Hexagonal Nanorods Research Articles

Composites of In/C hexagonal nanorods and graphene nanosheets for high-performance electromagnetic wave absorption

Composites of In/C hexagonal nanorods and graphene nanosheets for high-performance electromagnetic wave absorption

Growth-control of hexagonal CdS-decorated ZnO nanorod arrays with low-temperature preheating treatment for improved properties and efficient photoelectrochemical applications.

The limitations of oxide semiconductor-based solar cells in achieving high energy conversion efficiencies have prompted incessant research efforts towards the creation of efficient heterostructures. Despite its toxicity, no other semiconducting material can fully replace CdS as a versatile visible light-absorbing sensitizer. Herein, we explore the aptness of preheating treatment in the successive ionic layer adsorption and reaction (SILAR) deposition technique and improve the understanding of the principle and the effects of a controlled growth environment on thus-formed CdS thin films. Single hexagonal phases of nanostructured cadmium sulfide (CdS)-sensitized zinc oxide nanorods arrays (ZnO NRs) have been developed without the support of any complexing agent. The influences of film thickness, cationic solution pH and post-thermal treatment temperature on the characteristics of binary photoelectrodes have been investigated experimentally. Interestingly, the preheating-assisted deposition of CdS, which is rarely applied for the SILAR technique, resulted in improved photoelectrochemical performance similar to the post-annealing effect. The X-ray diffraction pattern revealed that optimized ZnO/CdS thin films were polycrystalline with high crystallinity. Examination of the morphology of the fabricated films via field emission scanning electron microscopy showed that film thickness and medium pH altered the growth mechanism of nanoparticles, thereby changing their particle sizes, which had a significant influence on the film's optical behavior. The effectiveness of CdS as a photosensitizer and the band edge alignment for ZnO/CdS heterostructures were evaluated using ultra-violet visible spectroscopy. Facile electron transfer in the binary system as evidenced in electrochemical impedance spectroscopy Nyquist plots, therefore, promotes higher photoelectrochemical efficiencies from 0.40% to 4.30% under visible light illumination as compared with the pristine ZnO NRs photoanode.

Self-assembly synthesis of Ru nanoparticles anchored on B, N co-doping carbon support for hydrogen evolution: Electronic state induced by the strong metal-support interactions

The strong metal-support interactions between metal and its support have been considered as an effective way to improve the electrocatalytic activity in heterogeneous catalysis, which can modulate metal d-band's energy level and, consequently, affect the adsorption/desorption of the intermediates on the metal nanoparticle's surface. In this paper, we use a self-assembly strategy for construction nano-sized Ru nanoparticles (NPs) anchored on B, N co-doping carbon nanorod carrier (Ru/BCN) as HER catalyst by using unique boron cluster-organic framework as precursor and self-sacrificing templates. This supramolecular framework forming with cucurbit [6]uril as the host and closo-[B12H12]2- as the guest can feature unique hexagonal nanorod morphology to confine the Ru NPs into framework through weak reductivity of closo-[B12H12]2-. After pyrolysis, the strong metal-support interactions between B, N co-doping carbon support (BCN) and Ru NPs have been found due to the synergistic coupling effect of co-dopants B and N, which can increase electron transfer between the metal nanoparticle and support. The overpotentials of 33 mV and 40 mV are required for as-prepared catalyst Ru/BCN to achieve a current density of 10 mA cm−2 in alkaline and acidic conditions, respectively, which are approximately one third of those of Ru/CN. These findings demonstrate that our synthetic way offers a potential route for fabricating co-doping carbon with B and N atoms to support Ru NPs with enhanced HER performance in pH-independent conditions.

Effect of Thermal Treatment on the Structure and Morphology of Vanadium Doped ZnO Nanostructures Obtained by Microwave Assisted Sol-Gel Method.

