Shape Of Nanorods Research Articles

Formation of Gold Bone Nanorods shape using copper as foreign metal ion

In this study, copper (Cu) is introduced as a foreign metal ion replacing platinum by modifying the recipe of GNBPs and the final structure obtained is gold bone nanorods (GBNRs). The aspect ratio and surface density of GBNRs were investigated by varying the growth time during the growth process from 30 minutes to 5 hours. It was found that the growth solution has been changed from colourless to light blue and violet colour with increasing growth time, indicating the formation of GBNRs. The UV-Vis analysis shows two resonance plasmon peaks for t-SPR and l-SPR at 583 nm and 766 nm with the intensity of 1.433 a.u and 2.236 a.u at the optimum 5 hours growth time. For morphological analysis, it was found that the sample with lower growth time produced gold nanosphere shapes and with increasing time, more GBNRs with large aspect ratios were produced. HR-TEM characterization reveals that bone nanorods are formed due to the influence of Cu foreign metal ions, which cause selective deposition of Au atoms onto {111} facet of gold nanorods, while simultaneously reducing the overgrowth rate of the {110} facet for the edge regions and the {100} facet for the tip regions of the nanorods. In addition, the influence of Cu foreign metal ions on the growth mechanism of Au nanoseeds into nanorods and the shape transformation of nanorods into bone nanorods are also discussed in this work. In conclusion, the GBNRs have been successfully synthesized using SMGM by induced Cu as foreign metal ions.

Development of hydrophilic carbon fiber textiles using seed-assisted hydrothermal deposition of ZnO nanostructures for enhanced interfacial interaction in CFRP composites

Two-step hydrothermal deposition of zinc-oxide (ZnO) nanorods was used to functionalize carbon fiber textiles in order to produce increased hydrophilicity on fiber surface. On carbon fiber textiles, tightly packed ZnO nanorods developed after five seed cycles and 5 h of growth treatment in a 30 mM precursor salt based on the hydrothermal synthesis. Extensive characterizations have been performed on field emission scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Energy-dispersive X-ray spectroscopy, High resolution transmission electron microscopy, Photoluminescence spectroscopy, and Raman spectroscopy to assess the different aspects such as structural, morphological, elemental, and wettability of the plain and ZnO-modified carbon fiber textiles. ZnO nanomaterial having hexagonal nanorods shape and wurtzite crystalline structure were uniformly deposited on the fabrics. Owing to the wettability study, ZnO prisms improved the hydrophilicity of virgin carbon fiber textiles to enable strong bonds with polymer matrix. The findings highlight the significant improvement in the static water contact angle as a result of the samples' ZnO coating's ability to reduce surface free energy. The improved hydrophilicity in carbon fiber may enhance the bonding between carbon fibers and matrix materials in composite materials. Hydrophilic carbon fibers are more easily wetted by the matrix materials, allowing for better penetration of the matrix into the fiber structure.

Temperature dependent electrocatalytic activity of molybdenum-based ZIF-67 nanorods for water splitting

Several strategies have been adopted to enhance the electrochemical features of metal-organic framework structures for water splitting, however, a suitable conditions can effectively boost the electrocatalytic activity. Herein, molybdenum-based zeolite imidazolate frameworks (Mo2gZIF-67 and Mo4gZIF-67) have been synthesized by solvothermal process and electrocatalytic activity was examined at various elevating temperatures of 1 M KOH electrolyte. Mo4gZIF-67 nanorods showed the overpotential (η10) of 358 mV at 20 °C, which was improved to 221 mV at 80 °C for the oxygen evolution reaction. Mo4gZIF-67 nanorods exhibited the Tafel slope of 77 mV dec−1 at 80 °C and followed the Volmer-Heyrovsky mechanism. LSV curves reveal that Mo4gZIF-67 nanorods showed a greater current density and a good turnover frequency (TOF) of 221.0 ms−1 at the fixed VRHE of 0.7 V. Similarly, Mo4gZIF-67 nanorods revealed the η10 of 181 and 93 mV at 20 and 80 °C, respectively for the HER process. Mo4gZIF-67 nanorods displayed a Tafel slope of 95 mV dec−1 and TOF of 213.50 ms−1. The enhanced electrocatalytic activity may be due to rising temperatures, enhanced electrical conductivity at rising temperatures, well defined nanorods shape and greater ECSA, which provided the active sites and facile the flow of charge carriers for oxygen and hydrogen evolution reaction. The electrocatalyst, Mo4gZIF-67 nanorods exhibited a uniform current density during stability tests for 30 h at 20 °C, which was increased at 80 °C. Temperature elevation remarkably enhanced the HER and OER characteristics of the Mo4gZIF-67 nanorods and suggested an effective electrocatalyst for water splitting.

