Large Surface Research Articles

Workability of Nanomodified Self-Compacting Geopolymer Concrete Based on Response Surface Method

Geopolymer concrete is more low-carbon and environmentally friendly than Portland cement concrete. Nanoparticle modification can help to improve the mechanical and durability performance of concrete, but due to its large specific surface area and high activity, it may deteriorate its workability. However, there is currently limited research on the effect of nanomodification on the workability of freshly mixed self-compacting geopolymer concrete (SCGC). This article conducted SCGC workability experiments using the response surface methodology, which included 29 different mixtures. The effects of nano-silica (NS), nano-calcium carbonate (NC), alkali content (N/B), and water cement ratio (W/B) on the workability of SCGC were studied. The experimental results show that the addition of NS and NC can reduce the slump expansion of SCGC, and the combination of the two significantly increases the amplitude of slump expansion with the change in nanomaterial content. An increase in N/B will reduce the expansion time and clearance value of SCGC. As N/B increases from 4% to 4.4%, the slump extension of SCGC decreases, and with a further increase in N/B, the slump extension increases significantly to 68.1 cm, which means that the slump extension of SCGC increases by 9.5% as N/B increases from 4.4 to 5. This study can provide a reference for optimizing the fresh performance of geopolymer concrete and improving the mechanism of nanomaterial-modified geopolymer concrete.

Study on the Sound Absorption Characteristics and Noise Reduction Mechanism of Coconut-Shell-Activated Carbon Particles and Coconut Fiber Composite Biomass Sound-Absorption Materials

Abstract Sound absorbing materials are widely used in the field of automotive industry. Biomass materials are abundant in nature, and some biomass has natural sound absorption and noise reduction properties. Biomass sound absorption material is green and pollution-free, and has obvious noise reduction effect on middle and high frequency noise, large specific surface area, light weight, and strong sound absorption effect. In order to analyze the sound absorption and physical properties of biomass sound absorbing materials, the noise reduction performance of the different structure of biomass sound absorbing materials were analyzed. In this paper, the biomass sound absorbing materials coconut fiber and coconut shell activated carbon particles were used to make samples. Coconut shell activated carbon sound absorption material (CSAC) was made. The cylindrical holes was made and filled with coconut fiber materials to form composite sound absorbing materials (CSAC-F). The acoustic performance of impedance tube was tested based on the acoustic absorption coefficient, and the physical performance was studied by means of Scanning Electron Microscope (SEM), Brunauer, Emmett and Teller (BET), X-ray diffraction (XRD), Fourier Transform Infrared Spectrometer (FTIR), Thermogravimetric (TGA) and other detection methods. In contrast, the sound absorption effect of CSAC-F was better in the middle and low frequency range. The microstructure of the material was analyzed and the mechanism of noise reduction was studied. This research will provide a new way for the research and development of sound absorbing materials in the automotive industry, and biomass sound absorbing materials have potential applications in the noise absorption and vibration control of automotive interior.

Coaxially Bi/ZnO@ZnSe Array Photocathode Enables Highly Efficient CO2 to C1 Conversion via Long-lived High-energy Photoelectrons.

The key aspect of the photoelectrochemical CO2 reduction reaction (PEC CO2 RR) lies in designing cathode materials that can generate high-energy photoelectrons, enabling the activation and conversion of CO2 into high-value products. In this study, a coaxially wrapped ZnO@ZnSe array heterostructure was synthesized using a simple anion exchange strategy and metallic Bi nanoparticles (NPs) were subsequently deposited on the surface to construct a Bi/ZnO@ZnSe photocathode with high CO2 conversion capability. This array photocathode possesses a large aspect ratio, which simultaneously satisfies a low charge carrier migration path and a large specific surface area that facilitates mass transfer. Additionally, the barrier formed at the n-n heterojunction interface hinders the transfer of high-energy photoelectrons from ZnSe to lower energy levels, resulting in their rapid capture by Bi while maintaining a relatively long lifetime. These captured electrons act as active sites, efficiently converting CO2 into CO with a Faradaic efficiency above 88.9 % at -0.9 V vs. RHE and demonstrating superior stability. This work provides a novel approach for synthesizing high-energy photoelectrode materials with long lifetimes.

