Addition Of Isopropanol Research Articles

Tailoring the crystalline and amorphous phase ratios of TiO2 through the use of organic additives during hydrothermal synthesis

The photocatalytic properties of TiO2 are primarily determined by its crystallinity and crystalline phase ratios. To improve the photocatalytic properties of TiO2, greater control over the formation of crystalline and amorphous phases during synthesis is therefore required. In this study, we demonstrate how the addition of minute amounts of three organic compounds (isopropanol, acetone and acetic acid) during hydrothermal treatment affects the amorphous and crystalline phase ratios: the addition of isopropanol or acetone accelerates the phase transition from anatase and brookite to rutile, whereas the addition of acetic acid inhibits the transformation of anatase to rutile, increasing the content of amorphous phase compared to samples where no organic compound was added. We show that the combination of the organic compound added, along with the duration of the hydrothermal treatment, can be used to tailor the phase composition of TiO2, so as to obtain either: i) TiO2 with a high content of both rutile and amorphous phase, ii) TiO2 with a high rutile content and iii) TiO2 with different ratios of all four phases, when the duration of synthesis is short (2–4 h). The materials synthesized exhibited high photocatalytic activity (in most cases higher than P25), which is attributed to the beneficial phase composition and high specific surface area.

Propeller shaped triarylamine acid: An ultra-sensitive fluorescence probe for distinguishing propanol isomers and water sensing in organic solvents

The photophysical properties of conformationally flexible (TPA-C) and partially rigidified (Cz-C) triarylamine acids were explored in solid as well as solution state and correlated with the structure. TPA-C and Cz-C exhibited moderate solid-state fluorescence (Φf = 6.2 % (TPA-C) and 5.6 % (Cz-C)) and self-reversible mechanofluorochromism. TPA-C produced fluorescent polymorphs (TPA-C-1 and TPA-C-2) with tunable fluorescence. TPA-C-1 showed unusual carboxylic acid intermolecular interactions whereas TPA-C-2 and Cz-C showed usual carboxylic acid dimer. TPA-C exhibited strong solvent polarity dependent tunable fluorescence (Φf = 0.01 to 0.11 compared to quinine sulphate standard) but Cz-C was non-emissive in the solution state. The dual emissive TPA-C showed highly sensitive fluorescence changes in organic solvents (CH3CN, THF, DMF, EtOH) when trace amount of water was added. In CH3CN, TPA-C showed weak fluorescence at 474 nm and addition of water (1 %) exhibited significant blue shift (λmax = 416 nm). The fluorescence intensity was gradually decreased with blue shifting in DMF, THF and EtOH with water addition. Importantly, TPA-C showed drastically different fluorescence in n-propanol (n-PA) and iso-propanol (IPA). TPA-C in n-PA showed fluorescence at 408 nm that was clearly red shifted to 438 nm with 0.1 % addition of IPA. The limit of detection (LOD) of water in CH3CN, DMF, THF and EtOH by TPA-C revealed 0.02, 0.7, 0.08 and 0.77 %, respectively. The LOD of IPA sensing in n-PA is 0.05 % and indicated the very efficient sensing and distinguishing propanol isomers. Thus, simple triphenylamine acid showed excellent water sensing and propanol isomers discrimination that could be attributed to the twisted intramolecular charge transfer (TICT) formation.

In situ fabrication of NIR-II responsive TiO2 bio-metasurface for photothermal antibacterial and enhanced osseointegration

