Desirable Surface Area Research Articles

Insights into synergetic modulation of nickel sites over graphene by introducing tungsten and light for efficient methanol electrooxidation

Cut-lost, highly active and stable (photo-)electrocatalysts are earnestly expected to overcome high energy obstacles in methanol oxidation reaction (MOR). A hybrid of NiW/graphene (NiW/G) is prepared by a simple self-designed electrosynthesis method. During the process of electrosynthesis, exfoliation of bulky graphite into graphene and generation of multivalent NiW bimetal precursor are both achieved. This obtained composite displays superior photoelectrocatalytic performance towards MOR. As for NiW/G-light, its area activity (peak current) and mass activity (peak current) are up to 343.4 mA cm−2 and 5960.7 mA mg−1 respectively, much higher than NiW/G, Ni/G and W/G. Operando electrochemical impedance spectroscopy, in-situ Fourier transform infrared spectroscopy and other ex-situ techniques uncover that the excellent MOR performance for NiW/G-light results from synergetic modulation of nickel sites by introducing tungsten and light, which provides desired adsorption behavior and high electrochemical active surface area. It’s found that introduction of W component promotes the formation of W-O-Ni(Ni3+) species, supporting more strong adsorption sites for methanol. This results in new reaction path between adsorbed methanol and OH* for producing formic acid. With application of light, the photo-generated hole promotes oxidation of residual Ni2+ into Ni3+ species, which provides additional formed NiOOH sites for MOR. It’s concluded introduction of tungsten and light is efficient for greatly enhancing methanol electrooxidation. This work is highly instructive for application of self-designed electrosynthesis method to construct dimetal/graphene composite and photoelectric synergistic catalysis towards MOR.

Bioactivity of Plant Nanoemulsions against Stored-Product Insects (Order Coleoptera): A Review1

Abstract As the risks arising from the use of chemical pesticides increase, researchers are continuously exploring alternatives that are safer for humans and the environment. Among these alternatives is the use of plant extracts; however, plant extracts have various disadvantages, including the instability of their compounds that evaporate with time, thereby reducing their effectiveness. With the development of nanotechnology and its applications, researchers are focused on testing the performance of plant-based nanocomposites for eliminating pests. Numerous issues with agricultural and insect pest control can be addressed by using nanotechnology, including increasing the physical stability, water dispersion, and bioavailability of oil emulsions and coating the desired surface area with small oil droplets. Thus, issues with essential oil application, such as volatility, low water solubility, and oxidation, can be resolved by using nanoformulations. These nanoformulations progressively release active ingredients on site, reducing the toxicity for nontarget species and demonstrating their potential as substitutes for synthetic pesticides in the management of stored-grain pests. Research on nanoemulsions from plant sources and their role in controlling stored-product coleopteran insects was reviewed with emphasis on articles from 2014 through 2023. This review compiles important data for this field of research, providing information for design of future studies.

Enhancing graphitization with desirable porosity for CO2 adsorption through a one-step strategy and a novel stepwise pyrolysis method from Terminalia boivinii tul tree dead leaves

The rising level of greenhouse gases in the atmosphere has led to concerns about climate change, making carbon dioxide (CO2) adsorption an increasingly important issue. Activated carbon-based materials with high surface area and porous structure have shown great potential for capturing CO2 from gas mixtures. In this study, we investigated the use of Terminalia boivinii tul tree dead leaves to synthesize activated carbon using a one-step strategy with KMnO4 and a novel stepwise pyrolysis strategy. We examined the effects of the stepwise pyrolysis strategy on carbon structure and CO2 adsorption and used X-ray diffraction (XRD) to analyze the degree of crystallinity and structural orientation of the synthesized activated carbon samples. The results of the XRD analysis showed that the HAC_850S sample exhibited higher intensity in the (002) plane than the HAC_850 sample, indicating a higher degree of crystallinity and suggesting that the sample treated with the step-wise pyrolysis strategy exhibited a more ordered carbon structure. This finding suggests that the use of waste biomass as feedstock to produce activated carbon using one-step KMnO4-assisted synthesis and step-wise pyrolysis can lead to the production of high-quality graphitized materials with desirable porosity and surface area suitable for CO2 adsorption. The study's results revealed that the sample treated by the HAC_850S process exhibited the highest CO2 adsorption capacity of approximately 41 mg/g, while the HAC_850 and PP_350 pyrolysis samples had adsorption capacities of around 36 mg/g and 30 mg/g, respectively. The findings suggest that the development of cost-effective and scalable methods to produce activated carbon for CO2 capture is possible, and the study's results contribute to the development of new technology and solutions capable of addressing the challenges associated with climate change.

