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Abstract In this study, we aimed to enhance and accelerate the electrochemical properties of a glassy carbon-based voltammetric sensor electrode. This was achieved through the modification of the electrode using a nanocomposite derived from a metal–organic framework, which was embedded onto a substrate consisting of metal oxide nanoparticles. The final product was an electrocatalyst denoted as NiO/Ni@C-Fe3O4/CeO2, tailored for the detection of the drug niclosamide. Several techniques, including FT-IR, XRD, XPS, FE-SEM, TEM, and EDS, were employed to characterize the structure and morphology of this newly formed electroactive catalyst. Subsequently, the efficiency of this electrocatalyst was evaluated using cyclic voltammetry and electrochemical impedance spectroscopy techniques. Differential pulse voltammetry was also utilized to achieve heightened sensitivity and selectivity. A comprehensive exploration of key factors such as the catalyst quantity, optimal instrumental parameters, scan rate influence, and pH effect was undertaken, revealing a well-regulated reaction process. Furthermore, the sensor's analytical performance parameters were determined. This included establishing the linear detection range for the target compound within a specified concentration interval of 2.92 nM to 4.97 μM. The detection limit of 0.91 nM, repeatability of 3.1%, and reproducibility of 4.8% of the sensor were calculated, leading to the observation of favorable stability characteristics. Conclusively, the developed electrochemical sensor was successfully employed for the quantification of niclosamide in urine samples and niclosamide tablets. This application highlighted not only the sensor’s high selectivity but also the satisfactory and accurate outcomes obtained from these measurements.

This study examines the interfacial interactions of cerium oxide nanoparticles (CeO2 NPs) with average particle size below 25 nm in aqueous environment in the presence of monovalent cations (Na+) and divalent cations (Ca2+) and humic substances (humic acid (HA) and fulvic acid (FA)). Characterization of the dynamic growth of nanoaggregate-CeO2-complexes formed, and assessesment of the colloidal stability of these nanoaggregate-CeO2-complexes in such aqueous environments were performed in order to determine possible risks to their environmental surroundings. Hydrodynamic diameter and zeta potential of CeO2 NPs were measured over time in these aqueous environments. Results indicated that Ca2+ was more efficient than Na+ in enhancing the homoaggregation of CeO2 NPs. The critical coagulation concentration (CCC) of Na+ (30 mM) was twice as large as the CCC of Ca2+ (15 mM) at pH 5 (pH below pH value of point of zero charge, pHPZC). The heteroaggregation of CeO2 NPs and HA was enhanced at higher Na+ concentrations (> 100 mM NaCl) due to electrostatic attraction and at higher Ca2+ concentrations (> 1 mM CaCl2) due to bridging effect. Furthermore, HA was more efficient than FA in enhancing CeO2 NPs heteroaggregation in the presence of Ca2+, and FA was more efficient than HA in enhancing CeO2 NPs heteroaggregation in the presence of Na+. [ABSTRACT FROM AUTHOR]

A comparison study examines six different metal oxides (CuO, ZnO, Fe3O4, Co3O4, NiO, and α-MnO2) for the degradation of malachite green dye using four distinct processes. These processes are as follows: sonocatalysis (US/metal oxide), sonocatalysis under ultra-violet irradiation (US/metal oxide/UV), sonocatalysis in the presence of hydrogen peroxide (US/metal oxide/H2O2), and a combination of all these processes (US/metal oxide/UV/H2O2). The effective operating parameters, such as the dosage of metal oxide nanoparticles (MONPs), the type of the process, and the metal oxides' efficiency order, were studied. At the same reaction conditions, the sonophotocatalytic is the best process for all six MOsNPs, CuO was the better metal oxide than other MOsNPs, and at the sonocatalysis process, ZnO was the best metal oxide in other processes. It was found that the metal oxide order for sonocatalytic process is CuO > α-MnO2 ≥ ZnO > NiO ≥ Fe3O4 ≥ Co3O4 within 15–45 min. The order of (US/metal oxide/UV) process is ZnO ≥ NiO ≥ α-MnO2 > Fe3O4 ≥ CuO ≥ Co3O4 within 5–40 min. The order of (US/ MOsNPs/ H2O2) process is ZnO ≥ CuO ≥ α-MnO2 ≥ NiO > Co3O4 > Fe3O4 within 5–20 min. The maximum removal efficiency order of the sonophotocatalytic process is ZnO ≥ CuO > α-MnO2 > NiO > Fe3O4 ≥ Co3O4 within 2–8 min. The four processes degradation efficiency was in the order US/MOsNPs ˂ US/MOsNPs/UV ˂ US/MOsNPs/H2O2 ˂ (UV/Ultrasonic/MOsNPs/H2O2). Complete degradation of MG was obtained at 0.05 g/L MONPs and 1 mM of H2O2 using 296 W/L ultrasonic power and 15 W ultra-violet lamp (UV-C) within a reaction time of 8 min according to the MOsNPs type at the same sonophotocatalytic/H2O2 reaction conditions. The US/metal oxide/UV/H2O2 process is inexpensive, highly reusable, and efficient for degrading dyes in colored wastewater. [ABSTRACT FROM AUTHOR]

Carbon and metal-oxide nanoparticles (NP) are currently synthesized worldwide for various applications in the solar-energy, optical, pharmaceutical, and biomedical industries, among many others. Gas phase methods comprise flame synthesis and flame spray pyrolysis (FSP), which provide high efficiency, low cost, and the possibility of large-scale applications. The variation of combustion operation parameters exerts significant effects on the properties of the NPs. An analysis of the latest research results relevant to NP flame synthesis can provide new insight into the optimization of these methods and the development of these techniques for a large scale. This review offers insight into the current status of flame synthesis for carbon and metal-oxide NPs—specifically containing analysis and comparison of the most common carbon and metal-oxide NP production techniques. The burner configurations used at the laboratory scale and large scale are also discussed, followed by the assessment of the influence of combustion parameters on the properties of NPs. Finally, the features of the measurement techniques applied for determining NP properties were described. [ABSTRACT FROM AUTHOR]