Synergetic photocatalytic degradation of the tetracycline antibiotic over S-scheme based BiOBr/CuInS2/WO3 ternary heterojunction photocatalyst

The present research investigated the photodegradation capability of a ternary BiOBr/CuInS2/WO3 heterojunction against the tetracycline (TC) antibiotic. BiOBr/CuInS2/WO3 heterojunction is formed using a straightforward physical mixing method, whereas pure photocatalysts (CuInS2, WO3) were synthesized hydrothermally and BiOBr by a coprecipitation process. The Field Emission Scanning Electron Spectroscopy examination validated the nanorod and nanosheet shape of the fabricated BiOBr-CuInS2-WO3. The photodegradation capabilities of the BiOBr-CuInS2-WO3 heterojunction were superior to those of other pure photocatalysts, and it followed the S-scheme charge transfer route as indicated by the band alignments. After 120 min of light irradiation, the BiOBr/CuInS2/WO3 S-scheme ternary heterojunction obtained a photodegradation rate of 98.9 %, much greater than other pure photocatalysts. According to electron spin resonance investigations and scavenging experiments, the radicals hydroxyl radicals (•OH), hole (h+), superoxide (•O2−) play a significant role in the photodegradation of TC. The ternary heterojunction's improved light absorption, lower recombination rate, and higher photocarrier separation rate were due to the fabrication of S-scheme heterojunction. The ternary BiOBr/CuInS2/WO3 photocatalyst's photodegradation efficacy was consequently enhanced. Investigations for photocatalyst reusability demonstrated its exceptional stability, with a 93.8 % degradation rate after five catalytic cycles.

Fabrication of one-dimensional Zn-doped Bi2S3 nanorods for photodiode applications.

In this research, the impact of the different zinc (Zn) concentrations on the physical and optoelectronic properties of Bi2S3 nanorods as self-powered and photodiode applications was investigated. The performance of P-N junction photodiodes has been for decades since they are crucial in energy applications. The structure, degree of crystallinity, and shape of Zn-doped Bi2S3 nanorods of various doping percentages formed onto the indium tin oxide (ITO) substrates by the dip coating technique are investigated using X-ray powder diffraction (XRD) and SEM. With increasing illumination time, the current-voltage (I-V) graphs demonstrate a rise in photocurrent. The diode's idealist factor was estimated using the I-V technique under 30 min of light illumination.

Sustainable fabrication of dimorphic plant derived ZnO nanoparticles and exploration of their biomedical and environmental potentialities

Although, different plant species were utilized for the fabrication of polymorphic, hexagonal, spherical, and nanoflower ZnO NPs with various diameters, few studies succeeded in synthesizing small diameter ZnO nanorods from plant extract at ambient temperature. This work sought to pioneer the ZnO NPs fabrication from the aqueous extract of a Mediterranean salt marsh plant species Limoniastrum monopetalum (L.) Boiss. and assess the role of temperature in the fabrication process. Various techniques have been used to evaluate the quality and physicochemical characteristics of ZnO NPs. Ultraviolet–visible spectroscopy (UV–VIS) was used as the primary test for formation confirmation. TEM analysis confirmed the formation of two different shapes of ZnO NPs, nano-rods and near hexagonal NPs at varying reaction temperatures. The nano-rods were about 25.3 and 297.9 nm in diameter and in length, respectively while hexagonal NPs were about 29.3 nm. The UV–VIS absorption spectra of the two forms of ZnO NPs produced were 370 and 365 nm for nano-rods and hexagonal NPs, respectively. FT-IR analysis showed Zn–O stretching at 642 cm−1 and XRD confirmed the crystalline structure of the produced ZnO NPs. Thermogravimetric analysis; TGA was also used to confirm the thermal stability of ZnO NPs. The anti-tumor activities of the two prepared ZnO NPs forms were investigated by the MTT assay, which revealed an effective dose-dependent cytotoxic effect on A-431 cell lines. Both forms displayed considerable antioxidant potential, particularly the rod-shaped ZnO NPs, with an IC50 of 148.43 µg mL−1. The rod-shaped ZnO NPs were superior candidates for destroying skin cancer, with IC50 of 93.88 ± 1 µg mL−1 ZnO NPs. Thus, rod-shaped ZnO NPs are promising, highly biocompatible candidate for biological and biomedical applications. Furthermore, both shapes of phyto-synthesized NPs demonstrated effective antimicrobial activity against various pathogens. The outcomes highlight the potential of phyto-synthesized ZnO NPs as an eco-friendly alternative for water and wastewater disinfection.