Molten salts synthesis of Mo2C nanoflake and its composites for enhanced lithium-storage performance

The rational design of negative and positive materials to make them have satisfactory specific capacity and rate capability is an effective strategy to enhance the electrochemical properties of Lithium-ion hybrid capacitors (LIHCs). Herein, hierarchical MC-X (X = 0, 1, 2, 3) nanosheet composites were prepared by salt template-assisted solid-state synthesis strategy. Among them, Mo2C nanosheets are more dispersed on the amorphous carbon, and the close contact between them makes molybdenum carbide have enough buffer space during the intercalation and deintercalation of Li+, and makes MC-2 have a desirable specific surface area (SSA) of 341.1 m2/g. Electrochemical tests showed that the specific capacity of Mo2C remained at 313 mAh/g after 1000 cycles at 0.1 A/g, respectively. Meanwhile, the badam shell biochar (B) was prepared by KOH activation. The best sample (B-3) exhibited a high SSA of 3729.969 m2/g and high specific capacities of 265.6 mAh/g at 0.1 A/g, respectively. Furthermore, the constructed MC-2//B-3 LIHC exhibits high power density (4.68 kW kg−1), energy density (81.19 Wh kg−1), and excellent long-cycle stability. Therefore, the key to building a desirable property LIHC is to give consideration to the electrochemical performance between the positive and negative electrodes.

The influence of structural topology of additively manufactured PEGDA monolith on adsorption performance for textile wastewater treatment

AbstractWith the rapid advancement of three dimensional (3D) printing technology that offers flexibility to achieve desired surface area and permeability for wastewater applications, structural topology design has the potential to significantly improve the adsorption performance. This present work involves fabricating the green water technology with four different complex monolithic structural designs (Kagome, gyroid, Fischer, and body‐centered cubic [BCC]) with specific surface areas varied from 19.4 to 39.84 mm2 via digital light processing (DLP) technique. All the monolithic structures with different structural topologies were grafted with chitosan to evaluate their adsorption performance in a batch process. The influence of different structural topology on the adsorption performance and efficiency was evaluated at an optimal temperature of 60°C with optimum pH of 6.3 for a reaction time of 2 h using synthetic methyl orange (MO) dye and textile wastewater. Results indicated that the body‐centered cubic (BCC) design exhibited the highest MO adsorption capacity (12.71 mg/g), with the highest permeability (2.57 10−7 m2) and surface area (39.84 mm2). Additionally, a direct relationship was found between the surface area and the permeability of the adsorbent as well as adsorption strength. Fifty percent of color and 2.46% of chemical oxygen demand (COD) removal efficiencies were achieved to verify the adsorbent feasibility in actual application. The present work mainly establishes the feasibility of 3D printing in fabricating different monolithic structures, which enables future topology optimization for improved wastewater management.

Sustainable and Scalable Synthesis of 2D Ultrathin Hierarchical Porous Carbon Nanosheets for High-Performance Supercapacitor.

2D carbon nanomaterials such as graphene, carbon nanosheets, and their derivatives, representing the emerging class of advanced multifunctional materials, have gained great research interest because of their extensive applications ranging from electrochemistry to catalysis. However, sustainable and scalable synthesis of 2D carbon nanosheets (CNs) with hierarchical architecture and irregular structure via a green and low-cost strategy remains a great challenge. Herein, prehydrolysis liquor (PHL), an industrial byproduct of the pulping industry, is first employed to synthesize CNs via a simple hydrothermal carbonization technique. After mild activation with NH4 Cl and FeCl3 , the as-prepared activated CNs (A-CN@NFe) display an ultrathin structure (≈3 nm) and a desirable specific surface area (1021 m2 g-1 ) with hierarchical porous structure, which enables it to be both electroactive materials and structural support materials in nanofibrillated cellulose/A-CN@NFe/polypyrrole (NCP) nanocomposite, and thus endowing nanocomposite with impressive capacitance properties of 2546.3 mF cm-2 at 1 mA cm-2 . Furthermore, the resultant all-solid-state symmetric supercapacitor delivers a satisfactory energy storage ability of 90.1 µWh cm-2 at 250.0 µW cm-2 . Thus, this work not only opens a new window for sustainable and scalable synthesis of CNs, but also offers a double profits strategy for energy storage and biorefinery industry.