Titanium implants, widely used in orthopedic and dental applications, often face challenges due to inadequate osseointegration and the risk of postoperative infections, which can potentially lead to implant failure. To address this issue, we developed a titanium implant with an in-situ fabricated anatase TiO2 metasurface, characterized by a subwavelength thickness and a preferential orientation of the (001) facets. This metasurface, which consists of uniformly distributed nano-crystallites of approximately 30 nm in size, aims to enhance both osseointegration and antibacterial properties. The addition of isopropanol (IPA) to the precursor solution used in the fabrication process played a crucial role in controlling the grain size and coating thickness of the metasurface. This process led to a redshift of the light absorption peak into the near-infrared (NIR)-II region, thereby increasing the penetration depth of photothermal therapy. The implants with TiO2 metasurface exhibited increased hydrophilicity, rapid apatite formation in simulated body fluid, and an effective photothermal response under NIR-II light, showing significant antibacterial activity against E. coli and S. aureus. In vivo experiments in rabbits indicated superior bone regeneration and osseointegration around the implants with TiO2 metasurface compared to the control titanium implants. At 4 weeks postoperatively, the bone volume to tissue volume (BV/TV) ratio within the implant was 53.94 %, and by 8 weeks, the implants were nearly entirely filled with new bone, with a BV/TV ratio of approximately 70 %. The findings suggest that the TiO2 metasurface, which combines antibacterial and bioactive features, has the potential to reduce the risk of postoperative infections and improve clinical outcomes.

Self-assembly synthesis of two dimensional vanadium oxide nanotriangles for photocatalytic application

For the first time, we report a Two Dimensional Phase Transfer Reaction (2DPTR) between the three different phases of 2D nanosheets and their applications in catalysis and hydrogen evolution. Plasmonic two-dimensional (2D) nanomaterials have created a niche for themselves in a variety of applications due to their unique and tunable optical properties. In the present work, we report a simple method for the synthesis of three different phases of the 2D vanadium oxide nanosheets to convert to each other at room temperature (amorphous, nanoflakes and nanotriangles). We developed a two-step method that first involves probe ultrasonication to mediate the synthesis of 2D vanadium oxide nanoflakes (VNFs) at room temperature and secondly, their phase transformation to VNTs using hydrogen peroxide or Isopropyl Alcohol (IPA) as the phase transfer reagents. 2D VNTs have been studied for morphological, structural, and optical properties by using a variety of instruments, including TEM, UV–Vis, EPR, RAMAN, and XPS. Thus, after treatment with hydrochloric acid (HCl), the 2D vanadium oxide nanoflakes are easily converted to the 2D amorphous nanosheets (Vam) which then regain crystallinity in the form of VNTs after the addition of Hydrogen peroxide or IPA, with a plasmonic peak around 450 nm. Oxygen vacancies are created in the VNFs, after treatment with HCl, which results in the crystal lattice breakdown. These oxygen vacancies were filled up again when the nanoflakes were treated with hydrogen peroxide or IPA and then resulted in the formation of VNTs. The UV–vis spectroscopy was performed with different addition of concentrations of H2O2, the limit of detection 34.1 µM and linear range 0 to 1000 µM found. Also, a selectivity study proved H2O2 in these 2D VNTs. Vam and VNT also showed effective photocatalytic activity against KMnO4 which is a strong oxidizing reagent used in water treatment. The synthesis and plasmonic nature of the 2D VNTs and the photocatalytic activity of Vam and VNT present in this study is a pioneer report for these novel 2D nanomaterials and they can be further explored with many possibilities in many fields including sensing, catalysis, energy, biomedicine, and many other significant applications in the near future.

Co-solvent strategy for highly efficient perovskite solar cells by spray coating

The ultrasonic spray coating has been shown to be an effective technique for scaling up production. The nucleation and crystallization process of the perovskite film prepared by the ultrasonic spraying approach is more complicated than that by the spin coating, but they are essential to gaining efficient perovskite solar cells (PSCs). At the same time, the green solvent is the primary problem that must be solved in the process of PSCs commercialization. In this paper, the low boiling point and green solvent isopropyl alcohol (IPA) is introduced into the perovskite precursor solution to prepare FAPbI3 perovskite by ultrasonic spraying. The addition of IPA enhanced the saturated vapor pressure of the precursor solution, which can create the local chemical microenvironment on the film surface and subsequently retard the nucleation rate from 8.31 s to 8.54 s at nucleation stage. The local chemical improves the initial homogeneity of the sol–gel phase and then leads to improved structural and optoelectronic properties within the FAPbI3 film via sufficient crystallization from the sol–gel phase to α-FAPbI3. Ultimately, IPA-based PSCs exhibit the champion device efficiency of 22.43 %. The good long-term stability of PSCs (maintain more than 90 % of the initial efficiency after 1000 h, and keep 80 % after 400 h) in ambient conditions.

