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Search for "defects" in Full Text gives 641 result(s) in Beilstein Journal of Nanotechnology. Showing first 200.

A graphene quantum dots–glassy carbon electrode-based electrochemical sensor for monitoring malathion

  • Sanju Tanwar,
  • Aditi Sharma and
  • Dhirendra Mathur

Beilstein J. Nanotechnol. 2023, 14, 701–710, doi:10.3762/bjnano.14.56

Graphical Abstract
  • significantly. Therefore, it can be inferred that not only quantum size effects, but also defects on the surface, contribute to the PL in GQDs. Size and morphology of GQDs were characterized using TEM and AFM. The TEM micrographs shown in Figure 3a confirm the formation of evenly dispersed GQDs with almost
  • . 1385 cm−1) and G bands (ca. 1585 cm−1) with an excitation wavelength of 532 nm as shown in Figure 5b, resembling those of a standard graphitic structure [38]. As a result of defects in the sp2-hybridized GQDs structure, the D band occurs due to transverse optical (TO) phonons about the k point of the
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Published 09 Jun 2023

Metal-organic framework-based nanomaterials as opto-electrochemical sensors for the detection of antibiotics and hormones: A review

  • Akeem Adeyemi Oladipo,
  • Saba Derakhshan Oskouei and
  • Mustafa Gazi

Beilstein J. Nanotechnol. 2023, 14, 631–673, doi:10.3762/bjnano.14.52

Graphical Abstract
  • induced by heat. The emission is caused by electrons transitioning from higher-energy molecular orbitals to lower-energy ones, typically the ground state or the lowest empty molecular orbitals. Luminescence may be caused by intrinsic defects, a particular moiety within the compound (metal or ligand
  • ), impurity-induced defects, or it may exist in pure crystals or molecules. According to the manner of the substance excitation, several distinct forms of luminescence are differentiated, as shown in Figure 6. A molecule, nanostructure, or atom must be able to absorb light radiation, resulting in electronic
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Published 01 Jun 2023

Titania nanoparticles for photocatalytic degradation of ethanol under simulated solar light

  • Evghenii Goncearenco,
  • Iuliana P. Morjan,
  • Claudiu Teodor Fleaca,
  • Florian Dumitrache,
  • Elena Dutu,
  • Monica Scarisoreanu,
  • Valentin Serban Teodorescu,
  • Alexandra Sandulescu,
  • Crina Anastasescu and
  • Ioan Balint

Beilstein J. Nanotechnol. 2023, 14, 616–630, doi:10.3762/bjnano.14.51

Graphical Abstract
  • (point defects), there are some deviations. The small oxygen deficiency observed even after calcination is related to remaining chlorine impurities and Ti3+ ions that resisted calcination. Phase composition and crystallites sizes of the TiO2 powders were investigated. The X-ray diffractograms of the
  • (Figure 2c). The highest number of spheres compared to the total number of particles are in sample TO-850-b (7.6%) and the fewest in sample TO-250-b (1.9%). The HRTEM images (Figure 3) show the crystal structure of the TO-850-a powder with point defects and some residual impurities at the particle surface
  • exclude the possibility that these defects are located on the TiO2 surface and that the concentration of defects is below the detection limit of XPS [52][53]. Another explanation would be this: The surface depth sensitivity of XPS is known to be 5–10 nm compared to 1 μm in PL. Hence, this technique
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Published 22 May 2023

Thermal transport in kinked nanowires through simulation

  • Alexander N. Robillard,
  • Graham W. Gibson and
  • Ralf Meyer

Beilstein J. Nanotechnol. 2023, 14, 586–602, doi:10.3762/bjnano.14.49

Graphical Abstract
  • . Systems where such transport is important are said to have significant ballistic transport compared to the classical scenario, that is, diffusive transport. Ballistic transport can be impacted by features of the system, such as surfaces, edges, defects, and inclusions [7][8][9]. Consequently, the effect
  • concentration of heat flux into areas smaller than the wire itself has significant implications for device design. Areas with more significant heat flow can amplify the effects of small changes in the wire. This is particularly true when impurities or defects are a concern [24]. Introduction of a source of
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Published 15 May 2023

