The Effect of Calcium and Iron (III) Oxides on Lead Spent Plates: Spectroscopic, Voltametric, and EIS Investigations.

In this study, xCaO‧5Fe2O3‧(95-x)Pb glasses and vitroceramics containing various concentrations of calcium ions (from 0 to 50 mol% CaO) were prepared using the spent anodic plate of a car battery. X-ray diffraction analysis revealed changes in the network structure as a function of CaO content. The intensities of the IR bands due to the sulfate and sulfite units were lowered, indicating a decrease in the sulfurization degree within the lead network. In the UV-vis spectra, the presence of electronic transitions of the Fe3+, Pb2+, and Fe2+ ions were identified. The EPR spectra were characterized by resonance signals centered at about g ~ 2 and 4.3, corresponding to the trivalent iron ions. For the samples with 5 ≤ x ≤ 12, the signals decreased abruptly, suggesting a Fe3+→Fe2+ interconversion and the formation of the Fe3O4 crystalline phase. A considerable increase in the intensity of the signal centered around g ~ 2 was observed as the CaO concentration increased to 30% in the host matrix. Our results confirm that the higher CaO levels of 3 mol% are responsible for the increase in the radius of curvature of the semicircle arcs in the EIS plots and the decrease in their conductivity.

Recent Advances in Photochargeable Integrated and All-in-One Supercapacitor Devices.

Photoassisted energy storage systems, which enable both the conversion and storage of solar energy, have attracted attention in recent years. These systems, which started about 20 years ago with the individual production of dye-sensitized solar cells and capacitors and their integration, today allow more compact and cost-effective designs using dual-acting electrodes. Solar-assisted batterylike or hybrid supercapacitors have also shown promise with their high energy densities. This review summarizes all of these device designs and conveys the cutting-edge studies in this field. Besides, this review aims to emphasize the effects of point, extrinsic, intrinsic, and 2D-planar defects on the performance of photoassisted energy storage systems since it is known that defect structures, as well as electrical, optical, and surface properties, affect the device performance. Here, it is also targeted to draw attention to how critical the design, material selection, and material properties are for these new-generation energy conversion and storage devices, which have a high potential to see commercial examples quickly and to be recognized by more readers.

Recycled and Nickel- or Cobalt-Doped Lead Materials from Lead Acid Battery: Voltammetric and Spectroscopic Studies.

The active mass of the plates of aspent car battery with higher wear after an efficient desulfatization can be used as sources of a new electrode. This paper proposes the recycling of spent electrodes from a lead acid battery and the incorporation of NiO or Co3O4 contents by the melt-quenching method in order to enrich the electrochemical properties. The analysis of X-ray diffractograms indicates the gradual decrease in the sulfated crystalline phases, respectively, 4PbO·PbSO4 and PbO·PbSO4 phases, until their disappearance for higher dopant concentrations. Infrared (IR) spectra show a decreasing trend in the intensity of the bands corresponding to the sulfate ions and a conversion of [PbO3] pyramidal units into [PbO4] tetrahedral units by doping with high dopant levels, yielding to the apparition of the PbO2 crystalline phase. The observed electron paramagnetic resonance (EPR) spectra confirm three signals located on the gyromagnetic factor, g~2, 2.2 and 8 assigned to the nickel ions in higher oxidation states as well as the metallic nickel nanoparticles. This compositional evolution can be explained by considering a process of the drastic reduction in nickel ions from the superior oxidation states to metallic nickel. The linewidth and the intensity of the resonance lines situated at about g~2, 2.17, 4.22 and 7.8 are attributed to the Co+2 ions from the EPR data. The best reversibility of the cyclic voltammograms was highlighted for the samples with x = 10 mol% of NiO and 15 mol% of Co3O4, which are recommended as suitable in applications as new electrodes for the lead acid battery.

Impact on the Photocatalytic Dye Degradation of Morphology and Annealing-Induced Defects in Zinc Oxide Nanostructures.