Synergetic electrochemical behavior of magnesium-doped ZnO nanorods with reduced graphene oxide

In this study, we synthesized magnesium-doped ZnO (Mg-ZnO) nanorods embedded in reduced oxide graphene layers (rGO) using the simplest one-pot hydrothermal method. The composites ZnO/rGO and Mg-doped ZnO-rGO (Mg-ZnO/rGO) are polycrystalline and showed successful doping of Mg in ZnO lattice which expands the ZnO lattice structure helping lithium storage by providing more sites. Mg doping in the ZnO lattice extenuates ZnO volume contraction and expansion which promotes structural stabilization of the electrode during multiple charging-discharging cycles. In composites, ZnO and Mg-ZnO attain the shape of nanorods and tightly interleaved theirselves in the sheet of rGO. XPS showed the dominant peak of C1s of sp2 bonding supporting the formation of reduced GO along with Zn, O and Mg elements. The performance of the materials is evaluated as anode for LIB. The ZnO/rGO anode exhibits a discharge capacity of 445 mAh/g at 100 mA g−1 that was significantly enhanced to 463 mAh/g after doping ZnO with 2 % Mg. With further increasing the concentration of Mg to 4 %, the Mg-ZnO/rGO anode achieves a higher discharge capacity of 520 mAh g−1 with better rate capability than its counterpart electrodes. The synergistic effects between Mg-ZnO and carbon-based nanomaterials are ascribed to the creation of additional contact sites to penetrate electrolyte ions into the electrode, thus resulting in the fast lithium-ion diffusion rate.

Oxygen plasma treatment WO3 nanorods for Improvement H2S gas sensing

Herein, the oxygen (O2) plasma has been used to post-treat tungsten oxide (WO3) nanorods to improve the sensing performance of the H2S gas sensor. The reactive DC magnetron sputtering process with the glancing-angle deposition (GLAD) technique was used to prepare the WO3 nanorods. After deposition, the WO3 nanorod thin films were treated with O2 plasma at different treatment power from 100 – 200 W. The physical structure of as-deposition and treated WO3 nanorod thin films was investigated crystal structure and morphology by grazing incident X-ray diffraction (GIXRD), field-emission scanning electron microscope (FE-SEM), and high-resolution transmission electron microscope (HRTEM). The result indicated that the WO3 nanorod structure transformed to the monoclinic polycrystalline phase. FE-SEM and HRTEM observed slight changes in the shape of the WO3 nanorods. The H2S sensing properties were measured at 10 ppm at 150 – 350°C operating temperatures. At an operating temperature of 200 °C, the response to H2S of O2 plasma treated WO3 nanorods is increased by a factor of 5 – 15, and the maximum response to H2S is 15. The results showed that the O2 plasma treatment process improved the sensing response of the WO3 nanorods.

