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Background: Nanotechnology is a tool being used intensely in the area of drug delivery systems in the biomedical field. Electrospraying is one of the nanotechnological methods, which is growing due to its importance in the development of nanoparticles comprising bioactive compounds. It is helpful in improving the efficacy, reducing side effects of active drug elements, and is useful in targeted drug delivery. When compared to other conventional methods like nanoprecipitation, emulsion diffusion, and double emulsification, electrospraying offers better advantages to produce micro/nanoparticles due to its simplicity, cost-effectiveness, and single-step process. Objective: The aim of this paper is to highlight the use of electrosprayed nanoparticles for biomedical applications. Methods: We conducted a literature review on the usage of natural and synthetic materials to produce nanoparticles, which can be used as a drug delivery system for medical purposes. Results: We summarized a possible key role of electrosprayed nanoparticles in different therapeutic applications (tissue regeneration, cancer). Conclusion: The modest literature production denotes that further investigation is needed to assess and validate the promising role of drug-loaded nanoparticles through the electrospraying process as noninvasive materials in the biomedical field.

Sputter grown copper (Cu) and titanium dioxide (TiO2) based transparent solar heat rejecting film has been developed on glass substrates at room temperature for energy saving smart window applications. The performance of as-deposited ultra-thin TiO2/Cu/TiO2 multilayers was elucidated, wherein the visible transmittance of the multilayer significantly depends on the crystal quality of TiO2 layers. In-situ nanocrystal engineering of TiO2 films with optimized sputtering power improves crystallinity of nano-TiO2 domains. The transparent heat regulation (THR) coating with an average transmittance of ∼70% over the visible spectral regime and infra-red reflectance of ∼60% at 1200 nm was developed at room temperature. Optical characterization, X-ray diffraction (XRD), high resolution-transmission electron microscopy (HR-TEM) and atomic force microscopy (AFM) have been utilized to analyze the crystallinity of TiO2 and quality of the multilayered structure. TiO2/Cu/TiO2 based prototype device has been demonstrated for the energy saving smart windows application.

Commercially pure titanium and titanium alloys have been among the most commonly used materials for biomedical applications since the 1950s. Due to the excellent mechanical tribological properties, corrosion resistance, biocompatibility, and antibacterial properties of titanium, it is getting much attention as a biomaterial for implants. Furthermore, titanium promotes osseointegration without any additional adhesives by physically bonding with the living bone at the implant site. These properties are crucial for producing high-strength metallic alloys for biomedical applications. Titanium alloys are manufactured into the three types of α, β, and α + β. The scientific and clinical understanding of titanium and its potential applications, especially in the biomedical field, are still in the early stages. This review aims to establish a credible platform for the current and future roles of titanium in biomedicine. We first explore the developmental history of titanium. Then, we review the recent advancement of the utility of titanium in diverse biomedical areas, its functional properties, mechanisms of biocompatibility, host tissue responses, and various relevant antimicrobial strategies. Future research will be directed toward advanced manufacturing technologies, such as powder-based additive manufacturing, electron beam melting and laser melting deposition, as well as analyzing the effects of alloying elements on the biocompatibility, corrosion resistance, and mechanical properties of titanium. Moreover, the role of titania nanotubes in regenerative medicine and nanomedicine applications, such as localized drug delivery system, immunomodulatory agents, antibacterial agents, and hemocompatibility, is investigated, and the paper concludes with the future outlook of titanium alloys as biomaterials. Graphic abstract

In this work, cycling-induced aging occurring in 18650-type LiFePO4/graphite full cells at different C-rates is studied extensively. The mechanism of performance degradation is investigated using a combination of electrochemical and microstructural analyses. Half-cell studies are carried out after dismantling the full cells, using fresh and cycled LiFePO4 cathode and graphite anode to independently study them. The results show that the capacity of LiFePO4 electrodes is significantly recovered. The rate of capacity fading in the discharge state considered as irreversible capacity in the graphite is higher than LiFePO4 half cells, indicating a greater degradation in the performance of this electrode. At relatively high current rates, this phenomenon is mainly attributed to the instability of the electrode/electrolyte interface and the solid electrolyte interphase (SEI) layer, causing the formation of active lithium ion-impermeable covering layer on the anode surface that strongly influences the cyclic aging. As a result, significant consumption of inventory active lithium ions occurred at relatively high current rates measured by half-cell studies. Forming thick covering layer and subsequently separation between active materials, which lead to the loss of electrical contact among them, result in electrode deactivation. To confirm this claim, various morphological, structural, and electrochemical analyses are employed.

Bacterial infections prolong the wound healing time and increase the suffering of patients, thus it is important to develop wound dressing that can inhibit bacterial infection. Herein, we use two methods including “doping method” and “secondary growth method” to prepare ZIF-8@gentamicin embedded in and coated on polyacrylonitrile/gelatin (PG) nanofibers, separately. Composite nanofibers prepared by the secondary growth method achieve higher drug loading than that of the doping method, and the release rate can be adjusted by pH. Simultaneously increasing drug loading and regulating its release rate are achieved in the secondary growth method, which cannot be achieved by the doping method. Furthermore, synergistic antibacterial property occurs in the composite nanofibers prepared by the secondary growth method, and gentamicin loaded on ZIF-8 promotes the antibacterial effect, which shows better antibacterial effect than the doping method. As a result, during the wound infection of mouse, composite nanofibers prepared by the secondary growth method exhibit a faster recovery effect than the doping method, which effectively shortened the wound healing time from 21 days to 16 days.