Insight into use of biopolymer in hybrid electrode materials for supercapacitor applications—A critical review

The shortage of natural resources due to the progression of the human population and environmental pollution has become crucial concern topics to resolve. One of the best ways to resolve this is to develop renewable energy-based storage systems. Supercapacitors are emerging as promising storage systems via providing rapid charging/discharging and high power delivery, but there is a need to explore low-cost, environment-friendly, non-toxic, abundant, and biodegradable electrode materials for supercapacitors. In this regard, biopolymers are observed to be popular for storage applications as they are of high porosity, cost-effective, easily available, low-weight, and environment friendly and have biodegradability properties. The biopolymer-based electrode has a desirable morphology and high surface area and exhibits admirable electrochemical properties. The focus of this report is to highlight (i) the inclusive details of supercapacitors and their types along with strategies to improve their electrochemical performance, (ii) biopolymers and their types used for supercapacitor applications, (iii) various synthesis routes that could be adopted for designing electrode materials based on biopolymers for supercapacitors, and (iv) challenges and future scope of biopolymers as the electrode material in supercapacitor applications. The detailed study here in this report is found to be a topic of interest for the scientific community to fabricate and prepare low-cost, eco-friendly, high electrochemical performance exhibiting electrode materials for supercapacitor applications.

Humidity sensitivity reducing of moisture swing adsorbents by hydrophobic carrier doping for CO2 direct air capture

The application of quaternary ammonium-based moisture-swing adsorbent provides an effective strategy for direct air capture (DAC) with low energy consumption of regeneration. This study optimized a fabrication method of shaped adsorbents and a hydrophobicity regulation method by doping polyvinylidene difluoride (PVDF). Characterization of the shaped adsorbents showed a desirable surface area and pore structure. Experiments of CO2 adsorption revealed that the adsorbents exhibited excellent CO2 adsorption capacity (∼0.90 mmol/g) in relative humidity (RH) range of 20 ∼ 85% was enhanced by 160% of that before doping. Meanwhile, a high CO2 adsorption rate (with a half-time of 3.6 ∼ 3.82 min) at 84.7% RH was displayed. The optimal doping ratio of PVDF was found to be 25% (QAR-25% PVDF). It can effectively release CO2 with 100% RH, and heat assistance (<60 °C) can be considered for optimal results. QAR-25% PVDF exhibited a cyclic capacity of 0.90 mmol/g after ten cycles, demonstrating its stability and reusability. DFT and microscopic characterization revealed the key role of C-F bond in promoting the hydrophobicity of adsorbents. Meanwhile, the isotherm of H2O/CO2 adsorption illustrated that doping PVDF could effectively reduce the humidity sensitivity of shaped adsorbents and improve CO2 adsorption rate significantly. Among DAC adsorbents reported previously, the adsorbents developed in this study showed higher functional group efficiency (ηQA = 0.89) at high humidity conditions. The fabrication method of shaped adsorbent provides a viable strategy for its large-scale deployment. Doping hydrophobic carriers into the adsorbent material is a simple yet effective way to reduce its humidity sensitivity, enabling it to better adapt to complex environmental conditions.

