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In the present study, silica aerogel was evaluated by a two-step catalytic process at the ambient pressure drying, under different synthesis conditions. The effects of the catalyst and water content in the hydrolysis step on the physical properties of silica aerogel, including density, porosity and shrinkage, were investigated. The results showed that increasing the water content in the hydrolysis step increased the shrinkage of gel network and density of obtained aerogel. Moreover, in the presence of insufficient water, NH4OH as the condensation catalyst in the gel formation step was more effective on the physical properties of silica aerogel, as compared to HCl as thehydrolysis catalyst; Moreover, the increase in the NH4OH content led to lower density and higher porosity. On the other hand, NH4OH effect on the physical properties of silica aerogel was not noticeable in the presence of enough water content. In the NH4OH/HCl molar ratio of 6, the best silica aerogel sample was obtained with the density of 0.214 g/cm3, porosity of 90% and shrinkage of 23%

Purpose To assess osteoconductive properties of carbon fibre implants used in surgery of spine injuries and disorders. Materials and methods Two clinical cases from a multicentre prospective study on nanostructured carbon fibrous implants applied for a variety of spinal pathology are presented. Results The usage of highly porous carbon fibre implant resulted in bone and carbon fusion in the clinical instances whereas implants with a residual porosity of 7–12 % showed no fusion between bone and carbon. The patients had satisfactory clinical condition and quality of life. Discussion Carbon fibrous implant characteristics are close to those of bone tissue, being inert and osteoconductive along with high mechanical strength that ensure bone and carbon fibrous fusion with highly porous implant

The search for bone substitutes that are biodegradable, ensure space maintenance, and have osteogenic predictability, is ongoing in the field of sinus augmentation. We thus compared the bone regeneration potential of nanostructured sponges (NS-Sponge) with that of collagen-stabilized inorganic bovine bones (BO-Collagen), gelatin sponges (Gelatin), and blood clots (Cont) in sinus augmentation of rabbits. NS-Sponge was prepared by thermally induced phase separation with porogen leaching techniques. All the materials were non-hemolytic and cytocompatible. The porous and nanofibrous NS-Sponge showed better dimensional stability to support cell growth and osteogenic differentiation. In vivo, the sinus membrane collapsed in Cont and Gelatin, while BO-Collagen and NS-Sponge maintained the elevated height as assessed by come-beam computed tomography. Limited bone regeneration was observed in Cont and Gelatin. In the entire implanted area, histological analysis revealed a higher percentage of new bone area at 4 weeks of BO-Collagen treatment; however, a significantly greater increase in new bone area was observed after 12 weeks of NS-Sponge treatment. The 12-week remnant NS-Sponge material was significantly lower than the 4-week remnant material. Overall, NS-Sponge may be highly recommended for sinus augmentation, as it exhibits numerous advantages, including excellent operability, clear imaging characteristics, space maintenance, biodegradability, and superior osteogenic potential. [ABSTRACT FROM AUTHOR]

Environmental pollution and energy shortage make the development of clean energy more and more urgent. As a kind of clean renewable energy, hydrogen have attracted great attentions in recent years. Recently, Co 3 O 4 -based materials have emerged as promising candidates for electrocatalytic hydrogen evolution reaction (HER), due to their attractive electrocatalytic activity, low cost as well as the electrochemical durability, which make it attract widely attentions. In this review, we summarize the application of Co 3 O 4 -based materials in electrocatalytic HER, including pure Co 3 O 4 , the doped Co 3 O 4 and the Co 3 O 4 -based composite materials. Furthermore, the strategies to enhance their electrocatalytic performance are summarized and discussed, such as morphological engineering, doping, as well as compositing with other materials. Finally, the limitation and challenges of Co 3 O 4 -based materials for HER, as well as their prospects for future research, are proposed. We believe that this review will be helpful for scientists to seek promising HER electrocatalytic materials. Image 1 • The application of Co 3 O 4 -based electrocatalysts in H 2 evolution is summarized. • The various modification strategies of Co 3 O 4 -based electrocatalysts are reviewed. • Challenges and future prospects of Co 3 O 4 -based electrocatalysts are proposed. [ABSTRACT FROM AUTHOR]

In this study, nanostructured YSZ powders were deposited on the Hastalloy X Superalloy substrate coated with a metallic bond coat by plasma spraying to produce a nanostructured thermal barrier coating with bimodal microstructure. After that, the coated samples were heat-treated using a Nd:YAG laser. Then, the microstructures of the conventional and nanostructured TBCs before and after the laser glazing process were examined using a scanning electron microscope (SEM). The coating phases were studied by X-ray diffractometry (XRD). The high-temperature corrosion behavior of the nanostructured plasma sprayed coating in the presence of Vanadium pentoxide and Sodium sulfate molten salt was compared with that of the conventional coatings before and after laser treatment at 1050 °C. The hot corrosion results showed that the coatings had a similar degradation mechanism based on which the corrosive molten salt reacted with the stabilizer of YSZ, producing hot corrosion products such as YVO 4. It led to an unwanted phase transformation from tetragonal (t) to monoclinic (m) Zirconia and the final degradation of the TBC system. However, reducing molten salt penetration, decreasing surface roughness and, reduction of the specific surface area are three important mechanisms that improved hot corrosion resistance, finally extending the lifetime of the glazed samples. The results also showed that the nanostructured TBC had higher hot corrosion resistance in comparison with other samples. [ABSTRACT FROM AUTHOR]

SmFe 12 -based compounds have been considered as promising candidates for next generation permanent magnet materials because of their excellent intrinsic hard magnetic properties with a minimum usage of rare earth elements. However, realizing high coercivity in anisotropic microstructure is a big challenge, which hinders their practical applications. In this work, a novel anisotropic granular microstructure of Sm(Fe 0.8 Co 0.2) 12 with a sufficiently large coercivity (µ 0 H c) of 1.2 T and with a high remanent magnetization of 1.50 T is demonstrated in thin films prepared by co-sputtering Sm(Fe,Co) 12 with boron. Detailed microstructure characterization using high resolution scanning transmission electron microscopy (STEM) and atom probe tomography (APT) indicate that the addition of B leads to the development of columnar-shaped Sm(Fe 0.8 Co 0.2) 12 grains with a size of ∼40 nm, which are surrounded by ∼3 nm-thick B-enriched amorphous intergranular phase. Domain wall pinning at the amorphous grain boundary phase is attributed to the high coercivity. This work provides a guiding principle for realizing high-coercivity anisotropic SmFe 12 -based permanent magnets, which can outperform Nd-Fe-B magnets and could be used as the next-generation high-performance permanent magnets in various applications. Image, graphical abstract [ABSTRACT FROM AUTHOR]

