Field Effect Scanning Electron Microscopy Research Articles

Bio-ultrasonic synthesis of tin oxide quantum dots: Effect of bio-carbon and their UV Photocatalytic activity

Abstract An ecofriendly synthesis is realized to elaborate tin oxide quantum dots (SnO2 -QDs) using the plant aqueous extract of Aloe Barbadensis Miller (Aloe Vera) and SnCl4.5H2O at room temperature as a biological solvent and a precursor respectively. The effect of Aloe Vera extract concentration on the properties of SnO2-QDs has been studied. Morphological and structural properties of the as synthesized nanoparticles have been characterized using field effect-scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD). The chemical composition of the nanoparticles was studied by Raman, energy dispersive X-ray (EDX) and Fourier transformation infra-red (FTIR) spectroscopy. The optical properties were investigated by UV–Vis spectrophotometer. The X-ray diffraction analysis showed that all samples have a tetragonal rutile structure, with an estimated crystal size closed to the exciton Bohr radius, indicating a strong confinement of the carriers in the material. The crystallite size of SnO2-QDs nanoparticles decreases as Aloe Vera plant extract concentration increases. The formation of SnO2-QDs and the presence of graphitic carbon in samples were confirmed by Raman spectroscopy, EDX analysis and Fourier transformation infra-red (FTIR) spectroscopy. The blue shift of absorption is the most likely attributed to the quantum confinement effect. An Ostwald-repining growth model based on the concept of surface energy has been proposed to explain the kinetic growth of SnO2 QDs. The improvement of photocatalytic activity of the photocatalyst for degradation of methylene blue (MB) might be caused by the size and the high surface area of the material.

Synergistic effect of the ferroelectric-ferrite approach on the structural, electrical and magnetic properties

ABSTRACT In the present report, the structure–property correlation of 0.9BaZr0.2Ti0.8O3-0.1NiFe2O4 (0.9BZT-0.1NFO) composite is studied. The X-ray Diffraction, Raman spectroscopy and Field Effect Scanning Electron Microscopy (FESEM) reveal the existence of ferroelectric and magnetic phases without any impurity and interdiffusion. The dielectric, ferroelectric and conductivity mechanisms of the sample are studied in a wide range of temperature (RT-500°C) and frequency (100 Hz–1 MHz), respectively. The dielectric constant is larger than 2000 in low frequency (<1 kHz), while it decreases to 500 when the frequency is larger than 4 kHz. Both small polaron and correlated barrier hopping contribute to the conduction mechanism. The multiferroism at room temperature is confirmed by P-E and M-H loop study. The composite obeys the Law of Approach to Saturation at a higher field. The saturation magnetization found from fitting is in good agreement with the experimental value.

An exhaustive exploration of Zn0.15Sn0.85(Se0.95S0.05)2 crystal-based photodetector and its potential application as a photocatalytic material

The research pioneers the exploration of synthesized quaternary Zn0.15Sn0.85(Se0.95S0.05)2 (ZSSS) crystals, demonstrating remarkable efficacy as optoelectronic switching devices and potent photocatalysts. The ZSSS photodetector recorded a stable photoresponse with remarkable rapid rise and decay times. The Langmuir-Hinshelwood kinetic model was used to look at the photocatalytic activity at different methylene blue concentrations. The researchers grew highly pure ZSSS crystals using the direct vapour transport (DVT) method. Field effect scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HRTEM) images reveal the layer growth mechanism in the grown crystals. The structural analyses of the grown crystals were carried out using an X-ray diffraction (XRD) pattern and temperature-dependent Raman spectroscopy. The Lorentzian function was fitted to experimental data to carry out the temperature-dependent Raman analysis. The grown crystals exhibit a direct optical bandgap of 1.69 eV. The electrical analyses explain the semiconducting nature of the crystals.

