Particle-like Morphology Research Articles

Visible light degradation of antibiotics catalyzed by nanoporous carbon/V2O5 nanocomposite: structural, optical and electrochemical properties

In this study, nanoporous carbon (NPC) decorated V2O5 (NPC/V2O5) nanocomposite synthesized by a hydrothermal technique using biomass-derived NPC nanoflakes towards the application of berberine hydrochloride (BH) dye degradation under visible light irradiation. The prepared samples were characterized by X-ray Diffraction (XRD), Raman spectroscopy, Field Emission Scanning Electron Microscopy (FE-SEM), Transmission Electron Microscopy (TEM), Energy-Dispersive X-ray (EDX), UV-Visible and Photoluminescence (PL) spectroscopy. Charge transfer resistance was measured by electrochemical impedance spectroscopy (EIS) and liner sweep voltammetry (LSV). XRD studies confirm the orthorhombic crystal structure of NPC/V2O5 nanocomposite. FE-SEM and TEM analysis validate their particle-like and sheet-like morphology of V2O5 and NPC respectively. Further, UV-visible DRS and PL spectra of the green synthesized NPC/V2O5 nanocomposite exhibited a low band-gap and reduced recombination rate compared to the pure counterpart which is better light-absorbing ability in the visible light region. Batch experiments represent the incorporation of NPC and V2O5 would lead to an increase the photocatalytic performance of NPC/V2O5 toward BH dye degradation. During the photocatalytic reaction, the NPC/V2O5 nanocomposite degraded rate around 97.7% against BH dye within 80 min while pure V2O5 degraded 92.5% of BH dye under same visible light irradiation time. Finally, the cyclic stability experiment exhibits the photocatalyst even stable after five consecutive tests.

Application of Y-MOF-CNT-Derived Y2O3-C@CNT Composites in Lithium-Sulfur Battery Separators.

In order to mitigate the shuttle effect of lithium polysulfides in lithium-sulfur batteries, we propose a yttrium-metal-organic framework-carbon nanotube (Y-MOF-CNT)-derived Y2O3-C@CNT composite for modifying the separator in this study. The Y-MOFs, comprising yttrium (Y) rare earth metal and terephthalic acid, exemplify a prototypical category of metal-organic framework (MOF) materials. They manifest the advantageous attributes associated with MOFs while concurrently possessing distinctive catalytic traits ascribed to rare earth elements. In this study, Y-MOF nanoparticles were synthesized on carbon nanotube (CNT) substrates via a facile aqueous solution method, succeeded by high-temperature carbonization to yield Y2O3-C@CNT composite materials. These composites were subsequently employed as coatings on one side of polyethylene (PE) separators. The resultant Y2O3-C@CNT composite inherits the particle-like morphology and porosity from its precursor Y-MOF, alongside the inherent conductivity in carbon-based materials. This amalgamation is conducive to polysulfide capture and catalytic conversion processes within lithium-sulfur batteries. The application of the Y2O3-C@CNT-coated PE separator effectively mitigated polysulfide shuttle effects and significantly enhanced the battery electrochemical performance. At a sulfur loading level of 3 mg cm-2 under a 0.5 C rate, an initial discharge specific capacity of 900 mAh g-1 was achieved. After 400 cycles, the discharge specific capacity remained at 483.85 mAh g-1 with a capacity retention rate of 53.7%. Upon increasing sulfur loading to 5 mg cm-2, the discharge specific capacity at a lower rate (0.1 C) reached 817.8 mAh g-1; even after 100 cycles, it maintained a value of 700 mAh g-1 with a capacity retention rate of 85.6%. Notably, our modified Y2O3-C@CNT separator demonstrated exceptional cycling stability, even under conditions involving high sulfur loading.