We have developed oxide TFTs with nanostructure by using a strategy based on near‐field nanolithography, such as wrapping insulator structure with nano‐splitting active layer or nanoscale and periodic degenerately doped heterostructures. These nanostructured TFTs enhanced in device performance, compared with normal single gate homogeneous IGZO TFTs. [ABSTRACT FROM AUTHOR]

In this research, the effect of zinc doping on physical properties of Sb2S3 thin films grown by the sol–gel dip-coating method, on the glass substrates was investigated. XRD patterns indicated that the Znx(Sb2S3)1-x (x = 0.02, 0.05, 0.07, 0.1) thin films have orthorhombic crystalline structure while the intensity of the peaks decreased with increasing Zn contamination. The FESEM images demonstrated that the grain size decreased with increasing Zn concentration. The porosity of the samples changed by different values of Zn. The optical transmission spectra exhibited a shift in the absorption edge for various zinc concentrations. The refractive index of sample with x = 0.02 has the highest value among all samples. In addition, the band gap of thin films is about 2.4–3.6 eV. The PL spectra showed the doped sample with the x value of 0.02 which has the highest visible emission. Also, the contact angle measurements showed that the surface of the films were hydrophilic. [ABSTRACT FROM AUTHOR]

Cubic boron nitride (cBN), a typical superhard material, has garnered significant interest for both fundamental scientific research and technical applications. Here, nanostructured cBN with high-density nanotwins and stacking faults was synthesized by rapid quenching using hexagonal boron nitride (hBN) as the starting material at a moderate temperature (2200 K) and low pressure (13 GPa). This synthetic nanostructured cBN exhibits high Vickers hardness (78 GPa), high fracture toughness (11.8 MPa·m1/2), and extremely high oxidization temperature (1565 K). We propose that the refined grain structure and excellent mechanical properties of the cBN synthesized in this study is attributed mainly to dislocation slips and (111) mechanical nanotwins that dominate this phase transformation. [ABSTRACT FROM AUTHOR]

An investigation was carried out to evaluate the isothermal oxidation behavior of nickel based superalloys at 1100 °C for 120 h. The alloys which were microstructured and nanostructured were developed by spark plasma sintering system. The oxidation test was carried out at a temperature of 1100 °C in air at different exposure time up to 120 h. The nanostructured nickel based alloy possessed better oxidation resistance with the formation of continuous adherent alumina, chromia scales, and spinel on the alloy surface and with no significant internal oxides. The oxidation rate of NiO was observed to be lower in the nanostructured nickel superalloy due to low diffusion rate of Nickel. The oxidation kinetics followed a parabolic oxidation law. [ABSTRACT FROM AUTHOR]

Over the past decade, the study of nanostructured high-entropy alloys (HEAs) has attracted great attention due to their high strength (grain boundary hardening) and improved thermal stability over conventional nanostructured metals and alloys. However, a lingering issue yet to be resolved by these studies is that of commercial viability; the synthesis processes used to date are costly, not easily scalable, and energy intensive. This work examines the thermal stability and mechanical properties of electrodeposited nanostructured HEAs, towards establishing a cost-effective and versatile synthesis route to commercialize this underutilized material class. Nanocrystalline, amorphous, and nanoglass alloys of NiFeCoW, NiFeCoMo, and NiFeCoMoW were systematically characterized to assess the stability of their structure and mechanical properties, compared against conventional nanocrystalline materials and HEA counterparts. The structural stability of these electrodeposited HEAs was shown to improve with increasing number of elements, from a peak temperature for grain growth of ∼270 °C in pure nanocrystalline Ni, to ∼500 °C in electrodeposited HEAs, corresponding to a near doubling of the activation energy for grain growth from 1.3 eV (Ni) to a maximum of 3.1 eV (NiFeCoW). This improved stability was matched with a 60 % increase in hardness after annealing to the point of nanograin nucleation (∼500 °C), to a maximum hardness of ∼8.4 GPa. Such hardening trends followed an extrinsic inverse-to-regular Hall-Petch relationship, where the inverse regime was largely dominated by grain boundary relaxation and nanoglass structural breakdown. With these results, we have established electrodeposition as a promising candidate route for fabricating nanostructured HEAs for applications at elevated temperatures. [Display omitted] • First comprehensive investigation of mechanical properties and thermal stability of electrodeposited nanostructured high-entropy alloys. • The family of NiFeCoMoW alloys is structurally stable up to ∼500 °C. • Annealing brings out an extrinsic inverse-to-regular Hall-Petch hardening transition. [ABSTRACT FROM AUTHOR]

• Carbon nanomaterials were synthesized in situ using a facile alcohol flame • Lower flame temperatures were achieved with increasing amounts of aqueous ammonia • Soot particles had concentrically stacked carbon layers with a diameter of 45 ± 5 nm • Carbon nanotubes (CNTs) were grown via the root growth mechanism • I G /I D ratios of CNOs (2.33) and CNTs (1.05) indicate good graphitic crystallization This study aimed to investigate the in-situ synthesis of nanostructured carbon materials using alcohol flames generated by a Bunsen lamp burner and a catalytic Ni substrate, as opposed to the chemical vapor deposition method. Four different liquid fuels were utilized, including n-butanol, ethanol, n-butanol/aqueous ammonia, and ethanol/aqueous ammonia. The carbon growth, morphology, and structure caused by the parameters of sampling position, temperature distribution, and liquid fuel type were investigated using the diffusion flame produced by the atmospheric alcohol lamp burner. The results show that the additive aqueous ammonia affects not only the flame temperature but also the axial position of the highest temperature. When using n-butanol and portions of 10 %, 20 %, and 30 % of aqueous ammonia mixed fuels, carbon nanotubes (CNTs), and carbon nano-onions (CNOs) are both observed; however, using ethanol and the portions of 10 %, 20 %, and 30 % of aqueous ammonia mixed fuels, only CNTs are synthesized. Soot particles show concentrically stacked carbon layers with a diameter of around 45 ± 5 nm. CNTs have no encapsulated Ni catalytic particles at the closed tip, showing the root growth mechanism and indicating differences from the top growth mechanism. In addition, graphene could be synthesized in pure n-butanol and n-butanol/ammonia flames, but not in pure ethanol and ethanol/ammonia flames. The I G /I D ratio values of the raw CNOs (2.33) and CNTs (1.05) are greater than 1, where I G /I D is the intensity ratio of Raman G -band and D -band peaks, indicating good crystallization of the graphite layer of these nanostructured carbon materials. Notably, flame synthesis via an alcohol Bunsen lamp burner simplifies operations saves resources, and improves conventional production, demonstrating a facile and efficient method. [ABSTRACT FROM AUTHOR]