In this paper, we conducted a fundamental study concerning the effect of thermal treatment on the structure and morphology of 2 mol% vanadium doped ZnO nanopowders obtained by microwave assisted sol-gel method (MW). The samples were analyzed by DTA, FTIR, XRD, SEM, and UV-Vis spectroscopy. The DTA results showed that above 500 °C, there was no mass loss in the TG curves, and ZnO crystallization occurred. The XRD patterns of the thermally treated powders at 500 °C and 650 °C showed the crystallization of ZnO (zincite) belonging to the wurtzite-type structure. It was found that in the 650 °C thermally treated powder, aside from ZnO, traces of Zn3(VO4)2 existed. FTIR spectra of the annealed samples confirmed the formation of the ZnO crystalline phase and V-O bands. The micrographs revealed that the temperature influenced the morphology. The increase in the annealing temperature led to the grain growth. The SEM images of the MW powder thermally treated at 650 °C showed two types of grains: hexagonal grains and cylindrical nanorods. UV-Vis spectra showed that the absorption band also increased with the increasing temperature of thermal treatment. The MW sample annealed at 650 °C had the highest absorption in ultraviolet domain.

Solvent free synthesis of carbon modified hexagonal boron nitride nanorods for the adsorptive removal of aqueous phase emerging pollutants

Contamination of potable water sources by emerging pollutants such as bisphenol-A and paracetamol, etc. is a major ecological concern. The present study delineates the suitability of carbon modified hexagonal boron nitride (HBCN) towards the elimination of Bisphenol-A (BPA) and paracetamol. The HBCN was obtained through an ecofriendly solvent free approach with a surface area of 224.48 m2/g which is about ∼ 11 times higher than commercially available hexagonal boron nitride (C-HBN). The HBCN possess multimodal pore network with an average pore diameter of 2 nm and an isoelectric point at pH: 4.57. The effect of process parameters like time, initial concentration and temperature were evaluated. The adsorption behaviour suited well with Langmuir isotherm suggesting monolayer adsorption with a maximum adsorption capacity of 49.75 mg g−1 (BPA) and 67.56 mg g−1 (paracetamol). The kinetic studies established chemisorption and pore filling as preferred adsorption mechanisms. The adsorption was exothermic in nature and exhibited better performance at lower temperatures making it as suitable material for domestic water purification. The HBCN demonstrated robust stability and reusability ∼ 80 % (BPA) and ∼ 71 % (paracetamol) through 5 adsorption–desorption cycles. The working adsorption mechanism being followed were confirmed through FTIR and BET studies: pre and post adsorption with HBCN.

Fabrication of Uniform ZnO Hexagonal Nanorods in the Presence of Mg2+ and Conversion to ZnO@ZnS Heterojunctions for Spatial Charge Separation

AbstractLarge‐scale uninform ZnO hexagonal nanorods were obtained by tuning the molar ratio of Mg2+ and Zn2+ without any organic surfactant or any further treatment, then the ZnO@ZnS heterojunction were obtained by in‐situ sulfidation method. The photocatalytic activity of as‐prepared photocatalyst sample was evaluated by their photocatalytic of Congo Red (CR) in a fixed‐bed microreactor and photocatalytic hydrogen production. The photocatalytic experiments showed that Z@ZS‐4 possesses higher photocatalytic performance for a sulfidation time up to 4 h. Probable photogenerated charge transfer mechanism has been proposed, and the corresponding photoluminescence and photoelectrochemical measurements revealed the higher charge transfer rate across the Z@ZS‐4 interface.

Effect of Ni doping on the adsorption and visible light photocatalytic activity of ZnO hexagonal nanorods

Pristine and 1, 1.5, 2, 2.5 and 3 wt% Ni doped ZnO nanorods are prepared by hydrothermal technique as an effective photocatalyst for the removal of Malachite Green (MG) dye from aqueous media. Kinetic modelling of photocatalytic degradation and adsorption properties of the catalysts are done by pseudo first order (PFO), pseudo second order (PSO), fractal like psuedo first order (FPFO), fractal like psuedo second order (FPSO), elovich, exponential and intra particle diffusion (IPD) models. In contrary to the general trend, adsorption efficiency of ZnO is decreased while photocatalytic property got enhanced with doping. As-prepared catalysts are well characterised using XRD, FESEM, XPS, EDS, BET, UV and PL. This study points out the effect of Ni doping on the adsorption and visible light photocatalytic properties of ZnO nanostrutures via detailed kinetic modelling and explanation through various characterisation techniques and show cases their practical application in the field of waste water management. Water quality analysis was done post to degradation studies and the purified water samples have pH in the permissible range of drinking water which shows the efficient removal of dye molecules from the solution.

