Search

In this study, the polygonal structure of WO3 nanoparticles was constructed by the hydrothermal route, and the prepared materials were utilized for supercapacitor applications. The synthetic materials are WO3 nanoparticles in their monoclinic phase, according to the X-ray diffraction data. The morphologies of the WO3 samples are polygonal like and scanning electron microscope and transmission electron microscopy have confirmed it. To investigate the supercapacitance behavior of polygonal WO3, various techniques were used, such as galvanostatic charge–discharge, cyclic voltammetry, and electrochemical impedance spectroscopy (EIS). The polygonal WO3 nanoparticle modified on Ni-foam as a working electrode has a specific capacitance value of 870 F g−1 at 0.25 A g−1. The polygonal structure of WO3 nanoparticle-coated Ni-foam electrodes was very stable compared to other fabricated electrodes over the 10,000 cycles. The fabricated polygonal structure of the WO3 electrode has high capacitance retention (100.2%) and high coulombic efficiency (99%). The polygonal structure of WO3 makes it a particularly effective electrode material and a substantially better candidate for energy storage, especially supercapacitors. [ABSTRACT FROM AUTHOR]

Abstract Transition metal orthovanadates are emerging 2D materials for promising electrochemical energy storage applications. Facile hydrothermal method for nanocrystalline indium vanadate (InVO4) semiconducting materials’ fabrication is economical because of its direct chemical synthesis. X‐ray diffraction studies, field emission scanning electron microscope (SEM) images, transmission electron microscopy (TEM), and photoelectron X‐ray spectrum are used to describe the semiconductor materials as synthesized. InVO4 microspheres have attracted a lot of attention in the energy and environmental sector. These microsphere‐derived semiconductor materials are recognized to offer the advantages of their large surface area, tunable pore sizes, enhanced light absorption, efficient carrier (electron–hole) separation, superior electronic and optical behavior, and high durability. From the results of SEM and TEM, InVO4 shows a microsphere construction with a mixture of nanosized particles. Diffuse reflectance UV–visible measurements are used to determine the bandgap, and it is found to be 2.1 eV for InVO4. The electrochemical analysis reveals a superior performance of the pseudocapacitor with hydrothermally derived microspheres of InVO4. Alongside an improved pseudocapacity, developed after 4000 cycles, it has excellent cycling stability with a retention of ≈94% of its original specific capacitance efficiency.

Modification of semiconductor oxides leads to a major development in functional characteristics. Characterisation of Pr6O11-TiO2, fabricated by a cost-effective hydrothermal – decomposition method reveals the nanorod like structure of this catalyst. The XRD pattern definite the formation of face-centred cubic or cubic close-packed structure of Pr6O11 and the high crystallinity indicate the existence of anatase TiO2. XPS analysis indicates the presence of both Pr3+and Pr4+ ions in Pr6O11. Pr6O11-TiO2 is more photoactive under visible light than Pr6O11, prepared TiO2 and TiO2-P25 (80% Anatase and 20% Rutile mixture) in the degradation of toxic azo dyes. Pr6O11-TiO2 is stable and recyclable consecutively. Pr6O11-TiO2 catalyst shows higher electrocatalytic activity in methanol oxidation than pure TiO2. These results reveal new insights on the efficiency of catalysts in photo- and electrocatalytic applications. [ABSTRACT FROM AUTHOR]

Developmentof coupled semiconductor oxides makes a significantadvancement in catalytic functional materials. In this article, wereport the preparation of nanobundle-shaped BiVO4–ZnOphotocatalyst by a simple hydrothermal process followed by thermaldecomposition. The photocatalyst was characterized by X-ray powderdiffraction (XRD), high-resolution scanning electron microscopy (HR-SEM),field emission scanning electron microscopy (FE-SEM), energy-dispersivespectroscopy (EDS), transmission electron microscopy (TEM), high-resolutiontransmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy(XPS), photoluminescence spectroscopy (PL), and UV–vis diffusereflectance spectroscopy (DRS). The XRD pattern confirmed formationof monoclinic scheelite BiVO4and the hexagonal wurtzitestructure of ZnO. HR-SEM images show nanobundle-like structure, andthe size of the nanospheres ranges from 20 to 40 nm. BiVO4–ZnO has increased absorption in the UV and visible regionwhen compared to ZnO. The catalytic activity of BiVO4–ZnOwas evaluated by the photodegradation of Acid Violet 7 (AV 7), EvensBlue (EB), and Reactive Red 120 (RR 120). The results revealed thatthe photocatalytic activity of BiVO4–ZnO was muchhigher than that of ZnO, BiVO4, and TiO2–P25under natural sunlight. BiVO4–ZnO is more advantageousthan ZnO and BiVO4in the degradation of AV 7, EB, andRR 120 because it has maximum efficiency at neutral pH 7. BiVO4–ZnO was found to be stable and reusable without appreciableloss of catalytic activity up to four consecutive cycles. The self-cleaningproperty of BiVO4–ZnO has been evaluated using contactangle measurements. Our results provide some new insights on the performanceof solar active photocatalysts on environmental remediation. [ABSTRACT FROM AUTHOR]

