Sonophotocatalytic mineralization of Norflurazon in aqueous environment

Norflurazon (4-chloro-5-(methylamino)-2-[3- trifluoromethyl)phenyl]pyridazin-3(2H)-one; C12H9ClF3N3O) is an excellent weed controlling agent being practiced in the agricultural lands. The excessive addition or the undissolved Norflurazon (maximum solubility 28 mg/L at 25 C) enters into the aquatic environment and causes the adverse effects associated with its high concentration. To avoid the perilous effects, visible light assisted photocatalysis set-up coupled with the 42 kHz ultrasound producing bath type sonicator is used to completely mineralize the Norflurazon. TiO2, ZnO and gold loaded zinc oxide nanocatalysts were utilized to study the mineralization of Norflurazon. AueZnO shows the greater efficiency for the sonophotocatalytic removal of Norflurazon among the various nanocatalysts employed to study the mineralization. The order of Norflurazon mineralization was sonophotocatalysis > sonocatalysis > photocatalysis. The additive effect was achieved for the sonophotocatalytic degradation. The high performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometric (LCMS) analyses were employed to identify the various intermediates produced during the mineralization. The identification of four pseudo molecular ions and various intermediates using the LCMS analysis evidently suggests the sonophotocatalytic degradation was preceded in various decay pathways. A suitable mechanism has been proposed for the sonophotocatalytic mineralization of Norflurazo

Effects of Ultrasound Irradiation on the Synthesis of Metal Oxide Nanostructures

High intensity ultrasound can be used for the production of novel nanomaterials, including metal oxides. According to previous works in this field, the most notable effects are consequence of acoustic cavitation. In this context, we have studied the preparation of different materials in the presence of ultrasound, including N-doped TiO2 nanopowder, NiTiO3 nanorods and MnOx thin films. Ultrasound did not show a significant effect in all the cases. Exclusively for NiTiO3 nanorods a reduction of the final particle size occurs upon ultrasonic irradiation. From these results, it can be concluded that the ultrasound irradiation does not always play a key role during the synthesis of metal oxides. The effects seem to be particularly relevant in those cases where mass transport is highly hindered and in those procedures that require the rupture of nanoparticle aggregates to obtain a homogenous dispersion.We want to acknowledge the Spanish Ministry of Economy and Competitiveness (MINECO) for financial support through projects PRI-PIBIN-2011-0816 and MAT2012-37676 (FONDOS FEDER). V. Manzi-Orezzoli is grateful to the Universitat d’Alacant for the award of a research initiation grant

SnO2-decorated multiwalled carbon nanotubes and Vulcan carbon through a sonochemical approach for supercapacitor applications

Multiwalled carbon nanotubes (MWCNTs) and Vulcan carbon (VC) decorated with SnO2 nanoparticles were synthesized using a facile and versatile sonochemical procedure. The as-prepared nanocomposites were characterized by means of transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Fourier transform infra red spectroscopy. It was evidenced that SnO2 nanoparticles were uniformly distributed on both carbon surfaces, tightly decorating the MWCNTs and VC. The electrochemical performance of the nanocomposites was evaluated by cyclic voltammetry and galvanostatic charge/discharge cycling. The as-synthesized SnO2/MWCNTs nanocomposites show a higher capacity than the SnO2/VC nanocomposites. Concretely, the SnO2/MWCNTs electrodes exhibit a specific capacitance of 133.33 F g−1, whereas SnO2/VC electrodes exhibit a specific capacitance of 112.14 F g−1 measured at 0.5 mA cm−2 in 1 M Na2SO4.S.A. thanks the Feng Chia University in Taiwan for the Visiting Professor appointment. The authors S.A. and T.L.V. thanks DST, New Delhi for the sanction of India–Spain collaborative research grant (DST/INT/Spain/P-37/11 dt.16th Dec 2011) and Generalitat Valenciana for the financial support through ACOMP/2014/137. In addition, acknowledgement is also given to the financial support of Ministry of Science and Technology, Taiwan, at the grant number of NSC-101-2221-E-035-031-MY3

evidence of bipolar resistive switching memory in perovskite solar cell

In hybrid inorganic-organic perovskite solar cells a very stable bipolar resistive switching behavior in the dark current-voltage characteristics at low-voltages has been observed. The possible use of the solar cell as an electrical memory with a moderate on-off contrast but very good stability over a prolonged time has been suggested. The reversible behavior and the long dynamics during the write/erase processes indicate that the physical mechanism behind the switching is related to polarization effects. A detailed analysis of the charge carrier trapping/detrapping, transport, and recombination mechanisms has been performed by taking the ion migration and the consequent charge carrier accumulation within the device into account. The charge transport during the write operation can be described by space-charge-limited conduction process. The formation and subsequent interruption of conducting pathways due to ion migration have been identified as the main cause of the resistive switching within the perovskite material. The strong interaction between the ion movement and the electron transport enables the operation of the perovskite solar cell also as a non-volatile memory