The efficient electron transport layer (ETL) plays a critical role in the performance of perovskites solar cells (PSCs). Ideally, an unobstructed network with smooth channels for electron flow is required, which is lacking in the pristine TiO2-based ETL. As a potential solution, here we tuned the structure of TiO2 via optimized heteroatom doping of Al. Different concentrations (1, 2, and 3 wt%) of Al were doped in TiO2 and were successfully applied as an ETL in PSC using spin coating. A significant difference in the structural, opto-electronic, chemical, and electrical characteristics was observed in Al-doped TiO2 structures. The opto-electronic properties revealed that Al doping shifted the absorption spectra toward the visible range. Pure titania possesses a bandgap of 3.38 eV; however, after 1, 2, and 3% Al doping, the bandgap was linearly reduced to 3.29, 3.25, and 3.18 eV, respectively. In addition, higher light transmission was observed for Al-doped TiO2, which was due to the scattering effects of the interconnected porous morphology of doped-TiO2. Al-doped titania shows higher thermal stability and a 28% lower weight loss and can be operated at higher temperatures compared to undoped titania (weight loss 30%) due to the formation of stable states after Al doping. In addition, Al-doped TiO2 showed significantly high conductivity, which provides smooth paths for electron transport. Thanks to the effective tuning of band structure and morphology of Al-doped TiO2, a significant improvement in current densities, fill factor, and efficiency was observed in PSCs. The combined effect of better Jsc and FF renders higher efficiencies in Al-doped TiO2, as 1, 2, and 3% Al-doped TiO2 showed 12.5, 14.1, and 13.6% efficiency, respectively. Compared to undoped TiO2 with an efficiency of 10.3%, the optimized 2% Al doping increased the efficiency up to 14.1%. In addition, Al-doped TiO2 also showed improvements in antibacterial effects, required for photoactive textiles. [ABSTRACT FROM AUTHOR]

The polymers like polymethyl methacrylate (PMMA) have unique characteristics, which made them to be considered as promising material for various biomedical, electronics and optics applications. Metal-oxide nanoparticles have huge applications in different approaches. This work includes a recent review on polymer like PMMA doped with metal-oxide nanoparticles such as SiO2 and CeO2. The previous studies showed that the nanocomposites of PMMA/metal-oxide nanoparticles have many applications in the biomedical, electronics, optical and optoelectronics fields. [ABSTRACT FROM AUTHOR]

The present study investigates the effective thermal conductivity of nanofluids containing crystalline or amorphous silicon dioxide (SiO2), or zirconium dioxide (ZrO2) nanoparticles dispersed in a mixture of water and glycerol with a mass ratio of 60:40. Such fluids are relevant as potential cutting fluids in tribology and feature a broad distribution of irregularly shaped non-spherical particles of dimensions on the order of (100 to 200) nm that were produced by comminution of larger particles or particle aggregates. A new steady-state guarded parallel-plate instrument was applied for the absolute measurement of the effective thermal conductivity of the nanofluids with an expanded uncertainty (coverage factor k = 2) of 3% for temperatures from (293 to 353) K and particle volume fractions up to 0.1. For a constant volume fraction of 0.03 for the three particle types, the measured thermal-conductivity ratios, i.e. the effective thermal conductivity of the nanofluids relative to the thermal conductivity of the base fluid, are less than 1.05 and not affected by temperature. In the case of the nanofluids with crystalline SiO2, with increasing particle volume fraction from 0.03 to 0.10 the thermal-conductivity ratios increase up to values of about 1.18 for all temperatures. A comparison of the measurement results with the Hamilton-Crosser model and an analytical resistance model for the effective thermal conductivity of nanofluids shows that the former one allows for better predictions for the present nanofluids with a relatively large viscosity. In this context, it could be shown that detailed knowledge about the sphericity and thermal conductivity of the dispersed nanoparticles is required for the modeling approaches. [ABSTRACT FROM AUTHOR]

Textile/Dyeing industries have been considered as one of the intense water-consuming units, resulting in the generation of a large volume of dye(s) contaminated effluent posing a heavy burden on the receiving water bodies. Therefore, the identification of methods to synthesize bulk quantity of adsorbent(s) and further their evaluation for the efficient treatment of effluent is one of the most prominent topics. Hence, microwave-assisted method was proposed for the rapid synthesis of nanocomposite (C-CS@ZnO) from natural biomolecule (chitosan-CS), a well-known crosslinker (tripolyphosphate) and metal-oxide (ZnO) nanoparticles. Detailed characterization was performed to identify the structure (SEM, XRD) and composition (FT-IR, XPS) of the sorbent. Sorption experiments with methyl orange (MO) dye solution were carried out under different pH (2.0–12.0), dye concentrations (150–350 mg L−1), reaction times (0–210 min) and temperature (25–45 °C) to establish the adsorbent at the lab-scale. The maximum sorption capacity (185.2 mg g−1) was obtained because of the ligand-exchange, Yoshida H-bonding and electrostatic interactions and was best elucidated by Freundlich (R2 ≥ 0.99) and pseudo-second-order (R2 ≥ 1) models. To simulate the field conditions, the effects of co-existing ions (anions/cations), cocktail dyes/ions mixture and regenerant were also studied. The obtained results suggest its promising applicability at a large scale for textile effluent treatment. [Display omitted] • Microwave approach for rapid synthesis of C-CS@ZnO beads for effluent treatment • Higher pH PZC = 8.8 supports the applicability of beads towards anionic dye removal. • Heterogenous MO sorption onto beads followed pseudo-second-order model. • Presence of Ca2+ (~89 %) and Mg+2 (~99 %) ions can synergize the MO sorption process. • 79.4 % to 91.4 % MO removal achieved from simulated wastewater (dyes + OM) sample [ABSTRACT FROM AUTHOR]