Temperature sensing materials based on the fluorescence intensity ratio in Li2Ba5W3O15:Dy3+ phosphors

One of the interesting uses of phosphors is the development of non-contact thermometers apart from their usage as visible photonic devices. A series of Dy3+-doped Li2Ba5W3O15 (LBW) phosphors were successfully synthesized using high temperature solid-state reaction process. The crystal structure and morphology of LBW:xDy3+ phosphors were studied using X-ray diffraction (XRD), Rietveld refinements and field effect scanning electron microscopy (FE-SEM) with energy dispersive x-ray (EDX) analysis. The XRD and photoluminescence (PL) analyses validated the effective substitution of Ba2+ ions with Dy3+ ions. Two prominent emission peaks were found at 493 and 583 nm corresponding to 4F9/2→6H15/2 and 4F9/2→6H13/2 transitions respectively under 368 nm excitation wavelength. A comprehensive analysis has been carried out on the usage of the Dy3+ doped LBW phosphors in fluorescence intensity ratio (FIR) thermometry. The optical temperature measurement performance of the LBW:xDy3+ phosphor was achieved by utilizing distinct thermal quenching transitions, specifically on 4F9/2→6H15/2,13/2, at temperatures ranging from 293 to 443 K. The as-prepared phosphors demonstrate excellent performance as optical thermometers, with a maximum relative sensitivity (Sr) of 0.7% K−1 at 293 K, an absolute sensitivity (Sa) of 4.68 K−1 at 443 K and a temperature resolution of ∼0.51 at 443 K. These values indicate that the phosphors are highly responsive to changes in temperature, making them suitable for non-contact thermometry applications.

Photocatalytic Degradation of Methylene Blue and Methyl Orange Dye by Using the Core-Shell Structure of Fe3O4@ZnS Nanoparticles

A straightforward and highly efficient method was developed for the synthesis of Fe3O4@ZnS core-shell nanoparticles (NPs). These synthesized materials were subsequently utilized for the photocatalytic degradation of methylene blue (MB) and methyl orange (MO) dyes. The structural characteristics of the prepared sample were meticulously investigated through X-ray diffraction (XRD) and field-effect scanning electron microscopy (FESEM). The XRD analysis confirmed the crystalline phase formation in the Fe3O4 nanoparticles, while a study in the Vibrating Sample Magnetometer (VSM) mode emphasized their strong ferromagnetic behavior. The degradation of dyes was comprehensively studied using UV-Vis analyses, taking into account factors such as pH and initial dye concentration in the decolorization process. The synthesized Fe3O4@ZnS core-shell nanostructure underwent thorough characterization using XRD, UV-Vis spectroscopy, SEM, Fourier-transform infrared spectroscopy (FT-IR), and VSM mode in PPMS. Furthermore, the reusability of the catalyst was explored, yielding promising results. The findings demonstrated the efficient photocatalytic degradation of MB and MO dyes under UV-visible irradiation, achieving significant results within 30-minute intervals.

Performance of pulsed plasma thruster at low discharge energy

As the size of satellites scales down, low-power and compact propulsion systems such as the pulsed plasma thruster (PPT) are needed for stabilizing these miniature satellites in orbit. Most PPT systems are operated at 2 J or more of discharge energy. In this work, the performance of a PPT with a side-fed, tongue-flared electrode configuration operated within a lower discharge energy range of 0.5‒2.5 J has been investigated. Ablation and charring of the polytetrafluoroethylene propellant surface were analyzed through field-effect scanning electron microscopy imaging and energy-dispersive X-ray spectroscopy. When the discharge energy fell below 2 J, inconsistencies occurred in the specific impulse and the thrust efficiency due to the measurement of the low mass bit. At energy 2 J, the performance parameters are compared with other PPT systems of similar configuration and discussed in depth.