Effect of hydrophilic/lipophilic balance on the porogenic properties of non-ionic surfactants for monolith preparation and chromatographic separation

The effect of hydrophilic/lipophilic balance (HLB) of polyoxyethylene ethers of different chain lengths on the microporogenic properties of the Brij surfactants has been studied. The objective of this work is to help better understand the role of each porogen and to set criteria for selecting the proper non-ionic surfactant, based on the HLB value. Seven recipes of different porogen compositions were first prepared and the highest efficiency was achieved using decane/decanol/dodecanol mixture with Brij® 30. Then, four other Brij surfactants covering the entire HLB scale were tested, and the prepared monoliths were characterized by SEM, BET, FT-IR and chromatography. The results showed that increasing the HLB from 9.72 to 18.84 was accompanied by an increase in monolith density and surface areas. The optimum HLB range was found to be 10 to 15. Surfactants of lower HLB formed either nonporous or less efficient columns, while those of higher HLB formed non-permeable columns. Adjusting the HLB was possible by mixing surfactants of different HLB. The prepared monoliths could be used in the isocratic mode with a mobile phase consisting of a mixture of ACN and water (20:80, v/v) at a flow rate of 1.5 μL min−1 to separate five sulfa drugs. The separation results showed that the elution order of the compounds correlated with their lipophilicity, with sulfamerazine (logp = 0.52) being the first to elute, and sulfaquinoxoline (logp=1.70) being the most retained. The asymmetry factors of the separated compounds ranged between 1.18 and 1.25, and the resolution was found to be in the range 2.92−7.80. The prepared monoliths could be also successfully separate a mixture of four different nonsteroidal anti-inflammatory drugs and a mixture of four benzoic acid derivatives. This work assists in optimizing the surfactant-based porogenic mixture to meet the desired porosity, surface area, morphology and chromatographic separation requirements.

Multivariate Porous Aromatic Frameworks with High Porosity and Hierarchical Structures for Enzyme Immobilization.

As materials with permanently porous structures and readily modifying availability, porous aromatic frameworks (PAFs) are considered as promising porous materials with versatile functionality. Currently the designable synthesis of PAFs with the desired surface area and pore size is still a challenge, and instead kinetically irreversible coupling reactions for PAFs synthesis has resulted in the unpredictable connection of building units. Herein, a series of PAFs with highly porous and hierarchical structures were successfully synthesized through a multivariate inspired strategy, where multiple building units with various topologies and sizes were selected for PAFs synthesis. All the PAFs synthesized through this strategy possessed hierarchical structures and high specific surface areas at the same time. Encouraged by their high surface area and hierarchical structures, we loaded lipase onto one of the multivariate PAFs. The enzyme loading content of the obtained lipase@PAF-147 was as high as 1456 mg g-1, which surpassed any other currently reported enzyme loading materials. The lipase@PAF-147 also exhibited favorable catalytic activity and stability to a model reaction of p-nitrophenyl caprylate (p-NPC) hydrolysis. This multivariate strategy inspired synthetic method broadens the selection of building units for PAFs design and opens a new avenue for the design of functional porous materials.

Efficient adsorptive removal of paracetamol and thiazolyl blue from polluted water onto biosynthesized copper oxide nanoparticles

Copper oxide nanoparticles (CuONPs) have received tremendous attention as efficient adsorbents owing to their low cost, desirable surface area, abundant active sites, potent textural characteristics and high adsorption capacities. However, CuONPs have not been employed to decontaminate water laden with increasing environmental contaminants such as thiazolyl blue and paracetamol. Herein, the adsorption of thiazolyl blue and paracetamol onto green synthesized CuONPs prepared from the aqueous leaf extract of Platanus occidentalis was studied. The BET, SEM, FTIR, XRD, EDX and pH point of zero charge showed the successful synthesis of CuONPs having desirable surface properties with a surface area of 58.76 m2/g and an average size of 82.13 nm. The maximum monolayer adsorption capacities of 72.46 mg/g and 64.52 mg/g were obtained for thiazolyl blue and paracetamol, respectively. The Freundlich, pseudo-second-order and intraparticle diffusion models were well fitted to the adsorption of both pollutants. The pH studies suggested the predominance of electrostatic and weaker intermolecular interactions in the adsorption of the thiazolyl blue and paracetamol, respectively. Spontaneous, physical, endothermic and random adsorption of the pollutants on CuONPs was obtained from the thermodynamic consideration. The biosynthesized CuONPs were found to be highly reusable and efficient for the adsorption of thiazolyl blue and paracetamol from water.

