Hybrid Plasmonic Nanostructures Research Articles

Boosting sunlight driven photocatalytic and catalytic performance of ZnFe2O4-ZnO nanohybrids by loading Ag nanoparticles

We report facile fabrication of magnetically separable Ag@ZnFe2O4-ZnO plasmonic hybrid nanostructures by a simple wet chemical route combined with cost-effective photodeposition. The successful formation of Ag@ZnFe2O4-ZnO hybrid nanostructures was confirmed using XRD, Raman, FESEM, TEM, HRTEM and SAED characterizations. The catalytic and photocatalytic capabilities of the synthesized magnetic Ag@ZnFe2O4-ZnO plasmonic hybrid nanostructures were evaluated with regard to 4-NP to 4-AP reduction in dark and photodecomposition of major anionic and cationic pollutants (MB, MG, MO, RhB) and emerging pollutant levofloxacin antibiotic under sunlight illumination, respectively. Results showed that Ag@ZnFe2O4-ZnO hybrid nanostructures exhibit excellent catalytic as well as photocatalytic response and reduced 98.1 % of 4-NP in only 6 min and decolorized 92.9, 93, 43.4 and 73.3 % of MB, MG, MO and RhB within only 18 min and 90.5 % of levofloxacin in 40 min of sun light irradiation, respectively. Further, the synthesized nanohybrids possess high stability and can be magnetically recovered due to its good magnetic response. In addition, the trapping experiments indicated that the main active compounds for the photodegradation of dyes are OH radicals. We demonstrate that the prepared Ag@ZnFe2O4-ZnO plasmonic hybrid nanostructures have potential application towards decomposition of organic pollutants and other emerging pollutants in wastewater for environmental remediation.

Polarization‐directed nanophotonic routers based on two‐dimensional inorganic molecular crystals

AbstractPhotonic and plasmonic hybrid nanostructures are the key solution for integrated nanophotonic circuits with ultracompact size but relative low loss. However, the poor tunability and modulability of conventional waveguides makes them cumbersome for optical multiplexing. Here we make use of two‐dimensional molecular crystal, α‐Sb2O3 as a dielectric waveguide via total internal reflection, which shows polarization‐sensitive modulation of the propagating beams due to its large polarization mode dispersion. Both experiments and simulations are performed to verify such concept. These Sb2O3 nanoflakes can be coupled with plasmonic nanowires to form nanophotonic beam splitters and routers which can be easily modulated by changing the polarization of the incidence. It thus provides a robust, exploitable and tunable platform for on‐chip nanophotonics.image

Facile fabrication of Ag@CoFe2O4-ZnO hybrid plasmonic nanostructures with enhanced photocatalytic performance

Facile fabrication of Ag@CoFe2O4-ZnO hybrid plasmonic nanostructures with enhanced photocatalytic performance

Chiral Au-Pd Alloy Nanorods with Tunable Optical Chirality and Catalytically Active Surfaces.

Integrating the plasmonic chirality with excellent catalytic activities in plasmonic hybrid nanostructures provides a promising strategy to realize the chiral nanocatalysis toward many chemical reactions. However, the controllable synthesis of catalytically active chiral plasmonic nanoparticles with tailored geometries and compositions remains a significant challenge. Here it is demonstrated that chiral Au-Pd alloy nanorods with tunable optical chirality and catalytically active surfaces can be achieved by a seed-mediated coreduction growth method. Through manipulating the chiral inducers, Au nanorods selectively transform into two different intrinsically chiral Au-Pd alloy nanorods with distinct geometric chirality and tunable optical chirality. By further adjusting several key synthetic parameters, the optical chirality, composition, and geometry of the chiral Au-Pd nanorods are fine-tailored. More importantly, the chiral Au-Pd alloy nanorods exhibit appealing chiral catalytic activities as well as polarization-dependent plasmon-enhanced nanozyme catalytic activity, which has great potential for chiral nanocatalysis and plasmon-induced chiral photochemistry.