Optimization of magnetic properties of MnFe2O4 by modulating molarity of NaOH as precipitating agent

Abstract MnFe2O4 nanoparticles were synthesized using the co-precipitation method with a wide range of molar concentrations of sodium hydroxide 0.76 M−3.0 M. X-ray diffraction, field effect scanning electron microscopy, transmission electron microscopy, and vibrating sample magne-tometry were employed to characterise the structural, morphological, and magnetic characteristics of nanoparticles. Field effect scanning electron microscopy and transmission electron microscopy images show that the particles were spherical in shape for all the samples except for sample prepared at a molar concentration of 1.3 M. Particle shape was found to depend on the molar concentration of NaOH. The hysteresis loops of the samples possessed a very small area and low coercivity. The crystallite size (cs), saturation magnetisation, coercivity, retentivity, squareness ratio and anisotropy constant were found to be dependent on the molar concentration on NaOH. M S was noted to be at a maximum of 64.4 emu g−1 at a molar concentration of 1.3 M. The ratio t/cs (where t is the thickness of the dead layer) was calculated to account for the variation in M S. H C was found to be maximum of ∼52 Oe at molar concentrations between 1.0 M and 2.0 M. M r and M r/M S were found to be a maximum of 8.95 emu g−1 and 0.15, respectively, for the molar concentration of 2.0 M.

Optimization of Vancomycin Antibiotic Removal from Synthetic and Real Wastewater Using UV/Fe3 O4 @Alg-ZnO Nanocomposite Photocatalysis: Response Surface Methodology Based on a Box-Behnken Design

Background: Vancomycin (VCM) is a critical antibiotic due to its high consumption and side effects, including increased bacterial resistance affecting treatment processes. This research investigated the efficiency of VCM antibiotic removal from an aqueous solution using a UV/Fe3 O4 @Alg-ZnO integrated process. Methods: Response surface methodology (RSM) and a Box-Behnken design were applied using Design-Expert software to optimize the number of samples and simultaneously understand the interactive effects between variables. X-ray diffraction (XRD), a vibrating-sample magnetometer (VSM), field effect scanning electron microscopy (FE-SEM), and Fourier transform infrared (FTIR) analyses were used to check the structural characteristics. The effects of initial catalyst concentration (0.1, 0.3, and 0.5 g/L), initial pollutant concentration (10, 30, and 50 mg/L), contact time (10, 30, and 50 minutes), and pH (3, 7, and 11) on VCM decomposition rate were investigated. Spectrophotometry, total organic carbon (TOC), and GC-MS analyses were used to check the efficiency of the process. Results: In this study, VCM and TOC removal efficiency was 92.64% and 85.38%, respectively, under optimal conditions. The reason for the reduction in the efficiency of the combined UV/Fe3 O4 @Alg-ZnO process in real raw sewage, after activated sludge (13%) and after activated sludge and stabilization ponds (24%), is the high COD, which causes the active radicals produced to be spent on other species instead of the VCM antibiotic. Conclusion: The current study showed that the UV/Fe3 O4 @Alg-ZnO process performs well in removing VCM and TOC. In real wastewater, this efficiency was significantly reduced.

NiFe2O4 nanoparticles as highly efficient catalyst for oxygen reduction reaction and energy storage in supercapacitor

Nickel ferrite (NiFe2O4) nanostructures (NSs) were synthesized via a low-cost and reproducible co-precipitation method. The as-synthesized material was annealed at different temperatures to investigate electrochemical performances for oxygen reduction reaction (ORR) and energy storage capacity. The X-ray diffraction (XRD) pattern confirmed the cubic structure of NiFe2O4 (NF) NSs. The decreased agglomeration and increased particle size were observed by field effect scanning electron microscopy (FE-SEM) with annealing temperature. The presence of Ni–O and Fe–O bonds at tetrahedral and octahedral sites was confirmed by Fourier transform infrared (FTIR) spectroscopy. The electrochemical analysis studied using cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS) demonstrated that the NF NSs annealed at 900 °C exhibited impressive electrochemical activity with a specific capacitance of ∼136 F/g, outperforming samples synthesized at lower temperatures. Moreover, the electrode material displayed excellent long-term stability over 3000 cycles for ORR activity. The remarkable electrochemical performance of NF NSs at higher annealing temperatures highlights their potential for future energy storage and conversion devices.