Layered double hydroxide/conductive polymer nanocomposites: Toward multifunctional biocompatible nanoadsorbents for wastewater treatment applications

ABSTRACT Layered double hydroxide (LDH)/conductive polymer nanocomposites combine the promising adsorption capabilities of 2D layered nanomaterials and the electric properties of conductive polymers, resulting in multifunctional adsorbents for wastewater treatment. In this work, a simple in situ polymerization of aniline was conducted in the presence of Zn-Fe LDH to synthesize a Zn-Fe LDH/PANI nanocomposite, which was characterized by XRD, FTIR, SEM, and BET. The composite showed a particle-like morphology with a size of 30–60 nm and a BET surface area of 23.27 m2/g and was used as an adsorbent for carbamazepine (CBZ). Zn-Fe LDH/PANI removed 98% of CBZ at pH 7, 0.2 g/L, and 40 mg/L CBZ. For biocompatibility, acute toxicity was assessed in vivo for ten days using male albino rats, and probit analysis (after 2, 6, and 24 hours) was used to determine the LD0, LD20, LD50, LD90, and LD100 values, which were calculated to be 890, 1051, 3188, 6371, and 11,300, respectively. During this time, the rats were weighed, and other observations were made, including mortality, behavior, injuries, and any symptoms of toxicity or side effects. Histopathological examination of organs such as the liver, kidney, brain, skin, intestine, and cecum for any pathological alterations was performed. Two green metrics were applied, the Analytical Eco-scale and the Analytical GREEness Calculator (AGREE).

Synthesis and Characterization of Nanocomposite Hydrogels Based on Poly(Sodium 4-Styrene Sulfonate) under Very-High Concentration Regimen of Clays (Bentonite and Kaolinite).

The aim of this work was to synthesize and study the functional properties of polymer-clay nanocomposite (PCNCs) based on poly(sodium 4-styrene sulfonate) (NaPSS) and two types of clay in the dispersed phase: bentonite and kaolinite, in order to advance in the development of new geomimetic materials for agricultural and environmental applications. In this study, the effect of adding high concentrations of clay (10-20 wt. %) on the structural and functional properties of a polymer-clay nanocomposite was evaluated. The characterization by infrared spectroscopy made it possible to show that the PCNCs had a hybrid nature structure through the identification of typical vibration bands of the clay matrix and NaPSS. In addition, scanning electron microscopy allowed us to verify its hybrid composition and an amorphous particle-like morphology. The thermal characterization showed degradation temperatures higher than ~300 °C with Tg values higher than 100 °C and variables depending on the clay contents. In addition, the PCNCs showed a high water-retention capacity (>2900%) and cation exchange capacity (>112 meq/100 g). Finally, the results demonstrated the ability of geomimetic conditioners to mimic the structure and functional properties of soils, suggesting their potential application in improving soil quality for plant growth.

Multiple morphologies and twin structure generated by a definite growth behavior of grain boundary M23C6 in tempered Fe–15Mn–3Al-0.7C steel

M23C6 carbide can precipitate simultaneously on both sides of austenite grain boundary in Fe–15Mn–3Al-0.7C steel tempered at 600 °C. In this paper, the morphology and growth behavior of M23C6 are studied by means of OM, SEM and TEM. The results show that the morphology of M23C6 located on both sides of grain boundary is different. On one side of the grain boundary, the carbides appear to be dispersed and disconnected, each with an irregular particle-like morphology, while on the opposite side, they are dispersed along the grain boundary in a short-rod morphology, and the adjacent ones tend to join together to form a network structure. In fact, regardless of which side of the grain boundary the carbides are on, they exhibit a definite growth behavior, growing along the close-packed plane and grain boundary. Also, the morphology of M23C6 depends on the angle between the close-packed plane and the grain boundary. In addition, twin structures with the same orientation can be found in both austenite and M23C6. A notable distinction between them is that there is a flat twin plane in the austenite twin structure but not in the carbide twin structure. Therefore, this paper highlights that the formation of these two twin structures is different. The austenite twin structure is caused by quenching treatment, while the carbide twin structure is formed by a new method called “growing-contacting”.