• Aloe genus are traditionally used for the treatments of diseases. • They are rich in phytochemicals. • Fabricated nanoparticles from different Aloe species have shown a number of applications. Aloe is a genus of flowering succulent plants (with above 500 species) found in the eastern Indian Ocean Islands, Madagascar, the Arabian Peninsula, and African continent. In recent years, Aloe genus have received much attention for their therapeutic benefits. Aloe genus contains several phytoconstituents. For instance, carotenoids, anthraquinone, fatty acids, phenolic acids, and sterols were isolated from Aloe aculeata, Aloe ferox, Aloe saponaria, Aloe legnica and Aloe vera. Similarly, polyphenols, flavonoids, and flavonols were reported in Aloe marlothii and Aloe melanacantha. All these phytochemicals play a vital role in nanoparticle (NP) fabrication. The functional group present in them act as a reducing agent which convert metal ions into metal or metal-oxide NPs. NPs obtained from different Aloe plants have shown various biological and other applications. For example, silver NPs fabricated from Aloe vera extract exhibited antibacterial, antioxidant, wound healing, and catalytic activities. Selenium NPs synthesized from Aloe vera showed antioxidant, antibacterial, and antifungal activities. Titanium dioxide NPs obtained from Aloe barbadensis and Aloe vera are also examined for their antibiofilm potential and photocatalytic activities, respectively. Overall, this review aims to provide an updated information on Aloe -based NPs fabrication (both metal and metal-oxide), characterization and their application in some cutting-edge areas. [ABSTRACT FROM AUTHOR]

Nano‐finishing of textiles with metal and metal oxide nanoparticles (NPs) is relatively simple, but insufficiently efficient binding between the fibers and NPs poses a big problem because of the poor stability of textile nanocomposites. A good way to overcome this problem is to activate the fibers by plasma. Selection of gas and optimization of plasma processing parameters lead to a generation of new functional groups improving the binding of NPs. Another approach relies on the formation of stable nano‐coatings by magnetron sputtering. Progress has been recently made in plasma‐assisted in situ synthesis of metal NPs where toxic chemical reducing agents were replaced with short plasma treatment. This review paper addresses substantial roles of plasma, which enhance the performance of nano‐finished textiles. [ABSTRACT FROM AUTHOR]

Erythritol has attracted wide attention due to high latent heat of 297.2 kJ/kg and excellent chemical stability as a medium‐ to low‐temperature thermal energy storage (TES) material. However, low thermal conductivity leads to extended charging and discharging time and severely affects its large‐scale application. In this article, three cheap nanoparticles (CuO, Al2O3, and Fe2O3) and triethanolamine (TEA) were used as heat transfer enhancers and dispersant to improve the TES performance of erythritol. Sedimentation of nanoparticles in erythritol indicates that TEA is an effective dispersant in erythritol for three kinds of nanoparticles. The experimental results show that the thermal conductivity increased from 0.671 W/(m·K) of erythritol to 0.722 W/(m·K) and 0.761 W/(m·K) of 1.5 wt% CuO and Fe2O3 nano‐enhanced phase change materials (NePCMs), respectively. Based on the DSC results, the melting temperature and heat of fusion of NePCMs stayed stable with nanoparticles but increased significantly after adding TEA. Furthermore, the charging/discharging cyclic behaviors of NePCMs were tested in the cycle test platform. During the cycle test, the melting time of 1.5 wt% CuO NePCM decreased from 657.9 s for pure erythritol to 615.8 s but increased to 757 s and 680.6 s for 1.5 wt% Al2O3 and 1.5 wt% Fe2O3 NePCMs. The solidification time decreased from 311.2 s for erythritol to 179.3 s, 198.5 s, and 132.4 s for 1.5 wt% CuO, 1.5 wt% Al2O3, and 1.5 wt% Fe2O3 NePCMs. Interestingly, the supercooling degree of NePCMs we got from the test was much lower than that from the DSC curves, indicating that the supercooling is related to the sample size. These results testify that CuO and Fe2O3 nanoparticles can improve the thermal conductivity of erythritol effectively. [ABSTRACT FROM AUTHOR]

This study described the antimicrobial activities of waste biomass-mediated Cu _2 O/ZnO bi-oxide (BiO) nanocomposites; The Orange peels extract (OPE), and lemon peels extract (LPE), were used to synthesize the bioxide nanoparticles (NPs) designated as OPE/BiONPs, and LPE/BiONPs respectively, and characterized with x-ray diffraction (XRD), and zeta potential (ZP); The average crystalline sizes computed were 11.57 nm and 13.36 nm for OPE/BiONPs and LPE/BiONPs respectively; The zeta potentials values were −36.8 mV, and −35.5 mV for OPE/BiONPs, and LPE/BiONPs respectively; Polyacrylonitrile (PAN) polymer and the BiONPs blends were electrospun into nanofibers to get unblended PAN nanofiber (NF), OPE/BiO NF, and LPE/BiO NF; Scanning electron microscopic (SEM) analysis was used to determine the morphology of the electrospun nanocomposites; The NF, the OPE/BiO NF, and LPE/BiO NF possessed average diameters of 833 ± 125, 282.86 ± 29, and 558.76 ± 81 nm respectively; The nanofibers were examined for their antimicrobial activities against five (5) pathogens of public health significance comprising Gram-positive ( Bacillus cereus and Enterococcus faecalis ) and Gram-negative ( Salmonella enteritidis, Escherichia coli, and Vibrio cholerae ) bacteria, using the standard dilution microplate-method; The synthesized nanomaterials showed various levels of inhibitory activities against the target pathogens. The LPE/BiO NPs exhibited 98% inhibition to the growth of Enterococcus faecalis at a concentration of 810 μ g ml ^−1 , while OPE/BiO NPs showed 71% inhibition to the Escherichia coli at a concentration of 243 μ g ml ^−1 . The LPE/BiONF had 72% inhibition of S. enteritidis at MIC of 2.7 mg ml ^−1 . The antimicrobial activities of CPE/BiONPs, LPE/BiONF and their NFCs could have a comparative advantage against commercial antibiotics and hence could be used in the control of waterborne pathogens.