Construction of Mo-Doped CuO Incorporated on Carbon Black Modified Disposable Sensor for the Voltammetric Detection of Metol in Environmental Samples

Abstract In this study, a molybdenum-doped copper oxide (Mo–CuO) composite was synthesized via a hydrothermal method and combined with carbon black (CB) to form Mo–CuO@CB. This composite was used to modify a screen-printed carbon electrode (SPCE) for the detection of Metol (MT), an industrial pollutant harmful to both human health and the environment. Structural and surface characterization was performed using high-resolution transmission electron microscopy, field-effect scanning electron microscopy, energy-dispersive spectroscopy, Raman spectroscopy, X-rssy photoelectron spectroscopy, and X-ray diffraction. Electrochemical techniques, including differential pulse voltammetry and cyclic voltammetry, were used to assess the sensor's performance. The Mo–CuO@CB@SPCE sensor exhibited a low detection limit of 2.7 nM, and limit of quantification is 82 nM, a broad linear range (5.0 × 10−9 – 170 mol L-1), and high sensitivity (4.148 μA μM⁻¹ cm⁻²), benefiting from the catalytic activity of Mo–CuO and the large surface area of CB. With recovery rates ranging from 96 % to 100.6% in pond, river, and tap water, the sensor effectively detects MT in environmental samples, ensuring reliable monitoring of this persistent pollutant.

Highly Active Oxygen Evolution Reaction of NiMoO4 Sub‐1 nm Nanowires Boosts Luminol Electrochemiluminescence

AbstractIn recent years, there has been an increasing research focus on the luminol–H2O electrochemiluminescence (ECL) system due to its ability to address the instability and toxicity of H2O2, which are common issues associated with the conventional luminol–H2O2 ECL system. To enhance the ECL efficiency of the luminol–H2O system, researchers have developed electrocatalytic materials with exceptional oxygen evolution reaction (OER) properties to facilitate water electrolysis into O2 to produce reactive oxygen species (ROS) and act as co‐reactant promoters. However, most of these materials are characterized by their nanoscale or microscale dimensions, resulting in relatively large sizes and low specific surface areas, which hinder the application of the luminol–H2O system. To address this challenge, nickel molybdate sub‐1 nm nanowires (NiMoO4 S1 NWs) with a large specific surface area is synthesized that can offer many active sites to enhance the performance of the OER to boost the ECL of luminol. This study demonstrates that the large amount of ROS generated by the OER of NiMoO4 S1 NWs play a crucial role in enhancing the ECL intensity of luminol. Finally, a NiMoO4 S1 NWs‐based ECL biosensor for the highly sensitive detection of the nucleocapsid proteins of SARS‐CoV‐2 is successfully constructed.

Nanotechnology-enhanced Phytonutraceuticals: Innovations in Characterization, Formulation, and Therapeutic Applications

Nanotechnology refers to the branch of science and engineering devoted to designing, producing, and using structures, devices, and systems by manipulating atoms and molecules at nano-scale, having one or more dimensions of the order of 100 nanometres (100 millionth of a millimetre) or less. Nanotechnology is the exploitation of the unique properties of materials at the nanoscale. Nanotechnology has gained popularity in several industries, as it offers better built and smarter products. The ability to manipulate structures at the atomic scale allows for the creation of nanomaterials. Nanomaterials have unique optical, electrical and/or magnetic properties at the nanoscale, and these can be used in the fields of electronics and medicine, amongst other scenarios. Nanomaterials are unique as they provide a large surface area to volume ratio. Unlike other large-scaled engineered objects and systems, nanomaterials are governed by the laws of quantum mechanics instead of the classical laws of physics and chemistry. Nanotechnology is the engineering of useful objects and functional systems at the molecular or atomic scale. Nano-formulations are widely used for phyto-nutraceuticals and drug delivery systems. These substances are generally having low solubility, leading to their poor absorption and bioavailability in the human body. In this regard, one of the most important applications of nanotechnology in food sector has been the formulation of novel neutraceutical compounds with improved properties viz., enhanced solubility, stability, bioavailability and efficacy. This is achieved by encapsulation of neutraceutical by nanoparticles, which modifies their pharmacokinetics (PK) and biodistribution (BD). Nano-formulations widely used for the purpose are nanoliposomes, nanoemulsions, nanoparticles, nanofibres. The particles are characterized by scanning probe microscope (SPM), Ultraviolet-visible spectroscopy (UV-Vis spectrophotometer, SEM, TEM, Dynamic light scattering (DLS).

