Zero-dimensional Nanostructures Research Articles

Review of: "Electronic nanostructures Nanostructures are divided into four categories of zero-dimensional, one-dimensional, two-dimensional nanomaterials and three-dimensional bulk nanostructures"

Review of: "Electronic nanostructures Nanostructures are divided into four categories of zero-dimensional, one-dimensional, two-dimensional nanomaterials and three-dimensional bulk nanostructures"

Review of: "Nanostructure electronic nanostructures are divided into four categories of zero-dimensional, one-dimensional, two-dimensional nanomaterials and three-dimensional bulk nanostructures"

Review of: "Nanostructure electronic nanostructures are divided into four categories of zero-dimensional, one-dimensional, two-dimensional nanomaterials and three-dimensional bulk nanostructures"

Biophysical translational posterity of green carbon quantum dots: the unparalleled versatility.

Carbon dots (CQDs), zero-dimensional carbon nanostructures, have attracted considerable interest among researchers due to their versatile applications. CQDs exhibit exceptional photoluminescent properties and high quantum yield, making them ideal candidates for bioimaging, drug delivery and environmental sensing. Their biocompatibility and tunable surface chemistry enable targeted therapeutic delivery and real-time imaging with minimal toxicity. Additionally, CQDs are emerging as promising materials in optoelectronics, offering sustainable alternatives in light-emitting diodes and solar cells. This review underscores the unparalleled adaptability of green CQDs in bridging the gap between laboratory research and practical applications, paving the way for innovative solutions in healthcare and environmental monitoring. Through comprehensive analysis, it advances the understanding of CQDs, positioning them at the forefront of next-generation nanomaterials with significant translational impact.

Theory of size quantization in monolayers of transition metal dichalcogenides

A theory of size quantization has been developed for both one-dimensional and zero-dimensional nanostructures, grown from monolayers of transition metal dichalcogenides. Expressions for the energy spectra of charge carriers have been obtained for both even and odd (relative to coordinate inversion) states in the quantum-confined line and point of monolayers of transition metal dichalcogenides, depending on their geometric dimensions. A numerical analysis of the quantum-confined energy states of electrons in nanostructures of monolayers of transition metal dichalcogenides has been conducted.

Numerical assessment of hydrothermal and entropy generation characteristics of graphene quantum dots nanofluid in a microchannel heat sink incorporating secondary channels and ribs

Efficient heat dissipation from electronic chips is essential for enhancing their performance and longevity. Significant progress has been achieved through the introduction of nanofluids and microchannel heat sinks. However, there is still a need for nanofluids that demonstrate exceptional thermal properties and stability. Graphene quantum dots nanofluid, an innovative carbon-based coolant with zero-dimensional nanostructures, presents promising features such as excellent chemical stability, surfactant-free preparation, superior thermal properties, and minimal impact on rheological characteristics. This study explores, for the first time, the hydrothermal behavior and entropy generation of graphene quantum dots nanofluid in a microchannel heat sink comprising secondary flow channels and ribs. To this end, a three-dimensional conjugate heat transfer model is built using ANSYS Fluent software, and the governing equations are solved using the finite volume method. The simulations are carried out considering temperature-dependent thermophysical properties under different concentrations ranging from 0 to 0.5 % and Reynolds numbers ranging from 100 to 500. The results reveal that the maximum bottom wall surface temperature decreases by 5.88 K, while the heat transfer coefficient improves by 24.9 % compared to the base fluid. Moreover, the total entropy generation reduces by 14.7 %. On the other hand, the pressure drop increases by 43 %. Overall, the highest increment in Performance Evaluation Criteria is 10.8 % at a Reynolds number of 100 and a concentration of 0.5 %, making this particular condition suitable for practical applications.

Aptamer Based on Silver Nanoparticle-Modified Flexible Carbon Ink Printed Electrode for the Electrochemical Detection of Chikungunya Virus.

Medical devices have progressed from their initial bulky forms to smart devices. However, their rigidity hampers their seamless integration into everyday life. The fields of stretchable, textile, and flexible electronics are emerging research areas with the potential to drive significant technological progress. This research presents a laboratory-based technique to produce highly sensitive and flexible biosensors for detecting the chikungunya virus. These biosensors are based on 0D nanomaterials and demonstrate significant advancements in voltammetry. The electrochemical platform was created utilizing the stencil printing (StPE) technique. Adapting the biosensor setup involved the selection of aptamer as the biorecognition element bound with silver nanoparticles (AgNPs). This biosensor was employed in the voltammetric identification of the Chikungunya virus antigen (CHIKV-Ag) within a solution containing 0.5 mM potassium ferro/ferri cyanide, a redox pair. The biosensor was employed to evaluate CHIKV-Ag within a human serum sample. It demonstrated a linear detection span ranging from 0.1 ng/mL to 1 μg/mL, with a detection limit of 0.1 ng/mL for CHIKV-Ag. The proposed approach, due to its flexibility in production and the electrocatalytic attributes displayed by the zero-dimensional nanostructure, presents innovative opportunities for cost-effective and tailored aptamer-based bioelectronics, thereby broadening the scope of this domain.