Optimization of process variables and characterization of mechanically agitated ceramic‐microsphere reinforced aluminium composite

AbstractThis study aims to investigate the effect of stir‐casting process parameters, including stirring speed, stirring time, and weight % of the ceramic microsphere, on the fabrication of an aluminium 6061‐ceramic microsphere composite. Experiments are conducted using a full‐factorial design approach to determine the effect of variables on mechanical properties. A field effect scanning electron microscope is used to analyze the fracture surfaces of the test specimen. Further, the results are subjected to the Anderson‐darling normality test to validate the accuracy of the model, and finally, an analysis of variance is performed to identify the most significant parameters that affect the mechanical properties. The results confirm the validity of the designed experimental model for enhancing the mechanical properties of the aluminium 6061‐ceramic microsphere composite. The optimum mechanical properties are attained for a stirring speed of 600 min−1, stirring time of 15 min, and 5 weight % of reinforcement. Furthermore, the weight percentage of the ceramic microsphere increase, the ductility of the composite decreases while its strength and hardness increase. Finally, the analysis of variance shows that all parameters significantly impact the mechanical properties of the designed composite.

Fabrication and Development of a Biomass-Based Supercapacitor with Enhanced Energy Storage Characteristics

In this work, a raw carbon waste parali biomass is collected to develop a supercapacitor. The activated carbon developed is characterized using X-ray diffraction (XRD), Field effect scanning electron microscope (FESEM), Energy dispersive spectroscope (EDS), and Brunauer–Emmett–Teller (BET) analyses. The porous and crystalline activated carbon achieved a remarkably high carbonaceous value of 99.85% carbon from 35.71% in raw state. The specific surface area obtained is 151.42 m2 g−1 and the porosity (average pore diameter) is 2–10 nm of the optimized activated carbon. The activated carbon is explored as electrode material for supercapacitor in aqueous electrolyte and the specific capacitance was found to be a maximum of 247 F g−1 at 1.2 A g−1 to a stable value of 180 F g−1 at 10 A g−1. The symmetrical supercapacitor device, featuring electrodes composed of carbon material, attains an impressive energy density of 54 Wh kg−1 along with outstanding coulombic efficiency and stability. The laboratory prototype supercapacitor has successfully powered consumer electronics, such as a DC (direct current) motor for 12.5 min and an LED (Light emitting diode) bulb for 14 min, on a single charge in each case.

Influence of 100 MeV 16O7+ ion irradiation on the structural, morphological, dielectric, and electromagnetic interference shielding properties of ferroelectric PVDF polymer

Polyvinylidene fluoride (PVDF), with β polymorph, is a versatile ferroelectric polymer in device fabrication. Its flexibility, lightweight, and ease of fabrication make it an alternative for electromagnetic interference shielding effectiveness (EMI-SE) improved through swift heavy ion (SHI) irradiation. For the first time, we modified PVDF thin films for EMI-SE applications, exposing them to a 100 MeV oxygen ion beam at varying fluencies. Our analysis encompassed investigating structural study, bonding interactions, surface morphology, and elemental analysis using X-ray diffraction (XRD), Fourier transform infrared spectrophotometry (FTIR), and Field Effect Scanning Electron Microscopy (FESEM) with Energy Dispersive X-ray Spectroscopy (EDS) respectively. Further, we measured dielectric response, cole-cole plot and EMI-SE in Ku-band (12–18 GHz) region using a vector network analyzer (VNA). The results revealed distinctive variations due to the deposition of 100 MeV oxygen ion beams, emphasizing the significant potential of irradiated PVDF thin films for EMI-SE applications. This study contributes to understanding the transformative impact of ion beam exposure on PVDF thin films and highlights their practical promise in emerging technological applications, particularly in EMI-SE.