Comparative study of surface, elemental, structural and optical morphologies of titanium dioxide-zinc oxide (TiO2-ZnO) and titanium dioxide-zinc oxide/graphene (TiO2-ZnO/Gn)

The aim of this study is to synthesize a highly dense nanosized TiO2-ZnO sample with graphene (TiO2-ZnO/Gn) thin film via solution immersion method and compare its properties with TiO2-ZnO thin film without graphene. To prepare the titanium dioxide solution, the titanium butoxide precursor was added to ethanol, glacial acetic acid and triton-x-100 with a drop of deionized water. Next, to prepare for the ZnO/Gn solution, the zinc nitrate hexahydrate was added to hexamethylenetetramine (HMTA). Then, a specific weight of graphene was added into the solution before left for ageing. The thin films will be characterized in order to consider and enhance the potential of TiO2-ZnO/Gn thin film in treating wastewater. Ultra-Violet Visible spectroscopy (UV–vis), X-ray Diffraction (XRD), and Field Emission Scanning Electron Microscopy (FESEM) were used to determine the optical, structural and morphological properties of the samples. From the UV–vis absorption spectra, the TiO2-ZnO/Gn shows the better UV–vis performance compared to the TiO2-ZnO sample. While the FESEM images for TiO2-ZnO/Gn confirmed the presence of the Gn deposited on the thin film with specific grain-like structures of TiO2, hexagonal nanorod ZnO and wrinkles shape of Gn. Finally, the XRD analysis confirmed the crystallinity of the samples, and the elements present on the glass substrate. It has shown that there are TiO2, ZnO and Gn peaks present in the XRD patterns. Thus, TiO2-ZnO/Gn is the best candidate to be used as the photocatalyst in treating the wastewater.

Fabrication and morphological, optical, and electrical characterisation of Cu-doped ZnO nanorod/coronene nanowire hybrid heterojunctions

The electrochemical deposition technique was employed to grow 1% and 3% Cu-doped ZnO nanorods on glass/ITO substrate. Then, coronene nanowire was deposited on the 1% and 3% Cu-doped ZnO surfaces via the thermal evaporation technique as an interfacial layer of hybrid heterojunctions. Structural analyses of different ratios of the Cu-doped ZnO layers revealed that they contain ZnO, CuZn, Cu2O and Cu16O14.15 phases, and further that a monoclinic coronene crystal structure could be detected from the XRD spectrum of ITO/coronene thin film. The elemental composition of the1% and 3% Cu-doped ZnO layers was investigated via SEM-EDX from which it was observed that the proportions of the elemental weight of Zn, O, and Cu were 73.4%, 23.5% and 3.1%, respectively, for 1% Cu- doped ZnO, and 71.2%, 21.1%, 7.7% for 3%Cu-doped ZnO. The surface morphological analyses revealed that the inorganic layer crystallised as hexagonal pillar nanorods and the organic layer as nanowires. It was also observed that the nanorod thickness increased from 130–230 nm to 270–450 nm with increasing Cu ratio. As a result of the optical analyses of the hybrid heterojunctions, it was found that the maximum absorption region of the heterojunctions was in the near-ultraviolet region and that they had very low transmittances (0.6%–0.77%). In addition, the absorption coefficients and the band gap energy were ≈ 107 (m−1) and were 3.09–3.25 eV, respectively, while the band gap energy of coronene thin film on ITO was 2.90 eV. Electrical analyses of Ag/ZnO:1%Cu/coronene/Ag and Ag/ZnO:3%Cu/coronene/Ag heterojunctions were performed in the ±0.4 V potential range in a dark environment at room temperature, and diode parameters were determined using various methods. It was found that Ag/ZnO:1%Cu/coronene/Ag and Ag/ZnO:3%Cu/coronene/Ag diodes had high rectification ratios with the values of 250 and 1140, respectively. It is also obvious that while the increase in Cu doping ratio increased the diode ideality factor, series resistances and barrier heights ranged from 1.31 to 13.7, 17 to 3283 Ω, and 0.43 to 0.55 eV, respectively, it decreased the reverse saturation current from 8.1 × 10–3 A to 8.2 × 10–5 A.

