their photocatalytic activity was studied. The study of hydrogen production over the sensitized photocatalysts confirmed the significant role of the dyes in the enhancement of hydrogen production. Dye molecules harness light radiation to produce strong oxidizing species, such as hydroxyl radicals, which in turn form hydrogen molecules. Combining sonolysis with photocatalysis processes proved that ultrasound waves inhibit the agglomeration of particles and maintain their surface area. This synergetic process increased the efficiency of hydrogen production by 7 times using photocatalysis only.
Collapse
Affiliation(s)
- Layla S Almazroai
- Department of Chemistry, Faculty of Applied Science, Umm Al-Qura University Makkah Saudi Arabia
| | - Rasha E El-Mekawy
- Department of Chemistry, Faculty of Applied Science, Umm Al-Qura University Makkah Saudi Arabia .,Department of Petrochemicals, Egyptian Petroleum Research Institute Nasr City Cairo Egypt
| |
Collapse
|
20
|
Photocatalytic Hydrogen Production: Role of Sacrificial Reagents on the Activity of Oxide, Carbon, and Sulfide Catalysts. Catalysts 2019. [DOI: 10.3390/catal9030276] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Photocatalytic water splitting is a sustainable technology for the production of clean fuel in terms of hydrogen (H2). In the present study, hydrogen (H2) production efficiency of three promising photocatalysts (titania (TiO2-P25), graphitic carbon nitride (g-C3N4), and cadmium sulfide (CdS)) was evaluated in detail using various sacrificial agents. The effect of most commonly used sacrificial agents in the recent years, such as methanol, ethanol, isopropanol, ethylene glycol, glycerol, lactic acid, glucose, sodium sulfide, sodium sulfite, sodium sulfide/sodium sulfite mixture, and triethanolamine, were evaluated on TiO2-P25, g-C3N4, and CdS. H2 production experiments were carried out under simulated solar light irradiation in an immersion type photo-reactor. All the experiments were performed without any noble metal co-catalyst. Moreover, photolysis experiments were executed to study the H2 generation in the absence of a catalyst. The results were discussed specifically in terms of chemical reactions, pH of the reaction medium, hydroxyl groups, alpha hydrogen, and carbon chain length of sacrificial agents. The results revealed that glucose and glycerol are the most suitable sacrificial agents for an oxide photocatalyst. Triethanolamine is the ideal sacrificial agent for carbon and sulfide photocatalyst. A remarkable amount of H2 was produced from the photolysis of sodium sulfide and sodium sulfide/sodium sulfite mixture without any photocatalyst. The findings of this study would be highly beneficial for the selection of sacrificial agents for a particular photocatalyst.
Collapse
|
21
|
|
22
|
Carbon Nanodots: A Review—From the Current Understanding of the Fundamental Photophysics to the Full Control of the Optical Response. C — JOURNAL OF CARBON RESEARCH 2018. [DOI: 10.3390/c4040067] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Carbon dots (CDs) are an emerging family of nanosystems displaying a range of fascinating properties. Broadly speaking, they can be described as small, surface-functionalized carbonaceous nanoparticles characterized by an intense and tunable fluorescence, a marked sensitivity to the environment and a range of interesting photochemical properties. CDs are currently the subject of very intense research, motivated by their possible applications in many fields, including bioimaging, solar energy harvesting, nanosensing, light-emitting devices and photocatalyis. This review covers the latest advancements in the field of CDs, with a focus on the fundamental understanding of their key photophysical behaviour, which is still very debated. The photoluminescence mechanism, the origin of their peculiar fluorescence tunability, and their photo-chemical interactions with coupled systems are discussed in light of the latest developments in the field, such as the most recent results obtained by femtosecond time-resolved experiments, which have led to important steps forward in the fundamental understanding of CDs. The optical response of CDs appears to stem from a very complex interplay between the electronic states related to the core structure and those introduced by surface functionalization. In addition, the structure of CD energy levels and the electronic dynamics triggered by photo-excitation finely depend on the microscopic structure of any specific sub-type of CD. On the other hand, this remarkable variability makes CDs extremely versatile, a key benefit in view of their very wide range of applications.