Evaluation of Morinda citrifolia extract as sustainable inhibitor for mild steel in saline environment

In this study, the Morinda citrifolia extract was evaluated as a sustainable inhibitor of mild steel in saline environments. The work aimed to determine the inhibition efficiency of new active material for metal corrosion inhibition. The powdered simplicia of M. citrifolia was extracted in the macerator for three days using a solvent daily. The functional group bonds of this extract were analyzed by Fourier Transform Infrared (FT-IR). The performance of M. citrifolia extracts was evaluated with potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) techniques using a three-electrode cell system. The surface morphology of mild steel was pictured by Field effect scanning electron microscopy (FE-SEM) coupled with energy dispersive X-ray spectroscopy (EDX). Potentiodynamic polarization results show decreasing corrosion current (Icorr) with the presence of an extract of M. citrifolia. Furthermore, resistance capacity transfer (Rct) increases with the addition of M. citrifolia extract. The optimum inhibition efficiency (%IE) was achieved at 300 mg L−1 concentrations with 85.10% efficiency by using the PDP technique. The mild steel morphology in the addition of M. citrifolia extracts is smoother than the surface without adding extracts. The increase in corrosion inhibition was associated with the molecule adsorption from the active compounds into the steel surface. The study results confirmed that M. citrifolia is a potential biomaterial engineering for corrosion inhibitors on mild steel in a saline environment.

Structural investigation, magnetic and DC electrical resistivity properties of Co0.5-xNixZn0.5Fe2O4 nano ferrites

The Ni2+ substituted Cobalt-Zinc nano ferrites, designated as Co0.5-xNixZn0.5Fe2O4 with x values ranging from 0.0 to 0.5, were synthesized using the sol–gel auto-combustion method. Various characterization techniques, including x-ray diffraction (XRD), field-effect scanning electron microscopy (FESEM), Fourier Transform Infrared (FTIR) spectroscopy, vibrating sample magnetometer (VSM), and DC electrical resistivity measurements, were employed to analyze the prepared samples. XRD analysis revealed a cubic spinel structure with a lattice constant ranging from 8.384 to 8.412 Å. FESEM examination indicated non-uniform-shaped spherical grains in the nanometer range for the synthesized samples. The FTIR spectra of the spinel ferrites revealed two distinctive bands, ν2 (580–592 cm−1) and ν1 (390–412 cm−1), which are the characteristics of spinel-structured ferrite nanomaterials. With progressive substitution (x varying from 0.0 to 0.5), the saturation magnetization (Ms) values exhibited a gradual decrease, starting from Ms = 60.97 emu/g (at x = 0.0) and reaching Ms = 38.79 emu/g (at x = 0.5). A discernible pattern was observed in coercivity (Hc), which rose from Hc = 115 Oe (at x = 0.0) to Hc = 920 Oe (at x = 0.5), with peak values determined through VSM analysis. Similar to semiconductors, the electrical resistivity experienced a decline with increasing temperature, indicative of a negative temperature coefficient.

A Simple Synthesis and Microstructure Analysis of Human Peptide LL-37@Gold Nanoparticles (Known as LL-37@AuNPs) Conjugates as Antimicrobials and Substances for Wound Healing.

The basis of the present study is a straightforward method involving fewer chemical species for conjugating gold nanoparticles (AuNPs) with the antimicrobial peptide LL-37 designated as LL-37@AuNPs. Investigating the microstructure characteristics of the resulting materials and their potential as antibacterial and wound-healing substances are the main objectives of this study. Zeta (ζ) potential, Fourier transform infrared (FTIR), X-ray diffraction (XRD), field effect scanning electron microscopy (FE-SEM), energy dispersive X-ray diffraction (EDS), transmission electron microscopy (TEM), and UV-Vis spectrophotometry were used to analyze the physico-chemical properties of LL-37@AuNPs. The magnitude of LL-37's zeta potential and the LL-37@AuNPs show that the specimens are electrically stable and resistant to flocculation and coagulation. The surface plasmon resonance (RPS) of AuNPs, which is positioned at a wavelength of about 531 nm, was found to be unaffected by the presence of the LL-37 antimicrobial peptide. The FTIR data show the functional group characteristics of the LL-37@AuNPs vibration bands, and the XRD diffractogram confirms the formation of the LL-37@AuNPs conjugate nanocomposite. Based on FE-SEM and TEM data, the bulk of AuNPs were found to have a circular shape, with an average size of about 22.88 ± 8.21 nm. It was discovered that the LL-37@AuNPs had a good ability to inhibit S. aureus from growing. The wound-healing percentage reached 85% on day 12 of the trial, significantly greater than the results of the negative controls. LL-37@AuNPs(4) is the sample that had the highest percentage of wound healing between days 3 and 12. Moreover, sample LL-37@AuNPs(4) contains 0.45 µL of LL-37, whereas sample LL-37@AuNPs(2) contains 0.22 µL of LL-37. The faster wound-healing rate in LL-37@AuNPs(4) was believed to be due to a higher concentration of LL-37, which was able to stop S. aureus from developing while suppressing the inflammation surrounding the wound. The study's findings reveal that LL-37@AuNPs might be made using a straightforward process, making them a powerful antibacterial and therapeutic substance. However, before this discovery is applied in the field of medicine, a more thorough investigation is necessary.