The efficient electron transport layer (ETL) plays a critical role in the performance of perovskites solar cells (PSCs). Ideally, an unobstructed network with smooth channels for electron flow is required, which is lacking in the pristine TiO2-based ETL. As a potential solution, here we tuned the structure of TiO2 via optimized heteroatom doping of Al. Different concentrations (1, 2, and 3 wt%) of Al were doped in TiO2 and were successfully applied as an ETL in PSC using spin coating. A significant difference in the structural, opto-electronic, chemical, and electrical characteristics was observed in Al-doped TiO2 structures. The opto-electronic properties revealed that Al doping shifted the absorption spectra toward the visible range. Pure titania possesses a bandgap of 3.38 eV; however, after 1, 2, and 3% Al doping, the bandgap was linearly reduced to 3.29, 3.25, and 3.18 eV, respectively. In addition, higher light transmission was observed for Al-doped TiO2, which was due to the scattering effects of the interconnected porous morphology of doped-TiO2. Al-doped titania shows higher thermal stability and a 28% lower weight loss and can be operated at higher temperatures compared to undoped titania (weight loss 30%) due to the formation of stable states after Al doping. In addition, Al-doped TiO2 showed significantly high conductivity, which provides smooth paths for electron transport. Thanks to the effective tuning of band structure and morphology of Al-doped TiO2, a significant improvement in current densities, fill factor, and efficiency was observed in PSCs. The combined effect of better Jsc and FF renders higher efficiencies in Al-doped TiO2, as 1, 2, and 3% Al-doped TiO2 showed 12.5, 14.1, and 13.6% efficiency, respectively. Compared to undoped TiO2 with an efficiency of 10.3%, the optimized 2% Al doping increased the efficiency up to 14.1%. In addition, Al-doped TiO2 also showed improvements in antibacterial effects, required for photoactive textiles.

Fabrication of gas sensors is witnessing great advancements due to recent progress in synthesis of metal-oxide nanoparticles with custom designed characteristics. Composition of nanoparticles allows access to the chemical features of the surface nanoparticles and utilization of physical features of the core nanoparticles. Furthermore, it enables formation of p − n heterojunctions among nanoparticles with depletion layers that enables to control the follow of charge carriers. Herein, nanoparticles of Fe3O4 and PdO are synthesized using a coprecipitation process and explored for their implementation for gas sensor applications. The mean grain sizes are 7.7 ∓ 2.3 nm and 6.4 ∓ 1.5 nm for Fe3O4 and PdO, respectively. The sensor devices are produced by depositing nanoparticles (dispersed) on substrates with pre-deposited interdigitated electrodes. Electrical characteristics are examined using impedance spectroscopy that enables calculation of the activation energy Ea = 0.66 ± 0.04 eV. The produced sensors are selective for both H2 and H2S within different concentration ranges, where their minimum responses at ambient temperature are 1200 and 10 ppm for H2 and H2S gases, respectively. The gas sensor devices fabricated in this work exhibit potential for practical implementation because of their numerous advantages that incorporate simplified fabrication technique, low power consumption due to their functionality at ambient temperature, extraordinary sensitivity, practical response time, as well as their core that consists of magnetic nanoparticles which simplify their recycling. [ABSTRACT FROM AUTHOR]

Fabrication of gas sensors is witnessing great advancements due to recent progress in synthesis of metal-oxide nanoparticles with custom designed characteristics. Composition of nanoparticles allows access to the chemical features of the surface nanoparticles and utilization of physical features of the core nanoparticles. Furthermore, it enables formation of p − n heterojunctions among nanoparticles with depletion layers that enables to control the follow of charge carriers. Herein, nanoparticles of Fe3O4 and PdO are synthesized using a coprecipitation process and explored for their implementation for gas sensor applications. The mean grain sizes are 7.7 ∓ 2.3 nm and 6.4 ∓ 1.5 nm for Fe3O4 and PdO, respectively. The sensor devices are produced by depositing nanoparticles (dispersed) on substrates with pre-deposited interdigitated electrodes. Electrical characteristics are examined using impedance spectroscopy that enables calculation of the activation energy Ea = 0.66 ± 0.04 eV. The produced sensors are selective for both H2 and H2S within different concentration ranges, where their minimum responses at ambient temperature are 1200 and 10 ppm for H2 and H2S gases, respectively. The gas sensor devices fabricated in this work exhibit potential for practical implementation because of their numerous advantages that incorporate simplified fabrication technique, low power consumption due to their functionality at ambient temperature, extraordinary sensitivity, practical response time, as well as their core that consists of magnetic nanoparticles which simplify their recycling. [ABSTRACT FROM AUTHOR]

