Synthesis Of Nanostructured Materials Research Articles

Synthesis and electrochemical properties of microcanals Mg-S-Cu-S as an electrode material for energy storage applications

The synthesis of novel nanostructured electrode materials is the community demand to overcome energy crises. Herein, the nanostructured copper-sulfide, copper-cadmium-sulfide and copper-magnesium-sulfide (Cu-S, Cd-S-Cu-S and Mg-S-Cu-S) electrodes are synthesized by chemical vapor deposition technique. The changes in crystal growth and surface morphologies of Cu-S, Cd-S-Cu-S and Mg-S-Cu-S electrodes are associated with the formation of heterostructures and change in energy fluxes. The weight % of Ni, Cu, S; Ni, Cd, Cu, S; and Ni, Mg, Cu, S are found to be 8, 62, 30; 6, 16, 48, 30; 15, 14, 45, 26 are observed in Cu-S, Cd-S-Cu-S and Mg-S-Cu-S electrodes respectively. The Mg-S-Cu-S electrode showed superior specific capacitance of 4393 and 5657 F/g at 1 mV/s and 1.0 A/g respectively. The maximum energy density and power density of Mg-S-Cu-S electrode are found to be 141 Wh/kg and 2120 W/kg respectively. The cyclic retention after 3000 cycles of Cu-S, Cd-S-Cu-S and Mg-S-Cu-S electrodes are found to be 80.8, 87.5 and 96.2 % respectively. The simulation results show that the Cd-S-Cu-S followed more capacitive-controlled while Mg-S-Cu-S followed more diffusive controlled process. Result show that the Mg-S-Cu-S electrode is comparatively more suitable for portable energy storage devices.

Study of the phase formation of transparent magnesium aluminosilicate glass-ceramic materials

Current trends in the development of materials for optics and laser technology were analyzed. The prospects of creating passively Q-switched Yb-Er glass lasers with eye-safe emission wavelengths based on glass-ceramic magnesium aluminosilicate materials for compact pulsed lasers were established. The main types of transparent glass-ceramic materials were analyzed and the main criteria for the synthesis of transparent nanostructured glass-ceramic materials with a crystalline phase content of approximately 70–80 vol.% were substantiated. Compositions of magnesium aluminosilicate glasses were synthesized and the differences of compositions with different types of optical transparency were determined, taking into account their thermal prehistory. The mechanism of phase formation and the differences of MgO, Al2O3, MgO/Al2O3 and RO2 in their composition, which determine the character of crystallization, optical transparency and density under the conditions of heat treatment with a duration of 0.5 and 6 hours, were studied. The developed magnesium aluminosilicate glasses can be used as a basis for the creation of protective and functional high-strength nanostructured glass-ceramic materials based on spinel or cordierite with adjustable optical transparency for optics and laser technology.

Bone marrow derived mesenchymal stem cells enriched PCL-gelatin nanofiber scaffold for improved wound healing

Electrospun nanofibers exhibit a significant potential in the synthesis of nanostructured materials, thereby offering a promising avenue for enhancing the efficacy of wound care. The present study aimed to investigate the wound-healing potential of two biomacromolecules, PCL-Gelatin nanofiber adhered with bone marrow-derived mesenchymal stem cells (BMSCs). Characterisation of the nanofiber revealed a mean fiber diameter ranging from 200 to 300 nm, with distinctive elemental peaks corresponding to polycaprolactone (PCL) and gelatin. Additionally, BMSCs derived from bone marrow were integrated into nanofibers, and their wound-regenerative potential was systematically evaluated through both in-vitro and in-vivo methodologies. In-vitro assessments substantiated that BMSC-incorporated nanofibers enhanced cell viability and crucial cellular processes such as adhesion, and proliferation. Subsequently, in-vivo studies were performed to demonstrate the wound-healing efficacy of nanofibers. It was observed that the rate of wound healing of BMSCs incorporated nanofibers surpassed both, nanofiber and BMSCs alone. Furthermore, histomorphological analysis revealed accelerated re-epithelization and improved wound contraction in BMSCs incorporated nanofiber group. The fabricated nanofiber incorporated with BMSCs exhibited superior wound regeneration in animal model and may be utilised as a wound healing patch.