Microplasma Nanoengineering of Hybrid Plasmonic Nanostructures for Rapid and Ultrasensitive Surface-Enhanced Raman Scattering-Based Sensing

Surface-enhanced Raman scattering (SERS) is a useful analytical tool that allows ultrasensitive molecular-level detection through an enhanced electromagnetic field generated by plasmonic metal nanoparticles (MNPs), which is helpful for biomedical-based detection, environmental pollution monitoring and chemical industry. Recent study suggests that porous MNP with enhanced SERS active area and hybrid plasmonic nanostructures such as core-shell NPs and metal-semiconductor-based NPs with designed and controlled plasmonic properties can further improve the SERS responses.Here we report a microplasma nanoengineering of plasmonic nanostrutures including Au-Ag core-shell NPs, Ag-GQD nanohydrids, and porous Au nanosturtures for ultrasensitive SERS-based applications. Microplasmas are low-emperature plasmas that feature microscale dimensions and a unique high-energy-density and a nonequilibrium reactive environment, which makes them promising for the fabrication of advanced nanomaterials and devices for diverse applications. Detailed characterization indicates the microplasma-enable controllable-designed growth of plasmonic nanomaterial with heterostructure effect, the providing enhanced charge transportation , adsorption ability or forster resonance energy transfer during Raman scattering. To understand the plasmonic effect, we use 3D confocal microRaman scattering study that shows that a large SERS volume was formed in the as-fabricated SERS-active substrates, leading to significant SERS properties of low limit of detection and high enhanced factor (EF) with the Rhodamine 6G (R6G) as the Raman probe. Furthermore, we also used the biomoleculars , medicines , and dyes as the target molecule. Our work not only provides environmentally friendly fabrication technique with strong potential for the design and growth of the nanostructure but also the fundamental insight of plasmonic nanostrutures for emerging applications including nanocataysis, sustainable energy, and biomedical imaging.

Enhancing in vitro photothermal therapy using plasmonic gold nanorod decorated multiwalled carbon nanotubes.

Photothermal therapy (PTT) is a promising approach for cancer treatment that selectively heats malignant cells while sparing healthy cells. Here, the light-to-heat conversion efficiency of multiwalled carbon nanotubes (MWCNTs) within the near-infrared biological transmission window is enhanced by decorating them with plasmonic gold nanorods (GNRs). The results reveal a significant photothermal enhancement of hybrid MWCNTs-GNRs compared to bare MWCNTs, displaying a 4.9 enhancement factor per unit mass. The enhanced plasmonic PTT properties of MWCNTs-GNRs are also investigated in vitro using PC3 prostate cancer cell lines, demonstrating a potent ablation efficiency. These findings advance innovative hybrid plasmonic nanostructures for clinical applications.

Microfaceting: A new logic for hot-carrier energy harvesting in hybrid plasmonic nanostructures

Microfaceting: A new logic for hot-carrier energy harvesting in hybrid plasmonic nanostructures

Chiral Plasmonic Hybrid Nanostructures: A Gateway to Advanced Chiroptical Materials.

Chirality introduces a new dimension of functionality to materials, unlocking new possibilities across various fields. When integrated with plasmonic hybrid nanostructures, this attribute synergizes with plasmonic and other functionalities, resulting in unprecedented chiroptical materials that push the boundaries of the system's capabilities. Recent advancements have illuminated the remarkable chiral light-matter interactions within chiral plasmonic hybrid nanomaterials, allowing for the harnessing of their tunable optical activity and hybrid components. These advancements have led to applications in areas such as chiral sensing, catalysis, and spin optics. Despite these promising developments, there remains a need for a comprehensive synthesis of the current state-of-the-art knowledge, as well as a thorough understanding of the construction techniques and practical applications in this field. This review begins with an exploration of the origins of plasmonic chirality and an overview of the latest advancements in the synthesis of chiral plasmonic hybrid nanostructures. Furthermore, representative emerging categories of hybrid nanomaterials are classified and summarized, elucidating their versatile applications. Finally, the review engages with the fundamental challenges associated with chiral plasmonic hybrid nanostructures and offer insights into the future prospects of this advanced field.