Engineering MXene Surface via Oxygen Functionalization and Au Nanoparticle Deposition for Enhanced Electrocatalytic Hydrogen Evolution Reaction

AbstractMXene, a family of 2D transition metal carbides and nitrides, presents promising applications in electrocatalysis. Maximizing its large surface area is key to developing efficient non‐noble‐metal catalysts for the hydrogen evolution reaction (HER). In this study, oxygen‐functionalized Ti3C2Tx MXene (Ti3C2Ox) is synthesized and deposited gold nanoparticles (Au NPs) onto it, forming a novel composite material, Au‐Ti3C2Ox. By selectively removing other functional groups, mainly ‐O functional groups are retained on the surface, directing electron transfer from Au NPs to MXene due to electronic metal‐support interaction (EMSI), thereby improving the catalytic activity of the MXene surface. Additionally, the interaction between Au NPs and ‐O functional groups further enhanced the overall catalytic activity, achieving an overpotential of 62 mV and a Tafel slope of 40.1 mV dec−1 at a current density of −10 mA cm−2 in 0.5 m H2SO4 solution. Density functional theory calculations and scanning electrochemical microscopy with ≤150 nm resolution confirmed the enhanced catalytic efficiency due to the specific interaction between Au NPs and Ti3C2Ox. This work provides a surface modification strategy to fully utilize the MXene surface and enhance the overall catalytic activity of MXene‐based catalysts.

Strategy for Enhancing Catalytic Active Site: Introduction of 1D material InSeI for Electrochemical CO2 Reduction to Formate

AbstractThe presence of oxygen vacancies (Vo) in electrocatalysts plays a significant role in improving the selectivity and activity of CO2 reduction reaction (CO2RR). In this study, 1D material with large surface area is utilized to enable uniform Vo formation on the catalyst. 1D structured indium selenoiodide (InSeI) is synthesized and used as an electrocatalyst for the conversion of CO2 to formate. The electrochemical treatment of InSeI leads to the leaching of Se and I from the catalyst surface and the formation of Vo. The resulting Vo promotes the activity of the CO2RR, which increases the local pH of the catalyst surface and chemically maintains the oxidized metal sites on the catalyst. Owing to these characteristics, activated In wire exhibited remarkable CO2RR activity, thereby surpassing 93% FEformate at 500 mA cm−2, with a maximum of 97.3% FEformate at 100 mA cm−2. Moreover, the catalytic activity remained consistent for over 50 h at 100 mA cm−2 (FEformate >88%). Thus, the findings imply that using 1D materials can facilitate the formation of oxygen vacancies on the catalyst surface and improve the selectivity and durability of CO2RR. This indicates the potential for further research on 1D materials as electrocatalysts.

Rational design of MoS2/CNT heterostructure with rich S-vacancy for enhanced HER performance

Molybdenum disulfide (MoS2) is a promising electrocatalyst for the hydrogen evolution reaction (HER) due to excellent stability and low cost. However, the utilization in electrocatalytic hydrogen evolution is constrained by inherent shortcomings, including fewer edge active sites, poor dispersion, and electrical conductivity. In this work, MoS2 was compounded with carbon nanotubes (CNTs), which are known for their high specific surface area and excellent electrical conductivity. These CNTs, laden with oxygen-containing functional groups, provided nucleation sites that facilitated the rapid assembly of MoS2 nanoflowers under hydrothermal conditions within 3 h. Due to their diminutive size (∼300 nm), these nanoflowers possess a large specific surface area and numerous active sites at their edges. Furthermore, MoS2 nanoflowers exhibited a high concentration of intrinsic S-vacancies. This heterojunction material exhibited superior HER properties. In addition, density functional theory simulation further confirmed that the MoS2 with S vacancy and CNT heterojunction electrocatalysts (VS-M/C) provided a fast charge transfer pathway for water electrolysis, and analysis showed that the conduction band minimum and valence band maximum were mainly contributed by the d orbits of Mo and the p orbits of C. This study proffered a novel approach for the engineering of high-performance MoS2-based HER electrocatalysts.