WO3 nanostructures produced from tungsten welding electrode scraps: Temperature influence on optical and morphological characteristics

Methods to produce WO3 nanostructures have become important due to the possibility of using this material in a wide range of technological applications. In this context, a hydrated WO3.2H2O structure was produced by the electrochemical dissolution of welding electrode scraps in an alkali aqueous solution, followed by acid precipitation. The thermal treatment of this precursor structure at 550, 700, 850, and 1000 °C was able to produce γ phase WO3 materials with a monoclinic crystalline structure at all the temperatures used, as demonstrated by XRD and RAMAN characterization. However, different treatment temperatures can yield materials with diverse morphologies and optoelectronic properties. For example, the material produced at 1000 °C presented an elongated nanorod shape, with dimensions, from the base, ranging between 50 and 500 nm, a length of about 4 μm, and the lowest Eg value. The spectroscopic characterization also demonstrated that above 700 °C, the thermal treatment could eliminate the crystallization water and create oxygen vacancies, mainly at 850 and 1000 °C; explaining the decrease in the Eg values with increased temperature. As proof of concept, photocatalytic degradation of the Reactive Black 5 dye demonstrated that the material produced at 1000 °C was able to discolor ca. 50% of the initial color. Broad DFT analyses were performed, carefully describing the surface properties and the influence of morphology on the material properties. Therefore, we demonstrated that a simple, fast and low-cost two-step process was successfully developed aiming at a noble reuse of residues of this important material.

Investigation into the Effects of Cross-Sectional Shape and Size on the Light-Extraction Efficiency of GaN-Based Blue Nanorod Light-Emitting Diode Structures

We investigated the effect of cross-sectional shape and size on the light-extraction efficiency (LEE) of GaN-based blue nanorod light-emitting diode (LED) structures using numerical simulations based on finite-difference time-domain methods. For accurate determination, the LEE and far-field pattern (FFP) were evaluated by averaging them over emission spectra, polarization, and source positions inside the nanorod. The LEE decreased as rod size increased, owing to the nanorods’ increased ratio of cross-sectional area to sidewall area. We compared circular, square, triangular, and hexagonal cross-sectional shapes in this study. To date, nanorod LEDs with circular cross sections have been mainly demonstrated experimentally. However, circular shapes were found to show the lowest LEE, which is attributed to the coupling with whispering-gallery modes. For the total emission of the nanorod, the triangular cross section exhibited the highest LEE. When the angular dependence of the LEE was calculated using the FFP simulation results, the triangular and hexagonal shapes showed relatively high LEEs for direction emission. The simulation results presented in this study are expected to be useful in designing high-efficiency nanorod LED structures with optimum nanorod shape and dimensions.

Demonstration of a Gel-Polymer Electrolyte-Based Electrochromic Device Outperforming Its Solution-Type Counterpart in All Merits: Architectural Benefits of CeO2 Quantum Dot and Nanorods.

For years, solution-type electrochromic devices (ECDs) have intrigued researchers' interest and eventually rendered themselves into commercialization. Regrettably, challenges such as electrolyte leakage, high flammability, and complicated edge-encapsulation processes limit their practical utilization, hence necessitating an efficient alternate. In this quest, although the concept of solid/gel-polymer electrolyte (SPE/GPE)-based ECDs settled some issues of solution-type ECDs, an array of problems like high operating voltage, sluggish response time, and poor cycling stability have paralyzed their commercial applicability. Herein, we demonstrate a choreographed-CeO2-nanofiller-doped GPE-based ECD outperforming its solution-type counterpart in all merits. The filler-incorporated polymer electrolyte assembly was meticulously weaved through the electrospinning method, and the resultant host was employed for immobilizing electrochromic viologen species. The filler engineering benefits conceived through the tuned shape of CeO2 nanorod and quantum dots, along with the excellent redox shuttling effect of Ce3+/Ce4+, synchronously yielded an outstanding class of GPE, which upon utilization in ECDs delivered impressive electrochromic properties. A combination of features possessed by a particular device (QD-NR/PVDF-HFP/IL/BzV-Fc ECD) such as exceptionally low driving voltage (0.9 V), high transmittance change (ΔT, ∼69%), fast response time (∼1.8 s), high coloration efficiency (∼339 cm2/C), and remarkable cycling stability (∼90% ΔT-retention after 25,000 cycles) showcased a striking potential in the yet-to-realize market of GPE-based ECDs. This study unveils the untapped potential of choreographed nanofillers that can promisingly drive GPE-based ECDs to the doorstep of commercialization.