The present study aims to prepare and And Characterization of zein nanofibers with simvastatin-loaded in it by electrospinning method using a polymeric matrix prepared from zein solution containing simvastatin antibiotics. The physical, cellular properties and drug release kinetics of the fibers were studied. Fiber formation was investigated by implementing a scanning electron microscope (SEM). The SEM images show a uniform network bead-free fiber structure created from the 1.5% simvastatin/zeinsolution. The viscosity of the 1.5% simvastatin/zein mixture increased to 0.402 P due to the presence of drug in zein solution. Also, the presence of the indicative peaks associated with simvastatin in the Fourier transform infrared (FTIR) spectra of the samples containing the drug, verifies the existence of the drug on the polymeric base of zein/polyethylene oxide (PEO). Also, around 53.887% of the loaded drug was released in the first 12 h of the release kinetics assay and the results of the MTT assay shows reduction in the number of live cells in the test sample. In conclusion, zein nanofibers containing simvastatin drug were found to be potential biodegradable polymers that can find application in bone tissue repair.

In the current study, a thermal resistant polysulfide composite was prepared by the incorporation of carbon fibers (CFs). Poly(ethylene tetrasulfide) (PETS) was used as the polysulfide matrix as is the most efficient in terms of productivity. The preparation of the PETS/CF composite was conducted via in situ polymerization. Different loading weight percentages (0.5, 1.0, and 2.0) of CF were incorporated into the PETS matrix. The morphology and structural properties of PETS/CF composites were assessed by scanning electron microscopy (SEM), X-ray diffraction (XRD) methods, and Fourier transform infrared (FTIR) technique. In addition, the thermal properties of the composites were examined utilizing differential calorimetry scanning (DSC) and thermogravimetric analysis (TGA) methods. Finally, the effect of incorporation of CF on the chemical resistance of samples was investigated using various solvents. The characterization results showed the successful preparation of the composites. Moreover, the thermal analysis confirmed the significant efficacy of the introducing of CF to the PETS matrix. Furthermore, PETS/CF composites showed a great resistance to different solvents which helps with hindering the solvents transmission within the PETS matrix.

Semiconductor-based photocatalysis is an efficient approach for degradation of organic pollutants. In this context, ZnO/g-C3N4 composite nanofibers containing carbonaceous species with different concentrations of g-C3N4 nanosheets (x = 0.25, 0.5, 1, 2, 10 wt%) noted as ZnO/carbon/(x wt%) g-C3N4 are prepared by electrospinning technique. For preparation of the composite nanofibers, bulk g-C3N4 is exfoliated to nanosheets, and then it is mixed with polyvinyl alcohol and appropriate zinc acetate content followed by electrospinning process. Thermal annealing of the as spun zinc acetate/poly(vinyl alcohol)/g-C3N4 nanosheets sample under N2 atmosphere leads to the formation of carbonaceous species (Zn–O–C) on the hexagonal wurtzite structured ZnO nanofibers. Moreover, the oxygen vacancy formed in the ZnO structure is verified by X-ray photoelectron spectroscopy (XPS) and electron spin resonance (ESR) techniques. The prepared ZnO/carbon/(0.25 wt%) g-C3N4 nanofibers demonstrated the highest photocatalytic degradation rate towards methylene blue (MB) at about 2.5 times (with degradation efficiency of 91.8% after 2 h) higher than the ZnO/carbon under similar conditions. To understand the reason behind the improved photocatalytic activity of ZnO/carbon/g-C3N4 composite nanofibers a mechanism of electron-hole generation, separation and transformation are suggested and a Z-scheme charge transfer approach is proposed.

The present study introduces a novel nanocomposite based on reduced graphene oxide, nitrogen-doped graphene quantum dots, and palladium and silver nanoparticles (rGO/NGQD/AgPd) as an electrocatalyst toward nitrite oxidation reaction. Metal nanoparticles were prepared via a green one-pot photochemical reduction procedure utilizing UV light and NGQD simultaneously as a reducing and directing agent. Formation of the nanocomposite was thoroughly demonstrated by the FT-IR, XRD, Raman, XPS, FE-SEM, and TEM characterization tests. Various electrochemical tests evaluated the efficiency of the prepared sensing platform on the surface of a gold working electrode. Sensitivity and limit of detection (LOD) were calculated to be 0.854 μA.μM−1.cm−2 and 0.052 μM, respectively, from the chronoamperometry data. Finally, the proposed sensor was successfully applied for the determination of nitrite ions in river and mineral water samples as natural water sources.