Vinylene‐Linking of Polycyclic Aromatic Hydrocarbons to π‐Extended Two‐Dimensional Covalent Organic Framework Photocatalyst for H2O2 Synthesis

AbstractPolycyclic aromatic hydrocarbons (PAHs) hold the predominant role either as individual molecules or building blocks in the field of organic semiconductors or nanocarbons. Connecting PAHs via sp2‐carbon bridges to form high‐crystalline π‐extended structures is highly desired not only for enlarging the regimes of two‐dimensional materials but also for achieving exceptional properties/functions. In this work, we developed 5,10‐dimethyl‐4,9‐diazapyrene as a key monomer, whose two methyl groups at the positions adjacent to nitrogen atoms, can helpfully increase the solubility, and serve as the active connection sites. In the presence of organic acids, this monomer enables smoothly conducting Knoevenagel condensation to form two vinylene‐linked PAH‐cored COFs, which show high‐crystalline honeycomb structures with large surface areas up to 1238 m2 g−1. Owing to the direct connection mode of PAH building blocks with vinylene, the as‐prepared COFs possess spatially extended π‐conjugation and substantial semiconducting properties. Consequently, their visible‐light photocatalysis with exceptional activity and durability was manifested to generate H2O2 up to 3820 μmol g−1 h−1 in pure water, and even 17080 μmol g−1 h−1 using benzyl alcohol as a hole sacrificial agent.

Optimization Strategies of Hybrid Lithium Titanate Oxide/Carbon Anodes for Lithium-Ion Batteries

Lithium-ion batteries, due to their high energy density, compact size, long lifetime, and low environmental impact, have achieved a dominant position in everyday life. These attributes have made them the preferred choice for powering portable devices such as laptops and smartphones, power tools, and electric vehicles. As technology advances rapidly, the demand for even more efficient energy storage devices continues to rise. In lithium-ion batteries, anodes play a crucial role, with lithium titanate oxide standing out as a highly promising material. This anode is favored for its exceptional cycle stability, safety features, and fast charging capabilities. The impressive cycle stability of lithium titanate oxide is largely due to its zero-strain nature, meaning it undergoes minimal volume changes during lithium-ion insertion and extraction. This stability enhances the anode’s durability, leading to longer battery life. In addition, the lithium titanate oxide anode operates at a voltage of approximately 1.55 V vs. Li+/Li, significantly reducing the risk of dendrite formation, a major safety concern that can cause short circuits and fires. The material’s spinel structure, with its large active surface area, further allows fast electron transfer and ion diffusion, facilitating fast charging. This review explores the characteristics of lithium titanate oxide, the various synthesis methods employed, and its integration with carbon materials to enhance cycle stability, coulombic efficiency, and safety. It also proposes strategies for optimizing lithium titanate oxide properties to create sustainable anodes with reduced environmental impact using eco-friendly routes.

3D Ternary Hybrid of VSe2/e‐MXene/CNT with a Promising Energy Storage Performance for High Performance Asymmetric Supercapacitor

AbstractMXene and TMDs are two of the emerging electrode materials for supercapacitors owing to their unique physicochemical properties such as high conductivity, large surface area, and rich redox active sites. However, sheet restacking, volume expansion and oxidation hinder these materials from being used in practical applications. In this work, a 3D ternary hybrid structure of metallic VSe2, Ti3C2Tx MXene and carbon nanotube was designed to address some of the challenges in 2D materials‐based electrodes for supercapacitor application. The exfoliated MXene and CNT decorated VSe2 3D structure showed excellent synergy between each component to deliver promising energy storage and cycling performance. The ternary hybrid structure also can suppress the surface oxidation of MXene sheets during the hydrothermal reaction. Furthermore, an asymmetric supercapacitor fabricated with VSe2/e‐MXene/CNT and MoS2/MXene delivered the highest energy density of 35.91 Wh/kg at a power density of 1280 W/kg and a remarkable cycle life.

