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Highly textured phase pure Cu _2 O thin films have been grown by a simple electrodeposition technique with varying deposition voltages (−0.3 to −1.0 V). The surface morphology characterized by Scanning Electron Microscopy (SEM) revealed that the deposited thin films coherently carpet the underlying substrate and are composed of sharp faceted well-defined grains of 0.5–1.0 μ m sizes. XRD analyses showed that all films are composed of polycrystalline cubic Cu _2 O phase only and have average crystalline domain size in the range of 30–73 nm. The preferred crystalline orientation of phase pure Cu _2 O films was found to be changing from (200) to (111) with increasing cathodic voltages and showed the highest (111) and (200) crystalline texture coefficient while growing at −1.0 and −0.8 V respectively. The optical bandgap of the as-grown samples was calculated in the range of 1.95–2.20 eV using UV–vis Transmission data. The performance of Cu _2 O/FTO photocathodes was tested by estimating LED “ON/OFF” modulated surface photovoltage into a photoelectrochemical cell at a zero bias.

In the current study, nanocrystalline CoY0.5xLa0.5xFe2-xO4 (where x = 0.00, 0.02, 0.04, 0.06, 0.08, and 0.10) ferrites have been synthesized via a sol-gel auto combustion process. The synthesized powders were pressed into pellet forms and sintered at 900 °C for 4 h in the air. X-ray diffractometry (XRD) confirmed the single-phase cubic spinel structure of the synthesized samples having the mean crystallite domain sizes ranging from 122 and 54 nm. FTIR spectroscopic analyses revealed two strong bands within the range of 600 to 350 cm−1, further confirming the cubic inverse spinel structure of the prepared materials. The surface morphologies and composition were investigated by Field Emission Scanning Electron Microscopy (FE-SEM) and Energy Dispersive X-ray (EDX) Spectroscopy. The magnetic hysteresis curves recorded at room temperature exhibit ferrimagnetic behavior. The highest coercivity (Hc∼1276 Oe) was found at a high doping (x = 0.10) concentration of Y3+ and La3+ in cobalt ferrite. Dielectric constant increase with increased doping concentration whereas real-impedance and dielectric loss decrease with increased in doping concentration and applied frequency. The band gap energy increased from 1.48 to 1.53 eV with increasing Y3+ and La3+concentrations in the UV–Vis region. The elevated levels of magnetic and dielectric substances in the ferrite nanoparticles suggest that the material could be used for magnetic recording media and high-frequency devices.

In this report, we study the Yttrium-doped Barium Titanate (Y-BT) Ba1 − xYxTiO3 (with x = 0.00, 0.01, 0.03, 0.05, 0.07 mmol) perovskite ceramics synthesized by sol-gel method. The as-made powder samples were pressed into a pellet shape and subsequently sintered at 1300 °C for 5 h in air. The structural, morphological, electrical, and optical properties of the synthesized samples were investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), impedance analyzer, and UV-Vis-NIR Spectroscopy respectively. The XRD study revealed the formations of single phase tetragonal structure of Barium Titanate (BT) with ∼23–33 nm mean crystallite size. The crystallite size increases initially with Y-doping, found at about 33 nm for x = 0.01, and reduces for increase in Y3+ concentration further. The microstructural study from FESEM depicts the uniform distribution of compact and well-faceted grain growth for Y-BT in contrast with undoped barium titanate. The average grain size (∼0.29–0.78 μm) of the Y-BT decreases with increasing doping concentration. Frequency-dependent impedance analyses show enhanced dielectric properties like dielectric constant, quality factor, and conductivity with low dielectric loss in the presence of Yttrium. The optical bandgap energy (∼2.63–3.72 eV) estimated from UV-Vis-NIR diffuse reflection data shows an increasing trend with a higher concentration of yttrium doping.

Herein, paper mill waste sludge (PMS) from two different sources has been investigated to extract calcium hydroxide, Ca(OH)2 by a facile and inexpensive extraction process. PMS samples, collected from local paper mill plants of Bangladesh, were the main precursors wherein HCl and NaOH were used for chemical treatment. The as-synthesized products were analysed by a variety of characterization tools including X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) elemental analyses. Our studies confirm that the extracted product contains Ca(OH)2 as a major content, albeit it also includes CaCO3 phase owing to the inescapable carbonation process from the surrounding environment. The particle size of the synthesized products is in the range of 450–500 nm estimated from SEM micrographs. The crystallite domain size of the same estimated from XRD analyses and was found to be approximately 47 and 31 nm respectively for product-A and product-B considering major (101) Bragg peak of Ca(OH)2. The yield percentage of the isolated products is about 65% for samples collected from both sources.

Cuprous oxide (Cu2O) nanorods have been deposited on soda-lime glass substrates by the modified successive ionic layer adsorption and reaction technique by varying the concentration of NaCl electrolyte into the precursor complex solution. The structural, electrical and optical properties of synthesized Cu2O nanorod films have been studied by a variety of characterization tools. Structural analyses by X-ray diffraction confirmed the polycrystalline Cu2O phase with (111) preferential growth. Raman scattering spectroscopic measurements conducted at room temperature also showed characteristic peaks of the pure Cu2O phase. The surface resistivity of the Cu2O nanorod films decreased from 15 142 to 685 Ω.cm with the addition of NaCl from 0 to 4 mmol and then exhibited an opposite trend with further addition of NaCl. The optical bandgap of the synthesized Cu2O nanorod films was observed as 1.88–2.36 eV, while the temperature-dependent activation energies of the Cu2O films were measured as about 0.14–0.21 eV. Scanning electron microscope morphologies demonstrated Cu2O nanorods as well as closely packed spherical grains with the alteration of NaCl concentration. The Cu2O phase of nanorods was found stable up to 230°C corroborating the optical bandgap results of the same. The film fabricated in presence of 4 mmol of NaCl showed the lowest resistivity and activation energy as well as comparatively uniform nanorod morphology. Our studies demonstrate that the nominal presence of NaCl electrolytes in the precursor solutions has a significant impact on the physical properties of Cu2O nanorod films which could be beneficial in optoelectronic research.

Spinel ferrite [Formula: see text][Formula: see text][Formula: see text]Fe2O4 was prepared by a conventional ceramic process followed by sintering at three different temperatures (1050[Formula: see text] C, 1100[Formula: see text] C and 1150[Formula: see text] C). X-ray diffraction (XRD) investigations stated the single-phase cubic spinel structure and the FTIR spectra revealed two prominent bands within the wavenumber region from 600 cm[Formula: see text] to 400 cm[Formula: see text]. Surface morphology showed highly crystalline grain development with sizes ranging from 0.27 [Formula: see text]m to 0.88 [Formula: see text]m. The magnetic hysteresis curve at ambient temperature revealed a significant effect of sintering temperature on both coercivity ([Formula: see text] and saturation magnetization ([Formula: see text]. Temperature caused a decrease in DC electrical resistivity, while the electron transport increased, suggesting the semiconducting nature of all samples and that they well followed the Arrhenius law from which their activation energies were determined. The values of Curie temperature ([Formula: see text] and activation energy were influenced by the sintering temperature. Frequency-dependent dielectric behavior (100 Hz–1 MHz) was also analyzed, which may be interpreted by the Maxwell–Wagner-type polarization. The UV–vis–NIR reflectance curve was analyzed to calculate the bandgap of ferrites, which showed a decreasing trend with increasing sintering temperature.