A novel synthetic method has been developed by utilizing the chemical reactivity of functionalized graphene and CNT with a covalent combination of chemically diverse GO/FCNT and toluene diisocyanate, thereby yielding a synergistic polymer nanocomposite. Comprehensive composite material has simultaneous covalent, as well as π-π, interactions confirming sp2-hybridized frameworks of graphene oxide and MWCNTs by Raman absorption spectra at 1345 and 1590 cm−1 of D and G bands, respectively. Toluene diisocyanate and GO/FCNT inspired polymeric formulation was obtained by the classical curing reaction initiated by ultrasound sonication. This method allowed 50 wt.% doping of GO/FCNT without segregation and ensured good adhesion to the law steel surface. The large surface area and morphological character of GO and FCNT by SEM and TEM ensure stable and dispersed integrated molecules. This has advantages over high-temperature and hazardous curing reaction, and overcomes the problem of graphene exfoliation. It also does not allow CNT slipping within the bundle, which can cause falling apart at higher concentration.

Cryomilled 5083 Al alloys blended with volume fractions of 15 pct, 30 pct and 50 pct unmilled 5083 Al were produced by consolidation of a mixture of cryomilled 5083 Al and unmilled 5083 Al powders. A bimodal grain size was achieved in the as-extruded alloys in which nanostructured regions had a grain size of 200 nm and coarse-grained regions had a grain size of 1 mm. Compression loading in the longitudinal direction resulted in elastic-perfectly plastic deformation behavior. As the volume fraction of coarse grains was increased, ductility increased and strength decreased. An enhanced tensile elongation associated with the occurrence of a Lüders band was observed in the bimodal alloys. Enhanced tensile ductility was attributed to the occurrence of crack bridging as well as delamination between nanostructured and coarse-grained regions during plastic deformation.

Although the research on zinc oxide (ZnO) has a very long history and its applications are almost countless as the publications on this subject are extensive, this semiconductor is still full of resources and continues to offer very interesting results worth publishing or warrants further investigation. The recent years are marked by the development of novel green chemical synthesis routes for semiconductor fabrication in order to reduce the environmental impacts associated with synthesis on one hand and to inhibit/suppress the toxicity and hazards at the end of their lifecycle on the other hand. In this context, this study focused on the development of various kinds of nanostructured ZnO onto Si substrates via chemical route synthesis using both classic solvents and some usual non-toxic beverages to substitute the expensive high purity reagents acquired from specialized providers. To our knowledge, this represents the first systematic study involving common beverages as reagents in order to obtain ZnO coatings onto Si for optoelectronic applications by the Aqueous Chemical Growth (ACG) technique. Moreover, the present study offers comparative information on obtaining nanostructured ZnO coatings with a large variety of bulk and surface morphologies consisting of crystalline nanostructures. It was revealed from X-ray diffraction analysis via Williamson–Hall plots that the resulting wurtzite ZnO has a large crystallite size and small lattice strain. These morphological features resulted in good optical properties, as proved by photoluminescence (PL) measurements even at room temperature (295 K). Good optical properties could be ascribed to complex surface structuring and large surface-to-volume ratios.

Ibrahim Elsayed,1,2 Sinar Sayed1 1Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Cairo University, Cairo, Egypt; 2Department of Pharmaceutical Sciences, College of Pharmacy, Gulf Medical University, Ajman, United Arab Emirates Abstract: Ocular drug delivery systems suffer from rapid drainage, intractable corneal permeation and short dosing intervals. Transcorneal drug permeation could increase the drug availability and efficiency in the aqueous humor. The aim of this study was to develop and optimize nanostructured formulations to provide accurate doses, long contact time and enhanced drug permeation. Nanovesicles were designed based on Box–Behnken model and prepared using the thin film hydration technique. The formed nanodispersions were evaluated by measuring the particle size, polydispersity index, zeta potential, entrapment efficiency and gelation temperature. The obtained desirability values were utilized to develop an optimized nanostructured in situ gel and insert. The optimized formulations were imaged by transmission and scanning electron microscopes. In addition, rheological characters, in vitro drug diffusion, ex vivo and in vivo permeation and safety of the optimized formulation were investigated. The optimized insert formulation was found to have a relatively lower viscosity, higher diffusion, ex vivo and in vivo permeation, when compared to the optimized in situ gel. So, the lyophilized nanostructured insert could be considered as a promising carrier and transporter for drugs across the cornea with high biocompatibility and effectiveness. Keywords: thin-film hydration, in situ, insert, confocal, transcorneal, tenoxicam

Dye-sensitized semiconductor oxide photoelectrodes in which light is absorbed by a monomolecular layer of dye chemisorbed on a porous oxide substrate have attracted considerable interest in the last 35 years, mainly for the conversion of sunlight to electricity, in dye-sensitized solar cells (DSSCs) with maximal efficiencies in the range 10–15%, and, most recently, as dye-sensitized photoelectrochemical cells (DSPECs) for the generation of solar fuels. In the latter direction, considerable progress has been achieved but the efficiency is notably lower than for electricity generation. In the present review, the basic physicochemical principles of the DSSC and DSPEC operation are described, several keynote results reported, and the factors limiting the performance and necessitating further research highlighted.