Comprehensive Analysis of the Potential Toxicity of Magnetic Iron Oxide Nanoparticles for Medical Applications: Cellular Mechanisms and Systemic Effects

Owing to recent advancements in nanotechnology, magnetic iron oxide nanoparticles (MNPs), particularly magnetite (Fe3O4) and maghemite (γ-Fe2O3), are currently widely employed in the field of medicine. These MNPs, characterized by their large specific surface area, potential for diverse functionalization, and magnetic properties, have found application in various medical domains, including tumor imaging (MRI), radiolabelling, internal radiotherapy, hyperthermia, gene therapy, drug delivery, and theranostics. However, ensuring the non-toxicity of MNPs when employed in medical practices is paramount. Thus, ongoing research endeavors are essential to comprehensively understand and address potential toxicological implications associated with their usage. This review aims to present the latest research and findings on assessing the potential toxicity of magnetic nanoparticles. It meticulously delineates the primary mechanisms of MNP toxicity at the cellular level, encompassing oxidative stress, genotoxic effects, disruption of the cytoskeleton, cell membrane perturbation, alterations in the cell cycle, dysregulation of gene expression, inflammatory response, disturbance in ion homeostasis, and interference with cell migration and mobility. Furthermore, the review expounds upon the potential impact of MNPs on various organs and systems, including the brain and nervous system, heart and circulatory system, liver, spleen, lymph nodes, skin, urinary, and reproductive systems.

The application of semiconductor nanomaterials in renewable energy

Abstract. In the development of renewable energy, the usage of solar cells, fuel cells, hydrogen energy, thermoelectric energy, and thermal energy has become a significant focus of research and development. Semiconductor nanomaterials play important roles in these fields. This paper focuses on the usage of TiO2 and In2O3 in renewable energy and finds out the trends and outlook of semiconductor nanomaterials in this field. TiO2 nanomaterials have attracted widespread attention due to their unique structure and excellent properties, such as their large specific surface area, high surface activity, and sensitivity. TiO2 nanomaterials are highly active in photovoltaic applications and play an important role in the search for renewable, clean energy technologies. In2O3 is an excellent n-type transparent semiconductor functional material, characterized by high sensitivity, low resistivity, good conductivity, high catalytic activity, and wide bandgap width. It has shown good competitiveness in gas sensors, solar cells, and photocatalysis fields. Although these semiconductor nanomaterials have many advantages, there are still some drawbacks that hinder their development. There is still much work to be done for the wider application of semiconductor nanomaterials in the field of renewable energy.

Efficient UV-Vis-NIR Responsive CO2 Reduction Photocatalyst with Black Pinecone-Shaped Carbon Nitride Loaded with Lanthanum Oxide.

Photothermal catalysis combines the advantages of photocatalysis and thermal activation, which provides a new research angle for CO2 catalytic reduction. In this study, Black carbon nitride with a three-dimensional (3D) pinecone-shaped structure (BPCN) was prepared by a simple solvothermal method using melamine as a precursor without the aid of a template. Lanthanum oxide doping on the BPCN catalysts (BPCN-La) was achieved by ultrasonic impregnation. This unique pinecone-shaped structure consists of self-assembled and interlaced carbon nitride rods (by SEM). The lanthanum element was distributed on the surface of the CN framework in the form of La2O3 (by XPS). The chemical structures of the samples were characterized by solid-state 13C nuclear magnetic resonance (13C NMR) and elaborated by density functional theory (DFT) analysis. This black carbon nitride expanded the light absorption band edge into the near-infrared (NIR) (300-1400 nm, by UV-vis absorption spectra) and had excellent photothermal conversion activity. La atom doping can significantly boost photogenerated electron excitation (by photocurrent test) and promote carrier separation and transfer (by PL). Upon incorporation of La atoms into BPCN, the highest occupied molecular orbital (HOMO) orbital is more concentrated on the oxygen atoms of La2O3. BPCN-La considerably narrowed the band gap width, exhibited an exceptional photothermal effect, and provided a large surface area, which significantly enhanced the photocatalytic reduction of CO2 reactions. The yields of CO reached 58.2 and 104.9 μmol·h-1·g-1 for BPCN and BPCN-La, respectively, with GCN as the control (6.3 μmol·h-1·g-1). Theoretical reaction pathways and selectivity for the photoreduction of CO2 on BPCN and BPCN-La were studied by DFT simulation. This work provides a new vision for the design of photothermal synergistic without extra-thermal input and full spectral response photocatalysts with high efficiency.