Structural, Optical, Magnetic and Dielectric Properties of Ce-Doped MgFe2O4 Prepared by Microwave Hydrothermal Method

The microwave hydrothermal method has been used to synthesize MgFe2-x Ce x O4 (x = 0.0 – 0.10) nanoparticles, which have been characterized using X-ray diffraction (XRD), fourier transform Infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), UV–vis spectrometer, vibrating sample magnetometer (VSM) and dielectric properties. XRD investigation confirms the cubic spinel structure, and the Debye–Scherrer formula was used to determine the crystallite size, showing values of 19 – 108 nm. FTIR confirms the presence of all functional groups and FE-SEM displays particle-like morphology. The UV-visible analysis was used to explain the variation of the optical bandgap as Ce3+ doping increased. VSM analysis of MgFe2-x Ce x O4 showed ferromagnetic behaviour. The samples exhibit low magnetization values ranging from 8.83 emu g−1 to 18.91 emu g−1. The values of the dielectric constant (ε′) and the dielectric loss (tanδ) decreased with frequency due to the influence of space-charge polarization and showed a dispersive behaviour at higher frequencies.

Selective solvent vapor induced self-assembly of silicon-containing bottlebrush block copolymer thin films to generate mesoporous silicon oxide patterns

Bottlebrush block copolymers (BBCPs) are intriguing architectures that can produce various anisotropic nanostructures dictated by the composition, length of the backbone and the lengths of side-chains. Here, we develop a facial approach toward ordered inorganic silicon oxide patterns and particles on substrates by solvent vapor induced thin film self-assembly of anisotropic bottlebrush block copolymers (BBCP) containing polydimethylsiloxane (PDMS) and polystyrene (PS) side chains. The in-plane cylindrical or stripes-like, spherical, and ordered porous morphologies as well as Janus particles-like morphology were fabricated on the substrate through solvent vapor annealing (SVA). The Janus particle-like morphology consisting of PS heads inserted in PDMS heads were directed to produce meso-to macroporous silicon oxide bowls after oxygen plasma etching. The effects of the solvent vapor on the molecular geometry and morphology of the BBCPs were described, and the influence of the backbone length on the self-assembly behavior of the thin film were discussed. This work demonstrates that silicon-containing BBCPs with a native etch contrast and a large difference in solubility parameters are potential candidates to generate ordered silicon oxide templates of different geometries with periodicity 80–150 nm providing access to length scales larger than linear block copolymers.

Impact of reaction temperatures on the particle size of V2O5 synthesized by facile hydrothermal technique and photocatalytic efficacy in dye degradation

In this study, the influence of hydrothermal reaction temperatures on V2O5synthesized via a green facile mild hydrothermal method at six different reaction temperatures ranging from 100 to 200 °C, at steps of 20 °C and the physical properties the synthesized samples have been investigated. The x-ray diffraction pattern confirms the stable orthorhombic crystal structure of the synthesized samples at all reaction temperatures. The scanning electron microscopy and transmission electron microscopy images demonstrate the particle-like morphology, and these characterizations affirmed that the particles’ size became larger with the increase in the reaction temperatures. To study the functional groups, Fourier-transform infrared investigation has been employed. The bandgap of the synthesized samples has been estimated using UV-vis diffuse reflectance spectra and was found to vary from 2.08 to 2.15 eV, which implies their suitability for absorbing a significant amount of visible light. The photocatalysis of methylene blue with synthesized samples has been carried out to investigate the photocatalytic efficiency. Pure V2O5 synthesized at a lower reaction temperature (100 °C) possesses a lower bandgap and, accordingly, higher photocatalytic efficiency.