Surfactant-free synthesis of nanostructured palladium materials under mild conditions and their highly catalytic selective hydrogenation

Nanostructured palladium (Pd) materials are highly efficient noble metal catalysts in various fields, but developing a simple and mild strategy to prepare Pd nanomaterials with high activity and selectivity still remains a big challenge. In this study, uniform-sized Pd popcorn-like nanospheres (PNSs) were successfully synthesized by the slow reduction of Pd(OAc)2 in anhydrous methanol under ambient conditions in the dark without any surfactant, additional reductant and support. The obtained Pd PNSs have rough surface with the average diameter of approximately 140 nm, and are composed of many smaller PNSs with the average size of about 12 nm. Pd PNSs have excellent catalytic performance in the hydrogenation of 4-nitrobenzaldehyde to 4-aminobenzaldehyde under mild conditions. Specifically, using the as-prepared Pd PNSs as catalyst, the 98 % conversion of 4-nitrobenzaldehyde and 98 % selectivity to 4-aminobenzaldehyde can be achieved within 1.5 h at 35°C under atmospheric pressure. After three recycling, the Pd PNSs can still maintain highly catalytic activity and selectivity. The very simple strategy developed here will be a valuable supplement to the methodology for the surfactant-free fabrication of other surface-active metallic nanomaterials for advanced applications.

Confined Synthesis of Noble Metal Clusters Assisted by Liquid Film for Photocatalytic CO2 Reduction.

The important concept of confined synthesis is considered a promising strategy for the design and synthesis of definable nanostructured materials with controllable compositions and specific morphology, such as highly loaded single-atom catalysts capable of providing abundant active sites for photocatalytic reactions. In recent years, researchers have been working on developing new confined reaction systems and searching for new confined spaces. Here, we present for the first time the concept of a bubble liquid film as a novel confined space. The liquid film has a typical sandwich structure consisting of a water layer, sandwiched between the upper and lower surfactant layers, with the thickness of the intermediate water layer at the micro- and nanometer scales, which can serve as a good confinement. Based on the above understanding and combined with the photodeposition method, we successfully confined synthesized Ag/TiO2, Au/TiO2, and Pd/TiO2 photocatalysts in liquid film. By HAADF-STEM, it can be seen that the noble metal morphologies are all nanoclusters of about 1 nm and are highly uniformly dispersed on the TiO2 surface. Compared with photodeposition in solution, we believe that the surfactant molecular layer restricts a limited amount of precursor to the liquid film, avoiding the accumulation of noble metals and the formation of large particle size nanoparticles. The liquid film, meanwhile, restricts the migration path of noble metal precursors, allowing for thorough in situ photodeposition and enables the complete and uniform dispersion of noble metal precursors, greatly reducing the photodeposition time. The uniform loading of the three noble metals proved the universality of the method, and the catalysts showed high activity for photocatalytic CO2 reduction. The rates of reduction of CO2 to CO over the Ag/TiO2 photocatalytic reached 230 μmol g-1 h-1.This study provides a new idea for the expansion of the confined reaction system and a reference for the study of liquid film as the confined space.

Synthesis of biowaste-derived nanostructured material for the nanomolar detection of glucose: Biological sample analysis