Revealing the Hidden Role of Radical Scavengers: Unraveling the Key to Tailoring the Formation of the hcp PdHx Phase in Graphene Liquid Cells

AbstractRadiation chemistry enables the synthesis of colloidal nanoparticles without chemical reducing agents, yielding metal nanoparticles via simple and direct processes. Aliphatic alcohols are widely used to promote the formation of nanoparticles in radiolytic synthesis by inhibiting the reoxidation of these metal nanoparticles by scavenging hydroxyl radicals. However, the role of the scavenger has been limited to simply accelerating the formation of the nanoparticles without altering their nature. Herein, the role of radical scavengers is investigated in determining the type of metal nanoparticles formed, with the scavenger concentration playing a crucial role. It is found that the addition of isopropyl alcohol controls the formation of hexagonal close‐packed (hcp) palladium hydride (PdHx) nanoparticles that are previously synthesized for the first time via radiation chemistry by increasing the concentrations of hydrated electrons and hydrogen radicals. This discovery reveals a more active role for radical scavengers in radiolytic syntheses, and this strategy can be used for the cost‐effective mass production of hcp PdHx nanoparticles.

Enhancement of Cu2ZnSn(S, Se)4 device performance using an IPA/MOE hybrid solvent system in ambient air.

In this work, a mixed precursor solvent system comprising isopropyl alcohol (IPA) and 2-methoxy ethanol (MOE) is introduced for the fabrication of Cu2ZnSn(S, Se)4 (CZTSSe) thin films under ambient conditions. The effects of different IPA/(MOE + IPA) ratios on the characteristics of CZTSSe films and the corresponding devices were investigated. Our research results indicate that the addition of IPA enhances the wettability of Cu-Zn-Sn-S precursor solution on the substrate, reduces Sn loss in the film during high-temperature annealing, and diminishes band tail states. Additionally, adding IPA leads to effective enlargement of grain size, improved crystallinity, and enhanced light absorption. However, excessive content of IPA negatively impacts CZTSSe film properties and the device's performance. Notably, when substituting 20% of MOE with IPA, the short-circuit current density (JSC) increased from 30.84 mA cm-2 to 35.55 mA cm-2 in the resulting CZTSSe device, and the efficiency improved from 9.19% to 10.63%. This work provides a new method of a solvent system for preparing efficient kesterite-based solar cells.

РЕЗУЛЬТАТЫ ИССЛЕДОВАНИЙ ПО ОПРЕДЕЛЕНИЮ РАЦИОНАЛЬНОГО СПОСОБА УДАЛЕНИЯ ЗАГРЯЗНЕНИЙ ИЗ МОТОРНОГО МАСЛА БЕЗ ЕГО СЛИВА ИЗ СИСТЕМЫ СМАЗКИ

Contaminants are formed in diesel internal combustion engines of tractors during operation under the influence of high temperatures and loads on the parts of the cylinder-piston group, which then enter the engine oil, which affects the service life of the oil and the characteristics of the machine-tractor unit. An important measure that affects the contamination of parts and the service life of the oil is flushing the lubrication system during routine replacement of used oil. However, for a number of well-known objective and subjective reasons, this technological method is practically not carried out under real operating conditions. Resource-saving technology for flushing the lubrication system with motor oil running in the tractor engine was developed at TSTU. A number of technological methods for cleaning oil from contaminants and resins under the influence of chemical reagents added to the oil, followed by idling the engine, have been developed. The dependences of changes in contamination, base number, viscosity and color of the oil on the cleaning method, the concentration of the addition of urea, monoethanolamine, and isopropanol reagents were obtained. It has been determined that the addition of isopropanol can increase the flash point of the oil. The dependences of the change in base number and viscosity on the concentration of monoethanolamine with isopropanol in the oil have been established. The rational concentration for adding this additive is 2–3% of the oil volume. It was determined that the color of the oil changes from 9 to 4 points per unit. CNT. Research on the use of finely dispersed contaminants as a separating agent and coagulant has established that 3% vol. carbamide dissolved in ammonium hydroxide allows you to get the best result. Research in this area will be continued and requires confirmation in a wide range of oils and the technological state of tractor engines.