Synthesis of hierarchical ZnO/NiO nanocomposite Wurtz hexagonal nanorods via hydrothermal for high-performance symmetric supercapacitor application

This paper describes a simple and well-controlled hydrothermal synthesis of transition metal hydroxide (TMH) based on Nickel Oxide-Zinc Oxide (NZ) nanocomposite to construct free-standing and stable hybrid Wurtz Hexagonal Nanorods (HN) via a hydrothermal technique. The NZ nanocomposite was characterized and analyzed utilizing a variety of techniques, including XRD, FTIR, FESEM, HRTEM, XPS, and Raman Spectroscopy. The fabrication of the symmetrical two-electrode system results in the NZ-15 nanocomposite. It had a high specific capacitance (Csp) of 933.2 Fg−1 at a current density (CD) of 1 Ag−1. And also obtain long-term cycle stability of capacitance retention of 79.64 % and the coulombic efficiency of 97.24 %, even after 5000 cycles. It had a maximum energy density (ED) of 23.7 Whkg−1 and a power density (PD) of 214.1 Wkg−1 as well. The electrode's practical use was tested by lighting them up with a commercial blue LED linked in series, which flashes for nearly 1 to 2 min with intermittent voltage drops. The high electrochemical performance and other results could be evidence that the development of innovative new electrode materials hybrid Wurtz HNs structure is a prominent candidate for high-energy-density supercapacitor applications (SCs).

Manufacturing of (Al–10Zn) / TiB2 in-situ nanocomposites by reactive liquid metallurgy and hot-extrusion for enhanced interfacial bonding and mechanical properties

This work systematically deals with the development of an (Al–10Zn) die-casting alloy reinforced with in-situ synthesized hexagonal-shaped TiB2 nano-rods through casting and hot-extrusion processes. The cast specimens were extruded at 673 K with an extrusion ratio of 2:1 to orient the micro-texture, generate sub-grains within grains, reorder the reinforced in-situ TiB2 nanoparticles in the matrix, and engender strain fields to improve the mechanical properties. The nanoscale hexagonal TiB2 nano-rods (∼89 nm length and 14 nm edge) were synthesized by the chemical reaction of two halide salts (K2TiF6 and KBF4) with (Al–10Zn). The fabricated AMNCs were characterized using diffracted beams (XRD), scattered beams (FESEM and EBSD) and transmitted beams (TEM) received from the specimen. The diffracted beams from the X-rays reveal the formation of a TiB2 phase with a major α-Al phase and an individual Zn phase. The scattered beams from FESEM and EBSD revealed the homogenous distribution of TiB2 with less particle-free spacing, refinement of grains to an ultrafine level, and the absence of imperfections such as voids and interfacial de-bonding. The strain fields were observed through transmitted beams in the TEM analysis which were engendered by the thermal misfit between the matrix and TiB2 reinforcement. Among the fabricated AMNCs, (Al–10Zn) + 6 wt% TiB2 nanocomposite exhibited higher mechanical strength (160 MPa UTS) whereas (Al–10Zn) + 4.5 wt% TiB2 nanocomposite retained the ductility with improved strength (151.7 MPa UTS and 40% elongation). The strengthening mechanisms were computed using the (a) Zheng and Chen model and (b) Modified Cylne model to estimate the contribution of individual strengthening, and compared with the experimental results. The grain size strengthening contributed more to the total strength owing to the Zener pinning effect by in-situ TiB2 nano-rods.