Enhanced Photocatalytic Oxygen Evolution Using Copper-Coordinated Perylene Diimide Nanorod Assemblies.

A crystalline supramolecular photocatalyst is prepared through metal-induced self-assembly of perylene diimide with imidazole groups at the imide position (PDI-Hm). Exploiting the metal-coordination ability of imidazole, a crystalline assembly of copper-coordinated PDI-Hm (CuPDI-Hm) in a nanorod shape is prepared which displays an outstanding photocatalytic oxygen evolution rate of 25,900 μmol g-1 h-1 without additional co-catalysts. The imidazole-copper coordination, along with π-π stacking of PDI frameworks, guides the arrangement of PDI-Hm molecules to form highly crystalline assemblies. The coordination of copper also modulates the size of the CuPDI-Hm supramolecular assembly by regulating the nucleation and growth processes. Furthermore, the imidazole-copper coordination constructs the electric field within the PDI-Hm assembly, hindering the recombination of photo-induced charges to enhance the photoelectric/photocatalytic activity when compared to Cu-free PDI-Hm assemblies. Small CuPDI-Hm assembly exhibits higher photocatalytic activity due to their larger surface area and reduced light scattering. Together, the Cu-imidazole coordination presents a facile way for fabricating size-controlled crystalline PDI assemblies with built-in electric field enhancing photoelectric and photocatalytic activities substantially.

Unleashing the power of solar light: WO3 nanorods decorated onto BiVO4 dendrites for tetracycline detoxification and water splitting.

The coupling of different oxide materials in a nanohybrid enables the customization of their optical and charge transport properties, leading to improved interfacial charge segregation and migration. In this study, BiVO4/WO3 (BVW), a sunlight-driven photocatalyst with distinct mole ratios was synthesized via a facile hydrothermal approach. The resultant catalyst exhibits a nanorods shape morphology decorated onto dendrite-like matrix and is studied for photocatalytic elimination of tetracycline (TC) and photoelectrocatalytic (PEC) H2 production. The effect of illumination time, solution pH, photocatalyst concentration, and mole ratios of BiVO4 to WO3 on the photocatalytic abatement of TC were tested sequentially as effective operating factors. Under optimal condition, 3:1 BiVO4:WO3 (31BVW) nanohybrid demonstrated a maximum degradation efficacy of 96.2% (rate constant ~0.0241 min-1), which is much better than its individual components and commercial TiO2-P25 (50.9%). The resultant by-products of TC decomposition were analyzed using GC-MS to explain the degradation mechanism. Moreover, as a photoanode, 31BVW showed a high photocurrent density of 0.64 mA/cm2 at 1.23 V vs RHE and a steady photocurrent for ~6 h under chronoamperometry study at1.23 V vs RHE. However, bare BiVO4 and WO3 exhibited the photocurrent density of 0.001 mA/cm2, and 0.015 mA/cm2, respectively at 1.23 V vs RHE. The Mott-Schottky analysis of 31BVW confirms their n-type behavior, with a calculated flat band potential of -0.067 V. The hydrogen production rate was theoretically calculated as 4.56 mmolcm-2 s-1 from chronoamperometric measurements. The photocatalyst's efficacy in TC degradation was further established via its reusability upto 7 cycles. Post degradation characterization of catalyst confirms its stability in lieu of practical usage. Comparative studies with existing literature revealed the superiority of reported photocatalysts in both applications. Overall, the binary BVW photocatalyst shows great potential for removing detrimental contaminants as well as H2 production via PEC water splitting due to efficient charge separation, reduced recombination, high surface area, and widen absorption window of the nanohybrid.

Hot-Injection Synthesis of HgTe Nanoparticles: Shape Control and Growth Mechanisms.

Understanding the growth mechanisms of HgTe nanoparticles (NPs) with varied shapes is crucial for their applications in infrared photodetection. Here, we investigated the growth mechanisms of HgTe NPs with nanorod, sphere, and tetrahedral shapes in depth. The HgTe NPs with a nanorod shape are obtained at low reaction temperatures and formed by breaking tetrapod branches, while HgTe NPs with sphere and tetrahedron shapes have been further achieved at increased reaction temperatures. The systematic crystal analyses demonstrate this effective shape control is related to the synergic effect among the anisotropic passivation of oleylamine, surface free energy, and reaction temperatures. Our findings have deepened the understanding of shape control of the HgTe NPs and inspired a growing passion in the design and engineering of infrared photodetectors using HgTe NPs.