Exploring the synergistic effects of La3+ substitution on dielectric performance of manganese cobalt ferrite: Implications for advanced electronic applications

La3+ substituted Mn0.5Co0.5Fe2O4 ferrites were synthesized through sol-gel auto-combustion route. The impacts of varying doping concentrations (0.03, 0.06 and 0.09) were studied on synthesized samples' structural, optical, morphological, vibrational, and dielectric properties. The spinel cubic phase of synthesized samples was confirmed by X-ray diffraction (XRD) analysis; increased La3+ concentration has altered the structural parameters of prepared ferrites. Diffuse Reflectance Spectroscopy (DRS) shows a decrease in band gap with increasing concentration of La3+. Morphology has been reviewed by Field Effect Scanning Electron Microscope (FE-SEM), and elemental composition was confirmed by Energy Dispersive X-ray (EDAX) spectra. In addition, M − O stretching bonds were verified employing Fourier Transform Infrared (FTIR) spectroscopy. Raman Spectroscopy shows five modes, further confirming the spinel structure. The XPS spectra verified the +2 oxidation state of Manganese. Finally, the dielectric constant, tangent loss, and AC (Alternating Current) conductivity were analyzed with temperature at several frequencies. The experimental results have unveiled intriguing findings: the dielectric constant exhibited its maximum value at the lowest frequency within the investigated range, and it demonstrated an increasing trend with the rising temperature at a specific frequency. Notably, introducing La3+ through substitution has led to a noteworthy enhancement in the dielectric constant, underscoring the novel impact of this dopant on the material's electrical properties. A positive correlation existed between AC conductivity and temperature; as the temperature increases, so does the AC conductivity. Also, it was found to be maximum at maximum frequency value for all samples. Additionally, it can be deduced that raising the La3+ concentration in crystal improves the dielectric characteristics of Manganese Cobalt ferrites.

Rapid adsorption and simultaneous photocatalytic effect of Ru doped flower like antimony tungstate

Ruthenium (Ru) doped antimony tungstate microflowers, prepared through hydrothermal process, have been investigated for simultaneous adsorption and photocatalysis. The pattern of evolution of microflower structures, however, can be tailored by the synthesis period. This change is observed from the field effect scanning electron microscope and transmission electron microscope images. A possible mechanism behind this morphological change has been developed. An argument based on the zeta potential may be responsible for this distinct morphology due to the strong electrostatic interactions. The variation of a particular x-ray diffraction peak corresponding to the plane with variation of Ru doping percentage shows the decrease in crystallinity along the perpendicular direction to this plane. Besides, the optimum Ru doping percentage is evaluated on the basis of photocatalytic efficiency towards methylene blue (MB) degradation under visible light. The highest dye removal efficiency is observed for 2% Ru doped Sb2WO6 (SWO) adsorbing 97% of the MB dye followed by photocatalytic degradation of almost 64% of the remaining dye in 80 min. Furthermore, using different dyes, it is concluded that Ru–SWO showcases high adsorption toward the cationic dyes while it neither adsorbs the anionic dye nor displays photocatalytic degradation.