Emergent methods to synthesize and characterize semiconductor CuO nanoparticles with various morphologies - an overview

Nanotechnology can be defined as the science and engineering involved in the design, synthesis and application of materials and devices on the nanometer scale. It is not in itself a single emerging discipline, but rather a meeting of several traditional sciences such as chemistry, physics, materials science, biology and engineering to bring together the required expertise needed to develop these new technologies. The unique properties of nanoscale materials provide benefits in remediation, pollution prevention, and efficient use of resources; however, the greatest contribution to green chemistry is likely to be the new manufacturing strategies available through nanoscience. So, the present review mainly focuses on the synthesis of semiconductor CuO nanomaterials from different starting materials by adopting various routes such as vapor-solid, vapor-liquid-solid, solid-liquid, etc. to reveal the morphological features of the precursor

Synthesis of TiO2/WO3 nanoparticles via sonochemical approach for the photocatalytic degradation of methylene blue under visible light illumination

Through an ultrasound assisted method, TiO2/WO3 nanoparticles were synthesized at room temperature. The XRD pattern of as-prepared TiO2/WO3 nanoparticles matches well with that of pure monoclinic WO3 and rutile TiO2 nanoparticles. TEM images show that the prepared TiO2/WO3 nanoparticles consist of mixed square and hexagonal shape particles about 8–12 nm in diameter. The photocatalytic activity of TiO2/WO3 nanoparticles was tested for the degradation of a wastewater containing methylene blue (MB) under visible light illumination. The TiO2/WO3 nanoparticles exhibits a higher degradation rate constant (6.72 × 10−4 s−1) than bare TiO2 nanoparticles (1.72 × 10−4 s−1) under similar experimental conditions.The author S.A. and T.S. thanks MOEF, New Delhi for the sanction of major research fund (MOEF reference No. 19-26/2009-RE dated 29th March, 2012). The author, S.A. also thanks DST, New Delhi for the sanction of India–Spain collaborative research grant (DST/INT/Spain/P-37/11 dt.16th Dec 2011). T.L.V. thanks the Generalitat Valenciana for the financial support through ACOMP/2013/076. Also, S.A. thank DST for sanctioning FIST (SR/FST/CSI-190/2008 dated 16th March 2009) project

Sonochemical Synthesis of Mesoporous NiTiO3 Ilmenite Nanorods for the Catalytic Degradation of Tergitol in Water

Ilmenite type titanates have very wide applications in various fields. In this paper, we report the synthesis of mesoporous NiTiO3 ilmenite nanorods via a sonochemical approach. The method is very facile and effective allowing the preparation of NiTiO3 nanoparticles with a high yield and uniform size distribution. The reaction intermediate and particularly the final product have been well characterized by various analytical tools (IR, XRD, Raman, TEM, BET, XPS). The final NiTiO3 nanoparticles can be described as a hierarchical structure composed of small nanoparticles interconnected generating nanoporous rods. In comparison with anatase TiO2 nanoparticles, the catalytic removal rate for the pollutant Tergitol (NP-9) by a process combined with ozonation is two and half-fold higher in the presence of mesoporous NiTiO3 ilmenite nanorods.S.A. thanks Feng Chia University in Taiwan for the Visiting Professor appointment. S.A. and T.L.V. thank DST, New Delhi, for the sanction of an India−Spain collaborative research grant (DST/INT/Spain/P-37/11 dt.16th Dec 2011) and Generalitat Valenciana for the financial support through ACOMP/2014/137. In addition, acknowledgement is given to the partial financial support of National Science Council (NSC), Tawian, Grant No. NSC-101-2221-E-035-031-MY3

Acid red 88 dye doped polyaniline framed by soft template method: A potential candidate for dye-sensitized solar cells

The metal-like band structure and the tripping transfer of electrons between bipolarons and polarons found in polyaniline make it for elevated scientific validity. Through a soft template in situ oriented oxidative polymerization, self-assembled nano tubular structures of Acid red (AR88) dye-doped Polyaniline in the presence of hydrochloric acid medium (AR88/PAni/HCl) were prepared and characterized well using different analytical tools. The AR88 (5x10-4 M) doped PAni prepared in the presence of 1 M HCl shows higher conductivity (2.2679 Scm−1) and seized its eminent electrical properties. The presence of sulfonic acid group-containing AR88 provides a better environment to give higher conductivity than the PAni-HCl. Due to its better optical transparency, the as-synthesized samples were used for photovoltaic applications. The AR88/PAni/HCl was used as a photosensitizer in dye-sensitized solar cells which shows photoconversion efficiency of around 1.58 %