p-i-n structured semitransparent perovskite solar cells have already been established as promising energy harvesting devices for building-integrated photovoltaics and flexible solar cells due to high transparency and low-cost fabrication. In this study, solution based p-i-n structured semitransparent perovskite solar cells (PSCs) have been developed using thin silver (Ag), zinc oxide (ZnO), and aluminium (Al)-doped ZnO nanoparticles (AZO) as buffer layers in addition to PCBM as an electron transport layer (ETL). The thickness of the ZnO and AZO layers are around ~100 nm. In the case of the thin Ag layer, poor interfacial band alignment and less transparency yield device performance with an inferior PCE of 2.53% when illuminated from the top electrode side. On the contrary, Al-doped ZnO possesses excellent optoelectronic performance as a buffer layer for their better electronic conductivity and interfacial band alignment and yield a photovoltaic device characteristic with a power conversion efficiency (PCE) of 5.87% when illuminated from the top electrode side, whereas the standard device with a metal electrode shows a PCE of 6.4%. The semitransparent device also has an average transparency of 21.8% in the visible region. Inverted structure semitransparent perovskite solar cells have been developed for flexible and building integrated photovoltaic (BIPV) applications. Solution processed perovskite solar cells with a power conversation efficiency of 5.87% and visible transmittance of 21.8% make an excellent candidate for BIPV and smart windows. Aluminum-doped zinc oxide (AZO) nanoparticles are found very effective buffer layer for the sputter grown top electrode over PCBM layer to reduce the interface damage and enhanced the overall photovoltaic performance.

As the critical component of proton exchange membrane fuel cell (PEMFC), proton exchange membrane (PEM) determine its overall performance. Current PEMs hardly meet the operating requirements of fuel cells, limiting their commercial applications. With the development of nanocomposite technology, nanofibers introduced into PEMs to prepare nanofiber composite proton exchange membranes (NCPEMs) have been widely studied. In an NCPEM, nanofibers can form long-range channels for proton transport, and reinforced skeleton to reach the target performance of PEMFCs. Focusing on NCPEM, this paper reviews on recent progresses in nanofiber preparation and NCPEM preparation techniques. Furthermore, different types of nanofibers incorporated into NCPEMs are reviewed in terms of fiber composition. The challenges and future perspectives regarding NCPEMs are also discussed.

Developing interfacial connections is one of the breakthrough strategies to improve the photocatalytic activity. Herein, ZnBi2O4 nanoparticles-ZnO nanorods heterojunction was successfully synthesized and used, as a dual-function photocatalyst, for photocatalytic degradation of Bisphenol A and hydrogen production with improved photocatalytic activity under simulated sunlight irradiation. The highest H2 production (3.44 mmol g−1 h−1) was obtained for ZnO-20 wt% ZnBi2O4 sample, which is around 12.7 times higher than pure ZnO. According to the HRTEM result, the intimate interfacial connections are formed between ZnO and ZnBi2O4 which could act as trapping centers for charge carriers and results in the boosted photocatalytic activity. Further, a high aspect ratio of 1D ZnO nanorods and small size of 0D ZnBi2O4 nanoparticles (~10 nm) increases the number of interfacial contacts and thus the charge carriers’ recombination was suppressed more efficiently. Based on the trapping experiments, ESR and Mott-Schottky analysis, ZnBi2O4–ZnO hybrid photocatalyst followed the S-scheme charge transfer mechanism.

Recently, the advantages of biopolymers over conventional plastic polymers are unprecedented, provided that they are used in situations in which they raise the functionality and generate extra benefits for human life. Therefore, biopolymers have received much attention because they play an important place in day-to-day life for their specific tunable characteristics, making them attractive in a wide range of applications. Biopolymers can produce materials with tunable properties such as biodegradability, biocompatibility, renewability, inexpensiveness, availability, which are critically important for designing materials for use in biomedical applications. In addition to these properties, smart biopolymers could be prepared by changing the polymer components, which would create more target oriented applications. Therefore, this review interprets how biopolymers and their various forms can be potentially used in biomedical applications, including drug delivery, infections, tissue engineering, wound healings, and other as wells. Special emphasis will be provided on the applications of biopolymers in the field of drug delivery, tissue engineering, infections, and wound healing, which indicate the advancement and employment of the various biopolymers in recent biomedical applications.

Bioprinting of body tissues has gained great attention in recent years due to its unique advantages, including the creation of complex geometries and printing the patient-specific tissues with various drug and cell types. The most momentous part of the bioprinting process is bioink, defined as a mixture of living cells and biomaterials (especially hydrogels). Among different biomaterials, natural polymers are the best choices for hydrogel-based bioinks due to their intrinsic biocompatibility and minimal inflammatory response in body condition. Gelatin methacryloyl (GelMA) hydrogel is one of the high-potential hydrogel-based bioinks due to its easy synthesis with low cost, great biocompatibility, transparent structure that is useful for cell monitoring, photocrosslinkability, and cell viability. Furthermore, the potential of adjusting properties of GelMA due to the synthesis protocol makes it a suitable choice for soft or hard tissues. In this review, different methods for the bioprinting of GelMA-based bioinks, as well as various effective process parameters, are reviewed. Also, several solutions for challenges in the printing of GelMA-based bioinks are discussed, and applications of GelMA-based bioprinted tissues argued as well. Impact statement Bioprinting has been demonstrated as a promising and alternative approach for organ transplantation to develop various types of living tissue. Bioinks, with great biological characteristics similar to the host tissues and rheological/flow features, are the first requirements for the successful bioprinting approach. Gelatin methacryloyl (GelMA) hydrogel is one of the high-potential hydrogel-based bioinks. This review provides a comprehensive look at different methods for the bioprinting of GelMA-based bioinks and applications of GelMA-based bioprinted tissues for tissue repair.