Evaluation of basalt powder as a natural heterogeneous catalyst in photo-Fenton like treatment of atrazine

Basalt powder was employed to degrade atrazine (ATZ) under ultra-violet (UV-C) and visible light (vis) irradiation. The characterization of clay catalyst samples was confirmed the presence of ferrous oxide responsible of the heterogeneous photo-Fenton like reactions. Initial tests, using an ATZ concentration of 20 mg L−1 and raw basalt (B-R) form, validated the photo-Fenton like process as the most efficient. The optimal conditions were identified to be: an initial pH of approximately 6, basalt sintered at 600 °C (B-600) with dosage of 0.5 g L−1 under UV-C and 0.75 g L−1 under vis, and initial H2O2 concentration of 1.6 mM. Consequently, ATZ removal (initially at 5 mg L−1) was measured at 96.0% and 55.8% under UV-C and vis light, respectively, after 180 min of irradiation, with reusability of three cycles. The efficiency of the photo-Fenton process was further investigated by monitoring the toxicity bioassays of growth bacteria inhibition and phytotoxicity of the treated solutions. The results indicated that, under both UV and Vis irradiation, even with high ATZ removal efficiency, the toxicity of the process effluent is less than the initial sample. The initial degradation products were determined by high performance liquid chromatography (HPLC), and ATZ degradation pathway in the photo-Fenton like system was proposed, in which the reaction is primarily initiated by alkylic oxidation. Finally, the reaction’s inhibition upon addition of isopropanol and chloroform as scavengers emphasized the significant role of hydroxyl radicals over superoxide in the oxidation of ATZ.

Microemulsions of Nonionic Surfactant with Water and Various Homologous Esters: Preparation, Phase Transitions, Physical Property Measurements, and Application for Extraction of Tricyclic Antidepressant Drugs from Aqueous Media.

Microemulsions are nanocolloidal systems composed of water, an oil, and a surfactant, sometimes with an additional co-surfactant, which have found a wide range of practical applications, including the extractive removal of contaminants from polluted water. In this study, microemulsion systems, including a nonionic surfactant (Brij 30), water, and esters selected from two homologous series of C1-C6 alkyl acetates and ethyl C1-C4 carboxylates, respectively, were prepared by the surfactant titration method. Phase transitions leading to the formation of Winsor II and Winsor IV microemulsions were observed and phase diagrams were constructed. The dependences of phase transitions on the salinity and pH and the addition of isopropanol as a co-surfactant were also investigated. Some physical properties, namely density, refractive index, electrical conductivity, dynamic viscosity, and particle size, were measured for a selection of Winsor IV microemulsions, providing further insight into some other phase transitions occurring in the monophasic domains of phase diagrams. Finally, Winsor II microemulsions were tested as extraction solvents for the removal of four tricyclic antidepressant drugs from aqueous media. Propyl acetate/Brij 30/H2O microemulsions provided the best extraction yields (>90%), the highest Nernst distribution coefficients (~40-88), and a large volumetric ratio of almost 3 between the recovered purified water and the resulting microemulsion extract. Increasing the ionic strength (salinity) or the pH of the aqueous antidepressant solutions led to an improvement in extraction efficiencies, approaching 100%. These results could be extrapolated to other classes of pharmaceutical contaminants and suggest ester- and nonionic surfactant-based microemulsions are a promising tool for environmental remediation.