The Nd 0.6 Sr 0.4 MnO 3 (NSMO) manganite system exhibits a phase transition from paramagnetic insulating (PMI) to ferromagnetic metallic (FMM) state around its Curie temperature T C = 270 K (bulk). The morphology-driven changes in the kinetically arrested magnetic phases in NSMO thin films with granular and crossed-nano-rod-type morphology are studied. The manganite thin films at low temperatures possess a magnetic glassy state arising from the coexistence of the high-temperature PMI and the low-temperature FMM phases. The extent of kinetic arrest and its relaxation was studied using the 'cooling and heating in unequal field (CHUF)' protocol in magnetic and magnetotransport investigations. The sample with rod morphology showed a large extent of phase coexistence compared to the granular sample. Further, with a field-cooling protocol, time-evolution studies were carried out to understand the relaxation of arrested magnetic phases across these morphologically distinct thin films. The results on the devitrification of the arrested magnetic state are interpreted from the point of view of homogeneous and heterogeneous nucleation of the ferromagnetic phase in the paramagnetic matrix with respect to temperature., (© 2024 IOP Publishing Ltd.)

Voriconazole is an antifungal agent that is used for treatment of Aspergillus infections, several side effects are connected with it. For overcome the limitations, excellent carriers for antifungal drugs may be nanostructured structures. This study aimed to isolating Aspergillus flavus from goat tracheal swabs also investigates the development of voriconazole-loaded solid lipid nanoparticles and nanostructured lipid carriers, then analyzes their characteristics, and compares the antifungal activities of these preparations with free voriconazole. Aspergillus flavus molds were isolated and defined. Voriconazole-lipid nanoparticles formulations were prepared and physiochemical properties, encapsulation efficiency, and drug release were investigated. Physical stability was characterized and identified for their suspension and dry powder after lyophilization with mannitol as a cryoprotectant and without of cryoprotectant. In vitro antifungal activity of voriconazole-lipid nanoparticles was tested. The lowest particle size values (121.8±5.3) were seen in voriconazolenanostructured lipid carriers (suspension). Formulations showed zeta potential values ranged from - 10.4±0.14mV to -29.3±1.31mV. Polydispersity index values were under 0.3. Morphologically, particles showed smooth surfaces, almost spheroid-like. Maximum values of encapsulation efficiency and drug release with voriconazole-nanostructured lipid carriers (suspension) were recorded. After 90 days, all lyophilized formulations exhibited good water stability. The least initial burst release amongst all experimented formulations was performed by voriconazole-nanostructured lipid carriers (suspension)+mannitol powder at pH 7.4. Voriconazole-nanostructured lipid carriers preparations showed higher antifungal activity against the examined isolates at 0.5µg/mL followed by voriconazole-solid lipid nanoparticles preparations, while free voriconazole resulted in the lowest inhibition values. All formulations, especially voriconazole-nanostructured lipid carriers+mannitol, could represent a promising formula for antifungal application. [ABSTRACT FROM AUTHOR]

In this communication, structure and charge, conduction mechanisms have been understood for sol–gel-grown nanostructured La0.6Nd0.1Sr0.3MnO3 (LNSMO) manganites prepared at different process temperatures under air and oxygen environments. Obtained X-ray diffraction patterns of all the samples were analysed using Rietveld refinements and obtained structural lattice parameters have been discussed in correlation with resistivity behaviour of the samples. Observed low temperature resistivity upturn behaviour has been examined in the context of electron–electron scattering mechanism. Metallic and insulating/semiconducting behaviours of all the nanostructured LNSMO manganites have been understood by using various models and mechanisms. Magnetoresistance isotherms have also been theoretically fitted and separate grain and grain boundary contributions have been studied for LNSMO manganite samples. All obtained fitting parameters have been discussed in the context of role of applied magnetic field, process temperature and annealing environment. [ABSTRACT FROM AUTHOR]

In the 21st century, energy demand and the attendant environmental degradation, are among the most challenging issues. The concern is due to the high dependence, globally on fossil fuels as a form of energy generation. Over 6.5 billion people worldwide require approximately 13 Terawatts of energy for their day-to-day needs. In order to achieve the required energy demand, there is a need to diversify into other forms of energy; in this case, renewable energy. In so doing, there is the need to study, extensively, alternative materials and sources needed for energy generation, storage, distribution and application. There has been a significant advancement in energy generation, conversion and storage, such as fuel cells and solar cells, photovoltaic cells, supercapacitors, batteries, etc. The emergence of nanostructured and composite materials has resulted in some significant contributions towards the improvement in the energy industry development. Renewable energy, such as wind and solar energies, depend considerably, on the environmental conditions, which are not always stable. Hence, in order to harness the energy from these sources and to adequately store such energy, there is a need for a high-performance energy conversion and storage system for the energy generation process. In this regard, carbon nanomaterials, metallic sulphides, titanium oxide and many other nanostructured materials have been studied, to a large extent, for energy conversions and storage devices. The importance of nanostructured and composite materials has shown, from researches, to resolve the issues surrounding energy from generation to storage. [ABSTRACT FROM AUTHOR]

The interface between water and folded proteins is very complex. Proteins have "patchy" solvent-accessible areas composed of domains of varying hydrophobicity. The textbook understanding is that these domains contribute additively to interfacial properties (Cassie's equation, CE). An ever-growing number of modeling papers question the validity of CE at molecular length scales, but there is no conclusive experiment to support this and no proposed new theoretical framework. Here, we study the wetting of model compounds with patchy surfaces differing solely in patchiness but not in composition. Were CE to be correct, these materials would have had the same solid-liquid work of adhesion (WSL) and time-averaged structure of interfacial water. We find considerable differences in WSL, and sum-frequency generation measurements of the interfacial water structure show distinctively different spectral features. Molecular-dynamics simulations of water on patchy surfaces capture the observed behaviors and point toward significant nonadditivity in water density and average orientation. They show that a description of the molecular arrangement on the surface is needed to predict its wetting properties. We propose a predictive model that considers, for every molecule, the contributions of its first-nearest neighbors as a descriptor to determine the wetting properties of the surface. The model is validated by measurements of WSL in multiple solvents, where large differences are observed for solvents whose effective diameter is smaller than ~6 Å. The experiments and theoretical model proposed here provide a starting point to develop a comprehensive understanding of complex biological interfaces as well as for the engineering of synthetic ones. [ABSTRACT FROM AUTHOR]