Plasmonic Nanocrystal Assembly-Semiconductor Hybrids for Boosting Visible to Near-Infrared Photocatalysis.

Plasmonic metal-semiconductor hybrid photocatalysts have received much attention because of their wide light harvesting range and efficient charge carrier generation capability originating from plasmon energy transfer. Here, we introduce a plasmonic metal-semiconductor hybrid nanostructure consisting of a Au core-satellite assembly and crystalline TiO2. The formation of Au@TiO2-Au core-satellite assemblies using TiO2 as a spacer and the subsequent growth of outer TiO2 shells on the core-satellite assemblies, followed by calcination, successfully generated Au core-satellite assembly@TiO2 nanostructures. Exquisite control over the growth of the TiO2 interlayer enabled the regulation of the gap distance between the core and satellite Au nanocrystals within the same hybrid morphology. Due to the structural controllability of the present approach, the gap-distance-dependent plasmonic and photocatalytic properties of the hybrid nanostructures could be explored. The nanostructures possessing the most closely arranged Au nanocrystals showed high photocatalytic activity under visible to near-infrared light irradiation, which can be attributed to strong plasmon coupling between the core and satellite Au nanocrystals that can expedite the formation of intense plasmon energy and its transfer to TiO2.

Interfacial States in Au/Reduced TiO2 Plasmonic Photocatalysts Quench Hot-Carrier Photoactivity.

Understanding the interface of plasmonic nanostructures is essential for improving the performance of photocatalysts. Surface defects in semiconductors modify the dynamics of charge carriers, which are not well understood yet. Here, we take advantage of scanning photoelectrochemical microscopy (SPECM) as a fast and effective tool for detecting the impact of surface defects on the photoactivity of plasmonic hybrid nanostructures. We evidenced a significant photoactivity activation of TiO2 ultrathin films under visible light upon mild reduction treatment. Through Au nanoparticle (NP) arrays deposited on different reduced TiO2 films, the plasmonic photoactivity mapping revealed the effect of interfacial defects on hot charge carriers, which quenched the plasmonic activity by (i) increasing the recombination rate between hot charge carriers and (ii) leaking electrons (injected and generated in TiO2) into the Au NPs. Our results show that the catalyst's photoactivity depends on the concentration of surface defects and the population distribution of Au NPs. The present study unlocks the fast and simple detection of the surface engineering effect on the photocatalytic activity of plasmonic semiconductor systems.

Computational Investigation of Advanced Refractive Index Sensor Using 3-Dimensional Metamaterial Based Nanoantenna Array.

Photonic researchers are increasingly exploiting nanotechnology due to the development of numerous prevalent nanosized manufacturing technologies, which has enabled novel shape-optimized nanostructures to be manufactured and investigated. Hybrid nanostructures that integrate dielectric resonators with plasmonic nanostructures are also offering new opportunities. In this work, we have explored a hybrid coupled nano-structured antenna with stacked multilayer lithium tantalate (LiTaO3) and Aluminum oxide (Al2O3), operating at wavelength ranging from 400 nm to 2000 nm. Here, the sensitivity response has been explored of these nano-structured hybrid arrays. It shows a strong electromagnetic confinement in the separation gap (g) of the dimers due to strong surface plasmon resonance (SPR). The influences of the structural dimensions have been investigated to optimize the sensitivity. The designed hybrid coupled nanostructure with the combination of 10 layers of gold (Au) and Lithium tantalate (LiTaO3) or Aluminum oxide (Al2O3) (five layers each) having height, h1 = h2 = 10 nm exhibits 730 and 660 nm/RIU sensitivity, respectively. The sensitivity of the proposed hybrid nanostructure has been compared with a single metallic (only gold) elliptical paired nanostructure. Depending on these findings, we demonstrated that a roughly two-fold increase in the sensitivity (S) can be obtained by utilizing a hybrid coupled nanostructure compared to an identical nanostructure, which competes with traditional sensors of the same height, (h). Our innovative novel plasmonic hybrid nanostructures provide a framework for developing plasmonic nanostructures for use in various sensing applications.