ZnO-decorated SiC@C hybrids with strong electromagnetic absorption

  • Liqun Duan,
  • Zhiqian Yang,
  • Yilu Xia,
  • Xiaoqing Dai,
  • Jian’an Wu and
  • Minqian Sun

Beilstein J. Nanotechnol. 2023, 14, 565–573, doi:10.3762/bjnano.14.47

Graphical Abstract
  • same time, wide effective absorption bandwidth (EAB ≥ 7 GHz) remains a great challenge. A good strategy is to form hierarchical heterostructures, characterized by diverse components, abundant heterogeneous interfaces, multiple reflective paths, and enrichment of structural defects [18][19][20
  • amorphous state (Figure 2e). The carbon shell may have a positive effect on the nucleation of ZnO particles. This is because oxygen-containing functional groups (such as carboxyl and hydroxy groups) and structural defects are generated on the SiC@C surface during the in situ carbonization [24], which both
  • SiC surface. As described in our previous work [24], the carbon shell may form a conductive network in the SCZ/wax composites (Supporting Information File 1, Figure S6b). Besides, abundant defects (such as nanopores in carbon) can also result in dipole polarization and Debye relaxations [24][38
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Published 04 May 2023

SERS performance of GaN/Ag substrates fabricated by Ag coating of GaN platforms

  • Magdalena A. Zając,
  • Bogusław Budner,
  • Malwina Liszewska,
  • Bartosz Bartosewicz,
  • Łukasz Gutowski,
  • Jan L. Weyher and
  • Bartłomiej J. Jankiewicz

Beilstein J. Nanotechnol. 2023, 14, 552–564, doi:10.3762/bjnano.14.46

Graphical Abstract
  • plasmonic metals or their alloys [23][24][25][26][27][28][29][30][31][32]. The chemical and electrochemical etching of GaN heteroepitaxial layers leads to various nanostructures formed on line defects (dislocations), such as straight nanopillars, bunches of nanopillars, and pits [31][32]. The nanostructured
  • in the formation of nanocolumns on line defects (dislocations), as was demonstrated in [45]. The nanostructured GaN platforms were then coated with Ag using a Quorum Q150TS sputter coater (Quorum Technologies Ltd., Laughton, UK) with a cleaning oxidized target function engaged [32]. The thickness of
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Published 03 May 2023

Observation of multiple bulk bound states in the continuum modes in a photonic crystal cavity

  • Rui Chen,
  • Yi Zheng,
  • Xingyu Huang,
  • Qiaoling Lin,
  • Chaochao Ye,
  • Meng Xiong,
  • Martijn Wubs,
  • Yungui Ma,
  • Minhao Pu and
  • Sanshui Xiao

Beilstein J. Nanotechnol. 2023, 14, 544–551, doi:10.3762/bjnano.14.45

Graphical Abstract
  • influenced by both the radiative part Qr and a nonradiative part Qnr via 1/Q = 1/Qr + 1/Qnr provided that the material is lossless. Qnr incorporates defects such as structural disorder, surface roughness, and fabrication errors. The simulation of the unit cell was performed by COMSOL Multiphysics with
  • defects are mainly located at the mode node of a specific mode, the loss caused by the defect will decrease. In contrast, disorders at an antinode will lead to obvious loss (small Qnr) and a dominant Q factor degradation. For our sample, a higher loss caused by defects occurs for the mode with shorter
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Published 27 Apr 2023

On the use of Raman spectroscopy to characterize mass-produced graphene nanoplatelets

  • Keith R. Paton,
  • Konstantinos Despotelis,
  • Naresh Kumar,
  • Piers Turner and
  • Andrew J. Pollard