Effects of Thermal Annealing on The Morphology and Structural Characteristics of Zinc Oxide Nanopowders for Triboelectric Nanogenerator Applications

The influence of thermal annealing on the surface morphologies and structural characteristics of zinc oxide (ZnO) nanopowders synthesized via the solution immersion method for triboelectric nanogenerator applications is reported in this paper. The ZnO nanopowders were thermally treated at different temperatures of annealing in the ranges between 300°C to 700°C for 1 hour, and their surface morphologies and structural properties were studied using field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD) analysis. The ZnO nanopowders have a polycrystalline, hexagonal wurtzite structure and are composed of ZnO nanoparticles and hexagonal nanorods. ZnO based tribolectric nanogenerators were fabricated with these nanopowders and their performance was assessed in terms of the output voltage. It is found that the ZnO based triboelectric nanogenerator fabricated with ZnO nanopowders annealed at 500°C has superior performance compared with the other nanogenerators, with an average output voltage of 1.95 V. This corresponds to a fourfold increase in output voltage relative to that of the ZnO based triboelectric nanogenerator fabricated with as-deposited ZnO nanopowders. In conclusion, thermal annealing significantly influences particle size and crystallinity of ZnO nanopowders, which in turn, influences the output voltage of ZnO based triboelectric nanogenerators.

A Paper-Based Photoelectrochemical Sensing Platform Based on In Situ Grown ZnO/ZnIn2S4 Heterojunctions onto Paper Fibers for Sensitively Detecting AFP.

Nowadays, developing a cost-effective, easy-to-operate, and efficient signal amplification platform is of important to microfluidic paper-based analytical devices (μPAD) for end-use markets of point-of-care (POC) assay applications. Herein, an ultrasensitive, paper-based photoelectrochemical (PEC) bioassay platform is constructed by in situ grown ZnO/ZnIn2S4 heterojunctions onto paper fibers, which acted as photoactive signal amplification probes for enhancing the sensitivity of antibodies-based diagnostic assays, for the sensitive detection of alpha-fetoprotein (AFP) targets. The crystalline flake-like ZnIn2S4 composited with hexagonal nanorods (NRs) morphology of ZnO is an in situ grown, at the first time, onto cellulose fibers surface supported with Au nanoparticle (Au NP) modification to improve conductivity of the device working zone. The obtained composites on paper fibers are implemented as a flexible paper-based photoelectrode to realize remarkable performance of the fabricated μPAD, resulting from the enhanced PEC activity of heterojunctions with effective electron-hole pair separation for accelerating photoelectric conversion efficiency of the sensing process under light irradiation. Once the target AFP was introduced into the biosensing interface assistant, with a specific recognition interaction of AFP antibody, a drastically photocurrent response was generated, in view of the apparent steric effects. With the concentration increase of AFP targets, more immune conjugates could be confined onto the biosensing interface, eventually leading to the quantitative decrease of photocurrent intensity. Combined with an ingenious origami design and permitting the hydrophobic/hydrophilic conversion procedure in the bioassay process, the ultrasensitive PEC detection of AFP targets was realized. Under the optimized conditions, the level of AFP could be sensitively tracked by the prepared μPAD with a liner range from 0.1 to 100 ng mL−1 and limit of detection of 0.03 ng mL−1. This work provides a great potential application for highly selective and sensitive POC testing of AFP, and finally, developments for clinical disease diagnosis.

Light-Responsive Hexagonal Assemblies of Triangular Azo Dyes.

The rational design of small building block molecules and understanding their molecular assemblies are of fundamental importance in creating new stimuli-responsive organic architectures with desired shapes and functions. Based on the experimental results of light-induced conformational changes of four types of triangular azo dyes with different terminal functional groups, as well as absorption and fluorescence characteristics associated with their molecular assemblies, we report that aggregation-active emission enhancement (AIEE)-active compound (1) substituted with sterically crowded tert-butyl (t-Bu) groups showed approximately 35% light-induced molecular switching and had a strong tendency to assemble into highly stable hexagonal structures with AIEE characteristics. Their sizes were regulated from nanometer-scale hexagonal rods to micrometer-scale sticks depending on the concentration. This is in contrast to other triangular compounds with bromo (Br) and triphenylamine (TPA) substituents, which exhibited no photoisomerization and tended to form flexible fibrous structures. Moreover, non-contact exposure of the fluorescent hexagonal nanorods to ultraviolet (UV) light led to a dramatic hexagonal-to-amorphous structure transition. The resulting remarkable variations, such as in the contrast of microscopic images and fluorescence characteristics, were confirmed by various microscopic and spectroscopic measurements.