Glucose electro-oxidation in an alkaline media was investigated using an electrode composed of carbon paste and sugarcane bagasse activated carbon (SBAC). The SBAC was prepared using an easy, affordable, and environmental friendly process. The porous activated carbon was produced using sugarcane bagasse through a pre-treatment process that involved carbonization at 650 °C and K2CO3. X-ray diffraction (XRD) was used to observe the formation of carbon crystallites during activation at higher temperatures. The Fourier-transform infrared (FTIR) spectrum shows functional groups that are present in the carbon material. The carbon sample's morphology was evaluated using scanning electron microscope (SEM). The surface roughness was studied using atomic force microscopy (AFM). Porous activated carbon derived from sugarcane bagasse was carefully mixed into electrode components such as graphite powder and mineral oil for glucose (GLS) detection. For precise GLS detection, the SBACs were employed as non-enzymatic electrochemical sensor probes in their as-prepared condition. According to the electrochemical experiments, the constructed sensor shows exceptional electrochemical performance towards glucose oxidation, including excellent selectivity, a low detection limit, good sensitivity, and a wide linear range. Investigation has been conducted on the oxidation of GLS in alkaline solutions with varying concentrations of halide ions such as iodide and chloride. The GLS oxidation peak current increased the performance of a SBAC modified electrode was compared to that of a bare carbon paste electrode (CPE). The role of sensitivity in minimizing halide poisoning is significant. The risk of poisoning is increased if iodide > chloride. As the modified electrode's voltage changes in a chloride solution containing glucose, the peak current gradually reduces. The redesigned electrode that is currently in use as a consequence not only promotes glucose oxidation but also shows strong resistance to electrode poisoning caused by halides. The sensitive and targeted SBAC/CPE has also improved its reliability while evaluating samples of human serum, urine, and breast milk.

Sol–Gel Synthesis of Nanostructured Mesoporous Silica Powder and Thin Films

Mesoporous materials are special nanoporous materials containing well-defined mesochannels with a pore diameter between 2 and 50 nm. The high surface area, ordered structure, tunable pore size, and easiness of functionalization have made mesoporous silica powder and thin films interesting materials for a wide range of applications including drug delivery, absorption, separation, catalysis, energy conversion, and storage. The sol–gel process has emerged as a promising technique for the synthesis of nanostructured mesoporous silica materials as it provides the advantages of low-temperature processing and easy control of the synthesis parameters. Although it offers several advantages over other synthesis techniques, it also has the drawbacks of high sensitivity to processing conditions. Hence, this review paper aims to give critical insights into the sol–gel process, the chemistry of sol–gel silica, the formation mechanism of mesoporosity, and the effects of the reaction parameters. A good understanding of these phenomena is essential to better control and optimize the properties of the final material for specific needs and applications. Additionally, this review paper discusses the different methods applied to the synthesis of nanostructured ordered mesoporous thin film silica, including the Electrochemically Assisted Self-Assembly method of synthesis. The EASA method is a novel and promising technique for the synthesis of well-ordered and vertically aligned pore channels of mesoporous thin films as it is required for mass transport applications. Moreover, the effects of sol composition, pH, applied potential, and deposition time on the final thickness of the thin film are elaborated on in detail. Furthermore, this comprehensive review highlights the potential and opportunities for future research and development in the area to further advance and use its full potential advantages.

Interfacial Electrochemical Polymerization of PEDOT@Polyoxometalates Thin Films As Electroactive Material for Energy Storage Devices

The urgent need for a decarbonized power sector has been one of the most important motivations to get a full transition from the fossil-fuel energy sources to a sustainable energy future based on renewable energy alternatives. In this regard, energy conversion and storage devices, such as batteries, fuel cells and supercapacitors, play a key role in supplying steady power and energy densities in order to guarantee the current energy demand [1]. Among the different alternatives, the design and synthesis of advanced functional nanostructured materials provide an important route to obtain efficient energy devices with high power densities, stability and remarkable energy densities [2].Conducting polymers (CP) have been extensively exploited in a wide application range as result of their remarkable charge-mobility, electrical conductivity, and the scalable synthesis processes. Additionally, the storage of charge, which occurs by a doping process, has been ideal for application as electrochemical supercapacitors [3]. In addition, the CPs network have provided an interesting electrode material in which other active materials (i.e., graphene, MOF) and redox species can be incorporated to induce additional pseudocapacitive processes in the electrode, enhancing the charge stored. The polyoxometalates (POMs), inorganic heteropolyanions received great attention due to their multielectron redox processes in aqueous media [4].Herein, we have explored the electrosynthesis of composite materials based on PEDOT and polyoxometalates (POMs) employing the electrochemical polymerization at a polarized organic | aqueous liquid | liquid interface (L|L), in which the POM acts as oxidizing agent of EDOT and electroactive specie incorporated in the polymer chain network as dopant. The polymerization process was based on the ion migration-controlled by the potential biasing of the water-oil interface. The resulting thin films show the presence of Mo and W within the polymer as well as the presence of different redox processes associated with the POM incorporated in the PEDOT. The induced pseudocapacitive processes in the composite materials have shown high stability in acid media, making it a good candidate as an electrode material in symmetric supercapacitors.