Effect of yttrium doping on the crystal structure, optical, and photocatalytic properties of hydrothermally synthesized ZnO nanorods

The hydrothermal technique was utilized to fabricate yttrium doped ZnO nanorods (Y-doped ZnO). Various spectroscopic approaches were used to examine the effect of yttrium doping on the crystal structure, shape, energy bandgap, and photocatalytic performance of ZnO nanorods. The fact that Y-doped ZnO nanocatalysts had the same hexagonal wurtzite crystal structure and nanorod shape as like undoped ZnO, signifying that doped yttrium ions have no effect on the structural as well as morphological features of ZnO nanorods. By doping yttrium into the ZnO sites, the bandgap energy of the ZnO nanorods was significantly altered, and the photodegradation activity was improved. The absorption edge of the Y-doped ZnO nanorods was shifted towards the higher wavelengths and blue shift in bandgap was observed. It has been confirmed that yttrium doping increases the light sensitivity of ZnO in the visible region while providing several active charge transporters on the nanorods surface as well. The photocatalytic activity of Y-doped ZnO nanocatalysts was significantly increased by generated charge carriers. For doping concentrations of 1 %, 3 % and 5 %, the photodegradation activity of Y-doped ZnO nanorods is 71 %, 97 %, and 82 %, respectively, whereas the photodegradation efficiency of pure ZnO nanorods is 22 %. The photodegradation efficiency of ZnO:Y3 was found to be 4.4 times higher than the pristine ZnO nanorods. In addition to the photodegradation, the Y-doped ZnO nanorods are anticipated to offer a valued platform to the widespread applications in the field of photocatalysis like electrochemical water splitting, hydrogen production and supercapacitors.

Light Induced Synthesis of Ag Nanorods for Potential Application as Optical Filter Tailored to Visible Domain

Monodispersed Ag nanorods were synthesized using a one-pot synthesis method. These Ag nanorods normally manifest dual surface plasmon resonance (SPR) peaks. This work presents a study of the variation of SPR peaks with variation in the shape of Ag nanorods. Shape variation was achieved through the degradation of a shape-controlling agent (PVP in this work) under white light irradiance with silica passivation to halt further shape variations. This paper also reports the growth & characterization of thin films of the synthesized rod-shaped silver nanoparticles on glass slides along with studies on band pass filter characteristics of the as-synthesized nanoparticles.

A high performance lead-free flexible piezoelectric nanogenerator based on AlFeO3 nanorods interspersed in PDMS matrix for biomechanical energy scavenging to sustainably power electronics

Since lead-based piezoelectric nanogenerators (PENGs) possess serious health risks, environmental problems, proper disposal issues, and biocompatibility concerns, this work presents the fabrication of a flexible piezoelectric nanogenerator utilizing lead-free orthorhombic AlFeO3 nanorods for biomechanical energy scavenging to sustainably power electronics. Hydrothermal technique is used to synthesize the AlFeO3 nanorods and the PENG was fabricated on Indium tin oxide (ITO) coated Polyethylene terephthalate (PET) flexible film with AlFeO3 nanorods interspersed in polydimethylsiloxane (PDMS). transmission electron microscopy proved that the AlFeO3 nanoparticles are of nanorods shape. Through x-ray Diffraction, it is validated that AlFeO3 nanorods have orthorhombic phase and crystalline structure. A high piezoelectric charge coefficient (d 33 ) of 400 pm V−1 is obtained from the piezoelectric force microscopy of AlFeO3 nanorods. With optimized concentration of AlFeO3 in the polymer matrix, an open circuit voltage (V OC) of 30.5 V, current density (J C) of 0.7888 μA cm−2 and an instantaneous power density of 240.6 mW m−2 are obtained under the application of a force of 1.25 kgf. To investigate the nanogenerator’s practical utility, the PENG is used for lighting multiple LEDs, charging of a capacitor and as a pedometer via biomechanical energy harvesting. Hence, it can be employed for developing various self-powered wearable electronics such as flexible skin, artificial cutaneous sensors, etc.