Computing strain-dependent energy transfer from quantum dots to 2D materials

Near-field interaction between the monolayers of two-dimensional (2D) materials has been recently investigated. Another branch under investigation has been the interaction between 2D materials and zero-dimensional (0D) nanostructures including quantum dots (QDs) and metal nanoparticles. In this work, we take one more step to engineering the interaction between those systems. We probe the effect of mechanical strain on the non-radiative energy transfer (NRET) rate from a 0D material, ZnCdSe/ZnSe QD, to a 2D material, monolayer (1L) WS2. It is known that the mechanical strain causes large shifts to the exciton energies in 1L WS2. As a result, our calculations show that strain can tune the NRET rate by engineering the overlap between the emission spectrum of ZnCdSe/ZnSe QD and the exciton resonances of 1L WS2.

A critical review on the environmental applications of carbon dots

The discovery of zero-dimensional carbonaceous nanostructures called carbon dots (CDs) and their unique properties associated with fluorescence, quantum confinement and size effects have intrigued researchers. There has been a substantial increase in the amount of research conducted on the lines of synthesis, characterization, modification, and enhancement of properties by doping or design of composite materials, and a diversification of their applications in sensing, catalysis, optoelectronics, photovoltaics, and imaging, among many others. CDs fulfill the need for inexpensive, simple, and continuous environmental monitoring, detection, and remediation of various contaminants such as metals, dyes, pesticides, antibiotics, and other chemicals. The principles of green chemistry have also prompted researchers to rethink novel modes of nanoparticle synthesis by incorporating naturally available carbon precursors or developing micro reactor-based techniques. Photocatalysis using CDs has introduced the possibility of utilizing light to accelerate redox chemical transformations. This comprehensive review aims to provide the reader with a broader perspective of carbon dots by encapsulating the concepts of synthesis, characterization, applications in contaminant detection and photocatalysis, demerits and research gaps, and potential areas of improvement.

Electron transport engineering with different types of titanium dioxide nanostructures in perovskite solar cells

The light-harvesting effects and electron transport engineering could be achieved by manipulating electron transport layer (ETL) morphology. In This research, three variant nanostructures (NSs) of titanium dioxide (TiO2) have been applied as the ETL in conventional structure of perovskite solar cells (PSCs). Device structures of FTO/TiO2 compact layer/TiO2 NS layer/Perovskite/Spiro-OMeTAD/Au are used for the fabrication of PSCs in ambient conditions. Zero and one-dimensional structures of TiO2 including TiO2 nanocrystals (NCs) with the dominant size of 25 nm, TiO2 nanorods (NRs) with diameters and lengths about 80 nm and 1–2 µm, and TiO2 nanofibers (NFs) with the same dimensional parameters of 100 nm and 2–12 µm were prepared through the hydrothermal method. Then the effects of ETL morphology on the electron transporting process, interfacial engineering, surface quality and cell performance have been investigated. Triple Cation Cs0.05(MA0.17-FA0.83)0.95Pb(I0.83Br0.17)3 perovskite is also used as the light harvester layer in PSCs due to its proper band gap energy, crystalline quality and longtime stability. According to the results, one-dimensional (1D) TiO2 nanostructures with medium size released the best current density of 21.9 mA/cm2 and maximum filling factor of 0.7. That is while the incomplete pore filling of the sublayer and lower open circuit voltage (VOC) 0.905 V had negative impacts on the power conversion efficiency of TiO2 NRs included perovskite solar cells. Remarkable results were achieved for the PSC with zero-dimensional (0D) TiO2 nanostructures as the compact ETL and highest VOC of 1.02 V led to the maximum power conversion efficiency of 14.88 % in ambient conditions.