INVESTIGATION ON HEAT TRANSFER IN CIRCULAR FINS WITH H-SHAPED CAVITY USING FINITE ELEMENT METHOD AND CONSTRUCTAL DESIGN

Through constructal design, this study examines how the geometrical configuration of channels embedded within an object in the presence of internal heat generation can be utilized for cooling through convection heat transfer. During the present study, the cavity is cooled by the convection heat transfer method. This work aims to provide an optimal tree structure for cooling electronic components with circular dimensions and internal heat generation in an H-shaped cavity. A structure for this purpose must be designed so that the maximum temperature obtained in the desired surface area is reduced to the minimum for a given production heat power. A study will also examine the dimensions of specific channels in order to decrease the maximum temperature that will be produced. In addition, it will study the geometric characteristics of the branching of the channels and their length. The finite element method will be used to simulate the heat transfer process. Following the validation of the created model, numerous parameters will be checked on the maximum temperature generated in the system. The results will be presented and discussed in appropriate charts and tables.

Structurally controllable hollow carbon spheres for gaseous benzene adsorption

Hollow carbon spheres (HCSs) with controllable morphology, stable physicochemical properties, high surface area, and large pore volume achieved without any acidic or alkaline activators, are likely to be an attractive adsorption material. Nevertheless, reports on applying HCSs for adsorption separation are relatively limited, especially for volatile organic compounds (VOCs). Herein, a series of HCSs were successfully synthesized by a simple one-pot, surfactant-free method and varying ethanol/water volume ratios, compositions of silicon alkoxides (tetrapropyl orthosilicate/tetraethyl orthosilicate, TPOS/TEOS), lag time for adding resorcinol-formaldehyde (RF) resin precursors, and system temperatures. The differences between these HCSs in terms of average particle size, internal cavity diameter, shell thickness, specific surface area, and porosity were well elucidated. HCS-11 synthesized at 10 °C had the most desirable specific surface area (2531.29 m2 g−1) and total pore volume (3.527 cm3 g−1) in this study, which was superior to many HCSs in the literature, and therefore was selected for subsequent benzene adsorption/desorption tests. As expected, HCS-11 exhibited a static benzene adsorption capacity of up to 21.363 mmol g−1 at 293 K. In addition, the effects of different initial concentrations, gas flow rates, and ambient temperatures on dynamic benzene adsorption by HCS-11 were systematically investigated. The high adsorption capacity of HCS-11 remained stable after six consecutive adsorption-desorption cycles, indicating its good thermal regeneration capability. The excellent porosity, high cyclic adsorption capacity, and rapid desorption kinetics of HCS-11 made it promising for VOC abatement.

Electrocatalytic oxygen evolution reaction at IrOx supported by Ni/Co-ZIF-67: Controlled ratio of metallic Ir and Ir3+ states

Dispersion of catalytic metal oxides over metal-organic framework (MOF) constructed a fascinated assembly for oxygen evolution electrocatalysis. A devised synthetic method for uniform dispersion and controlled particle size of catalyst materials could improve the catalytic parameters. We demonstrated a facile, surfactant-free method to immobilize ultrafine iridium oxide (IrOx) nanoparticles over nanosheet-shaped zeolitic imidazolate framework (ZIF) surface of bimetallic Ni/Co-ZIF-67. The optimum Ni/Co atomic ratio (1:6.5) improved the electronic conductivity and the combination with the well-dispersed IrOx nanoparticles (average 2.3 nm) provided IrOx@Ni/Co-ZIF-67. The optimized electrode assembly with 2.8 at.% (compared to 1.6 and 6.5 at.%) loading amount of IrOx led to superior OER performance. It appeared that catalytic activity correlated to the balanced ratio of metallic Ir0 and Ir3+ states. The active Ir3+ site coordinated by a hydroxyl group would likely promote the first dehydration step in alkaline media to initiate the catalytic OER, while the metallic Ir stabilizes the Ir3+ state. The desirable large surface area of ultrafine IrOx nanoparticles and the evenly controlled Ir0/Ir3+ species resulted in the high catalytic parameters. Additionally, the close electronic contact at the interface of IrOx and conductive Ni/Co-ZIF-67 should provide high catalytic OER performance.