The properties of nanomaterials such as perlite nanoparticles and their increased application have raised concerns about their probable toxic impacts on the aquatic ecosystems and algae. Here, a novel biochemical synthesis and immobilization of CuO is reported on perlite nanoparticles (CuO/Per-NPs) and its toxic effect on alga has been compared with nanoperlites. This biosynthesis of CuO/Per-NPs performed using phytochemicals of Haematococcus pluvialis, Sargassum angustifolium, and walnut leaves in the aqueous extract. The structural, morphological, and colloidal properties of the as-synthesized nanoparticles have been confirmed by various methods. According to the obtained results, the morphology of the synthesized CuO/Per-NPs was spherical with sizes ranging from about 13 to 24 nm. Besides, the effects of Per-NPs and CuO/Per-NPs on unicellular algae H. pluvialis were studied. The changes in the amount of chlorophyll a, chlorophyll b, and Carotenoids in the presence of different concentrations of Per-NPs (25, 50, 100 mg/L) were more than CuO/Per-NPs. Also, decreased growth rate and efficiency of photosystem II confirmed the toxic effects of Per-NPs. However, the toxicity of CuO/Per-NPs appears to be lower than that of Per-NPs, which can be due to the changes in the surface and cationic charge of modified nanoperlit. These changes lead to a decrease in the interaction of nanoparticles with H. pluvilalis and a reduction in ROS production. Finally, the results of GC-MS used to evaluate volatile compounds, indicated an increase in the number of phenolic compounds in comparison to the control samples in 25, 50, and 100 mg/L treatments of nano-perlite. Highlights: The toxicity of biosynthesized CuO/Per-NPs appears to be lower than that of Per-NPs which are used as superabsorbent of heavy metals in water environment. Decreasing growth rate and photosystem II efficiency confirmed the toxic effects of Per-NPs on Alga Haematococcus pluvialis. Lower toxicity effect of CuO/Per-NPs than Per-NPs can be due to the changes in the surface and cationic charge of modified nanoperlit. The changes in the surface of modified nanoperlit (CuO/Per-NPs) may lead to a decrease in the interaction of nanoparticles with H. pluvilalis and a reduction in ROS production. [ABSTRACT FROM AUTHOR]

Facile and efficient methods to prepare active electrodes for redox reactions of electrolyte ions are required to produce efficient and low-cost redox flow batteries (RFBs). Carbon-fiber electrodes are widely used in various types of RFBs and surface oxidation is commonly performed to enhance the redox reactions, although it is not necessarily efficient. Quite recently, a technique for nanoscale and uniform surface etching of the carbon fiber surface was developed and a significant enhancement of the negative electrode reaction of vanadium redox flow batteries was attained, although the enhancement was limited to the positive electrode reaction. In this study, we attempted to obtain an additional enhancement effect of metal-oxide nanoparticles without the need for further processing steps. A coating with carbonaceous thin films was obtained coating by sublimation, deposition, and pyrolysis of tin(II) phthalocyanine (SnPc) on a carbon fiber surface in a single heat-treatment step. The subsequent thermal oxidation concurrently achieved nanoscale surface etching and loading with SnO2 nanoparticles. The nanoscale-etched and SnO2-loaded surface was characterized by field-emission scanning electron microscopy (FESEM), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The activity for the vanadium ion redox reactions was evaluated by cyclic voltammetry (CV) to demonstrate the enhancement of both the positive and negative electrode reactions. A full cell test of the vanadium redox flow battery (VRFB) showed a significant decrease of the overpotential and a stable cycling performance. A facile and efficient technique based on the nanoscale processing of the carbon fiber surface was presented to substantially enhance the activity for the redox reactions in redox flow batteries.

In this study, the synthesis and characterization of functionalized flax fabric with adequate titanium and aluminium precursors is presented (AlCl3 or Ti(C4H9O)4). The modified flax fabrics were analysed both visually and instrumentally by IR spectroscopy and microscopy, scanning electron microscopy (SEM) and thermal analysis (DTA-TG). The data highlight that the nature and amount of functionalizing agent induce important morphological changes of the surface. These flax fabrics decorated with alumina or titanium dioxide nanoparticles are desired to be used as reinforcing agents of different recycled polyethylene terephthalate. The properties will be designed by the nature, processing route and amount of the precursors used for the surface modification of these cellulosic fibres/fabrics, the surface decoration increasing their thermal properties (especially thermal stability) but also surface properties (especially roughness, hydrophilic/hydrophobic ratio, etc.). All these factors will finally induce improved compatibility between phases and thus improved physico-mechanical and thermal properties. Taking into account the large amount of natural cellulosic fibres and recycled thermoplastic polymers, added-value products will be obtained and at the same time some environmental issues are solved. The expected applications can include the fabrication of automotive parts, protective panels for highways and railways, etc. [ABSTRACT FROM AUTHOR]

In Europe REACH framework directive imposes data acquisition concerning toxicity on acquatic species before the commercialization of chemicals to assess environmental risks. According to official methods, exposure tests are performed under in vitro and standardized conditions: OECD's guideline rules external variables such as water type, feeding conditions, and exposure time. As consequence, such obtained results could be different from effects observed in natural environments. This study collects effects within 24–96 h of exposure to nano metal-oxides (ZnO, TiO2) on D. magna obtained by the exposure under standard OECD conditions comparing them with results obtained by the exposure under more similar conditions to natural environment (i.e. mixture, feeding). High doses exposure determines gas-bubble disease. Animals exposed to LC10 actively ingest nanoparticles under both fasting and feeding conditions. Furthermore, body burial by a coat of nanoparticles thicker in mixtures than in single dispersions was recorded. Furthermore, results show that: (i) effects increase over time; (ii) n-ZnO results less effective than n-TiO2 in both single dispersion, and mixture; (iii) the presence of surfactant increases toxicity of nanoparticles; (iv) immobilization is a more sensitive endpoint than mortality; (v) feeding increases test sensitiveness improving differences among treated and controls till 96 h and allowing longer exposure times than standard OECD test. As general remark, this study provides evidence that in vitro ecotoxicological results obtained under standardized OECD conditions could be significant different to animals' responses under natural (feeding and mixtures) exposure conditions. [ABSTRACT FROM AUTHOR]

