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This work presents the synthesis of MoO3 and zirconium doped MoO3 nanoparticles by hydrothermal method and their characterizations by several analytical techniques. The XRD patterns of all the undoped and doped samples could be indexed to the hexagonal phase with rod shaped morphologies which were obtained from SEM images. The EDX patterns show the respective elemental composition in the samples thus revealing the effective doping of zirconium into the host lattice of MoO3 without any impurities. The structural features were substantiated by FTIR and Raman spectral studies. The band-gap energies tend to decrease on increasing the dopant concentration. The decrease in PL intensities after doping reveals the lower electron–hole recombination rate which is an important characteristic of photocatalytic studies. The XPS spectra of the NPs were studied to confirm the oxidation state of Zr ions. The doping of zirconium with MoO3 nanoparticles enhanced the photodegradation of Alizarin red S (ARS) in visible region which were studied by varying certain parameters such as catalytic dosage, dye concentration and so on. [ABSTRACT FROM AUTHOR]

WO3 nanoparticles doped with various Fe concentrations were prepared via acid-assisted precipitation method. The XRD patterns confirmed the monoclinic arrangement, and the crystallite size decreased on increasing the dopant concentration. The surface characterizations performed using SEM images and the EDS spectra exposed the particle size and effective doping of Fe3+ ions within the host lattices of WO3. The local structure and crystal quality were studied by FTIR and Raman spectra. From the absorption spectra, doping of Fe decreases the optical band-gap energy and a rise in Urbach energies. The increase in green emission intensities of photoluminescence spectra reveals the increasing oxygen vacancies in WO3 after doping. The temperature-dependent AC and DC conductivities were enhanced on increasing the Fe concentration. The dielectric parameters were elucidated on the basis of Maxwell–Wagner theory which depends on dopant composition. On the whole, the electrical properties of WO3 can be improved by doping with Fe ions. [ABSTRACT FROM AUTHOR]

Deep eutectic solvents (DESs), a new class of ionic liquids, have been considered to be the focus of researchers owing to their wide range of applications as green solvents. These solvents are involved in changing the size and morphology of nanomaterials during their synthesis. In this work, we have synthesised WO3–MgO nanocomposite using a DES prepared from cetyltrimethylammonium bromide (CTAB), urea and glycerol, which proved to enhance the pore volume of the composite. The X-ray diffraction peak patterns revealed a monoclinic arrangement for WO3 and cubic for MgO. The morphological and surface characterization studies were performed using scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectra and adsorption-desorption isotherms. The crystal qualities were obtained from Raman spectra and the band gap energy of WO3 increased upon forming a composite with MgO. The temperature dependent electrical conductivities and the dielectric and electric modulus properties of WO3–MgO were studied and from electrochemical studies, the specific capacitance value obtained was 272.5 F g−1 at a current density of 1 A g−1. [ABSTRACT FROM AUTHOR]

The growing demand for electricity has increased the interest of the researchers towards exploration of energy storing devices (ESDs). With the motif for developing electrochemical energy storage devices, this research work is focussed on the study of MoO3 nanoparticles and its doping with chromium as an efficient electrode material for energy storage applications. The nanoparticles were synthesized by hydrothermal method and were examined by powder X-ray diffraction, which determined the thermodynamically stable orthorhombic phase of MoO3, and their morphologies were examined using scanning electron microscopy displaying flake-like structures. The typical vibrational bands of Mo–O were identified from Infra-red and Raman spectral analysis. The ultra violet diffuse reflectance spectra revealed the decrease in optical band gap after doping with chromium. The temperature dependent AC and DC conductivities were enhanced on doping. Electrochemical behaviour of the nanoparticles was probed by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) measurements and galvanostatic charge–discharge (GCD) analysis for which specific capacitance (Csp) value of 334 Fg−1 was achieved for Cr-doped MoO3 nanoparticles. The electrochemical performance of the sample was found to be increased after doping with Cr. [ABSTRACT FROM AUTHOR]

In this present work, it is envisaged to enhance seed germination using Mo doped WO3 nanoparticles. Mo as a micro nutrient plays a vital role in germination and growth in plant biology. The pristine and Mo doped WO3 (Mo:WO3) nanoparticles are synthesized using acid assisted precipitation technique. Both pristine and doped samples were characterized by XRD, SEM/EDS, FTIR, Raman, UV-DRS, PL and XPS spectral techniques. The XRD pattern corroborates the monoclinic phase of synthesised products. The SEM and EDS analysis shows effective doping of Mo into host lattices of WO3. The structural aspects were confirmed using FTIR and Raman spectral studies. The doping of Mo lead to a decrease in band gap energy assisted with increase in Urbach energy. The defect states in energy levels were studied using PL analysis and the chemical composition using XPS. The WO3 nanoparticles show robust antibacterial activities against the Pseudomonas aeruginosa and Xanthomonas oryzae pv bacterial strains. The seed germination properties on kodo millet seeds were evaluated showing a more pronounced effect for Mo doped than pristine WO3 nanoparticles. Hence this material can be used in such a way that the dopant Mo aids in seed germination while WO3 acts as a good antibacterial agent that retards plant growth. [ABSTRACT FROM AUTHOR]

Herein we report the hydrothermal synthesis, characterization and biological applications of h-MoO3 and silver doped MoO3 nanoparticles (NPs). The phase formations of the synthesized NPs were identified using X-Ray diffraction studies and vibrational spectral studies. The average crystallite size of the NPs tends to decrease with increase in doping concentration. The surface morphology and the elemental composition of the nanoparticles were observed from SEM and EDAX analysis. The crystallite nature was obtained from HRTEM images. The band gap energies obtained from UV-DRS spectra for h-MoO3 (3.26 eV) were found to decrease as the concentration of the dopant (Ag) increases (3.22–2.76 eV). The antibacterial activity of the prepared nanoparticles was tested against some gram positive and gram negative bacterial strains viz., Staphylococcus aureus and Bacillus cereus, Citrobacter koseri and Pseudomonas aeruginosa respectively. Also their seed germination properties were studied on foxtail and finger millet seeds for a period of seven days. [ABSTRACT FROM AUTHOR]