Controlling surface morphology is a key issue for obtaining functional materials with surface-based properties. In this paper, we explore the possibility of using the self-separation of phases as a way of controlling the surface morphology features. We demonstrate using X-ray diffraction and transmission electron microscopy that a competitive self-separation of a nanocrystalline and an amorphous phases occurs in co-sputtered Zr-Mo thin films with a Mo content of 60 at%, corresponding to a composition intermediate to those necessary to form single-phased amorphous and nanocrystalline films. The dependence of the residual stress with the thickness at the biphased composition is discussed in terms of the morphology evolution and a possible mechanism for the self-separation of phases is presented. We show that the self-separation of phases as presented here is not limited to Zr-Mo alloys and can be extended to other systems. By changing the film thickness, it is possible to change the surface morphology of the films at the biphasic composition, due to the competitive growth of the nanocrystalline phase in the amorphous phase. In this way, it was possible to control the surface roughness and, because of this, tuning the film reflectance at a determined wavelength. The occurrence of an interference pattern in the reflectance spectra was discussed and associated to the presence of two different height levels at the film surface. [ABSTRACT FROM AUTHOR]

The present assets of fossil fuel-based energy resources are going to be end due to high consumption rate. These resources also are polluting the climate rapidly. With reference to these alarming situations, solid oxide fuel cells have got great attention in the field of energy conversion technologies due to their low emissions, fuel flexibility and higher efficiency characteristics. In the present investigation, two anode materials with compositions Al 0.1 Mn 0.1 Zn 0.8 O (AMZ) and Al 0.1 Mn 0.1 Ni 0.1 Zn 0.7 O (AMNZ) were prepared via solid state reaction. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis were accomplished to investigate the phase and surface morphology study of synthesized materials. The crystallite sizes of the prepared materials have been assessed using Scherer's formula and found to be 52 and 61 nm for AMZ and AMNZ, respectively. The conductivities of AMZ and AMNZ were obtained 4.4 and 5.2 S/cm, respectively at 650 °C. The activation energy was calculated by drawing Arrhenius plots. The prepared materials showed both ionic and electronic conduction behaviour as confirmed by electrochemical impedance measurements. The AMNZ composition has higher value of open circuit voltage (1.01 V) and power density (535 mW/cm2) in hydrogen atmosphere as compared with AMZ at 550 °C, which indicates that Ni contents in anode improvs the properties and can be considered as promising anode material at low temperature for fuel cell applications. [ABSTRACT FROM AUTHOR]

The effect of the Pt loadings and particles sizes on the stability of Pt(x wt%)/Al 2 O 3 catalysts were investigated in the partial oxidation of methane (POM) reaction. The Al 2 O 3 support was prepared by sol-gel method and different Pt loadings, varying from 0.5 to 2.0 wt% were incorporated to alumina through the incipient wetness impregnation method. The physicochemical features of the catalysts were determined by XRD, ICP-OES, Nitrogen-sorption, UV–Visible, H 2 -TPR, CO-DRIFTS, SEM-EDS, XPS and HRTEM techniques. The metal dispersion was evaluated in the cyclohexane dehydrogenation reaction. Lower Pt loadings resulted in well dispersed Pto nanoparticles with an enhanced activity in cyclohexane dehydrogenation and POM reactions. With increasing Pt loading to 2.0 wt%, the Pt nanoparticles of the Pt(2.0 wt%)/Al 2 O 3 showed a methane conversion of 63% in 24 h of time on stream, and the catalyst was very selective to H 2 and CO. Based on the HRTEM, XPS and Raman spectroscopy techniques, an increment in the Pt loadings evidenced an enrichment of Pto clusters on the surface, however, no heavy carbon deposits formation was observed. Image 1 • Partial oxidation of methane reaction over nanostructured Pt supported Al 2 O 3. • XRD, Nitrogen-sorption, H 2 -TPR, CO-DRIFTS, SEM-EDS, XPS and HRTEM. • The metal dispersion evaluated in the cyclohexane dehydrogenation reaction. • The effect of the Pt particles sizes and loadings on the stability of catalysts. • Enrichment of Pto nanoparticles on the surface avoids heavy carbon deposition. [ABSTRACT FROM AUTHOR]

The synthesis of bismuth ferrite (BiFeO3) in the nanocrystalline form is described in the present work with the help of self-combustion technique with DL-malic acid as fuel to obtain single-phase BiFeO3 nanopowders. The crystallization behavior for the formation of BiFeO3 was confirmed from the obtained powder diffraction pattern (p-XRD) and thermogravimetric analysis with simultaneous differential thermal analysis. Thermal measurements were carried out in the nitrogen atmosphere to determine the crystallization kinetics through various heating rates from simultaneous thermogravimetric–differential thermal (TG–DTA) analysis curve. The activation energies for the formation of BiFeO3 metal oxides formation were found to be around 124 kJ mol−1 and 113 kJ mol−1 from the phenomenological Johnson–Mehl–Avrami equation or in short JMA. The growth mechanism along three dimensions was observed for all heating rates. The formation of single-phase BFO in nanocrystalline nature was confirmed through microstructural investigations by the use of transmission electron microscopic analysis. The selected area electron diffraction pattern of nanostructure bismuth ferrite for the sample calcinated at 800 °C reveals the diffraction miller indices planes {104} and doublet peaks of {110}, {202} which is in good agreement with that of the present powder XRD pattern. The magnetization for the synthesized samples calcinated indicates that there exists the magnetic order and existence of room-temperature magnetic saturation for the multiferroic BiFeO3. [ABSTRACT FROM AUTHOR]