Collapse
|
23
|
Kainth S, Mehta A, Mishra A, Basu S. Implementation of a logic gate by chemically induced nitrogen and oxygen rich C-dots for the selective detection of fluoride ions. NEW J CHEM 2018. [DOI: 10.1039/c8nj02041h] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The widespread pollution of fluoride ions in the environment badly affects the ecological system due to their high toxicity, mobility and the difficulty of their degradation.
Collapse
Affiliation(s)
- Shagun Kainth
- School of Chemistry and Biochemistry
- Thapar Institute of Engineering & Technology
- Patiala-147004
- India
| | - Akansha Mehta
- School of Chemistry and Biochemistry
- Thapar Institute of Engineering & Technology
- Patiala-147004
- India
| | - Amit Mishra
- School of Chemistry and Biochemistry
- Thapar Institute of Engineering & Technology
- Patiala-147004
- India
| | - Soumen Basu
- School of Chemistry and Biochemistry
- Thapar Institute of Engineering & Technology
- Patiala-147004
- India
| |
Collapse
|
24
|
Thota SP, Thota SM, Srimadh Bhagavatham S, Sai Manoj K, Sai Muthukumar VS, Venketesh S, Vadlani PV, Belliraj SK. Facile one‐pot hydrothermal synthesis of stable and biocompatible fluorescent carbon dots from lemon grass herb. IET Nanobiotechnol 2017; 12:127-132. [PMCID: PMC8676458 DOI: 10.1049/iet-nbt.2017.0038] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 08/17/2017] [Accepted: 08/29/2017] [Indexed: 09/08/2023] Open
Abstract
Luminescent carbon‐based nanomaterials hold great promise due to their stable photo‐physical behaviour, biocompatibility and lower toxicity. This work involves economic and facile one‐pot green synthesis of water‐soluble nanostructures from lemon grass (LGNS) [Cymbopogon citratus (DC) Stapf ] as carbon source. High‐resolution transmission electron microscopy confirmed the formation of LGNS with lattice spacing of 0.23 nm matching low‐dimensional graphitic structures. The strong absorption exhibited at 278 nm could be attributed to л‐states of sp2 /sp3 hybridisation in carbon nanostructures. Fluorescence spectroscopy of LGNS exhibited strong excitation‐dependent emission properties over a broad range of wavelengths from 300 to 600 nm. Quantitatively, these LGNS were estimated to have quantum yield of 23.3%. Biomass derived LGNS could be potentially exploited for wide variety of applications like bioimaging, up‐conversion, drug delivery and optoelectronic devices. To this extent, synthesised LGNS were used to image yeast cells via multicolour/multi‐excitation fluorescence imaging.
Collapse
Affiliation(s)
- Sai Praneeth Thota
- Research in Molecular Modelling LabDepartment of ChemistrySri Sathya Sai Institute of Higher LearningPrasanthi NilayamAndhra Pradesh515134India
| | - Sai Manohar Thota
- Department of BiosciencesSri Sathya Sai Institute of Higher LearningPrasanthi NilayamAndhra Pradesh515134India
| | | | - Kaja Sai Manoj
- Research in Molecular Modelling LabDepartment of ChemistrySri Sathya Sai Institute of Higher LearningPrasanthi NilayamAndhra Pradesh515134India
- Department of PhysicsSri Sathya Sai Institute of Higher LearningPrasanthi NilayamAndhra Pradesh515134India
| | | | - Sivaramakrishnan Venketesh
- Department of BiosciencesSri Sathya Sai Institute of Higher LearningPrasanthi NilayamAndhra Pradesh515134India
| | - Praveen V. Vadlani
- Bioprocessing and Renewable Energy LaboratoryDepartments of Grain Science and Industry & Chemical EngineeringKansas State UniversityManhattanKS66506USA
| | - Siva Kumar Belliraj
- Research in Molecular Modelling LabDepartment of ChemistrySri Sathya Sai Institute of Higher LearningPrasanthi NilayamAndhra Pradesh515134India
| |
Collapse
|