Beilstein J. Nanotechnol. 2023, 14, 509–521, doi:10.3762/bjnano.14.42

Graphical Abstract
  • . For example, information on flake size, extent of structural defects, chemical or electronic doping, and strain and layer number can all be extracted from one spectrum [13][14][15][16][17][18]. As such, Raman spectroscopy is widely used by producers to assess the quality of their material, in
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Published 24 Apr 2023

Conjugated photothermal materials and structure design for solar steam generation

  • Chia-Yang Lin and
  • Tsuyoshi Michinobu

Beilstein J. Nanotechnol. 2023, 14, 454–466, doi:10.3762/bjnano.14.36

Graphical Abstract
  • either undergo radiative relaxation in the form of photons or nonradiative relaxation in the form of phonons (heat) to release and transfer energy to impurities/defects or dangling bonds on the material surface. When energy is released in the form of phonons, local heating of the lattice is induced
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Published 04 Apr 2023

Plasmonic nanotechnology for photothermal applications – an evaluation

  • A. R. Indhu,
  • L. Keerthana and
  • Gnanaprakash Dharmalingam

Beilstein J. Nanotechnol. 2023, 14, 380–419, doi:10.3762/bjnano.14.33

Graphical Abstract
  • Planck’s constant, and q is the wave vector of the phonon oscillations. These elementary excitation phonons are bosons with a wave vector of k = 2π/λ. Crystal defects and other such sources of anharmonicity can change their frequencies and, hence, their coupling characteristics to electrons and the
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Published 27 Mar 2023

Quasi-guided modes resulting from the band folding effect in a photonic crystal slab for enhanced interactions of matters with free-space radiations

  • Kaili Sun,
  • Yangjian Cai,
  • Uriel Levy and
  • Zhanghua Han

Beilstein J. Nanotechnol. 2023, 14, 322–328, doi:10.3762/bjnano.14.27

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  • enhancement are central for the manipulation of light–matter interactions. Optical resonators of various forms have been exploited for this purpose. What follows are a few representative examples investigated in the last several decades: Photonic crystal cavities are realized when small disorders or defects
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Published 06 Mar 2023

Bismuth-based nanostructured photocatalysts for the remediation of antibiotics and organic dyes

  • Akeem Adeyemi Oladipo and
  • Faisal Suleiman Mustafa

Beilstein J. Nanotechnol. 2023, 14, 291–321, doi:10.3762/bjnano.14.26

Graphical Abstract
  • /and surface defects are created without destroying the crystal structure (though it might be distorted), effectively separating photogenerated carriers. Doping with metallic (Mg, Ag, Ni, Fe, Li, Co, and Ni) and non-metallic ions (F, C, N, and O), can introduce an intraband close to the conduction band
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Published 03 Mar 2023

Structural, optical, and bioimaging characterization of carbon quantum dots solvothermally synthesized from o-phenylenediamine

  • Zoran M. Marković,
  • Milica D. Budimir,
  • Martin Danko,
  • Dušan D. Milivojević,
  • Pavel Kubat,
  • Danica Z. Zmejkoski,
  • Vladimir B. Pavlović,
  • Marija M. Mojsin,
  • Milena J. Stevanović and
  • Biljana M. Todorović Marković

Beilstein J. Nanotechnol. 2023, 14, 165–174, doi:10.3762/bjnano.14.17

Graphical Abstract
  • from this, surface defects can cause a redshift of the PL emission [35]. Based on the recorded PL spectra, we can conclude that the PL of these dots is dominantly governed by the core states in the conjugated π domains and the quantum confinement effect. Similar to other semiconducting quantum dots
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Published 30 Jan 2023

Antimicrobial and mechanical properties of functionalized textile by nanoarchitectured photoinduced Ag@polymer coating

  • Jessica Plé,
  • Marine Dabert,
  • Helene Lecoq,
  • Sophie Hellé,
  • Lydie Ploux and
  • Lavinia Balan