Nanostructured thin film coatings of copper oxide (Cu-oxide) were investigated to determine their physical structure, surface morphology, surface electronic bonding states, and optical properties. The Cu-oxide had been coated onto reflective aluminum substrates via a facile one-step sol–gel dip-coating route using a copper nitrate precursor. Characterizations were conducted using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), field emission scanning electron microscopy (FESEM), and ultra-violet visible (UV–Vis) spectroscopic methods, and representative sol-gel reactions using copper nitrate precursor were proposed. The XPS spectra confirmed the presence of copper oxide elements. Further exploration of the Cu2 p 3/2 peak in XPS spectra revealed that the electronic structure of the copper component consisted of tetrahedral Cu(I) and octahedral Cu(II) with the presence of octahedral Cu(II) enabling coatings to have high absorption levels across the solar spectrum. The deconvolution of the O1 s spectra exhibited three curve-fitting components: the lattice O2−, surface oxygen, and subsurface O− species. FESEM results showed that the coating surface was an agglomerated copper oxide nanoparticles structure forming a porous structure. The optical band-gap of Cu-oxide thin film coatings, via the Tauc plot, was 2.7 eV. [ABSTRACT FROM AUTHOR]

Abstract Nanostructured ZnO, ZnO/AZO, and ZnO/AZO/ZnO multilayer thin films were deposited on glass substrates by the sol-gel spin coating method. Structural, optical and photocatalytic properties of multilayer thin films as a function of Al doping concentration were studied. Field emission scanning electron microscopy (FESEM) images showed that surfaces of ZnO multilayer thin films have granular character. X-ray diffraction (XRD) analysis indicated that all multilayer thin films are polycrystalline with a hexagonal Wurtzite structure, and the crystallinity of multilayer thin films deteriorate with an increase in the Al doping concentration. X-ray photoelectron spectroscopy (XPS) and photoluminescence (PL) spectroscopy showed that oxygen vacancies in ZnO/AZO/ZnO thin films are higher than in ZnO/AZO thin films. The DRS result showed that the band-gap energy of ZnO multilayer thin films increases with increasing Al doping concentration. The prepared samples were examined by the photodegradation reaction of methylene blue (MB) under visible light irradiation. The AZO as the middle layer in the ZnO/AZO/ZnO thin films was found to improve the photocatalytic activity of the samples. The maximum photocatalytic activity (95.2%) was obtained at 20% Al concentration, and the photocatalytic activity of this sample stayed nearly unchanged after three cycles. Graphical abstract Image 1 Highlights • Multilayer thin films of ZnO and AZO were prepared by sol-gel method. • The increase in Al deteriorated the crystallinity of multilayer thin films. • Band-gap energy of ZnO multilayer thin films increased with increasing Al content. • According to the PL and XPS spectra, the oxygen vacancy is more for three-layers. • AZO as the middle layer, improved the photocatalytic activity of the film to 95.2%. [ABSTRACT FROM AUTHOR]

The access of dye-sensitized solar cells (DSSCs) in the photovoltaic market is still a challenge owing to low power-conversion-efficiency (PCE) and stability. The foremost aim of this review is to emphasize the technical issues in DSSCs that reduce their efficiency. A DSSC consists of glass substrates, photoanode, photosensitizer, electrolyte and catalytic counter-electrode. Electrode materials play a critical role in the photovoltaic (PV) performance of DSSCs. The PV performance of DSSCs depends on many factors e.g. electron collection at photoanode, light harvesting efficiency of photoanode, a scattering of electrons inside the photoanode, and the fast reduction of an electrolyte at the counter electrode. In this review, physical, electronic, and morphological properties of electrodes materials will be examined for efficient DSSCs. This review paper comprises of four parts. First part highlights the importance, structure and charge transport mechanism of DSSCs. The second section describes the types, electronic and morphological properties of photoanode materials. The third part covers the nature and catalytic properties of materials used for counter-electrodes. Finally, challenges, market and future directions of DSSCs will be described in the last part of this review. [ABSTRACT FROM AUTHOR]

Abstract Zn batteries are attractive for energy storage due to their low cost and intrinsic safety. However, the low utilization of active materials results in unsatisfied capacities. Herein, Zn batteries based on nanostructured NiCo 2 O 4 electrodes are developed. Through hydrothermal reactions, porous NiCo 2 O 4 nanosheets, nanowires, and nanoplates are fabricated, which are in-situ grown on the surface of nickel foam substrates, facilitating the electron transport and electrochemical reactions. In particular, the battery with the nanowire electrode exhibits the largest discharge capacity of 230.1 mAh g−1, which accounts for 68.7% of the theoretical capacity of NiCo 2 O 4. Based on the weights of NiCo 2 O 4 and consumed Zn, the energy density of the battery is 301.3 Wh kg−1, higher than most of the reported Zn batteries. At a high current density of 8 A g−1, the capacity is still 164.25 mAh g−1, with the retention of 71.38%, which illustrates the high rate performance. Moreover, after 1000 discharge-charge cycles, the capacity retention is 63.23%, which reveals remarkable cycling stability. The results show that the NiCo 2 O 4 nanowire electrode is attractive for Zn batteries with high capacity, energy density, rate performance, and cycling stability. Graphical abstract Image 1 Highlights • Nanostructured NiCo 2 O 4 is in-situ grown on the nickel foam substrate. • The NiCo 2 O 4 nanowire electrode exhibits the best electrochemical performance. • A Zn battery delivers the energy density of 301.3 Wh kg−1. • 71.38% of the capacity is preserved when the current increases from 0.5 to 8 A g−1. • The capacity retention researches 63.23% after 1000 discharge-charge cycles. [ABSTRACT FROM AUTHOR]

A pilot-scale research was conducted on nanostructured ceramic membrane bio-reactor( NCMBR) for treatment of comprehensive wastewater from industrial park. The quality of the effluent water was stable and good. During stable operation,the COD,NH3-N and TP concentrations of the influent water were 147-475,42-23. 5 and 0. 65-0. 85 mg/L,respectively,and those of the effluent water were 147-475,0. 08-0. 82 and 0. 18-0. 26 mg/L,respectively,so the average removal rates of COD,NH3-N and TP were 82%,97% and 72%,respectively,meeting the standard for Class-A emissions of Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant( GB18918-2002). In addition,the process has certain anti-impact capacity and ability to mitigate membrane fouling,meeting the objectives of upgrading and transformation. This study will provide reference for upgrading of existing sewage treatment plants. [ABSTRACT FROM AUTHOR]