Monte-Carlo simulation of mass density field coupled dynamics for microstructural evolution of Fe-Cr binary alloys

The phase transformation kinetics and micro-structure evolutions of four different Fe-Cr binary alloys, i.e. Fe-Cr (12.8%), Fe-Cr (20.0%), Fe-Cr (30.0%) and Fe-Cr (40.0%) at 673 K, are investigated by using the kinetic Monte-Carlo simulation combined with spatial coarse-grained mass density field description. For all studied Fe-Cr alloys, it is found that the number density of Cr-rich precipitate undergoes a rather rapid increasing at the nucleation stage and then gradually decreases with the simulation time increasing in the coarsening stage during aging. Increasing the Cr concentration in Fe-Cr alloy can significantly reduce the duration of nucleation and the time interval between nucleation and coarsening. From the coarse-grained mass density field models of Cr-rich precipitates at different aging stages for the four Fe-Cr alloys, we discover that the Cr-rich phase shows the isolated spherical particle-like morphology for the aged Fe-Cr (12.8%) alloy, revealing the nucleation and growth (NG) mechanism. Meanwhile, the Cr-rich precipitates possess a characteristic three-dimensional interconnected microstructure, a signature of spinodal decomposition mechanism. Otherwise, the Cr-rich phase morphology in Fe-Cr (20.0%) exhibits the characteristics of both NG mechanism and SD mechanism. It is also found that the short-range order parameter of Cr atoms in Fe-Cr alloy is indeed very sensitive to the change of atomic structure at the early stage of aging or nucleation stage, which, however, is almost independent of the changing of morphology of Cr-precipitates in the later coarsening process. Finally, the phase transformation kinetics of Cr-rich precipitates during aging are analyzed by calculating the phase volume fraction, average diameter and number density, concluding that the Cr-rich phase growth kinetics in Fe-Cr (20.0%) alloy can be described by the well-known Lifshitz-Slyozov-Wagner law in the coarsening stage. However, the coarsening kinetics of Fe-Cr (12.8%), Fe-Cr (30.0%) and Fe-Cr (40.0%) alloys are not caused by the LSW mechanism.

Synthesis and characterization of pyrochlore-type lanthanum cerate nanoparticles: Electrochemical determination of antibiotic drug sulfadiazine in biological and environmental samples

In recent eras, antibiotic drugs are essential for humans and the veterinary health system. However, the improper discarding of their residues are simply contaminating the food products and environmental samples. Here, pyrochlore-type lanthanum cerate nanoparticles (LaCe NPs) were prepared through a simple co-precipitation route and used as effective electrocatalyst for the detection of antibiotic drug sulfadiazine (SDZ). The structural investigations of prepared material were carried out using XRD, FT-IR, XPS, SEM, HR-TEM, and EDX along with Elemental mapping analysis, which confirm the good formation of pyrochlore type LaCe in the form of particle-like morphology with well-crystalline nature. A nanosized LaCe revealed superior electrochemical activity towards SDZ owing to the large surface area, facilitating mass and ionic transport and chemical stability phenomena. The as-prepared LaCe NPs demonstrated an excellent electrochemical performance towards SDZ determination with a low LOD (50 nM), a wide dynamic range of 0.04–1525 μM, and an acceptable sensitivity of 1.92 μA μM−1 cm−2. Furthermore, the LaCe NPs/GCE revealed excellent reproducibility, storage stability, and selectivity parameters. Additionally, the proposed sensor achieves a good SDZ recovery in milk and human urine samples. The results strongly suggest that the rare earth metal oxide of lanthanum cerate is an efficient catalyst for portable detection of SDZ.