Beilstein J. Nanotechnol. 2023, 14, 95–109, doi:10.3762/bjnano.14.11

Graphical Abstract
  • ] synthesized AgNPs on cotton fabrics using laser ablation, while Ahmad et al. [31] deposited AgNPs by the dip and dry method based on surface reduction reactions. However, the difference in expansion coefficients of the given metal layer and substrate can lead to surface defects under strain (cracks, loss of
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Published 12 Jan 2023

The influence of structure and local structural defects on the magnetic properties of cobalt nanofilms

  • Alexander Vakhrushev,
  • Aleksey Fedotov,
  • Olesya Severyukhina and
  • Anatolie Sidorenko

Beilstein J. Nanotechnol. 2023, 14, 23–33, doi:10.3762/bjnano.14.3

Graphical Abstract
  • ideal structure. In all cases of calculations for cobalt, the ferromagnetic behavior was preserved. Defects in the structure and local arrangement of the atoms cause a deterioration in the magnetic macroscopic parameters, such as a decrease in the magnetization modulus. Keywords: LAMMPS; magnetic
  • . Morphological analysis enables the identification of local defects in the crystal structure, which form different scale aggregates that can further serve as causes of deterioration of the target material functional characteristics [30][31]. Comprehensive studies in this area not only allow to establish the
  • magnetoelasticity or to study the influence of defects on the magnetic properties of materials. Results and Discussion As numerical experiments at the stage of modeling technological processes of niobium and cobalt sample manufacturing showed, the structure of the formed layers is not ideal. Visually, noticeable
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Published 04 Jan 2023

Electrical and optical enhancement of ITO/Mo bilayer thin films via laser annealing

  • Abdelbaki Hacini,
  • Ahmad Hadi Ali,
  • Nurul Nadia Adnan and
  • Nafarizal Nayan

Beilstein J. Nanotechnol. 2022, 13, 1589–1595, doi:10.3762/bjnano.13.133

Graphical Abstract
  • by many factors, such as the type of substrate [15], the deposition technique [16][17][18], the deposition conditions [19][20][21][22], and the annealing treatment [23]. Among these factors, heat treatment is a significant factor in rearranging the nanostructure, removing defects, and improving the
  • size increased with the laser energy up to 200 mJ. It decreased to reach a minimum at an energy of 240 mJ. This trend in crystallite size is due to the rearrangement of the nanostructure. The particles sizes increase, defects are reduced, and the dislocation density (δ) decreases from 6.53 × 1014 to
  • increase is due to the effect of the laser on the surface reducing defects and eliminating grain boundaries. Above 120 mJ, the grain size decreased with the increase of the laser energy to 16.6 nm for 240 mJ. This decrease is due to the diffusion of gas atoms from the chamber into the upper layer
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Published 28 Dec 2022

From a free electron gas to confined states: A mixed island of PTCDA and copper phthalocyanine on Ag(111)

  • Alfred J. Weymouth,
  • Emily Roche and
  • Franz J. Giessibl

Beilstein J. Nanotechnol. 2022, 13, 1572–1577, doi:10.3762/bjnano.13.131

Graphical Abstract
  • electron gas (2DEG) is that standing waves can be observed near defects as a result of scattering [13]. Sabitova et al. [11] acquired dI/dV images at various voltages above 0.6 V and observed wave-like patterns around the defects. We reproduced these measurements as can be seen in Figure S1, Supporting
  • behaviour as seen in the PTCDA/Ag(111) interface state. We identify a state that appears to be an array of one-dimensional quantum wells based on its shape in the dI/dV spatial maps. However, we do not observe scattering at defects and conclude that it is localized laterally at the PTCDA molecules. Methods
  • the PC islands. A further dataset showing both a pure PC island and a large PTCDA island is shown in Figure S3 and Figure S4 of Supporting Information File 1. At two positions on the island shown in Figure 2a, there are unknown defects that are indicated by black arrows. We acquired dI/dV spectra
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Published 22 Dec 2022

Induced electric conductivity in organic polymers

  • Konstantin Y. Arutyunov,
  • Anatoli S. Gurski,
  • Vladimir V. Artemov,
  • Alexander L. Vasiliev,
  • Azat R. Yusupov,
  • Danfis D. Karamov and
  • Alexei N. Lachinov