Highlights • Diatom biosilica improved migration of triphenylmethane dyes over silica gel. • Diatom biosilica layer reduced dispersive and convective mass transfer resistances. • Diatom biosilica has promise as nanostructured stationary phase for TLC. Abstract This study showed that a nanostructured, highly-porous stationary phase composed of randomly-deposited biosilica frustules isolated from living cells of diatom Pinnularia sp. significantly improved the conventional thin-layer chromatography (TLC) based separation of the triphenylmethane dyes malachite green and fast green relative to silica gel by two mobile phases (9:1:1 v/v 1-butanol:ethanol:water, 5:1:2 v/v 1-butanol:acetic acid:water). Although both stationary phases were composed of amorphous silica rich in silanol groups with particle size of 10–12 μm, diatom biosilica frustules were highly porous, hollow shells with surface structure dominated by 200 nm pore arrays. Diatom biosilica significantly improved the mobility of both malachite green and fast green, enabling the resolution of these analytes. The diatom biosilica layer had a high void fraction of 96% but reduced the flow velocity and permeability constant by a factor of two relative to silica gel. TLC performance was enhanced, as evidenced by ten-fold reduction in theoretical plate height for both analytes using the 1-butanol:acetic acid:water mobile phase, and an increased difference in retention time between malachite green and fast green (Δ R f = 0.26) using the 1-butanol:ethanol:water mobile phase. Analysis of plate height vs. solvent front position by the modified van Deemter equation suggested that dispersive mass transfer was reduced, leading to improved analyte resolution, and that surface of the frustule decreased boundary layer resistance, leading to increased analyte flux. Overall, the basis for improved chromatographic performance is believed to be the unique nano- and microstructure of the diatom biosilica frustule. [ABSTRACT FROM AUTHOR]

Abstract A series of pure HfB 2 ceramics have been prepared by sintering nano-grained powder using high-energy ball milling at 700–1600 °C and 5.5 GPa. The HfB 2 ceramics are characterized via various techniques for their residual stress, grain size, density, microstructures and defects, hardness, fracture toughness, thermal stability, and oxidation resistance. All properties strongly depend on the treatment temperature, but the exact manner of dependence for each property varies. The results identified that the HfB 2 ceramic sintered at a relatively low temperature of 1000 °C and 5.5 GPa – a bulk pure nano-grained composite for the first time – has the best overall performance. It has a relative density of 99.6%, a Vickers hardness of 26 GPa, a fracture toughness of 5.2 MPa m1/2, and excellent thermal stability and oxidation resistance at high temperatures. Additional strengthening and stabilizing effects are provided by microstructures and defects such as large-angle grain boundaries, stacking faults and twinning. Simultaneous high temperature and high pressure is an effective sintering route for HfB 2 ceramics with grain-size ranging from nanometer to micron. [ABSTRACT FROM AUTHOR]

Highlights • Superhydrophilic, ZnO nanostructures cause capillary pressure-driven rapid spreading. • Droplet evaporation unique for thin, hydrophilic, nanoporous layer on metal substrate. • Model provides definitive understanding of mechanisms for such droplet evaporation. • Evaporation heat transfer enhanced by a factor of three versus bare copper surface. • Surface characteristics for optimization of droplet evaporation identified using model. Abstract Previous studies of droplet spreading on superhydrophilic nanostructured surfaces have demonstrated that enhanced wetting and wickability of such surfaces can produce more rapid and extensive spreading of liquid droplets. There is also ample evidence from prior studies that these types of superhydrophilic nanostructured surfaces can exhibit enhanced vaporization heat transfer performance in for droplet evaporation and pool boiling processes. This study specifically explored the mechanisms of droplet vaporization on superhydrophilic nanoporous thin layers, at a fundamental level, for conditions in which liquid viscous forces and pore capillarity forces dominate, and liquid inertia forces are low. The investigation, summarized here, experimentally explored the droplet evaporation heat transfer performance on superhydrophilic, nanoporous, thin layers on a heated metal substrate. A thermal growth process was used to fabricate a layer of ZnO nanopillars a few microns thick on a copper substrate. The resulting nanoporous layer exhibited ultra-low contact angles and high wickability. The experiments indicate that, on these surfaces, a deposited droplet undergoes an initial rapid spreading phase followed by a slower vaporization phase, which shrinks the droplet until evaporation is complete. Although droplet evaporation without bubble nucleation is the primary focus of this work, the experiments also examined the added effects of bubble nucleation on droplet evaporation at high surface superheats. Based on experimental observations and data, a model of heat transport during the evaporation process was developed. The model predictions are shown to agree well with droplet evaporation time measurements for droplets of different initial sizes and a range of surface temperatures. The experiments and model indicate that the surfaces tested enhance droplet evaporation heat transfer performance by as much as a factor of three compared to an ordinary copper surface at the same conditions. The model is also used to explore the potential for more extreme augmentation of droplet evaporation heat transfer by further enhancement of surface wetting and wickability. The results of this study provide a clearer picture of the interconnection of droplet spreading mechanisms and evaporation heat transfer for these circumstances. [ABSTRACT FROM AUTHOR]

Sodium-ion batteries (SIBs) have been considered one of the optimal the large scale and low cost energy storage systems for smart grid system owing to the abundant sodium resource. Among various anode materials, the biomass-derived nanostructured porous carbons (BDNPCs) show some promising in SIBs due to obvious advantages of abundant resource, low cost, nontoxicity and high safety. In this review, the recent progress of the sodium storage performance of the biomass derived nanostructured porous carbons is summarized. Moreover, the dependent of SIB performances on the porous structures from BDNPCs is discussed. It is expected that this review may provide an in-depth understanding and guide rational design of high-performance anode materials by using low-cost, sustainable and natural biomass precursors. [ABSTRACT FROM AUTHOR]