Review and prospect on Metal-organic framework-based Separators for Lithium–Sulfur Battery

With the continuous advancement of technology, wearable smart devices and electric vehicles (EVs) have become an integral part of our daily lives. The increasing demand for energy from these devices and vehicles has driven the pursuit of high-performance rechargeable battery technology. In particular, the widespread adoption of electric vehicles has set higher standards for the energy density and cycle life of batteries. However, the energy density of the widely used lithium-ion batteries is currently limited by the theoretical capacity of commercial cathode materials, and there are certain challenges in terms of safety and cost-effectiveness. Therefore, the development of a new generation of rechargeable batteries with higher energy density, better safety, and more economical cost is particularly urgent. Lithium-sulfur batteries, due to their high energy density, high economic benefits, and high environmental friendliness, are considered to be one of the most promising successors to the widely used lithium-ion batteries. However, in practical applications, the electrochemical performance of lithium-sulfur batteries still needs to be improved. In particular, the poor conductivity of sulfur/lithium and the shuttle effect of polysulfides make the cycle life of the battery less than ideal, and lithium-sulfur batteries (LSB) are still far from achieving large-scale commercialization. The separator used in lithium-sulfur batteries plays a crucial role in its cycle performance and safety. The current commercial separator lacks the ability to effectively regulate the shuttle of polysulfides and is prone to thermal runaway at high temperatures. Therefore, to improve these issues, various functional materials have been used to modify the separator. Among them, as a new type of porous coordination polymer, metal organic frameworks (MOFs) have become a promising material for modifying separators due to their large specific surface area and highly ordered tunable nano-holes.At the same time, their rich inorganic nodes and designable organic ligands allow for the customization of pore chemistry at the molecular level, which can interact with the electroactive components in lithium-sulfur batteries in a tunable manner. This article reviews the reaction mechanism of lithium-sulfur batteries and the structural advantages of MOFs in terms of pore chemistry and morphology and briefly introduces the research progress of MOF-based interfacial layers for the functionalization of LSB separators in recent years. It elaborates on the mechanisms by which various modified separators improve electrochemical performance and provides a prospect for the development prospects of the field.

Transparent and Mechanically Robust Janus Nanofiber Membranes for Open Wound Healing and Monitoring.

The electrospun nanofiber membrane has demonstrated great potential for wound management due to its porous structure, large surface area, mechanical strength, and barrier properties. However, there is a need to develop transparent bioactive nanofibers with strong mechanical properties to facilitate the monitoring of the healing process. In this study, we present an electrospinning-based method for creating transparent (∼80-90%), strong (∼11-13 MPa), and Janus nanofiber membranes. The innovative square pattern architecture of the membrane includes a thin hydrophobic polycaprolactone layer on top of a layer of hydrophilic ethylene-vinyl alcohol nanofiber, which enables the absorption of excess biofluid from the wound and exhibits Janus wettability for water. Furthermore, incorporating 5% chitosan into the composition of the nanofibers accelerates the healing process through its antioxidant properties and antimicrobial activity against various bacteria, including drug-resistant strains. The developed membrane also demonstrates skin-repairing function, quick blood clotting (around 145 ± 12 s), and biocompatibility with keratinocyte (≥90%), as well as in vitro quick cell migration (∼24 h). With a tensile strength of 11-13 MPa, the membrane effectively adheres to the knee joint even after running 4 km. These optimal properties of the electrospun nanofiber membrane make it suitable for effective wound management and inspection of the healing process, without the need for frequent dressing changes.