Beilstein J. Nanotechnol. 2022, 13, 1551–1557, doi:10.3762/bjnano.13.128

Graphical Abstract
  • , associates of macromolecules are formed in the solution, and the influence of adhesion processes decreases, but the cohesive forces increase. In the entire thickness range from 3 nm to 1 µm, the films are solid, without significant defects and/or pin holes. The polymer films were studied by atomic force
  • microscopy (AFM) using an earlier described methodology [5]. The study of the film morphology showed that they are homogeneous, and within the entire thickness range from 3 nm to 1 µm the films are solid, without significant defects and/or pin holes. The observation confirms the good film-forming properties
  • thickness of the polymer or formation of multiple metallic dendrites. However, a number of microphotographs showed some defects in the form of shortcuts (Figure 2c). The origin of these artifacts is not entirely clear: they could be initially present in heterostructures, or they could have appeared during
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Published 19 Dec 2022

A TiO2@MWCNTs nanocomposite photoanode for solar-driven water splitting

  • Anh Quynh Huu Le,
  • Ngoc Nhu Thi Nguyen,
  • Hai Duy Tran,
  • Van-Huy Nguyen and
  • Le-Hai Tran

Beilstein J. Nanotechnol. 2022, 13, 1520–1530, doi:10.3762/bjnano.13.125

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  • non-smooth walls of the MWCNTs indicates the presence of defects such as vacancies, dangling bonds, interstitials, and pentagons [14]. Figure 3b shows the irregular shape of TiO2 particles smaller than 20 nm and their non-uniform distribution. In Figure 3c, some MWCNTs link with TiO2 clusters as
  • conjunctional bridges. TiO2 particles deposit only on the outside wall surface of the MWCNTs. Additionally, an agglomeration of TiO2 particles is only observed at the branching points, zigzag regions, and the end of MWCNTs where the defects are identified. However, the observation differs from previous studies
  • , in which the TiO2 particles are uniformly attached to CNTs by layer-by-layer coating or sol–gel methods [15][16][17]. Notably, the defects on the wall surface of MWCNTs, which enable π–π interactions, could be the active sites to generate the TiO2 agglomerations via hydroxy groups and, thus, enhance
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Published 14 Dec 2022

Dry under water: air retaining properties of large-scale elastomer foils covered with mushroom-shaped surface microstructures

  • Matthias Mail,
  • Stefan Walheim,
  • Thomas Schimmel,
  • Wilhelm Barthlott,
  • Stanislav N. Gorb and
  • Lars Heepe

Beilstein J. Nanotechnol. 2022, 13, 1370–1379, doi:10.3762/bjnano.13.113

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  • the shell surface, through which additional diffusion takes place. Therefore, the surface should be compartmented to exclude the influence of these side surfaces. Furthermore, a subdivision of the air volume into small individual volumes ensures better stability, since individual defects only affect a
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Published 21 Nov 2022

Near-infrared photoactive Ag-Zn-Ga-S-Se quantum dots for high-performance quantum dot-sensitized solar cells

  • Roopakala Kottayi,
  • Ilangovan Veerappan and
  • Ramadasse Sittaramane

Beilstein J. Nanotechnol. 2022, 13, 1337–1344, doi:10.3762/bjnano.13.110

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  • surface trap state defects [11][12]. In order to minimize the number of these defects, a wide-bandgap material, such as ZnS or ZnSe, is deposited on group I-III-VI QDs. Zhang et al. over coated a ZnS layer [13][14] on Cu-In-S and Cu-In-Se QDs to obtain highly efficient sensitizers for QDSCs. Hua Zhang et
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Published 14 Nov 2022

Recent trends in Bi-based nanomaterials: challenges, fabrication, enhancement techniques, and environmental applications

  • Vishal Dutta,
  • Ankush Chauhan,
  • Ritesh Verma,
  • C. Gopalkrishnan and
  • Van-Huy Nguyen