In this study, three different morphologies, nanoflower (NF), nano sponge (NS), and nano urchin (NU), of zinc oxide (ZnO) nanostructures were synthesized successfully via a mild hydrothermal method. After synthesis, the samples were annealed in the atmosphere at 300, 600, and 800 °C. Although annealing provides different degradation kinetics for different morphologies, ZnO NS performed significantly better than other morphologies for all annealing temperatures we used in the study. When the photoluminescence, electron paramagnetic resonance spectroscopy, BET surface, and X-ray diffraction analysis results are examined, it is revealed that the defect structure, pore diameter, and crystallinity cumulatively affect the photocatalytic activity of ZnO nanocatalysts. As a result, to obtain high photocatalytic activity in rhodamine B (RhB) degradation, it is necessary to develop a ZnO catalyst with fewer core defects, more oxygen vacancies, near band emission, large crystallite size, and large pore diameter. The ZnO NS-800 °C nanocatalyst studied here had a 35.6 × 10-3 min-1 rate constant and excellent stability after a 5-cycle photocatalytic degradation of RhB.

Photoluminescence and Photocatalytic Properties of MWNTs Decorated with Fe-Doped ZnO Nanoparticles.

The present work reports the photoluminescence (PL) and photocatalytic properties of multi-walled carbon nanotubes (MWCNTs) decorated with Fe-doped ZnO nanoparticles. MWCNT:ZnO-Fe nanocomposite samples with weight ratios of 1:3, 1:5 and 1:10 were prepared using a facile synthesis method. The obtained crystalline phases were evidenced by X-ray diffraction (XRD). X-ray Photoelectron spectroscopy (XPS) revealed the presence of both 2+ and 3+ valence states of Fe ions in a ratio of approximately 0.5. The electron paramagnetic resonance EPR spectroscopy sustained the presence of Fe3+ ions in the ZnO lattice and evidenced oxygen vacancies. Transmission electron microscopy (TEM) images showed the attachment and distribution of Fe-doped ZnO nanoparticles along the nanotubes with a star-like shape. All of the samples exhibited absorption in the UV region, and the absorption edge was shifted toward a higher wavelength after the addition of MWCNT component. The photoluminescence emission spectra showed peaks in the UV and visible region. Visible emissions are a result of the presence of defects or impurity states in the material. All of the samples showed photocatalytic activity against the Rhodamine B (RhB) synthetic solution under UV irradiation. The best performance was obtained using the MWCNT:ZnO-Fe(1:5) nanocomposite samples, which exhibited a 96% degradation efficiency. The mechanism of photocatalytic activity was explained based on the reactive oxygen species generated by the nanocomposites under UV irradiation in correlation with the structural and optical information obtained in this study.

Structure-Bioactivity Relationship of the Functionalized Polysulfone with Triethylphosphonium Pendant Groups: Perspective for Biomedical Applications.

Development of new biomaterials based on polysulfones tailored to act in various biomedical fields represents a promising strategy which provides an opportunity for enhancing the diagnosis, prevention, and treatment of specific illnesses. To meet these requirements, structural modification of the polysulfones is essential. In this context, for design of new materials with long-term stability, enhanced workability, compatibility with biological materials and good antimicrobial activity, the functionalization of chloromethylated polysulfones with triethylphosphonium pendant groups (PSFEtP+) was adopted. The surface chemistry analysis (Fourier transform infrared spectroscopy (FTIR), Energy-dispersive X-ray spectroscopy (EDX)), rheological properties, morphological aspects (Scanning electron microscopy (SEM), polarized light microscopy (POM)), and antimicrobial activity of the synthetized polysulfone were investigated to establish the relationship between its structure and properties, as an important indicator for targeted applications. Based on the obtained features, evaluated by the relationship between the rheological properties and microstructural aspects, and also the response at the biomaterial-bacteria interface, these qualities have been confirmed in their performance, in terms of thermal stability, antimicrobial activity, and also an increase in lifetime. Consequently, derived results constitute the preliminary basis for future tests concerning their functionality as gel matrices in biomedical devices.

Facile Preparation of PVDF/CoFe2O4-ZnO Hybrid Membranes for Water Depollution.

In this investigation, CoFe2O4-PVDF and CoFe2O4-ZnO-PVDF hybrid membranes were prepared using a modified phase inversion method in which a magnetic field was applied during the casting process to ensure a uniform distribution of nanomaterials on the membrane surface. Thus, better absorption of light and increased participation of nanoparticles in the photodegradation process is ensured. The influence of nanomaterials on the crystalline structure, surface morphology, and hydrophilicity properties of the PVDF membrane was investigated. The obtained results indicated that the hybrid membrane exhibited significant differences in its intrinsic properties due to the nanomaterials addition. The hydrophilicity properties of the PVDF membrane were improved by the presence of nanoparticles. The photocatalytic decomposition of aqueous Rhodamine B solution in the presence of the prepared membrane and under visible light irradiation was tested. The hybrid membrane containing CoFe2O4-ZnO on its surface exhibited a high removal rate.