Collagen is an insoluble fibrous protein that composes the extracellular matrix in animals. Although collagen has been used as a biomaterial since 1881, the properties and the complex structure of collagen are still extensive study subjects worldwide. In this article, several topics of importance for understanding collagen research are reviewed starting from its historical milestones, followed by the description of the collagen superfamily and its complex structures, with a focus on type I collagen. Subsequently, some of the superior properties of collagen-based biomaterials, such as biocompatibility, biodegradability, mechanical properties, and cell activities, are pinpointed. These properties make collagen applicable in biomedicine, such as wound healing, tissue engineering, surface coating of medical devices, and skin supplementation. Moreover, some antimicrobial strategies and the general host tissue responses regarding collagen as a biomaterial are presented. Finally, the current status and clinical application of the three-dimensional (3D) printing techniques for the fabrication of collagen-based scaffolds and the reconstruction of the human heart's constituents, such as capillary structures or even the entire organ, are discussed. Besides, an overall outlook for the future of this unique biomaterial is provided.

Burn wounds are susceptible to microbial invasion from both resident and exogenous bacteria, which becomes a critical public health issue and causes substantial economic burden. There is a perceived demand to produce new antimicrobial wound dressings that hinder bacterial colonization while accelerating the healing process and hence would provide an improved standard of care for patients. Since ancient times, herbal extracts from medicinally important plants have extensively been used for treating burn injuries. This work reports the utility of electrospun nanofibers containing plant extracts and antibiotics combination as a multifunctional scaffold for treating second-degree burns. First, we determined the various components of plant extracts from Gymnema sylvestre by two different processing methods and their synergism with minocycline antibiotics. Then, we prepared core-shell nanofibrous dressings with poly-e-caprolactone/gelatin laden with minocycline hydrochloride as a shell and gelatin infused with G. sylvestre extracts (ultrasound-assisted extracts and cold macerated extracts) as the core using coaxial electrospinning. The electrospun nanofibers displayed a smooth, continuous, and bead-free morphology with adequate wettability. The presence of extract components in the core-shell nanofibers resulted in enhanced mechanical properties when compared to pristine mats. The core-shell structures resulted in sustained release of the bioactive components when compared to nanofiber blends. Core-shell nanofiber mats containing plant extracts and antibiotic combinations displayed potent antimicrobial and antibiofilm properties while promoting the spread and proliferation of skin cells when compared to pristine mats. In a porcine model of cutaneous second-degree burns, we showed that wounds treated with the antimicrobial dressing improved re-epithelialization and collagen organization in comparison to untreated wounds.

Nowadays, the LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode material has attracted great research interest due to its high energy density and less usage of costly raw materials. However, the high nickel con...

Electrically conductive polypropylene nanocomposites filled with carbon-based nanofillers such as carbon nanotubes, graphene and carbon black are widely being used in different applications such as electromagnetic interference shielding, wearable electronics, sensors, soft actuators, structural health monitoring and energy storage capacitors. The electrical conductivity of polypropylene nanocomposites depends on multiple factors, and can be tailored by using different processing and pre/post-processing techniques. There has been a lot of research in the past decade or so to maintain the electrical conductivity of polypropylene nanocomposites at the lowest possible filler concentration. Low percolation threshold is critically important for several technical applications as a key factor to well tailor mechanical properties, maintain optical transparency, and bring cost-effectiveness in manufacturing. This review article presents a comprehensive insight of the methodologies that have been used by different researchers to achieve low/ultralow electrical percolation thresholds in carbon-based polypropylene nanocomposites. Most importantly, different parameters that directly influence the percolation threshold and electrical conductivity such as the type, size, aspect ratio, functionalization and nucleating ability of carbon nanofillers, inter-particle interactions, density, crystallinity, viscosity of matrices, nanocomposite morphology, interaction of nanofillers with the polymer matrix, as well as post-processing techniques like annealing have also been discussed in detail. Percolation threshold and its theory, as well as the conduction phenomena such as the tunneling effects are also mentioned. The research has been characterized based on carbon filler types and critical comparisons have been made between the studies using similar methodologies.