Effect of Isopropanol on the Fluorescence of Crude Oil-in-Water Dispersions

Fluorescence spectroscopy is a promising technique to quantify crude oil-in-water because it provides information on both dissolved and dispersed molecules. One of the challenges of measuring properties of dispersions is the creaming of droplets, mainly due to density differences with the continuous phase. The addition of isopropanol to oil-in-water dispersions is an often-recommended trick to prevent the creaming of dispersed oil and obtain more reproducible measurements. Although isopropanol does not in itself fluoresce, the aim of the present work was to investigate if the emission from crude oil-in-water would be affected by the addition of isopropanol. The data set comprised synchronous fluorescence and emission spectra of 193 samples of crude oil-in-water/isopropanol mixtures, with oil concentrations varying from 10 to 1271 mg L–1 covering typical concentrations along the water treatment system offshore and isopropanol mass fractions from 0 to 1. Selected spectral features were used as input for principal component analysis, from which it was observed that the samples clustered into three groups. The isopropanol content in each mixture and, consequently, the dielectric constants were found to be the main underlying factors driving the shape and intensity of the emission bands. In the range of 0.01 to 0.5 w/w of isopropanol, the samples became milky which cleared at higher isopropanol content. Additional experiments showed that significant changes in the spectral shapes and emission intensities were observed more as a function of the isopropanol content than of the actual oil concentration. Furthermore, the quantum yield of crude oil is highly dependent on the isopropanol-to-water fraction, which means that adding isopropanol to crude oil-in-water dispersions is not advisable for oil quantification purposes by fluorescence spectroscopy.

Fabrication of Naturally Derived Chitosan and Ilmenite Sand-Based TiO2/Fe2O3/Fe-N-Doped Graphitic Carbon Composite for Photocatalytic Degradation of Methylene Blue under Sunlight

Fabrication of chitosan and ilmenite sand-based novel photocatalysts through the catalytic graphitization of chitosan is reported. Nanocomposites consisted of TiO2, Fe2O3 and Fe nanoparticles dispersed on a nitrogen-doped graphitic carbon framework. The surface area, pore volume and macropore structure of the carbon matrix is disturbed by the heterogeneously distributed nanoparticles. The extent of graphitization expanded with increasing metal loading as indicated by variation in the ID/IG ratio. The nanomaterial's surface consists of Fe3+ and Ti4+, and graphitic, pyridinic and pyrrolic nitrogen were found in the carbon matrix. The band gap values of the composites varied in the 2.06-2.26 eV range. The photocatalytic activity of the synthesized nanomaterials was determined, and the highest rate constant for the photodegradation of methylene blue under sunlight was 4.4 × 10-3 min-1, which resulted with 10 mg/L MB and 25 mg of the best-performing catalyst. The rate constant rose with increasing concentrations of persulfate added to the medium. The rate constant greatly diminished with the addition of isopropyl alcohol as it scavenged hydroxyl radicals. The presence of co-pollutants including Pb2+, rhodamine B, PO43- and Cl- curtailed the rate of reaction. The activity reduced with an increasing number of uses of the catalyst.

Methanol, isobutanol, kerosene, dimethylfuran, ethanol, and isopropanol additives effects on soot concentration at hydrogen-enriched methane flames

One exciting research topic is biofuels’ effects on soot formation. For this purpose, the combustion behavior of different biofuel pairs, with the main fuel being hydrogen-enriched methane, was investigated in a burner, using laser-induced incandescence (LII). The soot concentrations in several flames were observed for methanol, isobutanol, kerosene, dimethylfuran, ethanol, and isopropanol fuels coupled with hydrogen-enriched methane. Soot concentration was determined for the additive fuels and the effects of soot particles in the flame and Reynolds number on the flame oscillation and soot interaction were examined. The highest soot formation was observed in the h-methane + kerosene and led to large soot fractal aggregates. The isobutanol has 8.8% higher Re sensitivity for oscillation than isopropanol for soot concentration. Also, isobutanol causes a higher amount of soot production as Re increases. The flame area/soot area ratio decreases 1.7 times faster with dimethylfuran usage compared to kerosene. The dimethylfuran created a higher soot field in the flame by 23.9% compared to methanol and 25.9% compared to ethanol. At the tests, the lowest soot concentration was observed in the addition of isopropanol in hydrogen-enriched methane flame.

Impact of Isopropyl Alcohol Addition on Engine Performance in Gasoline Engines

Impact of Isopropyl Alcohol Addition on Engine Performance in Gasoline Engines

Electronic and Structural Variations of a Nickel(0) N-Heterocyclic Phosphenium Complex in Comparison to Group 10 Analogues.