Electronic Structure and Excited State Dynamics of Cadmium Chalcogenide Nanorods

The cylindrical quasi-one-dimensional shape of colloidal semiconductor nanorods (NRs) gives them unique electronic structure and optical properties. In addition to the band gap tunability common to nanocrystals, NRs have polarized light absorption and emission and high molar absorptivities. NR-shaped heterostructures feature control of electron and hole locations as well as light emission energy and efficiency. We comprehensively review the electronic structure and optical properties of Cd-chalcogenide NRs and NR heterostructures (e.g., CdSe/CdS dot-in-rods, CdSe/ZnS rod-in-rods), which have been widely investigated over the last two decades due in part to promising optoelectronic applications. We start by describing methods for synthesizing these colloidal NRs. We then detail the electronic structure of single-component and heterostructure NRs and follow with a discussion of light absorption and emission in these materials. Next, we describe the excited state dynamics of these NRs, including carrier cooling, carrier and exciton migration, radiative and nonradiative recombination, multiexciton generation and dynamics, and processes that involve trapped carriers. Finally, we describe charge transfer from photoexcited NRs and connect the dynamics of these processes with light-driven chemistry. We end with an outlook that highlights some of the outstanding questions about the excited state properties of Cd-chalcogenide NRs.

Development and performance analysis of a 316 stainless steel autoclave for facile fabrication of carbon nanoarchitectures derived from natural potato and starch

In this study, we describe a facile hydrothermal method for synthesis of carbon nano-arrays, using materials available locally, resulting in an affordable autoclave system. Stainless steel type 1.4401 (with grade 316) possesses high temperature mechanical properties and anticorrosion characteristics and is therefore appropriate for autoclave device construction. For analysis, a systematic study of the three Von Misses stress models of an autoclave system was performed using Abaqus software. Also, the effect of the component's thickness on the stress concentration was examined. This was done to find the most optimal mode of the autoclave's resistance to stress caused by temperature and pressure. So, for further evaluation of this reactor in the laboratory, a series of experiments was designed. It is interesting to find that natural potato and chemical starch as low-cost precursors play a vital role in constructing carbon-based nanomaterials. In this study, by utilizing natural extracts and chemical precursors, the potential of designed autoclave systems has been explored in the fabrication of carbon materials with diverse shapes of nanorods and nanospheres. The structural, chemical compositional and morphological changes of the products were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDS), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) analyses. As the precursor was changed, a significant difference was observed in the shape and morphologies of the black nano-products. Such results suggest competition between designed and commercial autoclaves in the fabrication of nanomaterials. More importantly, these structure-controlled carbon nanomaterials with unique properties can be explored in many practical applications.

Ternary PtZrNi nanorods for efficient multifunctional electrocatalysis towards oxygen reduction and alcohol oxidation

Pt-based alloys with precise structure and composition design have been considered to be effective and robust novel electrocatalysts for fuel cells. Whereas, the sluggish kinetics of oxygen reduction reaction (ORR) and low intrinsic activity of Pt limited their real application on a large scale. Herein, a novel ternary PtZrNi nanorods (PtZrNi NRs) was synthesized via a facile wet-chemical method to achieve high electrocatalytic performance for both ORR and alcohol oxidation reaction owing to the synergism of chosen three elements and prominent one-dimensional morphology. Specifically, the PtZrNi NRs show enhanced mass and specific activities of 0.755 A mgPt-1 and of 0.97 mA/cm2 at 0.9 VRHE towards ORR in acidic media, which are 4.7 and 4.4 times of those of commercial Pt/C, respectively. Additionally, in alkaline media, the PtZrNi NRs also exhibit superior ORR mass and specific activities of 3.216 A mgPt-1and 4.13 mA/cm2, enhanced by 34.6 and 31.3 times compared with those of commercial Pt/C, respectively. The PtZrNi NRs retain the nanorod shape well without agglomeration after an accelerated durability test (20000 cycles). This work may offer a new perspective for engineering high-performance Pt-based electrocatalysts for commercial fuel cells.