The cleanup of oily wastewater and crude-oil spills is a global challenge. Traditional membrane materials are inefficient for oil/water separation under harsh conditions and limited by sorption speeds because of the high viscosity of crude oil. Herein, a kind of Graphene-wrapped polyphenylene sulfide fibrous membrane with superior chemical resistance and hydrophobicity for efficient oil/water separation and fast adsorption of crude oil all-weather is reported. The reduced graphene oxide (rGO)@polyphenylene sulfide (PPS) fibrous membrane can be applied in the various harsh conditions with Joule heating and solar heating. In addition, the oil(dichloromethane)/water separation flux of rGO@PPS reached 12 903 L m-2h-1, and the separation efficiency reached 99.99%. After 10 cycles, the rGO@PPS still performed high separation flux and filtration efficiency. More importantly, the rGO@PPS still retained its high conductivity, excellent filtration efficiency, and stable hydrophobicity after acid or alkali treatment. Moreover, the rGO@PPS can be heated by solar energy to absorb viscous crude oil during the day, while at night, the crude oil can be adsorbed by Joule heating. The time to adsorb crude oil can be reduced by 98.6% and 97.3% through Joule heating and solar heating, respectively. This all-weather utilization greatly increases the adsorption efficiency and effectively reduces energy consumption.

Herein, Austenitic 316 low carbon stainless steel, a widely used grade for various applications, was studied to understand the effect of processing methods on the material properties. Steel samples were processed using spark plasma sintering (SPS), laser metal deposition (LMD), and cold spray (CS) techniques. Significant difference in hardness and yield strength was observed among the processed samples. The CS sample showed highest hardness (~ 378 Hv) and yield strength (~ 1390 MPa) compared to other samples. In addition to the desirable mechanical properties, corrosion resistance has a significant role in determining the service life of steel in corrosive environments. All the processed samples showed lower corrosion rate than the commercial steel. Results obtained from various characterization tools will be presented in-detail.

The study aimed to investigate the mechanical reliability and in vitro bioactivity of the three-dimensional (3D) printed hydroxyapatite (HA) reinforced polylactic acid (PLA) porous scaffolds. The experiments have been performed to study the effect of HA wt.% in PLA matrix, infill density, and post-printing thermal-stimulus on the flexural and compressive strength. Next to this, the best combination of input parameters, in-response of the observed mechanical properties, was determined to print the test specimens for the analysis of reliability, through Weibull distribution. Further, the fracture morphology of the developed PLA/HA porous scaffolds has been investigated, using scanning electron microscopy, to observe the involved fracture mechanism. Moreover, the in vitro cell-culture with osteoblastic bone marrow mesenchymal stem cells-lines has been studied after 1, 3, and 7 days of seeding. The results of the study highlighted that the processing parameters have a strong impact on the mechanical properties of the 3D printed porous scaffolds. Further, the in vitro analysis showed excellent growth, proliferation, and differentiation of osteoplastic cells. Along with these, the result of the Weibull distribution advocated that the printed porous scaffolds are mechanically reliable. Overall, the present study unequivocally advocates that the 3D printed PLA/HA scaffold can be used for potential tissue engineering and biomedical applications.

Electrospinning is a promising technique for the fabrication of bioscaffolds in tissue engineering applications. Pertaining issues of multiple polymer jets and bending instabilities result in random paths which lend poor controllability over scaffolds morphology for affecting the porosity and mechanical stability. The present study alleviates these challenges by demonstrating a novel self-directing single jet taking a specifically patterned path to deposit fibers into circular and uniform scaffolds without tuning any externally controlled parameters. High-speed camera observation revealed that the charge retention and dissipation on the collected fibers caused rapid autojet switching between the two jetting modes, namely, a microcantilever-like armed jet motion and a whipping motion, which sequentially expand the area and thickness of the scaffolds, respectively, in a layered-like fashion. The physical properties showed that the self-switching dual-jet modes generated multilayered microfibrous scaffolds (MFSs) with dual morphologies and varied fiber packing density, thereby establishing the gradient porosity and mechanical strength (through buckled fibers) in the scaffolds. In vitro studies showed that as-spun scaffolds are cell-permeable hierarchical 3D microporous structures enabling lateral cell seeding into multiple layers. The cell proliferation on days 6 and 9 increased 21% and 38% correspondingly on MFSs than on nanofibrous scaffolds (NFSs) done by conventional multijets electrospinning. Remarkably, this novel and single-step process is highly reproducible and tunable for developing fibrous scaffolds for tissue engineering applications.

Morphological changes of copper oxide (CuO) nano-structures have been studied in detail for renewable energy and electronic applications. The CuO nano-structures were grown on a silicon substrate via a two-stage process starting with radio frequency sputtering for the seed layer followed by chemical bath deposition. The study was focused on controlling the shape and size of the CuO nano-structures depending on various growth conditions, such as reaction time, growth temperature, and vertical/horizontal orientation of the substrate containing the sputtered-grown seed layer. Structural, optical, crystallographic, and morphological characteristics of the nano-structures were obtained through field-emission scanning electron microscopy, x-ray diffraction crystallographic analysis, and UV–Vis spectroscopy.