Efficient removal of carcinogenic Rosaniline Hydrochloride (Fuchsine) dye with Mg doped FeTiO nanocomposites: Experimental and statistical evaluation

This study focuses on the synthesis of new nanostructured absorbent materials and removal of hazardous Rosaniline Hydrochloride (fuchsine) dye from polluted water. For this, Mg doped FeTiO nanocomposite (FTMO-NCs) was synthesized by co-precipitation method and thoroughly characterized to study its surface properties. The TEM image shows the FTMO-NCs are consists of crystalline particles sized in few nanometers of scale. The SAED pattern suggests the nanoscale polycrystalline nature of the FTMO-NCs. The homogeneously distributed MgO on the FeTiO-NCs further validates the spectra. Furthermore, the successful mixture of MgO with the FeTiO surface and the formation of FTMO-NCs are indicated by the well-defined elemental mapping of Fe, Ti, O, and Mg. Dye adsorption capacity, stability, and regeneration capability of the synthesized FTMO-NCs was evaluated by a series of experiments and varying parameters, such as, agitation time, nanocomposite mass, solution pH, dye concentration, etc. The pseudo-second-order kinetic model was found to be applicable based on the kinetic parameters calculated with a high correlation coefficient of 0.999. The findings indicate that the Langmuir isotherm is a better fit for the experimental data for the fuchsine adsorption on the FTMO-NPs in comparison to the other four models and shows the maximum adsorption capacity (Qmax) of 555.5 mg/g. Moreover, a double layer model was applied to study the statistical prediction of the favorability of the adsorption process of the dye on the nanocomposite. The Nm value for fuchsine adsorption was 550 mg/g, 255 mg/g, and 218 mg/g, respectively at 298 K, 308 K, and 318 K. The use of Mg-doped FeTiO nanocomposites (FTMO-NCs) for removing Rosaniline Hydrochloride (fuchsine) dye is a novel approach that brings together the unique properties of both materials. The incorporation of magnesium (Mg) into the FeTiO nanocomposite introduces new synergies and enhances the adsorption capabilities of the material. This innovation is particularly significant because Mg doping can influence the surface chemistry and electronic structure of the nanocomposite, leading to improved dye removal efficiency.

Metal-organic framework-derived self-grown core-shell V2O5 for high-performance zinc ion storage

The nanostructure designing strategy is one of the most effective methods to carry out the optimization of cathode materials for aqueous zinc ion batteries (ARZIBs). The design and synthesis of materials with stable nanostructure and short ion/electron transport paths are expected to alleviate the dilemma faced by vanadium-based materials, such as poor electrical conductivity and structural changes. Ostwald ripening is a promising option in the design and fabrication of special nanostructures such as hollow and core shells. Selecting vanadium-based metal-organic frameworks (V-MOF) as reactants, we successfully obtained vanadium oxide precursors with self-growing core-shell structures in one-step. As the reaction time increases, the vanadium oxide precursors undergo the process of microspheres → core-shell → yolk shell, which is thought to be the result of Ostwald ripening. After annealing, the vanadium oxide precursor becomes a "core-shell" structure vanadium pentoxide (core-shell V2O5). The ARZIBs assembled with core-shell V2O5 cathodes showed superior capacity (309.4 mAh/g at 0.1 A/g) and cycling stability (91.4 % capacity retention after 4000 cycles at 3A/g). Hence, we successfully realized the self-growth of vanadium oxide with core-shell structure in one step but also revealed the crystallization process based on Ostwald ripening and its zinc storage mechanism, which provides new possibilities for the facile synthesis of special nanostructured ARZIB cathode materials.