(Invited, Digital Presentation) Photovoltaic Applications Using Energy Transfer Characteristics from Quantum Dots

Silicon-related materials are most commonly used in solar cells and become now an invaluable material. However, a reported maximum energy conversion efficiency of Si solar cell is close to reaching its theoretical limits. To further improve the cell performance and create new functions, it will become increasingly important to functionalize Si materials using nanostructures. One- and zero-dimensional Si nanostructures called Si nanowires (SiNWs) and Si quantum dots (Si QDs) are increasingly being used as new solar cell materials. Our group has shown that the conversion efficiency of solar cells can be increased by the non-radiation energy transfer (NRET) from Si QDs [1]. Recently, research has been developed on compound semiconductor QDs and perovskite QDs, and the conversion efficiency has been successfully increased [3-7].n-type SiNW arrays were fabricated by electroless etching and Bosch & nanoimprint lithography followed by CVD process. The CVD process was performed to form p-type Si layer for pn homojunction. Hybrid heterojunction cells of PEDOT:PSS and n-SiNWs were also fabricated. Passivation by ozone and hydrogen were applied to improve the solar cell properties [2]. After the cell fabrications, the solar cells were coated with Si QDs, CdZnS/ZnS QDs, CdZnSe/ZnS QDs and perovskite QDs. The fabrication methods and conditions of QDs have been reported elsewhere [1-7]Energy transfer effects such as NRET are new ways of increasing solar cell efficiency. To effectively use the NRET effect, the surface of Si QDs should be fully passivated by ligand molecules. The NRET process is a highly distance-dependent phenomenon, and its dependence on the length of the passivation ligands clearly showed this. NRET efficiency was increased by shortening the ligand length from 1-octadecene to 1-octene, resulting in higher JSC, ultimately providing higher energy conversion efficiency. The efficiency was increased about 1-2 % by adding SiQDs. We also observed the same effect for CdZnS/ZnS QDs, CdZnSe/ZnS QDs and perovskite CsPbCl3 QDs. In these cases, in addition to the NRET effect, the radiative energy transfer (RET) effect also contributes to the increase in conversion efficiency.

Design of zero-dimensional graphene quantum dots based nanostructures for the detection of organophosphorus pesticides in food and water: A review

Design of zero-dimensional graphene quantum dots based nanostructures for the detection of organophosphorus pesticides in food and water: A review. • A systematic study of zero-dimensional graphene quantum dots (GQDs) for organophosphorus pesticide (OPPs) sensing is summarised in brief. • Zero-dimensional GQDs pinpoint OPPs in food and water samples. • GQD-based nanostructures enable OPPs sensing via a variety of ways, including fluorescence resonance energy transfer (FRET), photo-induced electron transfer (PET), and the inner filter effect (IFE), etc. • The selectivity of an OPPs sensor has been reviewed in the presence of various interferences. • In the future, GQD nanostructures will open up new avenues for OPP sensing. From its inception, traditional analytical approaches have been the primary strategies for sensing organophosphorus pesticides (OPPs). Unfortunately, traditionally reported methods are suffering from plentiful limitations that include their cost factor, poor responsiveness, low specificity, tedious, etc. Recently, graphene quantum dots (GQDs) have been widely applied to researchers’ recognition of OPPs sensing in water and food samples, due to their outstanding and versatile attributes. Moreover, the combination of other nanomaterials like inorganic and organic materials, along with surface tuning of GQDs such as doping and functionalization, shows the potential to boost the performance of the sensing system. Despite this indubitable development, there is no detailed report on the design of zero-dimensional GQD-based nanostructures for the detection of OPPs in food and water. Therefore, we have addressed the GQDs-centered nanostructures for the recognition of OPPs in water and food. Importantly, it covers the consumption of OPPs and their impact on human health, while the synthesis and properties of nanosized GQDs have been reviewed. Besides, GQDs based on fluorescent, electrochemical, and colorimetric nanoprobe for monitoring OPPs have been illustrated. Moreover, sensing mechanisms, anti-interference potential, current challenges, and future research have been described. Fascinatingly, modification of GQDs enabled sensors exhibits supreme responsiveness and specificity for recognition of OPPs in provided samples. Accordingly, existing architectured GQDs mediated nanoprobes furnish the lower detection limit for OPPs up to a picogram. In near future, the nano-design of GQD-centered sensors will open up a new door for sensing OPPs in real-time samples.

On-Surface Chemistry on Low-Reactive Surfaces

Zero-dimensional (0D), mono-dimensional (1D), or two-dimensional (2D) nanostructures with well-defined properties fabricated directly on surfaces are of growing interest. The fabrication of covalently bound nanostructures on non-metallic surfaces is very promising in terms of applications, but the lack of surface assistance during their synthesis is still a challenge to achieving the fabrication of large-scale and defect-free nanostructures. We discuss the state-of-the-art approaches recently developed in order to provide covalently bounded nanoarchitectures on passivated metallic surfaces, semiconductors, and insulators.

Photoactivatable carbon dots as a label-free fluorescent probe for picric acid detection and light-induced bacterial inactivation.