Abstract: Functional heterofibrous hybrid materials are prepared in an integrative approach from aqueous dispersions of nanofibrillated cellulose and sepiolite by applying high shear homogenization and ultrasound irradiation. Both types of nanofibers remain physically cross‐linked forming homogeneous and very stable high‐viscosity gels that can be shaped as films and considered as “hybrid nanopapers” as well. The presence of sepiolite modifies the surface roughness of the films resulting from the casting process, which can be rendered hydrophobic, as the hydrophilic characteristics of both components resulted modulated. In addition, these fibrous hybrid systems can benefit from the properties provided by the two components, such as mechanical behavior, surface properties, and chemical reactivity. Moreover, further assembly of these hybrid nanopapers to other particulate solids, such as carbon nanotubes, magnetite, or ZnO nanoparticles, results in multifunctional hybrid nanopapers, opening a versatile way for developing other numerous organic–inorganic materials of interest in diverse applications. [ABSTRACT FROM AUTHOR]

Recently, China became one of the largest nanomaterial markets in the world. The wide use of ZnO nanoparticles in a number of products implies an increasing release in marine environment and consequently the evaluation of the potential effects upon marine organisms largely cultured in China for commercial purposes, such as invertebrate bivalves is a current need. To this aim, survival, bioaccumulation, and transcription pattern of key genes, p53, PDRP, SOD, CAT, and GST, involved in DNA damage/repair and antioxidation, in Mytilus galloprovincialis digestive gland, exposed to ZnO NPs (<100 nm) and ZnO bulk (150-200 nm) for 4 weeks, were evaluated. ZnSO4 was also assessed to appraise the role of zinc ions. Starting from 72 h, increasing mortality values along the exposure time were observed for all ZnO compounds. The highest difference was evident after 28 d when NPs resulted three times more toxic than bulk, (LC50) = 0.78 mg Zn/L (confidence limits: 0.64, 1.00) and 2.62 mg Zn/L (confidence limits: 1.00, 4.00), respectively. For ZnSO4 the (LC50) was always the lowest reaching the minimum value at 28 d 0.25 mg Zn/L (confidence limits: 0.10-0.40). Digestive gland showed higher uptake rate of ionic Zn respect to ZnO NPs and bulk during the first three days of exposure. In particular at the end of the exposure time (28 d) at 1 mg Zn/L the rank of Zn uptake rate was Zinc ion > ZnO NPs > ZnO bulk. The relative expression of investigated genes evidenced that distinct actions of apoptosis and antioxidation occurred in M. galloprovincialis exposed to ZnO NPs with a peculiar pattern dependent on exposure time and concentration. Application of the qRT-PCR technique revealed evidence of sensitivity to the nanomaterial since the first time of exposure. [ABSTRACT FROM AUTHOR]

Metal-based nanoparticles (NPs) are the most widely used engineered nanomaterials. The individual toxicities of metal-based NPs have been plentifully studied. However, the mixture toxicity of multiple NP systems (n ≥ 3) remains much less understood. Herein, the toxicity of titanium dioxide (TiO2) nanoparticles (NPs), silicon dioxide (SiO2) NPs and zirconium dioxide (ZrO2) NPs to unicellular freshwater algae Scenedesmus obliquus was investigated individually and in binary and ternary combination. Results show that the ternary combination systems of TiO2, SiO2 and ZrO2 NPs at a mixture concentration of 1 mg/L significantly enhanced mitochondrial membrane potential and intracellular reactive oxygen species level in the algae. Moreover, the ternary NP systems remarkably increased the activity of the antioxidant defense enzymes superoxide dismutase and catalase, together with an increase in lipid peroxidation products and small molecule metabolites. Furthermore, the observation of superficial structures of S. obliquus revealed obvious oxidative damage induced by the ternary mixtures. Taken together, the ternary NP systems exerted more severe oxidative stress in the algae than the individual and the binary NP systems. Thus, our findings highlight the importance of the assessment of the synergistic toxicity of multi-nanomaterial systems. [ABSTRACT FROM AUTHOR]

Development of efficient antimicrobial metal-oxide nanoparticles (MONPs) is important to advance in the biomedical and in the industrial fields. Herein, ZnO-CuO nanoparticles with improved antibacterial were developed by simple double precipitation technique and their properties were studied. The bactericide ability of ZnO-CuO nanoparticles was investigated againstEscherichia coli. The ZnO-CuO0.5exhibited high activity againstE.coliat high and low concentration levels. The MONPs were analyzed via FTIR, UV-visible/DRS, PL, SEM/EDS, TEM, XRD and TGA analysis. These results show the formation of hexagonal wurtzite-monoclinic phase morphology and the thermal characteristics of the ZnO-CuO nanoparticles emphasize the potential of these dual nanooxide materials. The intensity of the emission band of ZnO was decreased following the increase in the CuO concentrations and the order is as follows: CuO < ZnO-CuO0.5< ZnO-CuO0.1< ZnO. The co-assembled MONPs developed may function as potential candidates for advanced biomedical and industrial applications. [ABSTRACT FROM PUBLISHER]

Recently, III-V semiconductor nanowires (NWs) are widely investigated as field-effect transistors (FETs) for high-performance electronics, optoelectronic, and others; nevertheless, effective control in their device performances, especially the threshold voltage is still not well attained, which can potentially limit their practical uses for technological applications. This study reports a simple but highly reliable metal-oxide nanoparticle (NP) surface decoration approach onto the device channel in order to manipulate electrical characteristics of III-V NWFETs, such as the threshold voltage and transistor operation, through the manipulation of free electrons in the NW channel (i.e., InAs, InP, and In0.7Ga0.3As) via depositing various metal-oxide NPs with different work functions. Without any passivation layer, this decoration approach can yield the stable NW device characteristics in ambient. Notably, the versatility of our decoration scheme has also been illustrated through the realization of highperformance enhancement-mode InAs NW-paralleled-arrayed devices as well as the configuration of highly efficient InAs NW NMOS inverters, comprising of both depletion and enhancement mode devices. All these results further elucidate the technological potential of this decoration approach for future high-performance, low-power nanoelectronic device fabrication, and circuit integration. [ABSTRACT FROM AUTHOR]