Novel Synthesis of Sensitive Cu-ZnO Nanorod-Based Sensor for Hydrogen Peroxide Sensing.

We aimed to synthesize sensitive electrochemical sensors for hydrogen peroxide sensing by using zinc oxide nanorods grown on a fluorine-doped tin oxide electrode by using the facial hydrothermal method. It was essential to keep the surface morphology of the material (nanorods structure); due to its large surface area, the concerned material has enhanced detection ability toward the analyte. The work presents a non-enzymatic H2O2 sensor using vertically grown zinc oxide nanorods on the electrode (FTO) surfaces with Cu nanoparticles deposited on zinc oxide nanorods to enhance the activity. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-Ray (EDX), X-ray diffraction (XRD), and electrochemical methods were used to characterize copper–zinc oxide nanorods. In addition to the high surface area, the hexagonal Cu-ZnO nanorods exhibited enhanced electrochemical features of H2O2 oxidation. Nanorods made from Cu-ZnO exhibit highly efficient sensitivity of 3415 μAmM−1cm−2 low detection limits (LODs) of 0.16 μM and extremely wide linear ranges (0.001–11 mM). In addition, copper-zinc oxide nanorods demonstrated decent reproducibility, repeatability, stability, and selectivity after being used for H2O2 sensing in water samples with an RSD value of 3.83%. Cu nanoparticles decorated on ZnO nanorods demonstrate excellent potential for the detection of hydrogen peroxide, providing a new way to prepare hydrogen peroxide detecting devices.

Mesoporous hexagonal nanorods of NiCo2O4 nanoparticles via hydrothermal route for supercapacitor application

Binary metal oxide with a mesoporous microstructure has been considered a potential candidate electrode material for supercapacitor. The mesoporous microstructure of binary metal oxide improves electric conductivity. A mesoporous hexagonal microstructure of NiCo2O4 nanorods has been fabricated by a chemical hydrothermal method. Mesoporous hexagonal nanorods composed of small nanoparticles with an average thickness of 412 nm are prepared with a 14-hour hydrothermal reaction time. As synthesized, mesoporous hexagonal nanorods of NiCo2O4 as an electrode material show the highest specific capacitance of 1061 F/g and 184 mF/cm2 areal capacitance. The specific energy and specific power density of the NiCo2O4 electrode are 39 WhKg−1 and 683 Wkg−1. The equivalent charge resistance (Rs) and charge transfer resistance (Rct) of the NiCo2O4 electrode are 0.70 Ω and 43 Ω respectively. The NiCo2O4 electrode had an initial capacitance retention value of 81% after 3000 cycles.

Controlling the growth of hexagonal CsxWO3 nanorods by Li+-doping to further improve its near infrared shielding performance

In order to develop a novel high efficient energy-saving film, Li, Cs co-doped tungsten bronze (Li m Cs n WO 3 , m + n = 0.35) nanoparticles with excellent near-infrared (NIR) shielding properties were prepared by a facile solid state reaction method. It has been clarified that Li + -doping can control the crystal growth of Cs x WO 3 , resulting in formation of hexagonal nanorods with high aspect ratio, which is conducive to enhancing the local surface plasmon resonance (LSPR) and improving the NIR shielding performance. The as-prepared Li m Cs n WO 3 films from dispersion of nanoparticles with Li/Cs = 0.2:0.8 could exhibit excellent transparent heat shielding performance with the maximum visible light transmittance 75.18% and NIR shielding rate 97.65%. Moreover, the temperature difference between the outside surface and air in the box for the film glass during the thermal insulation test is 3 times that of ordinary glass. In addition, the regulation mechanism of Li + -doping on the crystal structure and NIR shielding properties were investigated. It is found that the mixed alkali effect in the Li m Cs n WO 3 nanoparticles is favorable for obtaining hexagonal Cs 0·32 WO 3 crystal grains with improved NIR shielding performance and stable crystal structure. This work has great significance for promoting industrial production and practical applications in the field of energy-saving window films. • Li m Cs n WO 3 nanorods were synthesized by a facile solid-state reaction method. • Li, Cs co-doping can lead to the growth of Li m Cs n WO 3 nanorods with high aspect ratio. • The mixed alkali effect is helpful for forming stable hexagonal nanorods. • The Li m Cs n WO 3 nanorods exhibit improved near infrared shielding performance.