Facile synthesis, structural, morphological, photocatalytic and optical properties of CoFe2O4/ZnO hybrid nanostructures

This study has been endeavoured to investigate the potential of magnetically separable CoFe2O4–ZnO hybrid nanostructures towards the complete mineralization of organic pollutants. Facile co-precipitation method was performed to obtain CoFe2O4–ZnO nanostructures, which were well characterized. The structure, composition and morphology of the materials were confirmed via XRD, Raman, FESEM, TEM and HRTEM which revealed the successful formation of CoFe2O4–ZnO heterojunctions with particle-like morphology having size in range of 10.4–27.6 nm. The optical properties were studied using PL and DRS whereas UV–visible spectroscopy was utilized for examining photocatalytic performance. The photodegradation property of the prepared nanophotocatalysts was assessed by the decomposition of organic dyes and results showed that CoFe2O4–ZnO nanostructures exhibit highly enhanced performance over pristine CoFe2O4 due to the high light utilization ability and heterojunction formation which delays the charge carrier recombination and improves the photodecomposition capability. Additionally, the novel photocatalyst recycled well up to four consecutive degradation cycles and photocatalytic mechanism supported by scavenger experiments was also proposed. This study provides sunlight responsive magnetically separable CoFe2O4–ZnO photocatalyst which efficiently achieves the goal of rapid purification wastewater.

Gradient SERS Substrates with Multiple Resonances for Analyte Screening: Fabrication and SERS Applications

Surface-enhanced Raman spectroscopy (SERS) provides a strong enhancement to an inherently weak Raman signal, which strongly depends on the material, design, and fabrication of the substrate. Here, we present a facile method of fabricating a non-uniform SERS substrate based on an annealed thin gold (Au) film that offers multiple resonances and gap sizes within the same sample. It is not only chemically stable, but also shows reproducible trends in terms of geometry and plasmonic response. Scanning electron microscopy (SEM) reveals particle-like and island-like morphology with different gap sizes at different lateral positions of the substrate. Extinction spectra show that the plasmonic resonance of the nanoparticles/metal islands can be continuously tuned across the substrate. We observed that for the analytes 1,2-bis(4-pyridyl) ethylene (BPE) and methylene blue (MB), the maximum SERS enhancement is achieved at different lateral positions, and the shape of the extinction spectra allows for the correlation of SERS enhancement with surface morphology. Such non-uniform SERS substrates with multiple nanoparticle sizes, shapes, and interparticle distances can be used for fast screening of analytes due to the lateral variation of the resonances within the same sample.

RETRACTED: Oxygen vacancy induced high specific capacitance in Sr2CoSbO6

Sr2CoSbO6, a double perovskite compound known to have oxide ion vacancies, is not well explored for its electrical properties. In the present article, we study the effect of the aliovalent doping of Na+ at Sr site in Sr2CoSbO6 on their electrochemical performance. The X-ray diffraction (XRD) and Scanning Electron Microscope (SEM) techniques confirm the phase formation and reveal particle-like morphologies for all the samples. The cyclic voltammetry study reveals the specific capacitance increases with increasing Na concentration and a specific capacitance value of 228 F/g is obtained for the maximum dopant composition. Excellent cycling stability of 92% of initial capacitance retention even after 2000 continuous cycles at a high scan rate of 100 mVs-1 in an aqueous 1 M KOH electrolyte solution and a 98% of coulombic efficiency at a current density of 1 A/g is observed. These values suggest that the Na doped Sr2CoSbO6 can find application as supercapacitors material.

Conductive and superhydrophobic Ag/PDMS films with high stability for passive de-icing and electromagnetic shielding

In this work, silver nanoparticles (AgNPs) are synthesized and sprayed onto the surface of cotton fabric to produce a conductive film. Then a layer of poly(dimethyl siloxane) (PDMS) was deposited onto the film to prepare Ag/PDMS composite film. The Ag film is with FCC crystalline and particle-like morphology, while layers of organic PDMS are cladding the Ag micro-nano structures. With increasing spraying time, nano‑silver particles changed from round spherical to worm-like, resulting rougher and higher electrical conductivity. By optimizing the PDMS coatings, the contact angle of surface winkled-like microstructure reached 163° and volume resistivity was 9.2 × 10−3 Ω·cm. In addition to the improvement of interfacial adhesion, the introduction of PDMS made the loose particles closely connected, which enhanced the stability of the structure. Meanwhile, the films exhibited great electron-thermal effects, which could be applied in high-speed deicing. Combined with superhydrophobicity, the electromagnetic shielding efficiency can reach 75 dB. The Ag/PDMS films maintained high electromagnetic shielding effectiveness even for servicing in harsh environments, showing that this conductive superhydrophobic fabric composite can be applied as a new electromagnetic shielding material for flexible electronic devices.