In this work, a novel memory capacitor structure has been presented with AlOx/Al2O3 bilayer dielectrics on high mobility Epitaxial-GaAs substrate. We have demonstrated the chemical and electrical properties of metal–electrode/AlOx/Al2O3/epi-GaAs-based memory device in detail. Sputter-grown non-stoichiometric AlOx has been used for both the charge trapping layer and blocking layer due to its intrinsic charge trapping capability and high bandgap. Ultra-thin tunneling layer of thicknesses 5 nm and 15 nm were prepared by atomic layer deposition technique and memory properties were compared on promising high mobility Epitaxial-GaAs/Ge heterostructure. The proposed device shows excellent charge trapping properties with a maximum memory window of 3.2 V at sweep voltage of ± 5 V, with good endurance and data retention properties. Oxygen-deficient AlOx layer acted as a charge trapping layer without any additional blocking layer which is impressive for non-volatile memory application on high mobility epi-GaAs substrate. In addition, density Functional Theory (DFT) has been employed to understand the physical origin of the intrinsic charge trapping defects in AlOx dielectric layer.

In the past 30 years, researchers have worked towards reducing the size of ordinary three-dimensional (3D) materials into 1D or 2D materials in order to obtain new properties and applications of these low-dimensional systems. Among them, functional nanofibers with large surface area and high porosity have been widely studied and paid attention to. Because of the interesting properties of nanofibers, they find extensive application in filtration, wound dressings, composites, sensors, capacitors, nanogenerators, etc. Recently, a variety of nanofiber preparation methods such as melt blowing, electrospinning (e-spinning), centrifugal spinning and solution blow spinning (SBS) have been proposed. This paper includes a brief review of the fundamental principles of the preparation of nanofibers for solution jet spinning, the influence of experimental parameters, and the properties and potential applications of the solution-blown fibers. And the industrialization and challenges of SBS are also included.

Heterogeneous catalysts for CO2 reduction derived from porous, crystalline frameworks have emerged as efficient systems with comparable activity and superior selectivity to their inorganic counterparts. The spatial arrangement of active sites in such catalytically active frameworks is critical to their performance in CO2 reduction. This review presents a comprehensive and critical analysis of (thermal) CO2 reduction over catalysts derived from porous, crystalline frameworks, whose structural and chemical diversity offers unprecedented opportunities to regulate reactivity. Thermodyamic considerations and the impact of process parameters on reaction intermediates, governing mechanisms for CO2 reduction and catalyst stability are discussed. Strategies for leveraging the flexibility of porous, crystalline frameworks to improve their stability and promote CO2 reduction are presented which include: use as sacrificial precursors to an active phase; integration within composites; and as hosts for nanoparticle encapsulation. Finally, future challenges and research prospects are highlighted.

Controlled self-assembly of plasmonic photonic nanostructures provides a cost-effective and efficient methodology to expand plasmonic photonic nano-platforms with unique, tunable, and coupled optical characteristics. Keeping advantages and challenges in view, this review highlights contemporary advancements towards the development of self-assembly of a plasmonic photonic nanostructure using a colloidal solution and a self-assembly modeling technique along with exploring novel optical properties and associated prospects. The potential applications of self-assembled plasmonic photonic nano-systems to investigate next-generation optoelectronic devices, the need to reduce and increase scaling up aspects, and improve the performance, are also covered briefly in the review. The need of considerable efforts for the design and development towards establishing novel cost-effective methods to fabricate controlled self-assembled smart nano-plasmonic platforms is also highlighted in this mini-review. Key confronting issues that precisely limit the self-assemblies of photonic nanostructures and desired integration with other device components, mainly including uniformity within miniaturized devices are also discussed. This review will serve as a guideline and platform to plan advanced research in developing self-assembled plasmonic photonic nano-systems to investigate smart functional optical devices.

Piezoelectric catalysis is an emerging research field in recent years. Since the catalytic reaction usually occurs on the surface, the specific surface area is very important for piezoelectric catalysis. Therefore, nanoparticles and nanowires have been developed for piezoelectric catalysis and have attracted widespread attention. However, in actual water applications, the use of nanoparticles will cause secondary pollution. Therefore, an overall deformable nanoporous system is urgently needed to adapt to the shapes of various ultrasonic transducer heads. We have obtained macroscopically inorganic flexible barium titanate nanofiber membranes through electrospinning technology. Without traditional organic mixtures, the surface of the piezoelectric material can fully come into contact with water. The fiber membrane is macroscopically integrated, deformable, and can fully adapt to multiple ultrasonic transducers of various shapes. Calcium doping can effectively improve the catalytic effect, and the catalytic rate (k × 103) of the material with the highest doping concentration can reach 24.47 min−1. In addition, studies have found that lowering the calcination temperature can effectively improve the flexibility of the fiber membrane, which can be attributed to smaller barium titanate grains formed at low temperature. This work provides a generic method for preparing flexible inorganic piezoelectric materials that can be adapted to a variety of surfaces, and successfully applies it in the field of piezoelectric catalysis, which provides an important way for the practical research of piezoelectric catalysis in the future.