Exploring the role of graphene-metal hybrid nanomaterials as Raman signal enhancers in early stage cancer detection

Molecular diagnosis plays a significant role in detection of biomolecules linked to early stage cancer since it offers greater sensitivity and reliability for identification of biomarker level changes as the disease progresses. The application of vibrational spectroscopy in biomarker detection is defined by the fingerprint spectrum of a molecule originating from single-molecule vibrations. This characteristic makes surface enhanced Raman spectroscopy (SERS) a promising tool for identification of biomarkers. The performance of the SERS technique largely depends on the material being used as the SERS substrate. Graphene, with its large surface area and abundance of aromatic regions, is considered advantageous as SERS substrate. Combining graphene with metal nanomaterials considerably increases SERS signal intensity, thereby enhancing detection sensitivity. Therefore, this review emphasizes the significance of selecting graphene-metal nanohybrids as suitable SERS substrates for signal amplification. The detail understanding of the mechanism of graphene-metal hybrid in SERS based detection of early stage cancer is also presented. Furthermore, several examples demonstrated the application of graphene-metal hybrid nanomaterials in detecting biomarkers and cancer cell differentiation using SERS imaging.

Application of iron oxide and its composites containing carbon nanoparticles to the solution of environmental problems

The radioactive materials and the secondary waste after a nuclear power plant accident pose a big environmental problem. The nontoxic iron oxide and iron oxyhydroxide, and their composites with carbon materials were applied to solve the problem. Coal oxide produced by modified Brodie method using coal, NaOH, and γ-Fe2O3 were treated by a hydrothermal process. When the diluted dispersion mixture was treated with SrCl2, the composite particles were attracted to a magnet. On the other hand, the composite without SrCl2 was not attracted. This means only the SrCl2-adsorbed composite can be recovered by a magnet. Hematite doped with various amounts of Nb was synthesized. Its catalytic activities for photo-Fenton reaction were investigated for degradation of methylene blue (MB) in the presence of H2O2 under visible light. Nb-doped hematite calcined at 600 ºC produced smaller particles and showed higher catalytic activity than those calcined at 700 ºC. It was shown that the sample with higher Nb doping showed a better catalytic activity, i.e., the sample with 40 atomic percent of Nb calcined at 600 ºC has the highest catalytic activity. The hematite with 7.4 atomic percent of Nb calcined at 600 ºC showed unique characteristics since it has rapid decomposition rate of MB as well as ferrimagnetic-like characteristics, which makes it separable by a magnet. The polymorphism of iron(III) oxyhydroxide was controlled by adding acetic acid, ethylenediamine, and citric acid. The lepidocrocite obtained by adding the additive of citric acid resulted in the presence of citric acid in the particles and revealed a large specific surface area and negative Zeta potential, which showed an extremely high catalytic activity of MB decomposition for photo-Fenton reaction.

Mapping of drought-induced changes in tissue characteristics across the leaf profile of Populus balsamifera.

Leaf architecture impacts the ease of gases diffusion, biochemical process, and photosynthetic performance. For balsam poplar, a widespread North American species, the influence of water availability on leaf anatomy and subsequent photosynthetic performance remains unknown. To address this shortcoming, we characterized the anatomical changes across the leaf profile in three-dimensional space for saplings subjected to soil drying and rewatering using X-ray microcomputed tomography. Our hypothesis was that higher abundance of bundle sheet extensions (BSE) minimizes drought-induced changes in intercellular airspace volume relative to mesophyll volume (i.e. mesophyll porosity, θIAS) and aids recovery by supporting leaf structural integrity. Leaves of 'Carnduff-9' with less abundant BSEs exhibited greater θIAS, higher spongy mesophyll surface area, reduced palisade mesophyll surface area, and less veins compared with 'Gillam-5'. Under drought conditions, Carnduff-9 showed significant changes in θIAS across leaf profile while that was little for 'Gillam-5'. Under rewatered conditions, drought-induced changes in θIAS were fully reversible in 'Gillam-5' but not in 'Carnduff-9'. Our data suggest that a 'robust' leaf structure with higher abundance of BSEs, reduced θIAS, and relatively large mesophyll surface area provides for improved photosynthetic capacity under drought and supports recovery in leaf architecture after rewatering in balsam poplar.