In this article, we report the fabrication of a stable Ag–ZnO–SnO2 nanochain by template free hydrothermal method and its photocatalytic activity for the first time. This composite material represents a potential new class of photocatalysts with enhanced light absorption, hydrophobic and electronic properties of ZnO. This catalyst has been characterized by X-ray diffraction (XRD), high resolution scanning electron microscopy (HRSEM), field emission scanning electron microscopy (FESEM), elemental mapping, energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance spectroscopy (DRS) and photoluminescence spectroscopy (PL). XRD and elemental mapping reveal the presence of SnO2 and Ag in the catalyst. Ag–ZnO–SnO2 has increased absorption in the visible region when compared to ZnO. This three component nano junction system exhibits enhanced photocatalytic activity for the degradation of azo dyes, Acid Black 1 (AB 1) and Acid Violet 7 (AV 7) under UV light (365 nm), far exceeding those of the single and two component systems. Ag–ZnO–SnO2 is found to be reusable without appreciable loss of catalytic activity up to four runs. Based on the band gap energies of ZnO and SnO2, a mechanism is proposed for the photodegradation of dyes. Hydrophobicity and photoconductivity of Ag–ZnO–SnO2 have been evaluated. Nanochain exhibiting higher positive photoconductivity can be useful for soliton wave communication as well as solar cell applications. Our results provide some new insights on the fabrication of Ag–ZnO–SnO2 and its performance as an active photocatalyst, self cleaning and conducting material. [ABSTRACT FROM AUTHOR]

A new fluorescent sensor 2-(2-(3-chloro-4-fluorophenyl)hydrazono)-5,5-dimethyl cyclohexane-1,3-dione (A) and 2-(2-(4-chloro-2-nitrophenyl)hydrazono)-5,5-dimethyl cyclohexane-1,3-dione (B) composed of a β-diketones of aryl hydrazones synthesized by simple and cost-effective method. Various analytical tools analyzed the structural investigations of the synthesized substituted β-diketones of aryl hydrazones like FT-IR, 1 H, 13 C NMR and UV-Vis techniques, Single-crystal X-ray diffraction studies (SCXRD) (for A), Scanning electron microscopy (SEM), and fluorescence spectroscopy. SEM also investigates surface morphology modifications of aryl hydrazones and Ni 2+ complex. Furthermore, the metal sensing (Chemo sensing) behavior of newly prepared aryl hydrazones of β-diketones derivatives was further studied by fluorescence spectroscopy. The aryl hydrazones sensor materials show admirable fluorescence selectivity with enrichment to Ni 2+ over different cations in an aqueous ethanol solution with a recognition extremity of 4 μM-7 μM. A joint experimental and theoretical investigation was led on the chemical structure employing a density functional theory (DFT) (B3LYP), engaging a 6-31G basis set. The DFT technique's enhanced geometrical bond angles and lengths exhibited great covenant with the experimental results. The highest occupied molecular (HOMO) orbital and lowest unoccupied (LUMO) molecular orbital energy has been concluded. The cytotoxicity studies show these compounds impede the growth of KB cells highly and from the studies to evaluate their capability to accurately dock aryl hydrazones to antibodies of cancer protein such as 4LRH, 4L9K, 4 EKD and 4GIW cancer proteins., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Rutile TiO 2 are widely used for applications of coatings, cosmetics, photoelectric devices and so on. However, effective control of well-defined morphology, size and composition of rutile TiO 2 nanoparticles from agglomeration has always been a challenge. A new synthesis strategy was proposed to prepare rutile TiO 2 with controllable morphology varied from flower-like structures to single-separated nanorods. The β-FeOOH nanoparticles were generated by the hydrolysis of FeCl 3 solution and could prevent the aggregation of TiO 2 nanocrystals at early stages of the reaction; thus, could control the morphology of rutile nanoparticles. The morphology of rutile TiO 2 nanoparticles could be controllably regulated from flower-like structures to individually separated nanorods. Meanwhile, the preformed β-FeOOH also played a role of dopant. Fe ions were substitutionally doped into the bulk lattice of TiO 2 nanocrystals and reduced the bandgap, which extended the solar radiation absorption range of rutile TiO 2 . The prepared TiO 2 may be suitable for novel UV-blue light shielding agents and many other applications in photoelectric devices, photocatalysis, and so on due to its small size, unprecedented discrete rod-like structure and unique UV-vis light permeability.