Facile Synthesis of Magnetically Separable Ag@Fe3O4 Hybrid Plasmonic Nanostructures for Catalytic and Antibacterial Applications

Facile Synthesis of Magnetically Separable Ag@Fe3O4 Hybrid Plasmonic Nanostructures for Catalytic and Antibacterial Applications

Enhanced near-infrared photoresponse for efficient organic solar cells using hybrid plasmonic nanostructures

Nonfullerene organic solar cells (OSCs) have recently made remarkable progress as one of the most promising next-generation photovoltaic technologies. Still, it is highly desirable to enhance the light harvesting for the sake of photoactive layer with a limited thickness. In this work, we developed efficient nonfullerene OSCs through incorporating hybrid plasmonic metal nanostructures (MNS) consisted of gold nanobipyramids (AuNBPs) and gold nanospheres (AuNSs). The synergistic localized surface plasmon resonance (LSPR) of hybrid MNS has been predesigned to perfectly match with the absorption range of nonfullerene photoactive layer especially in the near-infrared (NIR) region, subsequently delivering enhanced light harvesting and photo-response. The plasmonic enhancement mechanisms were systematically investigated by theoretical simulations and various experimental measurements, showing that hybrid MNS exhibited significant broadband near field enhancement and scattering effect as well as the advantage in electrical aspect to facilitate the charge extraction and transport. As a result, the power conversion efficiency (PCE) was improved from 15.46% to 16.62% for OSCs based on PM6:Y6 due to the synergistic plasmonic effect of hybrid MNS. Overall, this work paves the way for using plasmonic MNS with tunable optical properties as an alternative approach for the development of high-performance OSCs.

Photo-enhanced dehydrogenation of formic acid on Pd-based hybrid plasmonic nanostructures.

Coupling visible light with Pd-based hybrid plasmonic nanostructures has effectively enhanced formic acid (FA) dehydrogenation at room temperature. Unlike conventional heating to achieve higher product yield, the plasmonic effect supplies a unique surface environment through the local electromagnetic field and hot charge carriers, avoiding unfavorable energy consumption and attenuated selectivity. In this minireview, we summarized the latest advances in plasmon-enhanced FA dehydrogenation, including geometry/size-dependent dehydrogenation activities, and further catalytic enhancement by coupling local surface plasmon resonance (LSPR) with Fermi level engineering or alloying effect. Furthermore, some representative cases were taken to interpret the mechanisms of hot charge carriers and the local electromagnetic field on molecular adsorption/activation. Finally, a summary of current limitations and future directions was outlined from the perspectives of mechanism and materials design for the field of plasmon-enhanced FA decomposition.

Plasmon Effect of Ag Nanoparticles on TiO2/rGO Nanostructures for Enhanced Energy Harvesting and Environmental Remediation.

We report Ag nanoparticles infused with mesosphere TiO2/reduced graphene oxide (rGO) nanosheet (TiO2/rGO/Ag) hybrid nanostructures have been successfully fabricated using a series of solution process synthesis routes and an in-situ growth method. The prepared hybrid nanostructure is utilized for the fabrication of photovoltaic cells and the photocatalytic degradation of pollutants. The photovoltaic characteristics of a dye-sensitized solar cell (DSSC) device with plasmonic hybrid nanostructure (TiO2/rGO/Ag) photoanode achieved a highest short-circuit current density (JSC) of 16.05 mA/cm2, an open circuit voltage (VOC) of 0.74 V and a fill factor (FF) of 62.5%. The fabricated plasmonic DSSC device exhibited a maximum power conversion efficiency (PCE) of 7.27%, which is almost 1.7 times higher than the TiO2-based DSSC (4.10%). For the photocatalytic degradation of pollutants, the prepared TiO2/rGO/Ag photocatalyst exhibited superior photodegradation of methylene blue (MB) dye molecules at around 93% and the mineralization of total organic compounds (TOC) by 80% in aqueous solution after 160 min under continuous irradiation with natural sunlight. Moreover, the enhanced performance of the DSSC device and the MB dye degradation exhibited by the hybrid nanostructures are more associated with their high surface area. Therefore, the proposed plasmonic hybrid nanostructure system is a further development for photovoltaics and environmental remediation applications.

