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In this work, we have successfully synthesized the cost-effective, abundant in nature and environmentally friendly SrMoO 4 /MWCNT-PVP by using the co-precipitation technique for hydrogen evolution reaction (HER). Prepared nanocomposites were characterized by XRD, which confirms the formation of tetragonal structure of SrMoO 4 and indexed with JCPDS (01-074-3912). Raman spectra confirm the combination of SrMoO 4 with carbon composite (verified by D and G band 1.02 I D /I G ratio) and its functional group was further analyzed with the help of FTIR spectra. Synthesized product morphology was characterized by using SEM and TEM images, which confirms formation of well-defined dumb-bell shaped nanostructures with the combination of carbon nanotube and also it further confirms the formation of polycrystalline nature of the material. The elemental composition was analyzed by EDS images, which confirms the occurrence of Sr, Mo, O, and C in an appropriate form with a uniform distribution, respectively. MWCNT in SrMoO 4 incorporation led to decrease overpotential of 204 mV and 110 mV/dec Tafel slope of the material, which was examined by the LSV curves and Tafel plot analysis. Electrochemical impedance spectroscopy was also investigated, and it delivered the small charge-transfer resistance of 248 Ω, which further supporting the HER analysis and denoting the promising HER kinetics. Therefore, our work unlocks a new path for the properly tuned nanostructured morphology of metal oxide with carbon composite for electrochemical hydrogen evolution reaction application. [ABSTRACT FROM AUTHOR]

Water splitting is an important method for hydrogen production. Notably, tantalum oxide has the potential to employ extensive variety appliances because of its outstanding electrical and optical properties. Tantalum pentoxide (Ta 2 O 5) nanopowders were produced using the sol–gel process. The effect of calcination time plays a main role on Ta 2 O 5 crystal structure configuration. Transmission electron microscope images explored obtained Ta 2 O 5 nanorod formation and investigated by electrochemical studies for its use in electrochemical water-splitting applications. The calculated specific capacitance values of Ta 2 O 5 electrodes at different temperature conditions were 146.4, 191.7, and 221.7 F/g. Fabricated Ta 2 O 5 electrodes showed overpotential of 304, 278, and 267 mV. Current densities of Ta 2 O 5 electrodes at different calcinations times were 353, 419, and 461 mA/g. Ta 2 O 5 powder calcined for 6 h revealed high specific capacitance and low overpotential, indicating better electrochemical reactivity suitable for water oxidation applications. [ABSTRACT FROM AUTHOR]

Photoelectrochemical (PEC) water splitting using various semiconductor materials is one of the exciting ways to generate hydrogen and oxygen. Nowadays, electrode fabrication is one of the important tasks and depends on various applications. In the PEC water-splitting application, the synthesized materials can enhance the bandgap by using controlled size and morphology. By altering the bandgap of synthesized nanomaterials, one can enhance the PEC activity and photoconversion efficiency. Recently, ZnO nanostructures have gained much attention due to their attractive and multifunctional properties and have been considered as an outstanding material for fabrication. Therefore, branched and unbranched ZnO nanorods were grown on Indium Tin Oxide (ITO) substrate by chemical vapor deposition (CVD) growth method. The hexagonal phase of the branched ZnO nanorods was confirmed by X-ray powder diffraction pattern. The formation of branched ZnO nanorods was examined by the scanning electron microscopy analysis. Owing to their unique structure, branched nanorods display excellent light absorption capability with good PEC performance. Therefore, branched ZnO nanorods are uniquely excellent material for PEC water-splitting applications. [ABSTRACT FROM AUTHOR]

Photoelectrochemical (PEC) water splitting is beneficial and has received attractive attention due to a greater potential to generate hydrogen and oxygen from water by using plentiful solar light to solve the problem of energy crisis. Various active semiconductor materials are used in PEC water splitting applications. Nevertheless, in past decades, most of the researchers suggested that titanium oxide (TiO 2) is the best photoanode for this type of applications. Now, Zinc oxide (ZnO) is considered a perfect substitution to TiO 2 due to its comparable energy band structure and superior photogenerated electron transfer rate. In this study, bare and phosphorous-doped ZnO nanorods were successfully developed on fluorine-doped tin oxide-coated glass (FTO) substrate by chemical vapor deposition. X-ray diffraction (XRD) pattern authenticated hexagonal structure formation with strong diffraction peak of (101), which showed that ZnO nanorods were perfectly developed along c axis. The optical and morphological properties were analyzed by UV–Vis and scanning electron microscopy images. The energy-dispersive X-ray spectra demonstrated that doping agent phosphorous was present in ZnO nanorods. The PEC properties of the developed ZnO nanorods were further investigated and obtained results suggested that a small amount of phosphorous-doped ZnO nanorods enhances their PEC performance. [ABSTRACT FROM AUTHOR]

Molybdenum oxide (MoO 3) nanomaterials have received remarkable attention in biomedical applications, energy storage devices, and conversion devices. Orthorhombic phase molybdite (α-MoO 3) was successfully synthesized via hydrothermal method and the structure was confirmed through standard characterizations. Electrochemical performance was explored to evaluate specific capacitance, current densities, and stability. Product-specific capacitances were 164, 243, and 350 F/g at 10 mV/s and current densities were 194, 305, and 440 mA/g. M3 electrode showed 84% retention toward oxygen evolution reaction activity. The chronoamperometry study was conducted over 10 h to determine the long-term stability of M3 electrode. It showed high stability and good conductivity. Thus, it can be said that MoO 3 is a promising material to improve electrochemical performance and be used in preparing an efficient electrochemical energy conversion device. [ABSTRACT FROM AUTHOR]

Ni–Zn ferrites exhibit properties like high resistivity, high Curie temperature, and low relative loss. In this paper, the impact of the small doping of Europium on structural, magnetic and optical properties of Ni–Zn ferrites has been investigated. The samples were prepared through the Sol-Gel method and grounded powders were calcined at 500 °C for 4hrs. Cubic crystalline structure with Fd-3m space group was confirmed for all ferrites by XRD and Ritveld refinement. Surface morphology of the samples was revealed by SEM. The cation distribution and crystal deformation were observed from Raman spectra with increasing Eu3+ ions content. The band gap energy values were calculated from UV–Visible spectra which are in the order of 1.6 eV and these values were directly proportional to the lattice constant. Room temperature magnetic properties were studied and the variation in the properties with the doping was discussed. From magnetic properties of Eu doped Ni–Zn ferrites it was found that these are suitable for core material in transformers and in power transmission. XRD patterns of the Eu doped Ni–Zn Ferrites. [Display omitted] • Nanoparticles of Eu doped Ni–Zn Ferrites were prepared at low temperatures. • (500 °C) through Sol-Gel method. • Band gap energy of 1.6 eV has been obtained in these samples and those are used as a semiconducting material. • FTIR data confirmed the cubic spinel structure of the materials of the present investigation. [ABSTRACT FROM AUTHOR]