The bonding interactions and electronic structure of a diphosphine pincer ligand featuring an N-heterocyclic phosphenium/phosphido (NHP±) central moiety with nickel are explored. Treating Ni(COD)2 with the pincer ligand [PPP]Cl in the presence of a two-electron phosphine donor ligand PMe3 generates chlorophosphine complex (PPClP)Ni(PMe3) (2a). The cationic Ni complex [(PPP)Ni(PMe3)][BPh4] (3a) can be prepared by subsequent halide abstraction from 2a with NaBPh4. The assignment of 3a as a Ni0/NHP+ complex, based on analysis of structural parameters and computational investigations, lies in contrast to its previously reported group 10 MII/NHP- (M = Pd, Pt) analogues. The activation of O-H bonds across the Ni-PNHP bond is demonstrated by the addition of isopropanol to afford the metal hydride species [(PPOiPrP)Ni(PMe3)(H)][BPh4] (4). Notably, the installation of a P-H bond in the NHP unit by treatment of 2a with LiAlH4 yields (PPHP)Ni(PMe3) (6). The ambiphilic nature of the P-H bond was demonstrated through reactivity studies of P-H bond cleavage in comparison to a Pd analogue (PPHP)Pd(PPh3) (8).

Effects of isopropanol ratio at different excess air ratios on combustion and emissions characteristics of an isopropanol/gasoline dual-fuel combined injection SI engine

Energy crises and environmental issues require the development of green fuels for engines. Isopropanol is an excellent performance renewable alternative fuel for SI engines. It can be prepared by IBE fermentation. However, there have been few studies on the use of isopropanol/gasoline dual fuel in SI engines, especially based on the combined injection technology. For dual-fuel engines, the combined injection technology can further achieve clean combustion by flexibly controlling the fuel composition in the cylinder. Therefore, it is significant to combine the isopropanol/gasoline dual-fuel with the combined injection technology. The effects of the isopropanol ratio at different λ values on combustion and emissions characteristics of an isopropanol/gasoline dual-fuel combined injection SI engine were studied in this paper. The injection mode is isopropanol direct injection plus gasoline port injection. Six isopropanol ratios (0 %, 20 %, 40 %, 60 %, 80 %, 100 %) and five λ values (0.9, 1, 1.1, 1.2, 1.3) are set. The engine was tested at 1500 rpm with an intake pressure of 50 kPa. It is shown that isopropanol addition improves combustion, increases Pmax and maximum heat release rate, and shortens ignition delay period, rapid combustion period, and combustion duration. As the isopropanol ratio increases, the IMEP increases and the COVIMEP decreases. The improvements in combustion, IMEP and COVIMEP brought by the addition of isopropanol were more obvious under lean-burn conditions. Isopropanol addition effectively reduces unburned HC emissions, CO emissions, and NOx emissions. A higher isopropanol ratio in the mixture leads to better power and emissions performance. Isopropanol is a promising alternative fuel for engines, but its corrosive properties can damage the rubber parts of engines.

Development of the Microemulsion Electrokinetic Capillary Chromatography Method for the Analysis of Disperse Dyes Extracted from Polyester Fibers.

The study aimed to develop a method for the separation of dispersed dyes extracted from polyester fibers. Nine commercially available disperse dyes, which were used to dye three polyester fabrics, were tested. Extraction of dyes from 1 cm long threads was carried out in chlorobenzene at 100 °C for 6 h. The separation was performed using microemulsion electrokinetic capillary chromatography (MEEKC) with photodiode array detection. Microemulsion based on a borate buffer with an organic phase of n-octane and butanol and a mixture of surfactants, sodium dodecyl sulphate and sodium cholate, were used. The addition of isopropanol and cyclodextrins to microemulsion resulted in a notable improvement in resolution and selectivity. The content of additives was optimized by using the Doehlert experimental design. Values of the coefficient of variance obtained in the validation process, illustrating the repeatability and intermediate precision of the migration times fit in the range of 0.11–1.24% and 0.58–3.21%, respectively. The developed method was also successfully applied to the differentiation of 28 real samples—polyester threads collected from clothing. The obtained results confirmed that proposed method may be used in the discriminant analysis of polyesters dying by disperse dyes and is promisingly employable in forensic practice.