The zero-dimensional carbon nanostructure known as carbon dots showed attractive attributes such as multicolour emission, very high quantum yield, up-conversion, very good aqueous solubility, eco-friendliness, and excellent biocompatibility. These outstanding features of the carbon dots have raised significant interest among the research community worldwide. In the current work, water-soluble nitrogen, silver, and gold co-doped bimetallic carbon dots (BCDs) were prepared using the one-pot hydrothermal method with citric acid as a sole carbon source. As prepared BCDs showed size in the range of 4-8nm and excitation-independent emission behaviour with maximum emission observed at 427nm. Additionally, these BCDs showed a very high quantum yield value of 50% and fluorescence lifetime value of 10.1ns respectively. Interestingly, as prepared BCDs selectively sense picric acid (PA) by exhibiting "selective fluorescence turn-off" behaviour in the presence of PA with a limit of detection value (LOD) of 46nM. Further, as prepared BCDs were explored for photodynamic therapy to inactivate bacterial growth in the presence of light (400-700nm) by generating singlet oxygen. Thus as prepared BCDs offer lots of potentials to use a nanoprobe to detect picric acid in an aqueous medium and to design next-generation antibacterial materials.

Quantized Exciton Motion and Fine Energy-Level Structure of a Single Perovskite Nanowire.

The quantum-confinement effect profoundly influences the exciton energy-level structures and recombination dynamics of semiconductor nanostructures but remains largely unexplored in traditional one-dimensional nanowires mainly due to their poor optical qualities. Here, we show that in defect-tolerant perovskite material of highly luminescent CsPbBr3 nanowires, the exciton's center-of-mass motion perpendicular to the axial direction is severely confined. This is reflected in the two sets of photoluminescence spectra emitted from a single CsPbBr3 nanowire, each of which consists of doublet peaks with linear polarizations perpendicular and parallel to the axial direction. Moreover, different exciton states can be mixed by the Rashba spin-orbit coupling effect, resulting in two single photoluminescence peaks with linear polarizations both along the nanowire axis. The above findings mark the emergence of an ideal platform for the exploration of intrinsic one-dimensional exciton photophysics and optoelectronics, thus bridging the long-missing research gap between the well-studied two- and zero-dimensional semiconductor nanostructures.

Phosphorene quantum dots: synthesis, properties and catalytic applications.

Phosphorene quantum dots (PQDs) belong to a new class of zero-dimensional functional nanostructures with unique physicochemical and surface properties in comparison with few-layer phosphorene and other 2D analogues. Tunable band gap as a function of number of layers, ease of passivation and high carrier mobility of PQDs have attracted considerable attention in catalysis research due to which spectacular progress has been made in PQD research over the last few years. PQDs are now considered as promising catalytic materials for electrocatalytic water splitting and nitrogen reduction, lithium-sulfur batteries, solar light-driven energy devices and biocatalysis, either in pristine form or as an active component for constructing heterostructures with other 2D materials. In the light of these recent advances, it is worthwhile to review and consolidate PQD research in catalytic applications to understand the challenges ahead and suggest possible solutions. In this review, we systematically summarize various synthetic strategies including ultrasonic and electrochemical exfoliation, solvothermal treatment, blender breaking, milling, crushing and pulsed laser irradiation. Furthermore, the physiochemical properties of PQDs are discussed based on both experimental and theoretical perspectives. The potential applications of PQDs in catalysis with special emphasis on photocatalysis (solar light-driven energy devices) and electrocatalysis (oxygen evolution reactions and hydrogen evolution reactions) -are critically discussed along with the present status, challenges and future perspectives.

Recent Advances of Nanostructured Materials for Photoelectrochemical Bioanalysis

Nowadays, the emerging photoelectrochemical (PEC) bioanalysis has drawn intensive interest due to its numerous merits. As one of its core elements, functional nanostructured materials play a crucial role during the construction of PEC biosensors, which can not only be employed as transducers but also act as signal probes. Although both chemical composition and morphology control of nanostructured materials contribute to the excellent analytical performance of PEC bioassay, surveys addressing nanostructures with different dimensionality have rarely been reported. In this review, according to classification based on dimensionality, zero-dimensional, one-dimensional, two-dimensional, and three-dimensional nanostructures used in PEC bioanalysis are evaluated, with an emphasis on the effect of morphology on the detection performances. Furthermore, using the illustration of recent works, related novel PEC biosensing patterns with promising applications are also discussed. Finally, the current challenges and some future perspectives in this field are addressed based on our opinions.