Abstract One of the key barriers to commercial development of thermoelectric materials for conversion of heat into electricity is the issue of thermal transport, which diminishes the temperature gradient needed for sustaining the thermoelectric conversion process. The translation of bulk thermoelectric materials into nanostructures such as superlattices, nanowires and quantum dots is useful to mitigate thermal conductivity, through an increase in the mechanisms responsible for phonon scattering. Theoretical principles behind superlattices, phonon glass electron crystals (PGECs) and energy filtering are introduced within the context of thermal conductivity reduction. Case studies using SrTiO 3 based oxide materials and titanium-based sulfide materials are used to illustrate structural modifications of the thermoelectric crystal lattice which have been successfully employed to reduce thermal conductivity and hence improve the thermoelectric figure of merit. In particular, the SrTiO 3 , a perovskite-type oxide class of materials was selected because of the high tunability of its crystal structure through introduction of selective doping, ability to create of an elastic strain field due to radii mismatch of the dopant atom which produces a wider range of phonon scattering and buildable crystal architecture through interleaving with dopant cations to form superlattices. On the other hand, design of TiS 2 compounds are a variant on the concept of dichalcogenides, which produce highly anisotropic layered crystal structures, which in turn lend itself to quantum confinement and enhanced phonon scattering effects. Notable nanoarchitectural design of the TiS 2 crystal lattice includes nanoblock integration, metal and organic layer intercalation, and misfit layer sulfides which give rise to interesting transport characteristics of the resulting crystal. These strategies all point towards further enhancement of the thermoelectric figure of merit through mitigation of thermal conductivity for ultimate utilization in energy harvesting applications. Highlights • Thermoelectricity is a promising renewable energy conversion technology with the ability to convert a temperature gradient into useful electricity without any need for moving parts. • One of the powerful strategy to improve the thermoelectric performance is reducing the thermal conductivity, in particular the lattice thermal conductivity so that its thermal conduction is comparable with glass thermal conduction. • Nanostructure approach is a useful strategy to mitigate thermal conductivity through an increase in the mechanisms responsible for phonon scattering. • Titanium-based thermoelectric materials play a role in the search for superior thermoelectric material due to their unique electronic structure. [ABSTRACT FROM AUTHOR]

Abstract Vanadium oxide nanotube is a new type of nanotubular material which opens new horizons for application in many areas. The important catalytic and electrochemical property of vanadium oxide as well as the unique shape of the nanotubes has been the impetus for studying this novel type of nanostructured material. The paper review focuses on recent advances of synthesis vanadium oxide nanotubes. Methods of synthesis vanadium oxide nanotubes (sol-gel, hydrothermal) of nanostructured-based on electrochemical and catalytic processes and metal dichalcogenides, Inorganic nanotubes, and oxide and hydroxide nanotubes and details the synthesis and structural properties of vanadium oxides get are reviewed. Highlights • Nanoscale transport phenomena have been summarized. • Review recent progress in nanotechnology by improving gas separation membranes. • Highlight translational challenges and opportunities in the field of vanadium oxide nanotube. [ABSTRACT FROM AUTHOR]

The mixed oxides of SiO2–TiO2, MoO3–SiO2–TiO2, CoO–SiO2–TiO2 and MoO3–CoO–SiO2–TiO2 are prepared from a stable homogeneous mixture based on transition metals. During the preparation, it is necessary to know the duration of the stability of this solution, to control its stability, use the Zetasizer. The sol-gel process is one of the most widely used synthetic methods. This leads to the formation of homogeneous products. In present study; the structure, composition, particle size, morphology and porosity of the particles are obtained. The nanostructured mixed oxides has been characterized by physico-chemical analysis methods, including Acidity, Zeta potential, FTIR, BET, X-ray diffraction and TEM. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • LSCZ oxide cathode material was successively synthesized by sol-gel. • The crystallite size of proposed material was calculated 47.55 nm from XRD patterns using Scherer's formula. • LSCZ cathode was tested with different electrolytes and anodes. • The maximum power density was found to be 850 mW/cm2 at 550 °C. Abstract Nanostructure cathode material with composition of La 0.10 Sr 0.90 Co 0.20 Zn 0.80 O 5-δ (LSCZO) was synthesized by wet chemical route. The crystallite size was found 47.55 nm and porosity was observed in the structure. The oxygen ion and electron transport phenomena were studied from anode to cathode and vice versa by electrical conductivity and electrochemical performance studies. The conductivity measurements were carried and found 20.29 and 4.87 S/cm2 in air and hydrogen atmosphere, respectively. The area specific resistance (ASR) was observed 0.07 Ω/cm2 at 550 °C. Arrhenius plots were drawn to calculate activation energy and found to be 0.09 eV. Excellent performance of 850 mW/cm2 has been recorded at 550 °C. [ABSTRACT FROM AUTHOR]

Abstract Carbon nanotubes have long attracted great scientific interest because of their simplicity, ease of synthesis and unique properties. The novel properties of nanostructured carbon nanotubes including its high surface area, stiffness, tensile strength, thermal and electrical properties which become suitable for the application in the fields of energy storage, hydrogen storage, electrochemical supercapacitor, field-emitting devices, transistors, nanoprobes and sensors, composite material, templates, etc. In this study, carbon nanotubes were synthesized through arc discharge plasma with two different configurations, transverse and axial field, applied across arc plasma synthesis process to enable a much rapid rate growing of tubular carbon multi-walled carbon nanotubes (MWCNTs). TEM, FESEM, RAMAN, FTIR and XRD were used to investigate the morphology and structural evolution of the MWCNT samples produced with different synthesis environment. Introduction of magnetic field during the MWCNTs synthesized through arc discharge plasma technique has also been found to enhance the carbon nanotube growth, increase the high aspect ratio and its chemical stability, and shows potential for regulating the number of walls formed. [ABSTRACT FROM AUTHOR]

This study examines the effect of molar concentration on the structural, optical, and electrical properties of the nanostructured CdS film prepared by the chemical bath deposition technique. The optical properties show that the energy gap of nanostructured CdS increases from 2.27 to 2.57 eV as molarity increases from 0.2 to 0.6 M. The optoelectronic properties of a CdS/Si heterojunction photodetector prepared at different molar concentrations were investigated. The highest value of figure of merit is 1.5 × 10−4 Ω−1 for CdS film deposited at 0.2 M. The CdS/SiO 2 /Si photodetector prepared at 0.2 M demonstrated the highest responsivity of 0.34 A/W, specific detectivity of 1.1 × 1012 Jones at 550 nm, and external quantum efficiency of 80% at 500 nm. The fast response time was found for photodetector fabricated at 0.2 M. [ABSTRACT FROM AUTHOR]