Solution combustion synthesis of nanostructured Ni/W-containing electrocatalysts for hydrogen evolution reaction: The effect of fuel-to-oxidant ratio

The effect of varying fuel-to-oxidant ratio (φ) on the physicochemical properties and electrocatalytic performance for the hydrogen evolution reaction (HER) of nanostructured NiW materials produced via solution combustion synthesis (SCS) method was investigated. Agar and nickel nitrate served as the fuel and oxidant, respectively. TGA-MS results revealed that a fuel-to-oxidant ratio of 9 (φ9) provides the optimal conditions for reducing metal oxides to metallic phases due to the highest emission of reducing gas species (H2, CH4, and NH3). N2 adsorption/desorption measurements indicated that under fuel-rich conditions (φ > 1), both the specific surface area and porosity expanded with increasing the fuel quantity. Microscopy characterization was found to be consistent with N2 adsorption/desorption and TGA-MS results, revealing that the increased gas expulsion from higher fuel content led to more pronounced coral-like structures comprising of nano-sized particles and pores. Evaluation of electrocatalytic activity in an acidic medium (0.5 M H2SO4) revealed that the φ9 sample demonstrated the highest electrocatalytic HER performance. XRD and XPS analyses correlated well with this result, attributing the enhanced HER activity to the presence of the Ni0.9W0.1 metallic phase, limited oxide formation, and the highest proportions of metallic Ni and W atomic states, beyond mere surface area effects. Consequently, this study provides valuable insights into the importance of the fuel-to-oxidant ratio in optimizing the SCS method for controlled synthesis of nanostructured NiW materials in terms of morphology and composition, with implications for their potential development as high-performance, cost-effective electrocatalysts.

Ultraviolet light–assisted synthesis of nanostructured carbon materials for supercapacitor electrodes by using zinc oxide structures as template and catalyst

Ultraviolet light–assisted synthesis of nanostructured carbon materials for supercapacitor electrodes by using zinc oxide structures as template and catalyst

Nickel modified TiO2/C nanodisks with defective and near‐amorphous structure for high‐performance sodium‐ion batteries

AbstractLow‐cost sodium‐ion batteries (SIBs) are the star products in grid‐scale energy storage applications. Finding befitting anode materials is crucial to the advancement of SIBs. In this study, a novel two‐dimension (2D) nanostructured anode material composed of TiO2/C nanodisks and Ni nanoparticles that were synthesized by a facile metal‐organic frameworks derived method is reported. By introducing divalent Ni2+ ions in the synthesis process, TiO2/C microblocks were successfully transformed into the desirable 2D nanodisks, enabling the active materials to be more efficiently and fully utilized due to short diffusion path and substantive exposed active sites. Another important role of Ni2+ ions is as a doping source for TiO2, resulting in the formation of a defective and near‐amorphous TiO2/C structure, which aids in improving the kinetics. In addition, some Ni nanoparticles formed and attached to the surface of the TiO2/C nanodisks, which not only act as conductive bridges to make all the nanodisks electrically active but also act as pillars to prevent them from stacking. This unique 2D nanostructured anode material manifests high reversible capacities, excellent cycle performance, and impressive rate capability. This work provides a new means for the controllable synthesis of 2D nanostructured materials for energy storage applications.

Advances in the Fabrication of Nanoporous Anodic Aluminum Oxide and Its Applications to Sensors: A Review.