With the objective of development of electrochemical charge storage devices, currently the research in this field is centred on the study of MoO3 nanoparticles doped with copper as an efficient supercapacitor electrode material. The synthesized nanoparticles were examined by powder X-ray diffraction which determined the metastable hexagonal phase of MoO3 and their morphologies were examined using scanning electron microscopy displaying regularly arranged well-defined microrods. The typical vibrational bands of Mo–O were identified from Infra-red and Raman spectral analysis. The ultra violet diffuse reflectance spectra revealed the decrease in optical band gap from 2.96 to 2.78 eV with an increase in Cu concentration. The surface area was recorded to be higher for 5% wt Cu doped nanoparticles (14 m2/g) which was examined from Brunauer–Emmett–Teller (BET) isotherms. Electrochemical behaviour of the nanoparticles was probed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy measurements for which a maximum specific capacitance (Csp) value of 530 Fg−1 was achieved for 5% wt Cu doped MoO3 nanoparticles. [ABSTRACT FROM AUTHOR]

Different phases of tungsten trioxide (WO3) nanoparticles were synthesised by hydrothermal method involving the extracts of avverhoea bilimbi, citrus limon and tamarindus indica as capping agents. These synthesized nanomaterials were characterized through X-ray diffraction, Raman spectra, Transmission electron micrographs, diffuse reflectance spectra and photoluminescence spectral techniques. The X-ray diffraction patterns and Raman spectra corroborate the formation of different crystal phases viz., monoclinic (m-WO3), orthorhombic (o-WO3) and hexagonal (h-WO3). The morphological and topographical studies were acquired from SEM and TEM images. The surface parameters were examined from BET isotherms. The absorption spectra reveal that the optical band gap energy is found to be higher for h-WO3. The adsorption of Cu(II) ions were found to be effective provided with optimum conditions and the adsorption capacity was found to be 174.5 mgg−1 by the h-WO3 nanoparticles. A study on Langmuir, Freundlich, D–R and Temkin isotherm models, deviation in D–R model implies that the adsorption is chemisorption process and follows pseudo-second order kinetics. The adsorption process is found to be spontaneous and exothermic from the thermodynamic parameters. [ABSTRACT FROM AUTHOR]

A novel Schiff base (E)-N-(pyridine-2-yl)thiophen-2-ylmethylene)hydrazine carbothioamide (L), has been synthesised by the condensation of thiophen-2-carbaldehyde and 4-(pyridin-2-yl)-thiosemicarbazide, using solvent free microwave synthesis. The Co(II), Ni(II), Cu(II) and Zn(II) complexes of the Schiff base are also prepared. They are characterised by elemental analysis, EI-mass spectrum, 1H &13C-NMR spectrum, FTIR, UV-vis spectra, magnetic, EPR spectra and thermal analysis. The "SNSN" donor ligand binds the metal ion in tetradentate mode through thiophenyl and thioenolic sulphur atoms and imino and pyridine nitrogen atoms. The electronic spectra along with magnetic measurements demonstrate tetrahedral geometry for Co(II), Ni(II) and Zn(II) complexes, and square planar geometry for Cu(II) complex. All the complexes are found to be thermally stable from thermogravimetric studies. The complexes show enhanced antibacterial activity than the ligand against various bacterial strains. The BSA binding activity of the complexes shows that the affinity for binding is greater towards copper complex. The cytotoxicity of the ligand and its complexes are tested on HT29 colon cancer cells using MTT assay. [ABSTRACT FROM AUTHOR]

Correction and removal of expression of concern for 'Deep eutectic solvent mediated synthesis and fabrication of a WO3–MgO nanocomposite as an electrode material for energy storage applications' by C. Joel et al., New J. Chem., 2023, 47, 2797–2808, https://doi.org/10.1039/D2NJ05642A. [ABSTRACT FROM AUTHOR]

A series of oxovanadium(IV) complexes [VO(salala)(phen)] (1), [VO(salala)(bpy)] (2), and [VO(napala)(phen)] (3) where salala and napala are N‐salicylidene‐β‐alanate and N‐napthalidene‐β‐alanate, respectively, and phen = 1,10‐phenanthroline and bpy = 2,2′‐bipyridine have been synthesized. The single‐crystal X‐ray crystallographic data of complex 2 reveal that its crystal structure exists in the monoclinic space group P21/a. All the complexes adopted distorted octahedral geometry and are confirmed through various spectral techniques including FTIR, UV–Vis, ESI mass, EPR, molar conductance, and magnetic measurements. To gain insights into the electronic structure of these synthesized complexes, density functional theory calculations have been carried out although UV absorption spectra of these complexes are simulated from time‐dependent density functional theory calculations. The cyclic voltammograms reveal the irreversible and the one‐electron transfer process of the complexes. The chemical nuclease activity of the complexes has also been done on pUC19 DNA. The results show that complex 2 acts as an excellent enzyme mimic of vanadium‐dependent bromoperoxidase involving in the effective bromination of phenol red at room temperature in acetonitrile medium. So investigation on the vanadium complex catalyzed conversion of organic substrates to corresponding brominated products has been a field of active research and found that the complex is certainly a VHPO mimic. [ABSTRACT FROM AUTHOR]