Beilstein J. Nanotechnol. 2022, 13, 1316–1336, doi:10.3762/bjnano.13.109

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  • , heterostructure formation, interface modification, and Bi-content enhancement, have been employed. Defect formation Vacancies and defects affect the electrical properties of Bi-based semiconductor photocatalysts and, hence, govern the photocatalytic efficacy. Rao et al. reported an N2-assisted heat treatment
  • vacancies in monolayered Bi2WO6 nanosheets with a thickness of 1.0 nm have recently been shown [82]. The Bi defects were shown to promote the adsorption and activation of reactant molecules, which reduced the energy barrier even more. The photocatalytic performance corroborated this. The presence of
  • and deposition and doping of metals and non-metallic elements are the most common doping methods. Metal ions modify the crystal structure of the Bi-based semiconductor photocatalysts or induce defects. Also, the photocatalytic properties may be altered by doping or deposition of metallic components
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Published 11 Nov 2022

Enhanced electronic transport properties of Te roll-like nanostructures

  • E. R. Viana,
  • N. Cifuentes and
  • J. C. González

Beilstein J. Nanotechnol. 2022, 13, 1284–1291, doi:10.3762/bjnano.13.106

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  • ionization energy of the defects found on these nanostructures also favors the control of doping and, consequently, the electrical properties of the nanowires. These superior quality transport properties demonstrate the potential use of t-Te roll-like nanostructures for electronic device applications. (a–c
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Published 08 Nov 2022

Rapid fabrication of MgO@g-C3N4 heterojunctions for photocatalytic nitric oxide removal

  • Minh-Thuan Pham,
  • Duyen P. H. Tran,
  • Xuan-Thanh Bui and
  • Sheng-Jie You

Beilstein J. Nanotechnol. 2022, 13, 1141–1154, doi:10.3762/bjnano.13.96

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  • oxide with wide bandgap (3.5–5 eV), high availability, non-toxicity, low cost, and native structural defects [18][19]. The large bandgap energy is the limitation of MgO, reducing the photocatalytic performance and applicability of MgO [20]. Various efforts have been made to enhance the absorption in the
  • nm with an excitation wavelength (770 nm) in the visible range, which could be caused by the native structural defects in MgO [18]. 3% MgO@g-C3N4 shows intense fluorescence at 420 nm via excitation at 850 nm, due to the recombination of charge carriers. The photogenerated electrons from the valance
  • atoms [64][65][66]. Also, Liang and co-workers reported that the recombination of the e−–h+ pairs could be inhibited by doping MgO into g-C3N4 [32]. When MgO is added, the defect concentration increases and Mg and O vacancies are generated in MgO@g-C3N4. These defects work as the electron traps, which
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Published 18 Oct 2022

Recent advances in green carbon dots (2015–2022): synthesis, metal ion sensing, and biological applications

  • Aisha Kanwal,
  • Naheed Bibi,
  • Sajjad Hyder,
  • Arif Muhammad,
  • Hao Ren,
  • Jiangtao Liu and
  • Zhongli Lei

Beilstein J. Nanotechnol. 2022, 13, 1068–1107, doi:10.3762/bjnano.13.93

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  • . Surface passivation with different functional groups generates surface defects, which produces fluorescence and also generates new active sites for modification for specific applications. CDs can be chemically modified by many heteroatoms, including N, P, and S, and many other chemicals that increase
  • high QY because nitrogen atom doping helps to stabilize the surface defects of CDs and enhances fluorescence emission. Moreover, owing to its five valence electrons and an atomic size that is similar to carbon, nitrogen is a common dopant and the most frequently employed method of enhancing PL
  • contrast to nitrogen, phosphorus atoms are larger than carbon atoms. As a result, it has the potential to act as an n-type donor and create substitutional defects in the carbon cluster, changing the electronic and optical characteristics of CDs with great impact on polarizability, quantum yield, and
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Published 05 Oct 2022
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