Structural, Optical, and Magnetic Studies of the Metallic Lead Effect on MnO2-Pb-PbO2 Vitroceramics.

MnO2-lead materials have attracted attention in their applications as electrodes. This work reports a detailed spectroscopic study of the compositional variation of MnO2-xLead vitroceramic materials with varied Pb contents. The concentration variation of lead and manganese ions issystematically characterized throughthe analysis of X-ray diffraction (XRD), Fourier transform infrared (FTIR), ultraviolet-visible (UV-Vis), and electron paramagnetic resonance (EPR) spectroscopy.The MnO2-xLead samples consist of a vitroceramic structure with Pb, PbO, PbO2,and Mn3O4 crystalline phases. The introduction of higher Pb content in the host vitroceramic reveals the [PbO6]→[PbOn] conversion, where n = 3, 4, and the formation of distorted [MnO6] octahedral units. The UV-Vis data of the samples possess the intense bands between 300 and 500 nm, which are due to the presence of divalent lead ions (320 nm) and divalent and trivalent manganese ions (420 and 490 nm, respectively) in the structure of glass ceramics. The EPR data show resonance lines located around g ~ 8 and 4.3, and a sextet hyperfine structure at g ~ 2, which isascribed to the Mn+3 and Mn+2 ions.

New Polymeric Adsorbents Functionalized with Aminobenzoic Groups for the Removal of Residual Antibiotics.

In this paper, we present the synthesis of new polymeric adsorbents derived from macroporous chloromethylated styrene-divinylbenzene (DVB) copolymers with different cross-linking degrees functionalized with the following aminobenzoic groups: styrene-6.7% DVB (PAB1), styrene-10% DVB (PAB2), and styrene-15% DVB (PAB3). The new polymeric products, PAB1, PAB2, and PAB3, were characterized by FTIR spectroscopy, thermogravimetric analysis, and EDX, SEM, and BET analysis, respectively. The evolution of the functionalization reaction was followed by FTIR spectroscopy, which revealed a decrease in the intensity of the γCH2Cl band at 1260 cm-1, and, simultaneously, the appearance of C=O carboxylic bands from 1685-1695 cm-1 and at 1748 cm-1. The thermal stability increased with the increase in the cross-linking degree. The data obtained from the EDX analysis of the novel cross-linked copolymers confirmed the functionalization with aminobenzoic groups through the presence and content of nitrogen, as follows: PAB1: N% = 0.47; PAB2: N% = 0.85; and PAB3: N% = 1.30. The adsorption performances of the novel polymeric adsorbents, PAB1, PAB2, and PAB3, were tested in the adsorption of three antibiotics, tetracycline, sulfamethoxazole, and amoxicillin, from aqueous solutions, by using extensive kinetic, equilibrium, and thermodynamic studies. The best adsorption capacity was demonstrated by the tetracycline. Amoxicillin adsorption was also attempted, but it did not show positive results.

Chemical Modification of Chitosan for Removal of Pb(II) Ions from Aqueous Solutions.

Biomacromolecule have a significant contribution to the adsorption of metal ions. Moreover, chitosan is one of the most studied biomacromolecule, which has shown a good performance in the field of wastewater treatment. In this context, a new adsorbent of the aminophosphonic modified chitosan-supported Ni(II) ions type was prepared from the naturally biopolymer, chitosan. In the first step, modified chitosan with aminophosphonic acid groups was prepared using the "one-pot" Kabachnik-Fields reaction. It was characterized by different techniques: FTIR, SEM/EDAX, TGA, and 31P-NMR. In the second step, the modified chitosan with aminophosphonic acid was impregnated with Ni(II) ions using the hydrothermal reaction at different values of pH (5, 6 and 7). The physical-chemical characteristics of final products (modified chitosan carrying aminophosphonic groups and Ni(II) ions) were investigated using FTIR, SEM images, EDAX spectra and thermogravimetric analysis. In this work, the most important objective was the investigation of the adsorbent performance of the chitosan modified with aminophosphonic groups and Ni(II) ions in the process of removing Pb(II) ions from aqueous solutions by studying the effect of pH, contact time, and Pb(II) ions concentration. For removal of Pb(II) ions from the aqueous solution, the batch adsorption method was used.