Advanced refractive index sensor using 3-dimensional metamaterial based nanoantenna array

Photonic researchers have increasingly exploiting nanotechnology. Due to the advent of numerous prevalent nanosized manufacturing methods that enable adequate shaped nanostructures to be manufactured and investigated as a method of exploiting nano-structured. Owing of the variety of optical modes, hybrid nanostructures that integrate dielectric resonators with plasmonic nanostructures also offer enormous potentials. In this work, we have explored a hybrid coupled nano-structured antenna with stacked lithium tantalate (LiTaO3)/Aluminium oxide (Al2O3) multilayer operating at infrared ranging from 400 nm-2000 nm. Here, the sensitivity response has been explored of the hybrid nano-structured array made up of the gold metal elliptical disk placed on the top of a quartz substrate and excite the different modes in both materials. It shows large electromagnetic confinement at the separation distance (d) of the dimers due to strong surface plasmon resonance (SPR). The influence of the structural dimensions is investigated to optimise the sensitivity of stacked elliptical dimers. The designed hybrid coupled nano-structure with the combination of gold (Au) and Lithium tantalate (LiTaO3) /Aluminium oxide (Al2O3) with h 1 = h 2 = 10 nm each 10 layer exhibits bulk sensitivity (S), which is the spectrum shift unit per refractive index (RI) change in the surrounding medium was calculated to be 730 and 660 nm/RIU with major axis, (a) = 100 nm, minor axis, (b) = 10 nm, separation distance (d) = 10 nm, height, (h) = 100 nm (with or without stacked). The outcomes from the proposed hybrid nanostructure have been compared with a single metallic (only gold) elliptical paired nano-structure to show a significant improvement in the sensitivity using hybrid nano-structure. Depending on these findings, we demonstrated a roughly two-fold increase in sensitivity (S) by utilising a hybrid nano linked nano-structure with respect to identical nano structure, which competes with traditional sensors with the same height, (h) based on localised surface plasmon resonances. Our innovative plasmonic hybrid nanostructures provide a framework for developing plasmonic nanostructures for use in various sensing applications.

Plasmonic Hybrid Nanostructures in Photocatalysis: Structures, Mechanisms, and Applications.

(Sun)Light is an abundantly available sustainable source of energy that has been used in catalyzing chemical reactions for several decades now. In particular, studies related to the interaction of light with plasmonic nanostructures have been receiving increased attention. These structures display the unique property of localized surface plasmon resonance, which converts light of a specific wavelength range into hot charge carriers, along with strong local electromagnetic fields, and/or heat, which may all enhance the reaction efficiency in their own way. These unique properties of plasmonic nanoparticles can be conveniently tuned by varying the metal type, size, shape, and dielectric environment, thus prompting a research focus on rationally designed plasmonic hybrid nanostructures. In this review, the term "hybrid" implies nanomaterials that consist of multiple plasmonic or non-plasmonic materials, forming complex configurations in the geometry and/or at the atomic level. We discuss the synthetic techniques and evolution of such hybrid plasmonic nanostructures giving rise to a wide variety of material and geometric configurations. Bimetallic alloys, which result in a new set of opto-physical parameters, are compared with core-shell configurations. For the latter, the use of metal, semiconductor, and polymer shells is reviewed. Also, more complex structures such as Janus and antenna reactor composites are discussed. This review further summarizes the studies exploiting plasmonic hybrids to elucidate the plasmonic-photocatalytic mechanism. Finally, we review the implementation of these plasmonic hybrids in different photocatalytic application domains such as H2 generation, CO2 reduction, water purification, air purification, and disinfection.

