The relationship between local structure and photo-Fenton catalytic ability of glasses and glass-ceramics prepared from Japanese slag

Local structure and the photo-Fenton reactivity of iron-containing glasses and glass-ceramics prepared from Japanese domestic waste slag were investigated. The largest rate constant (k) of (2.8 ± 0.08) × 10−2 min−1 was recorded for the methylene blue degradation test by using H2O2 with a heat-treated ‘model slag’. The 57Fe Mössbauer spectrum was composed of a paramagnetic doublet with isomer shift of 0.18 ± 0.01 mm s−1 attributed to distorted FeIIIO4 tetrahedra. These results indicate that the paramagnetic Fe3+ provided strong photo-Fenton catalytic ability, and that waste slag can thus be recycled as an effective visible-light activated photocatalyst

Chemically Synthesized Iron-Oxide-Based Pure Negative Electrode for Solid-State Asymmetric Supercapacitor Devices

Among energy storage devices, supercapacitors have received considerable attention in recent years owing to their high-power density and extended cycle life. Researchers are currently making efforts to improve energy density using different asymmetric cell configurations, which may provide a wider potential window. Many studies have been conducted on positive electrodes for asymmetric supercapacitor devices; however, studies on negative electrodes have been limited. In this study, iron oxides with different morphologies were synthesized at various deposition temperatures using a simple chemical bath deposition method. A nanosphere-like morphology was obtained for α-Fe2O3. The obtained specific capacitance (Cs) of α-Fe2O3 was 2021 F/g at a current density of 4 A/g. The negative electrode showed an excellent capacitance retention of 96% over 5000 CV cycles. The fabricated asymmetric solid-state supercapacitor device based on α-Fe2O3-NF//Co3O4-NF exhibited a Cs of 155 F/g and an energy density of 21 Wh/kg at 4 A/g

Facile synthesis of multitasking composite of Silver nanoparticle with Zinc oxide for 4-nitrophenol reduction, photocatalytic hydrogen production, and 4-chlorophenol degradation

The multifunctional zinc oxide electrode was used in numerous applications. This study includes the cat-alytic performance of zinc oxide, which is further enhanced by the silver nanoparticle. The facile and cost-effective hydrothermal method is used to fabricate ZnO and Ag/ZnO composites. The Ag/ZnO-based catalyst is mainly constructed to reduce the water pollution caused by industrial discharges, which contains ha-zardous compounds like 4-nitrophenol (4-NP), 4-chlorophenol (4-CP), and many other organic compounds. Removal of these hazardous organic compounds from potable water sources is essential for both ecosystem and human beings. In this study, Ag/ZnO composite was used as an efficient catalyst for catalytic reduction of hazardous 4-NP, and photocatalytic degradation of 4-CP. Catalytic reduction of the 4-NP using the Ag/ZnO composite is based on the Langmuir-Hinshelwood principle. In addition to this study Ag/ZnO composite was tested for photocatalytic hydrogen production. The high charge transfer efficiency of Ag in the Ag/ZnO composite is helpful for enhancement in catalytic performance for hydrogen production and 4-CP de-gradation. The catalytic activity of Ag/ZnO in the 4-CP degradation increased from 59% to 96% and for hydrogen production rate increased from 1.9 to 12 mu mol h(-1), as compared with the catalytic activity of ZnO. (C) 2022 Elsevier B.V. All rights reserved.FALS

Dielectric and magneto-electric behavior of (x) Co0.8Mn0.2Fe2O4 and (1−x) PbZr0.52Ti0.48O3 composites

The multiferroics with ferroelectric (FE) and ferromagnetic (FM) phases (x) [Co0.8Mn0.2Fe2O4] + (1−x) [PbZr0.52Ti0.48O3] composite samples with x = 0.25, 0.50 and 0.75, were prepared by ceramic route. X-ray diffraction (XRD) patterns of as-prepared samples exhibit the presence of lead zirconate titanate PbZr0.52Ti0.48O3 (PZT) and Co0.8Mn0.2Fe2O4 (CMFO) phases in the PZT-CMFO composites. The values of grain size were found to be decreased in the range of 680–390 nm with increasing the ferrite contents from x = 0.25 to 0.75. The temperature dependent dc resistivity (ρ) of the composites was reduced with increasing x contents. The values of dielectric constant (ε′) 7x103-20 x103 were found to be increased at 30 Hz frequency. The variations in (ε′) with frequency (20 Hz -1MHz) were caused by interfacial polarization occurred in the composites. The changes in AC conductivity (σac) of composite samples were found to be increased with the frequency. The higher value of magneto-electric (ME) coefficient (0.641μv/cm Oe) was obtained for x = 0.25 of composite sample. © 2021 Elsevier B.V.1