Carbon-based materials exhibit distinct structures and dimensionality which allow modification of their electrical properties and enable them to be integrated in various commercial systems. One of the interesting characteristics of carbon-based materials is efficient electron field emission (FE), which makes them good candidates for displays, in electron microscopy, lithography, sensing, micro- and nanoelectronics, X-ray sources and medical applications. While nano carbon materials have been extensively studied for FE applications, their usefulness, electron emission concerns, and fundamental mechanisms for FE technologies are buried in the reported literature, and cross comparison of all nano carbon materials together is rarely explored. Here we present a comprehensive overview of fundamental and FE properties of all carbon-based materials including diamond, nanocrystalline diamond, graphite, carbon nanotubes, carbon nanofibers, carbon nanowires, carbon nanorods, graphene, and amorphous and nanostructured carbon. Some of these carbon materials, such as amorphous and nanostructured carbon, possess the added benefit of room temperature production over large areas on a variety of substrates. We have compiled an up to date summary which critically discusses the material factors, and the factors that control electron emission of these materials. We also propose unique ideas to further improve electron emission for the design of energy efficient carbon-based cold cathode materials for next generation large area electronic devices.

Tin dioxide (SnO2), the most stable oxide of tin, is a metal oxide semiconductor that finds its use in a number of applications due to its interesting energy band gap that is easily tunable by doping with foreign elements or by nanostructured design such as thin film, nanowire or nanoparticle formation, etc., and its excellent thermal, mechanical and chemical stability. In particular, its earth abundance and non-toxicity make it very attractive for use in a number of technologies for sustainable development such as energy harvesting and storage. This article attempts to review the state of the art of synthesis and properties of SnO2, focusing primarily on its application as a transparent conductive oxide (TCO) in various optoelectronic devices and second in energy harvesting and energy storage devices where it finds its use as an electron transport layer (ETL) and an electrode material, respectively. In doing so, we discuss how tin oxide meets the requirements for the above applications, the challenges associated with these applications, and how its performance can be further improved by adopting various strategies such as doping with foreign metals, functionalization with plasma, etc. The article begins with a review on the various experimental approaches to doping of SnO2 with foreign elements for its enhanced performance as a TCO as well as related computational studies. Herein, we also compare the TCO performance of doped tin oxide as a function of dopants such as fluorine (F), antimony (Sb), tantalum (Ta), tungsten (W), molybdenum (Mo), phosphorus (P), and gallium (Ga). We also discuss the properties of multilayer SnO2/metal/SnO2 structures with respect to TCO performance. Next, we review the status of tin oxide as a TCO and an ETL in devices such as organic light emitting diodes (OLEDs), organic photovoltaics (OPV), and perovskite solar cells (including plasma treatment approaches) followed by its use in building integrated photovoltaic (BIPV) applications. Next, we review the impact of SnO2, mainly as an electrode material on energy storage devices starting from the most popular lithium (Li)-ion batteries to Li–sulfur batteries and finally to the rapidly emerging technology of supercapacitors. Finally, we also compare the performance of doped SnO2 with gallium (Ga) doped zinc oxide (ZnO), the main sustainable alternative to SnO2 as a TCO and summarize the impact of SnO2 on circular economies and discuss the main conclusions and future perspectives. It is expected that the review will serve as an authoritative reference for researchers and policy makers interested in finding out how SnO2 can contribute to the circular economy of some of the most desired sustainable and clean energy technologies including the detailed experimental methods of synthesis and strategies for performance enhancement.

LiNi0.8Co0.1Mn0.1O2 (NCM811) has been considered as a promising cathode for Li-ion batteries (LIBs) due to its high electrochemical capacity and low cost; however, poor cycling stability is one of ...

Alternative current electroluminescence (ACEL) can be identified as an efficient light-emitting technique among a number of different light emission methods. Open-air fabrication capability of the ...

p-type cupric oxide (p-CuO) thin films on n-type silicon substrates were grown to make p-CuO/n-Si heterojunctions. The CuO deposition on Si was carried out using radio frequency (RF) magnetron sputtering followed by rapid thermal annealing at 350°C. Plasma nitridation was used to incorporate nitrogen (N) for improving the electrical conductivity of the CuO thin films. The crystalline structure and surface composition of RF-sputtered CuO were characterized by x-ray diffraction and x-ray photoelectron spectroscopy. It was observed that the introduction of nitrogen in CuO improves the photovoltaic properties, such as the open-circuit voltage, short circuit current, and the photocurrent of the p-CuO-n-Si heterojunction.

Two-dimensional (2D) transition-metal dichalcogenide (TMD) semiconductors exhibit many important structural and optoelectronic properties, such as strong light-matter interactions, direct bandgaps tunable from visible to near-infrared regions, flexibility and atomic thickness, quantum-confinement effects, valley polarization possibilities, and so on. Therefore, they are regarded as a very promising class of materials for next-generation state-of-the-art nano/micro optoelectronic devices. To explore different applications and device structures based on 2D TMDs, intrinsic material properties, their relationships, and evolutions with fabrication parameters need to be deeply understood, very often through a combination of various characterization techniques. Among them, steady-state photoluminescence (PL) spectroscopy has been extensively employed. This class of techniques is fast, contactless, and nondestructive and can provide very high spatial resolution. Therefore, it can be used to obtain optoelectronic properties from samples of various sizes (from microns to centimeters) during the fabrication process without complex sample preparation. In this article, the mechanism and applications of steady-state PL spectroscopy in 2D TMDs are reviewed. The first part of this review details the physics of PL phenomena in semiconductors and common techniques to acquire and analyze PL spectra. The second part introduces various applications of PL spectroscopy in 2D TMDs. Finally, a broader perspective is discussed to highlight some limitations and untapped opportunities of PL spectroscopy in characterizing 2D TMDs.