Polarized Photoluminescence Enhancement of Monolayer MoS2 Coupled with Plasmonic Salisbury‐Type Absorber

AbstractThe plasmon‐mediated manipulation of light–matter interaction in 2D atomically transition‐metal dichalcogenides (TMDs) critically depends on the design of plasmonic nanostructures to achieve the maximum optical field in TMDs. Here, a metal–isolator–metal Salisbury‐type perfect absorber is fabricated to serve as a generator of the localized surface plasmons. The significant photoluminescence (PL) enhancement up to 60‐fold is observed experimentally in the monolayer MoS2 on the top of this gold plasmonic hybrid nanostructures. Furthermore, the PL linear polarization can approach ≈60% around the peak of exciton emission and is independent on the polarization of the excitation laser. This Salisbury‐type plasmon–exciton hybrid system paves a new way to develop optoelectronic devices based on TMDs.

Matrix shaped plasmonic hybrid nanostructure with direction-dependent functionality for multianalyte detection and biosensing

A Surface plasmon resonance based hybrid nanosystem with the competence of single and multiple analytes analysis is demonstrated using a symmetry modified sensory platform for promising application in biosensing. Plasmonic properties of the designed 2 × 2 matrix system arising from higher-order plasmonic modes generated near groove positions in the structure are analyzed numerically and calibrated for enhanced sensor performance and multi-functionality. The asymmetric defect/ percentage of asymmetry (Δ) in the structure, incorporated by means of a position-wise shift of Ag nanodisc exhibits pivotal results in performance parameters, including intra channel sensitivity (S intra), channel separation factor (CH factor ), figure of merit (FOM) and Q-factor. The pairs of sensing windows of the hybrid structure show a geometric symmetry along the x and −x direction and an asymmetry along its perpendicular (y and −y). Among the symmetric and asymmetric channels, spatially resolved plasmonic modes of asymmetric channels facilitate the multi quantification of analytes in a single stimulation, whereas symmetric ones confirm the presence of the different analytes in the given specimen. With the sensor function flexible to light incidence direction, the matrix system can be effectively employed across medical diagnostics and healthcare monitoring.

Dopamine-mediated self-assembled anisotropic Au nanoworms conjugated with MoS2 nanosheets for SERS-based sensing

Surface-enhanced Raman scattering (SERS) utilizing plasmonic metals coupled with transition metal dichalcogenide (TMD) has received increasing attention in bio-applications due to the synergistically enhanced detection sensitivity. However, there have been several issues to be addressed such as strong SERS background signals and low Raman intensities of analytes. In this study, we report a novel approach for high SERS performance based on anisotropic hybrid plasmonic nanostructures of gold nanoworms (Au NWs) conjugated with 2D Molybdenum disulfide (MoS2) nanosheets. To significantly enhance the SERS enhancement factor (EF), we optimized the gap between Au NWs and MoS2 to ~2 nm by controlling the thickness of polydopamine (PDA). Thus, giant localized electric field enhancement and synergistic coupling effect occurred in the hybrid plasmonic nanostructures, generating abundant hot spots. Consequently, SERS EF of the order of ~107 was achieved, which was 104 times higher than that of colloidal Au nanoparticles. Further, we showcase that our AuNW@MoS2 can detect the 10−10 M level thiram, a typical pesticide, under soil-pollutant muddy condition, evidencing the powerful multimodal sensory platform of our hybrid substrates. This work provides new insight into the rational design of plasmon-coupled 2D nanohybrids for high-performance SERS substrates with a premise for the practical and viable biosensing applications.