Nanoporous anodic aluminum oxide (AAO) is an important template for 1D nanomaterial synthesis. It is used as an etching template for nanopattern transfer in a variety of contexts, including nanostructured material synthesis, electrical sensors, optical sensors, photonic and electronic devices, photocatalysis, and hardness and anticorrosion improvement. In this review, we focus on various fabrication methods, pore geometry modification, and recent advances of AAO, as well as sensor applications linked to our environment, daily life, and safety. Pore geometry is concerned with the material composition, applied voltage mold, electrolyte type, temperature, and anodizing time during the fabrication of AAOs and for adjusting their pore size and profile. The applied voltage can be divided into four types: direct current anodization (DCA), reverse pulse anodization, pulse anodization (PA), and hybrid pulse anodization (HPA). Conventional AAOs are fabricated using DCA and mild anodization (MA) at a relatively low temperature (-5~15 °C) to reduce the Joule heating effect. Moreover, the issues of costly high-purity aluminum and a long processing time can be improved using HPA to diminish the Joule heating effect at relatively high temperatures of 20-30 °C with cheap low-purity (≤99%) aluminum. The AAO-based sensors discussed here are primarily divided into electrical sensors and optical sensors; the performance of both sensors is affected by the sensing material and pore geometry. The electrical sensor is usually used for humidity or gas measurement applications and has a thin metal film on the surface as an electrode. On the contrary, the AAO optical sensor is a well-known sensor for detecting various substances with four kinds of mechanisms: interference, photoluminescence, surface plasma resonance, and surface-enhanced Raman scattering (SERS). Especially for SERS mechanisms, AAO can be used either as a solid support for coating metal nanoparticles or a template for depositing the metal content through the nanopores to form the nanodots or nanowires for detecting substances. High-performance sensors will play a crucial role in our living environments and promote our quality of life in the future.

Retraction Note: Synthesis and characterizations of MgO nano-structured materials for opto-electronic and nano-photonic utilities

Retraction Note: Synthesis and characterizations of MgO nano-structured materials for opto-electronic and nano-photonic utilities

Tensorial stress-plastic strain fields in α - ω Zr mixture, transformation kinetics, and friction in diamond-anvil cell

Various phenomena (phase transformations (PTs), chemical reactions, microstructure evolution, strength, and friction) under high pressures in diamond-anvil cell are strongly affected by fields of stress and plastic strain tensors. However, they could not be measured. Here, we suggest coupled experimental-analytical-computational approaches utilizing synchrotron X-ray diffraction, to solve an inverse problem and find fields of all components of stress and plastic strain tensors and friction rules before, during, and after α-ω PT in strongly plastically predeformed Zr. Results are in good correspondence with each other and experiments. Due to advanced characterization, the minimum pressure for the strain-induced α-ω PT is changed from 1.36 to 2.7 GPa. It is independent of the plastic strain before PT and compression-shear path. The theoretically predicted plastic strain-controlled kinetic equation is verified and quantified. Obtained results open opportunities for developing quantitative high-pressure/stress science, including mechanochemistry, synthesis of new nanostructured materials, geophysics, astrogeology, and tribology.

Tunable 1D and 2D Polyacrylonitrile Nanosheet Superstructures.

Carbon superstructures are widely applied in energy and environment-related areas. Among them, the flower-like polyacrylonitrile (PAN)-derived carbon materials have shown great promise due to their high surface area, large pore volume, and improved mass transport. In this work, we report a versatile and straightforward method for synthesizing one-dimensional (1D) nanostructured fibers and two-dimensional (2D) nanostructured thin films based on flower-like PAN chemistry by taking advantage of the nucleation and growth behavior of PAN. The resulting nanofibers and thin films exhibited distinct morphologies with intersecting PAN nanosheets, which formed through rapid nucleation on existing PAN. We further constructed a variety of hierarchical PAN superstructures based on different templates, solvents, and concentrations. These PAN nanosheet superstructures can be readily converted to carbon superstructures. As a demonstration, the nanostructured thin film exhibited a contact angle of ∼180° after surface modification with fluoroalkyl monolayers, which is attributed to high surface roughness enabled by the nanosheet assemblies. This study offers a strategy for the synthesis of nanostructured carbon materials for various applications.