The Characteristic of Ph-Sensing of Potentiometric on Zinc Oxide and Aluminium-Doped Zinc Oxide Nanostructures

Numerous investigations have been conducted to increase the sensitivity and stability of metal oxide semiconductors as pH-sensing membranes. This paper will describe the pH sensing and characterisation of zinc oxide (ZnO) and aluminium-doped zinc oxide (ZnO:Al) as potentiometric pH sensors. The hydrothermal technique was used to grow ZnO and ZnO:Al thin film nanostructures with doping concentrations of 1, 3, and 5 at% Al on the cleaned ITO substrates. The pH potentiometric sensing was performed in a wide pH range of 4-12 and produced sensitivity, including stability of the nanostructures. The prepared samples were also characterized by X-ray diffraction analysis (XRD), field effect scanning electron microscope (FESEM), and energy dispersive X-ray (EDX) to explore the influence of aluminium concentration on structural and morphology characteristics and then prepared as electrodes for pH sensing. From the XRD result, the sharp peaks and high peak intensities demonstrated well crystalline of the synthesized ZnO nanorods. Furthermore, the FESEM shows the growth of array nanorods perpendicular over the surface of ITO. The sensitivity of the pH sensor with 3 at% ZnO:Al exhibits higher sensitivity (43.80 mV/pH) and larger linearity (0.9507).

Synthesis and characterization of lead free multidoped ferroelectric material: (Bi0.85Nd0.15)(Fe0.5Ti0.5)O3

The Nd and Ti doped bismuth ferrite compound (Bi0.85Nd0.15)(Fe0.5Ti0.5)O3 has been synthesized through a solid state reaction method. Its various properties, such as structural, dielectric and ferroelectric features were thoroughly investigated. The XRD analysis confirms the phase formation with monoclinic symmetry of the compound. The field effect scanning electron microscope (FE-SEM) micrograph/image shows the surface morphology and uniformly distributed grains over its surface. Energy dispersive X-ray (EDX) suggests the presence of all ingredients with appropriate purity (constituent elements are in well ratios of their atomic and weight percentage). Investigation of impedance and dielectric data was carried out in an extensive range of temperature and frequency. Prepared material data expose a significant improvement in the electrical and dielectric characteristics. Frequency dependent ac-conductivity diagram/plot of present material obeys Jonscher’s universal power law. The PE loop tracer study confirms the ferroelectric nature of the material. Present study offers several interesting features of the material for further device applications.

ZnO/CdS based high performance broadband photo-chargeable flexible supercapacitor

Photo-chargeable supercapacitors are attracting significant research interest as promising alternative to energy storage devices suitable for next-generation smart appliances. In this work, a heterojunction of cadmium sulphide (CdS) nanoparticles and zinc oxide (ZnO) nanorods is obtained for designing a broadband photo responsive symmetrical supercapacitor. Ultraviolet (UV) absorption by ZnO and visible light interaction with the CdS nanoparticles in the heterostructure contribute synergistically to deliver UV to visible broad spectral response. The heterojunction formation is confirmed by field effect scanning electron microscopy and high-resolution transmission electron microscopy with elemental mapping. Areal capacitance was measured in both the dark and under illumination conditions using cyclic voltammetry and galvanostatic charge–discharge, supported by impedance spectroscopy. Enhancement of areal capacitance from the dark condition was observed between ∼238% to ∼1264% for different illumination in broad spectral range measured from the cyclic voltammetry measurements at a constant scan rate of 50 mV s−1 and achieved a highest capacitance value of ∼139 µF cm−2 under 475 nm visible light for the scan rate of 10 mV s−1. Moreover, the charge generation and storage mechanism under illumination were verified by phototransient response and open-circuit potential measurements. The excellent electrochemical performance observed by maintaining high efficiency (∼94.7%) with improved cyclic stability upto 5000 cycles. A good capacitance retention (∼90%) in bending mode when heterojunction applied in bendable devices provide broad future prospect for the metal oxide-sulphide interface in photo-chargeable smart devices.