Recently, aluminum titanate (Al2TiO5)-based nanostructures have been proved to serve as an efficient photocatalytic material with satisfactory photodegradation capacity. In this study, the citrate sol–gel method was used to synthesize these nanostructures and inspect the significant impacts of nitrogen-doping-originated crystalline defects on their photocatalytic performance in some details for the first time. The results indicated that the penetration of nitrogen atoms into AT crystal lattice, depending on the nitriding time and temperature, can induce a great deal of the residual stress and result in propagating the existing cracks and breaking down the particles. The XPS and FTIR results confirmed the formation of some new bonds in the crystal structure (including O-Ti-N and Ti-N), the substitutional and interstitial replacement of nitrogen atoms with oxygen atoms, oxygen vacancies, and the attachment of nitrogen species at superficial oxygen sites. These events may vary the bandgap values from 2.88 eV for pristine AT to 2.73 eV for the nitrided one, thereby manipulating the charge carrier recombination rate and activation of superficial catalytic reactions in the particles. Numerically, the band structure variations can efficiently increase the photodegradation efficiency of methylene blue (MB) and apparent rate constant (k) by 1.4 times (from 38.9 to 55.9%) and 1.8 times (from 0.0038 to 0.0068 min−1), respectively. Finally, the results show that the synthesized photocatalyst can successfully compete with TiO2-based photocatalysts in terms of photocatalytic performance.

Fused filament fabrication (FFF), a much-appreciated three-dimensional printing (3DP) technology, has triggered the industrial innovations by providing viable and cost-effective solutions for design validations, product prototyping, and the production of high-performance functional components. Indeed, the main credit of its successful career goes to material and printing flexibilities. However, the technology still faces various downsides, including poor finish, geometrical fits and tolerances, anisotropy, in-printing errors, and limited mechanical strength, that cannot be easily outweighed as these suppress its practical implications. As of utmost necessity, this review paper discusses the various abilities and inabilities of this technology to generate a roadmap of futuristic tasks for better outcomes. The review paper will act as a first-hand reference, through the well-defined possible directions, to the young researchers and senior scientist.

We have developed an electrical circuit-based compact numerical fitting model to determine industry-related physical parameters of solar cells utilizing only 3–8 current–voltage coordinate points without any specific selection of an experimental coordinate axis. The proposed compact numerical fitting model was effectively tested to determine the peak power point, fill factor and efficiencies for organic and inorganic solar cells, as well as for solar panels. This research facilitates cost-effective energy management of solar modules and farms.

Neural electrodes are developed for direct communication with neural tissues for theranostics. Although various strategies have been employed to improve performance, creating an intimate electrode-tissue interface with high electrical fidelity remains a great challenge. Here, we report the rational design of a tunnel-like electrode coating comprising poly(3,4-ethylenedioxythiophene) (PEDOT) and carbon nanotubes (CNTs) for highly sensitive neural recording. The coated electrode shows a 50-fold reduction in electrochemical impedance at the biologically relevant frequency of 1 kHz, compared to the bare gold electrode. The incorporation of CNT significantly reinforces the nanotunnel structure and improves coating adhesion by ∼1.5 fold. In vitro primary neuron culture confirms an intimate contact between neurons and the PEDOT-CNT nanotunnel. During acute in vivo nerve recording, the coated electrode enables the capture of high-fidelity neural signals with low susceptibility to electrical noise and reveals the potential for precisely decoding sensory information through mechanical and thermal stimulation. These findings indicate that the PEDOT-CNT nanotunnel composite serves as an active interfacing material for neural electrodes, contributing to neural prosthesis and brain-machine interface.

Electrospinning is well thought of as the most potent nanofiber producing technique, which is applicable in biomedical fields. The generation of electrospun nanofibers as drug carriers has widely been shown much interest over the past years. Electrospun nanofibers meet various advantages as drug delivery platforms including high surface area, acceptable mechanical properties based on the choice of the polymer, high processability, and the possibilities for surface modifications. Silk fibroin protein has gained a great attention as a drug delivery carrier due to ease of purification, sterilization, processability without using chemical crosslinkers, good biocompatibility, tailorable biodegradability, low immunogenicity, and high capacity to stabilize the loaded drugs. These characteristics along with advantageous benefits of electrospinning provide opportunities for producing suitable nanofibers based on silk fibroin for drug delivery purposes. It is also possible to incorporate various functional moieties to the electrospun silk fibroin nanofibers to enhance its biological activities. This review covers the progress in electrospinning of silk fibroin as a drug carrier in recent years.