Sonocatalytic degradation of fluoroquinolone compounds of levofloxacin using titanium and zirconium oxides nanostructures supported on paper sludge/wheat husk-derived biochar

The present study aimed at treating a water medium containing pharmaceutical compounds such as levofloxacin (LEV). For this purpose, ultrasound (US)-based degradation of LEV was catalyzed by TiO2 and ZrO2 nano-catalysts supported on biochar (BC). BC was obtained from a precursor composite of paper sludge and wheat husk. The application of BC-ZrO2 led to a degradation efficiency of 54.65% within 60 min. When BC-TiO2 was used, a lower degradation efficiency of 49.62% was obtained at the same reaction time. However, increasing the time to 120 min improved the sonocatalytic degradation of LEV by BC-TiO2 (72.88%) compared to that of BC-ZrO2 (66.42%). In the presence of H2O2 and S2O82−, the LEV degradation efficiency of US/BC-TiO2 increased from 72.88% to 87.98% and 94.03%, respectively, and for the US/BC-ZrO2 process, it increased from 66.42% to 76.79% and 90.14%, respectively. The addition of isopropanol caused the most suppressive effect on the sonocatalytic degradation of LEV for both US/BC-TiO2 (decreasing from 72.88% to 13.99%) and US/BC-ZrO2 (decreasing from 66.42% to 16.43%) processes. The reusability test results showed an approximately 20% reduction in the sono-reactor performance within three consecutive experimental runs with no substantial change in the functional groups of the as-prepared sonocatalyst. Intermediates of LEV decomposed by the two sonocatalytic processes were also identified.

Versatile nanoarchitectonics of Pt with morphology control of oxygen reduction reaction catalysts

ABSTRACT Electro-catalytic activity of Pt in the oxygen reduction reaction (ORR) depends strongly on its morphology. For an understanding of how morphology affects the catalytic properties of Pt, the investigation of Pt materials having well-defined morphologies is required. However, the challenges remain in rational and facile synthesis of Pt particles with tuneable well-defined morphology. A promising approach for the controlled synthesis of Pt particles is ‘self-assembly of building blocks’. Here, we report a unique synthesis method to control Pt morphology by using a self-assembly route, where nanoflower, nanowire, nanosheet and nanotube morphologies of Pt particles have been produced in a controlled manner. In the growth mechanism, Pt nanoparticles (5–11 nm) are rapidly prepared by using NaBH4 as a reductant, followed by their agglomeration promoted by adding 1,2-ethylenediamine. The morphology of the resulting Pt particles can be easily controlled by tuning hydrophobic/hydrophilic interactions by the addition of isopropanol and H2O. Of the Pt particles prepared using this method, Pt nanotubes show the highest ORR catalytic activity in an acid electrolyte with an onset potential of 1.02 V vs. RHE.

Synthesis and Hydrodynamic Modeling Study of Epoxy/Carbon Nanospheres (Epoxy-CNS) Composite Coatings for Water Filtration Applications

Coatings for filtration applications based on epoxy resin mixtures with isopropanol were synthesized using the dip-coating technique. The nanomaterials used were carbon nanospheres (CNS) synthesized by chemical vapor deposition (CVD) and commercially obtained Vulcan XC-72 (VC). The permeation flux and permeability of the coatings were determined by vacuum filtration of pure water applying different working pressures obtaining maximum values of 0.5555 cm3/s and 1.19 × 10−9 m2, respectively, for the CNS6 coating at 26,664 Pa. The minimum values obtained for the permeation flux and permeability were 0.0011 cm3/s and 1.21 × 10−11 m2, for the coating CNS3 at 39,996 Pa. This study analyzed the effect of nanomaterials and the addition of isopropanol at different volumes on the permeability of the coatings. The results show that the permeability was influenced by the number of pores present rather than by their diameter. The number of pores were obtained between the ranges 1–12 μm for all the coatings. The study of computational fluid dynamics (CFD) through a free and porous medium, showed that it is possible to accurately determine flow velocities (m/s) through and inside the composite coatings. Understanding the flow behavior is a practical strategy to predict the performance of new nanocomposite coatings.