Applications of novel quantum dots derived from layered materials in cancer cell imaging

Quantum dots (QDs) is one of the very important zero dimensional nanostructure which are known as the semiconductor nanocrystals. These nanostructures are of great interest due to their unique optical properties such as high absorption amplitude, strong fluorescence and high resistance to photobleaching. Therefore, quantum dots are widely used as a fluorescence indicator in vitro and in vivo in the field of bioimaging. In addition, quantum dots are widely used in the preparation of multifunctional thranostic nanomaterials. Although organic dye and quantum dots synthesized with heavy metals has been used for cell imaging in recent years, but the production of quantum dots from two-dimensional nanostructures due to having unique properties such as more stable fluorescence, less toxicity and more eco-friendly has recently received more attention. Graphene oxide, molybdenum disulfide, and black phosphorus are the most popular two-dimensional layered nanostructures used to synthesize quantum dots. These quantum dots are used to imaging different types of cancers. Recently, they have also been used in techniques such as magnetic resonance imaging (MRI) and computed tomography (CT) for normal cell imaging. In this review the synthesis methods as well as surface modifications of QDs derived from two dimensional nanostructures are discussed. Furthermore the newest applications of these QDs in the field of cancer cellular imaging are reviewed.

Dark-level trapping, lateral confinement, and built-in electric field contributions to the carrier dynamics in c-plane GaN/AlN quantum dots emitting in the UV range

c-plane GaN/AlN quantum dots (QDs) are promising zero-dimensional quantum nanostructures that exhibit single photon emission properties up to room temperature and even above. In this context, it is of prime interest to gain a deeper insight into the recombination dynamics of photogenerated electron–hole pairs captured by such dots. Hence, in this work, we study the time-resolved photoluminescence (PL) properties in the low injection regime and at cryogenic temperatures of c-plane GaN/AlN QD ensembles emitting above the bulk GaN bandgap in order to properly understand the nature of the recombination channels behind the observed non-exponential decay time profiles. Such decays reveal the existence of a relaxation channel competing with the radiative recombination one. It is thus observed that for the former process the dynamics is independent of the dot height, which is attributed to a reversible nonradiative transfer that could be mediated by a spin-flip process to a dark-level state. The radiative recombination process is recognizable thanks to the characteristic dependence of its lifetime with the emission energy, which is well accounted for by the built-in electric field inherent to quantum nanostructures grown along the c axis and the variations in the lateral confinement at play in such QDs. Those conclusions are drawn from the analysis of the time evolution of the PL spectra by means of a simple analytical model that enables to exclude any screening of the built-in electric field.

Electrochemical-Based Biosensors on Different Zinc Oxide Nanostructures: A Review.

Electrochemical biosensors have shown great potential in the medical diagnosis field. The performance of electrochemical biosensors depends on the sensing materials used. ZnO nanostructures play important roles as the active sites where biological events occur, subsequently defining the sensitivity and stability of the device. ZnO nanostructures have been synthesized into four different dimensional formations, which are zero dimensional (nanoparticles and quantum dots), one dimensional (nanorods, nanotubes, nanofibers, and nanowires), two dimensional (nanosheets, nanoflakes, nanodiscs, and nanowalls) and three dimensional (hollow spheres and nanoflowers). The zero-dimensional nanostructures could be utilized for creating more active sites with a larger surface area. Meanwhile, one-dimensional nanostructures provide a direct and stable pathway for rapid electron transport. Two-dimensional nanostructures possess a unique polar surface for enhancing the immobilization process. Finally, three-dimensional nanostructures create extra surface area because of their geometric volume. The sensing performance of each of these morphologies toward the bio-analyte level makes ZnO nanostructures a suitable candidate to be applied as active sites in electrochemical biosensors for medical diagnostic purposes. This review highlights recent advances in various dimensions of ZnO nanostructures towards electrochemical biosensor applications.

Plasmon-Enhanced Near-Field Optical Spectroscopy of Multicomponent Semiconductor Nanostructures

Multicomponent semiconductor nanostructures were studied by local spectral analysis based on surface-enhanced Raman scattering by semiconductor nanostructures located on the surface of an array of Au nanoclusters near the metallized tip of an atomic force microscope. In the gap between the metal nanoclusters and the tip, where a semiconductor nanostructure is located, there is a strong increase in the local electric field (hot spot), resulting in a dramatic enhancement of the Raman scattering signal. An unprecedented enhancement of the Raman scattering signal by two-dimensional (over 108 for MoS2) and zero-dimensional (106 for CdSe nanocrystals) semiconductor nanostructures was achieved. The use of the method for mapping the Raman scattering response of a multicomponent system of MoS2 and CdSe made it possible to identify components with a spatial resolution far exceeding the diffraction limit.