A novel combination of titanium oxide (TiO2)/gold (Au)/multiwalled carbon nanotubes (MWCNTs) nanocomposite (NC) was synthesised by sol– gel method. MWCNT functionalisation by modified Hummers method. TiO2 /Au nanoparticles (NPs) were synthesised by biological method using Terminalia chebula bark extract. MWCNT/TiO2 /Au NC samples were characterised by X‐ray diffraction, ultraviolet–visible–diffuse reflectance spectra, microRaman, scanning electron microscopy and high‐resolution‐transmission electron microscopy analyses. The photocatalytic performance of the obtained for NC toward the decomposition of congo‐red and the antimicrobial activity for inhibition of Gram positive (Bacillus subtilis, Streptococcus pneumonia and Staphylococcus aureus), Gram negative (Shigella dysenderiae, Proteus vulgaris and Klebsiella pneumonia) and fungal strains have been evaluated and the results are compared with positive control ampicillin. The metal and metal–oxide NPs have a lower sorption capacity. The herbicidal bond to the tested CNTs by the combination of electron donor–acceptor interactions and hydrogen bonds. In particular, the dispersion of NC and control of sodium borohydride, it has more efficient effect on the photodegradation and antibacterial activity of positive control of ampicillin. The NC material has exhibited maximum photodegradation and antibacterial activity results of zone of inhibition when compared with control samples. [ABSTRACT FROM AUTHOR]

Metal-based nanoparticles (NPs) are the most widely used engineered nanomaterials. The individual toxicities of metal-based NPs have been plentifully studied. However, the mixture toxicity of multiple NP systems (n ≥ 3) remains much less understood. Herein, the toxicity of titanium dioxide (TiO2) nanoparticles (NPs), silicon dioxide (SiO2) NPs and zirconium dioxide (ZrO2) NPs to unicellular freshwater algae Scenedesmus obliquus was investigated individually and in binary and ternary combination. Results show that the ternary combination systems of TiO2, SiO2 and ZrO2 NPs at a mixture concentration of 1 mg/L significantly enhanced mitochondrial membrane potential and intracellular reactive oxygen species level in the algae. Moreover, the ternary NP systems remarkably increased the activity of the antioxidant defense enzymes superoxide dismutase and catalase, together with an increase in lipid peroxidation products and small molecule metabolites. Furthermore, the observation of superficial structures of S. obliquus revealed obvious oxidative damage induced by the ternary mixtures. Taken together, the ternary NP systems exerted more severe oxidative stress in the algae than the individual and the binary NP systems. Thus, our findings highlight the importance of the assessment of the synergistic toxicity of multi-nanomaterial systems.

The present study aims to experimentally and numerically investigate diesel engine's combustion, performance, and exhaust emission characteristics fuelled with tamarind seed oil methyl ester (TSOME) and nanoparticles as fuel additives. The Diesel-RK, a complete thermodynamic cycle engine analysis tool, is employed to assess the engine characteristics. Cerium Oxide (CeO 2) and Aluminium Oxide (Al 2 O 3) nanoparticles are introduced as additives and dispersed in pure TSOME at a concentration of 30 ppm to obtain TSOME + CeO 2 and TSOME + Al 2 O 3 blends correspondingly. The tests are conducted when the engine is loaded from 0 to 100% with intervals of 25%. The research reveals that incorporating CeO 2 and Al 2 O 3 improves the BTE by 17–18% compared to that of TSOME. TSOME + CeO 2 and TSOME + Al 2 O 3 substantially decreased CO 2 , HC, and smoke emissions compared to those of conventional diesel fuel. Furthermore, when CeO 2 and Al 2 O 3 nanoparticles are added into the TSOME fuel, oxides of nitrogen emissions are mitigated by 6–7% compared to TSOME by reducing the fuel consumption. Also, the addition of nanoparticles led to an improvement in combustion characteristics compared to pure TSOME due to the high catalyst role of nanoparticles, which accelerate the chemical reactions during the combustion cycle. Furthermore, the nanoparticles-added test fuels have generally presented the competitive results with each other, but the CeO 2 nanoparticle presented slightly better results in terms of exhaust emissions, while Al 2 O 3 added test fuel gave slightly better results in terms of engine performance. Finally, the results of this research show that metal oxide-based nanoparticles such as CeO 2 and Al 2 O 3 as a fuel additive can improve the characteristics of diesel engines fuelled by biofuels. • Impact of CeO 2 and Al 2 O 3 nanoparticles in TSOME biodiesel in CI engines was experimentally and numerically investigated. • Noticed a good correlation between numerical and experimental results. • Addition of nanoparticles to TOMSE showed enhancement in the BTE by 17–18%. • Oxides of nitrogen emissions are lessened by 6–7%. • Observed an improvement in combustion characteristics with the addition of nanoparticles. [ABSTRACT FROM AUTHOR]