Modulation of hierarchical porosity in metal-doping graphene/carbon hybrid aerogels for capacitive energy storage

Carbon aerogels hold great promise as the electrode materials for energy storage owing to their desirable porous structures and specific surface areas. Here, we report a scalable approach for the preparation of Co-doped graphene/carbon hybrid aerogel (CGCA) with hierarchically porous structure through a dual cross-linking strategy. By adjusting the cross-linking structure of the hydrogel precursor, the porous structure of CGCA can be readily regulated and the specific surface area of CGCA can achieve 1217 m2 g−1. As a result, the CGCA samples not only manifest improved electrical conductivity, but also possess enhanced capacitance storage capacity. The optimized CGCA electrode displays a high specific capacitance of 371 F g−1 at 1 A g−1 and maintains a large specific capacitance of 57 % at 150 A g−1. Meanwhile, the supercapacitor assembled with CGCA electrodes shows a high specific capacitance of 80 F g−1 at 0.5 A g−1 and good cyclic stability with a capacitance retention of 95 % after 10,000 cycles. Moreover, the supercapacitor device can provide a high energy density of 11.1 Wh kg−1 at a power density of 250 W kg−1. The superior energy-storage behaviors of CGCA make them promising electrode materials for high-performance supercapacitors.

Titanium Phosphate Grafted on Mesoporous SBA-15 Silica as a Solid Acid Catalyst for the Synthesis of 5-Hydroxymethylfurfural from Glucose

The grafting of titania on SBA-15 followed by its phosphation was presented to prepare a mesoporous Lewis–Brønsted bifunctional solid acid catalyst for the tandem conversion of glucose via fructose to 5-hydroxymethylfurfural (HMF). Titania was dispersed on SBA-15 as an amorphous surface layer containing abundant coordinatively unsaturated tetrahedral Ti ions, which was reactive and readily transformed upon phosphation into a new titanium phosphate phase with the chemical formula identified as Ti2O3(H2PO4)2·2H2O. The ordered mesoporous structure was well maintained after three modification cycles, affording a desirable surface area of over 300 m2/g. The SBA-15-supported titanium phosphate layer affords higher overall acidity and Brønsted to Lewis acid ratio, compared with the conventional post-phosphated bulk anatase titania. The tetrahedral Ti ions and the adjacent protonated phosphate groups on the titanium phosphate layer could form Lewis–Brønsted acid pairs at molecular level proximity, which largely enhanced the selective tandem catalysis for glucose conversion via fructose to HMF. An optimized HMF yield of 71% was achieved at 160 °C in a water–methyltetrahydrofuran biphasic system over the SBA-15-supported titanium phosphate catalyst. The catalyst exhibited good hydrothermal stability with a rather limited silicon and phosphate leaching, and no distinct pore collapse or performance loss over three sequential reaction runs.

Chitosan-coated fluoro-functionalized covalent organic framework as adsorbent for efficient removal of per- and polyfluoroalkyl substances from water

Covalent organic frameworks (COFs) are a class of newly developed crystalline porous materials that show great potential toward environmental applications. Most of COFs exhibit high hydrophobicity, which restrict their applications in aqueous environment. In this article, a novel covalent organic framework (COF) was developed and used as an efficient adsorbent for highly removal of per- and polyfluoroalkyl substances (PFASs) from water. Firstly, a fluoro-functionalized COF (F-COF) was synthesized at room temperature by Schiffbase reaction. A layer of chitosan was then modified on the surface of F-COF via cross-linking polymerization reaction. The obtained chitosan/F-COF possesses desirable hydrophilicity, surface wettability, and high specific surface area, showing high adsorption capacity towards PFASs via electrostatic interaction, hydrogen bond interaction, fluorine-fluorine interactions, and channel size selection. The adsorption performances of chitosan/F-COF toward typical PFASs such as perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and ammonium perfluoro(2-methyl-3-oxahexanoic) acid (GenX) were investigated, and extremely perfect adsorption performances were obtained, with maximum adsorption capacities (qmax) of 8307.1, 6177.1, and 4603.3 mg/g as well as rate constants of 2.3 × 10−3, 1.3 × 10−3, and 6.4 × 10−4 g/mg min−1 for PFOS, PFOA, and GenX, respectively. Moreover, the chitosan/F-COF shows good simultaneous uptake ability for PFASs with the simultaneously removal efficiencies over 88.4% for three PFASs in lake water and sewage samples. Our study reveals a great application prospect of chitosan/F-COFs in pollutant removal and environmental remediation.