Analysis of transformation of a thin graphite-like carbon layer on the detonation nanodiamond surface into diamond

The article considers the process of obtaining nanostructured diamond materials due to phase transformation of thin films based on carbon non-diamond forms on the nanodiamond surface into diamond. For the synthesis of nanostructured diamond polycrystalline superhard material, various variants of the initial mixture based on nanodiamond with non-diamond carbon on the surface are proposed (surface-graphitized nanodiamond, surface-graphitized nanodiamond with addition of purified nanodiamond, detonation diamond-containing charge with a surface layer of “amorphous” carbon, including purified nanodiamond additives). The influence of the structure of a thin non-diamond layer on the parameters of graphite to diamond transition is revealed. For a carbon film with a disordered structure (the so-called “amorphous” carbon), the transition pressure to diamond will be about 10–15 GPa, which is significantly higher than the phase transformation pressure for thin graphite films in this temperature range. It is shown that the increase in the pressure of transformation of a thin layer of “amorphous” carbon is caused by its lower surface energy compared to the surface energy of graphite. It has been established that the region of transformation of a thin graphite-like film with a thickness of about 1 nm, formed on the 2–10 nm nanodiamond surface into diamond will be below the graphite-diamond equilibrium line in the temperature range of 1000– 2500 °C. Additional introduction of purified nanodiamond particles leads to a decrease in the pressure of transformation of thin layers of non-diamond carbon into a diamond structure from 10–15 to 2–7 GPa, which is due to the effect of the surface of catalytically active diamond nanoparticles on the thermodynamic stimulus of phase transformation.

Advanced ORR Catalysts Based on Intermetallic Nanoparticles and Metal Organic Frameworks

Over the past decade, substantial resources have been devoted to developing proton exchange membrane fuel cells (PEMFCs). The high cost and insufficient durability of oxygen reduction reaction (ORR) catalysts are the main factors delaying the commercialization of high-efficiency fuel cells. Development of new catalysts with enhanced activity and durability would have a transformative effect on fuel cells and related energy devices. Catalyst design for ORR requires creation of catalytic sites with high ORR activity, but these sites must also have good accessibility for transport of reactants (oxygen, protons, electrons) and products (water). They must also have high durability, with lifetimes of up to 30,000 hours required for heavy duty vehicle applications. The most successful ORR catalysts for PEMFCs are PtM/C, i.e., nanoparticles of Pt alloys with a base metal (e.g., Co, Ni) dispersed on a nanostructured carbon catalyst support. Tuning properties of both the PtM nanoparticles and the C support is necessary to achieve high performance and durability. In recent years, intermetallic PtM nanoparticles in which Pt and M occupy distinct sites in a highly ordered structure have emerged as a leading candidate for PEMFC applications. However, development of nanostructured carbon supports with improved control of morphology and pore properties is needed to fully reap the benefits of advanced intermetallic nanoparticle catalysts. Herein, we report recent advances in development of both intermetallic PtM nanoparticles and nanostructured carbon supports with controlled morphology and pore seize distribution. By combining novel nanostructured materials synthesis with advanced characterization and fuel cell testing, we demonstrate a path to produce highly active catalysts with sufficient durability to meet the challenging requirements of heavy duty trucking applications.

Recent Advances on the Design and Applications of Antimicrobial Nanomaterials.

Present worldwide difficulties in healthcare and the environment have motivated the investigation and research of novel materials in an effort to find novel techniques to address the current challenges and requirements. In particular, the use of nanomaterials has demonstrated a significant promise in the fight against bacterial infections and the problem of antibiotic resistance. Metal nanoparticles and carbon-based nanomaterials in particular have been highlighted for their exceptional abilities to inhibit many types of bacteria and pathogens. In order for these materials to be as effective as possible, synthetic techniques are crucial. Therefore, in this review article, we highlight some recent developments in the design and synthesis of various nanomaterials, including metal nanoparticles (e.g., Ag, Zn, or Cu), metal hybrid nanomaterials, and the synthesis of multi-metallic hybrid nanostructured materials. Following that, examples of these materials' applications in antimicrobial performance targeted at eradicating multi-drug resistant bacteria, material protection such as microbiologically influenced corrosion (MIC), or additives in construction materials have been described.