In welding, there is a potential risk due to metal-oxide nanoparticles (MONPs) exposure of workers. To investigate this possibility, the diameter and number particles concentration of MONPs were evaluated in different biological matrices and in personal air samples collected from 18 stainless-steel welders and 15 unexposed administrative employees engaged in two Italian mechanical engineering Companies. Exhaled breath condensate (EBC) and urine were sampled at pre-shift on 1st day and post-shift on 5th day of the workweek, while plasma and inhalable particulate matter (IPM) at post-shift on 5th day and analysed using the Single Particle Mass Spectrometry (SP-ICP-MS) technique to assess possible exposure to Cr 2 O 3 , Mn 3 O 4 and NiO nanoparticles (NPs) in welders. The NPs in IPM at both Companies presented a multi-oxide composition consisting of Cr 2 O 3 (median, 871,574 particles/m3; 70 nm), Mn 3 O 4 (median, 713,481 particles/m3; 92 nm) and NiO (median, 369,324 particles/m3; 55 nm). The EBC of welders at both Companies showed Cr 2 O 3 NPs median concentration significantly higher at post-shift (64,645 particles/mL; 55 nm) than at pre-shift (15,836 particles/mL; 58 nm). Significantly lower Cr 2 O 3 NPs median concentration and size (7762 particles/mL; 44 nm) were observed in plasma compared to EBC of welders. At one Company, NiO NPs median concentration in EBC (22,000 particles/mL; 65 nm) and plasma (8248 particles/mL; 37 nm) were detected only at post-shift. No particles of Cr 2 O 3, Mn 3 O 4 and NiO were detected in urine of welders at both Companies. The combined analyses of biological matrices and air samples were a valid approach to investigate both internal and external exposure of welding workers to MONPs. Overall, results may inform suitable risk assessment and management procedures in welding operations. [Display omitted] • In inhalable particulate matter Cr 2 O 3 nanoparticles were the predominant, followed Mn 3 O 4 and NiO, during welding operations. • In exhaled breath condensate of welders higher Cr 2 O 3 and NiO nanoparticles were found in post-shift than pre-shift samples. • The translocation of inhaled Cr 2 O 3 and NiO nanoparticles were found in plasma of welders. • The methodology and findings step forward risk assessment and management in environmental and occupational health. [ABSTRACT FROM AUTHOR]

The effect of humic acid (HA) or fulvic acid (FA) on reactive oxygen species (ROS) generation by six metal-oxide nanoparticles (NPs) and their toxicities toward Escherichia coli was investigated under UV irradiation. Dissolved organic matter (DOM) decreased OH generation by TiO 2 , ZnO, and Fe 2 O 3 , with FA inhibiting OH generation more than HA. The generated OH in NPs/DOM mixtures was higher than the measured concentrations because DOM consumes OH faster than its molecular probe. None of NPs/FA mixtures produced O 2 − . The generated O 2 − concentrations in NPs/HA mixtures (except Fe 2 O 3 /HA) were higher than the sum of O 2 − concentrations that produced as NPs and HA were presented by themselves. Synergistic O 2 − generation in NPs/HA mixtures resulted from O 2 reduction by electron transferred from photoionized HA to NPs. DOM increased 1 O 2 generation by TiO 2 , CuO, CeO 2 , and SiO 2 , and FA promoted 1 O 2 generation more than HA. Enhanced 1 O 2 generation resulted from DOM sensitization of NPs. HA did not increase 1 O 2 generation by ZnO and Fe 2 O 3 primarily because released ions quenched 1 O 2 precursor ( 3 HA*). Linear correlation was developed between total ROS concentrations generated by NPs/DOM mixtures and bacterial survival rates ( R 2 ≥ 0.80). The results implied the necessity of considering DOM when investigating the photoreactivity of NPs. [ABSTRACT FROM AUTHOR]

The thermal decomposition of manganese and cobalt-terephthalate Metal-Organic Framework precursors was utilized as a synthetic route for fabrication of Co 3 O 4 , Mn 3 O 4 and Mn 2 O 3 nanoparticles. The prepared metal oxide nanoparticles of Co 3 O 4 , Mn 3 O 4 and Mn 2 O 3 possess average size diameter of 40, 60 and 80 nm respectively. The findings demonstrate that spinel structure nanoparticles of Co 3 O 4 and Mn 3 O 4 exhibit efficient catalytic activity toward heterogeneous olefin epoxidation in the presence of tert -butyl hydroperoxide. In addition, Co 3 O 4 and Mn 3 O 4 nanoparticles illustrated excellent catalytic stability and reusability for nine and four cycles, respectively, toward olefin oxidation. [ABSTRACT FROM AUTHOR]

Metal and metal-oxide nanoparticles (NPs) are used in numerous applications and have high likelihood of entering engineered and natural environmental systems. Careful assessment of the interaction of these NPs with bacteria, particularly biofilm bacteria, is necessary. This perspective discusses mechanisms of NP interaction with bacteria and identifies challenges in understanding NP-biofilm interaction, considering fundamental material attributes and inherent complexities of biofilm structure. The current literature is reviewed, both for planktonic bacteria and biofilms; future challenges and complexities are identified, both in light of the literature and a dataset on the toxicity of silver NPs toward planktonic and biofilm bacteria. This perspective aims to highlight the complexities in such studies and emphasizes the need for systematic evaluation of NP-biofilm interaction. [ABSTRACT FROM AUTHOR]

Dendrimer-encapsulated ruthenium oxide nanoparticles (DEN-RuO2) have been used as catalysts in lithium-oxygen (Li-O2) batteries for the first time. The results obtained from ultraviolet-visible spectroscopy, electron microscopy and X-ray photoelectron spectroscopy show that the nanoparticles synthesized by the dendrimer template method are ruthenium oxide, not metallic ruthenium as reported by other groups. The DEN-RuO2 significantly improves the cycling stability of Li-O2 batteries with carbon electrodes and decreases the charging potential even at ten times less catalyst loading than those reported previously. The monodispersity, porosity, and large number of surface functionalities of the dendrimer template prevent the aggregation of the RuO2 nanoparticles, making their entire surface area available for catalysis. The potential of using DEN-RuO2 as a standalone cathode material for Li-O2 batteries is also explored. [ABSTRACT FROM AUTHOR]