Fabrication of Polyaniline Structures for Enhanced Supercapacitance: Effect of PANI Morphologies

This work is conducted with the aim to see the effect of Polyaniline (PANI) morphologies on the specific capacitance of the electrode material. The paper presents a low-temperature synthesis and electrochemical analysis of PANI morphologies (granular, pebbles, spheres, tubes, flakes, and fibers). The supercapacitive behavior of all fabricated electrodes was tested via a two-electrode setup in 0.1 M H2SO4 electrolyte. The electrochemical analysis showed that amongst all the PANI morphologies, nanofibers had the highest specific capacitance (752.27 Fg-1), a good energy density (66.86 Whkg-1), and a good retention rate (40%). The reason may be attributed to a larger π-π stacking interaction with maximum d-spacing (3.52 Aº) that gives a desirable contact surface area for the electrolyte ions to transport efficiently across the electrolyte. Also, it has a low value of Rb (4.67 W), Rct (0.56 W), a good (251 Hz), a very less relaxation time (0.0039s), and a high knee frequency value (825.2 Hz). PANI fibers can prove to be an effective electrode material that could enhance the specific capacity of the electrode at the same time is economical and environmentally friendly.

Spinal Implant Osseointegration and the Role of 3D Printing: An Analysis and Review of the Literature.

The use of interbody implants for spinal fusion has been steadily increasing to avoid the risks of complications and donor site morbidity when using autologous bone. Understanding the pros and cons of various implant designs can assist the surgeon in choosing the ideal interbody for each individual patient. The goal of these interbody cages is to promote a surface area for bony ingrowth while having the biomechanical properties to support the axial skeleton. Currently, the majority of interbody implants consists of metal or polyether ether ketone (PEEK) cages with bone graft incorporated inside. Titanium alloy implants have been commonly used, however, the large difference in modulus of elasticity from bone has inherent issues. PEEK implants have a desirable surface area with the benefit of a modulus of elasticity closer to that of bone. Unfortunately, clinically, these devices have had increased risk of subsidence. More recently, 3D printed implants have come into the market, providing mechanical stability with increased surface design for bony ingrowth. While clinical outcomes studies are limited, early results have demonstrated more reliable and quicker fusion rates using 3D custom interbody devices. In this review, we discuss the biology of osseointegration, the use of surface coated implants, as well as the potential benefits of using 3D printed interbodies.

Hierarchical hybrid of n-doped carbon sheets-wrapped tungsten oxide nanoparticles for enhanced Li ion storage

Herein, we introduce a simple method to construct a hierarchical hybrid (termed as WO3/NC) by wrapping WO3 nanoparticles with nitrogen-doped carbon nanosheets which originate from pyrolyzation of folic acid. The as-prepared hybrid presents multihole nanostructures and desirable large surface areas, which are conductive to access of electrolyte and ion diffusion, particle dispersion and alleviation of volume change. Meanwhile, intimate contraction of WO3 nanoparticles with carbon sheets enhances electroconductivity of hybrid and facilitates electron transportation in electrode reaction. Therefore, as a negative electrode for Li ion battery, the electrochemical property of the as-synthesized WO3/NC hybrid is largely boosted. Compared with bare WO3 anode, the hybrid electrode exhibited a higher Li-storage capacity value of 588.2 mAh g−1 with a more stable cycling ability during 150 cycles under 0.1 A g−1. Moreover, at 0.2, 0.5 and 1 A g−1, WO3/NC electrode delivered an enhanced rate capability and the specific capacity could attain 500.5, 385.4 and 239.6 mAh g−1. The vastly promoted electrochemical performance for Li-storage of WO3/NC could be associated with to its advantageous hierarchical architecture and optimized component.