Synergistic Effects of Mechanical, Thermal, and Optical Properties of Polyimide Composite Films Reinforced with WO3 Nanorods

AbstractIn this study, WO3 nanorods are directly blended with polyamic acid (PAA) solutions to improve the electrochromic capacity of WO3/PAA composite films. Specifically, the hexagonal WO3 nanorods are prepared as inorganic reinforcements using a hydrothermal method and modified by γ‐aminopropyl triethoxysilane. After curing at 300 °C, the WO3 nanorods/polyimide (PI) composite films demonstrate excellent mechanical and thermal properties. The tensile strength of the 1 wt% WO3/PI composite film is ≈110.27 MPa. The thermal stability of the 5 wt% WO3/PI composite film is better than that of the others, and the T5 (5% thermal weight loss temperature) value is ≈560.05 °C. Moreover, the WO3/PAA composite films demonstrate electrochromic behaviors. The electrochromic range of the 5 wt% WO3/PAA composite film exceeds to 68%. For the WO3/PAA samples, the oxidation peak of the WO3 nanorods is evident in the cyclic voltammetry curves. The color contrast of WO3/PI nanocomposites can be enhanced owing to the significant synergistic effects of the electron donor–acceptor system.

Rapid Synthesis of Hexagonal-Shaped Zn(Al)O-MMO Nanorods for Dye-Sensitized Solar Cell Using Zn/Al-LDH as Precursor.

This study reports a simple new technique for the preparation of novel hexagonal-shaped mixed metal oxides (MMO) nanorods using Zn/Al-layered double hydroxide (LDH) as a precursor for dye-sensitized solar cell (DSSC) application. The effect of the Zn to Al molar ratio demonstrated a sound correlation between the obtained nanorods’ diameter and the fabricated DSSCs efficiency. Additionally, the optical behavior of the fabricated MMO film as well as the absorption enhancement due to the utilized dye are also demonstrated; a cut-off phenomenon at around 376 nm corresponds to the attained hexagonal nanorods. The open-circuit voltage augmented noticeably from 0.6 to 0.64 V alongside an increase in the diameter of nanorods from 64 to 80 nm. The results indicated that an increment in the diameter of the nanorods is desirable due to the enhanced surface area through which a higher amount of dye N719 was loaded (). This, in turn, expedited the transport of electrons within the MMO matrix resulting in an advanced short-circuit current. Of the devices fabricated, ZA-8 exhibited the highest fill factor and efficiency of 0.37% and 0.69%, respectively, because of its boosted short-circuit current and open-circuit voltage.

Membranes based on porous hexagonal boron nitride nanorods for ultrafast and effective molecular separation

Effective and ultrafast molecular separation capable of exclusively transporting target molecules is highly desirable for the sustainable development of the ecosystem. Ensuring both high permeability and selective rejection is particularly challenging, especially, for long-term service in a harsh environment. Herein, we demonstrate the simultaneously functionalized hexagonal boron nitride nanorods (BNNDs) with ultrahigh porosity (specific surface area 1437 m2 g−1) that can be assembled into supported membranes for high-performance molecular separation. The BNNDs membranes with controllable thicknesses exhibit abundant nanochannel network and superhydrophilic that render ultrafast water permeance (326 L m−2 h−1) without pressure drive and efficiently selective molecular screening in both aqueous and organic solutions. In addition, the membranes possess the flexibility and high tolerance to acidic, alkaline media for over one month. Such fast permeability and excellent separation performance offer these porous BNNDs membranes promising opportunities for practical molecular separation and purification applications.