Mucosal Delivery of HIV-1 Glycoprotein Vaccine Candidate Enabled by Short Carbon Nanotubes.

The HIV-1 envelope glycoprotein spike is the target of antibodies, and therefore represents the main viral antigen for antibody-based vaccine design. One of the challenges in HIV-1 vaccine development is finding efficient ways for the immune system to recognize and respond to HIV-1 without establishing an infection. Since HIV-1 enters the body at mucosal surfaces, induction of immune response at these sites is a preferred preventive approach. Nasal administration is a very effective route for mucosal immunization since it can stimulate mucosal immune responses both locally and distantly. In this paper, Luna develops a safe, short carbon nanotube (CNT)-based, needle-free delivery platform known as "CNTVac". The size of short CNT was controlled to possess HIV-1 particle-like morphology (100-200 nm) capable of efficiently delivering a broad range of antigens intranasally. PEG-Lipid served as the antigen conformation protector and mucosal barrier penetration enhancer (Schematic Figure) was localized between V1V2 antigens, which caused highly enhanced local IgA and systemic antibody IgG responses in mice and rabbits. The short CNT incorporated with PEG-Lipid could not only serve as efficient delivery system but also reduce the amount of lipid usage in order to balance the vaccine dosage in order to eliminate the potential adverse effect. These data suggest a promising platform technology for vaccine delivery.

Tuned S-Scheme Cu2S_TiO2_WO3 Heterostructure Photocatalyst toward S-Metolachlor (S-MCh) Herbicide Removal.

A dual S-scheme Cu2S_TiO2_WO3 heterostructure was constructed by sol–gel method using a two-step procedure. Due to the synthesis parameters and annealing treatment the heterostructure is characterized by sulfur deficit and oxygen excess allowing the passivation of oxygen vacancies. The photocatalytic activity was evaluated under UV and UV–Vis irradiation scenarios using S-MCh as reference pollutant. The heterostructure is composed on orthorhombic Cu2S, anatase TiO2 and monoclinic WO3 with crystallite sizes varying from 65.2 Å for Cu2S to 97.1 Å for WO3. The heterostructure exhibit a dense morphology with pellets and particle-like morphology closely combined in a relatively compact assembly. The surface elemental composition indicate that the heterostructure maintain a similar atomic ratio as established during the synthesis with a slight sulfur deficit due to the annealing treatments. The results indicate that the three-component heterostructure have higher photocatalytic efficiency (61%) comparing with two-component heterostructure or bare components. Moreover, Cu2S_TiO2_WO3 exhibit a superior constant rate (0.114 s−1) due to the high concentration of photogenerated charge carriers, efficient charge separation and migration.

Structural Role of CeO<sub>2</sub> in the Modified Borate Glass-Ceramics

A new type of cerium borate glass-ceramic is prepared and studied. The microstructure and crystallization behaviors of the glass samples were investigated by X-ray diffraction (XRD), electron diffraction (ED), and 31P NMR spectroscopy. The microstructures of samples contain 2 are amorphous in nature. More addition of CeO2 transforms the glass to glass-ceramics without thermal annealing. The morphological change of the microstructure of these materials was followed by transmission electron microscopy (TEM). The obtained results have revealed that the addition of more than 0.8 mol% CeO2 can promote nucleation and crystallization routes that are combined with the establishment of diverse crystalline phases. Glasses with lower contents of CeO2showed no tendency to crystallization. The crystals of CeO2 containing glasses were spheroid like morphology that was assigned to the three-dimensional fast growth of the well-formed structural species in the boro-apatite phase. In addition, the cerium free glass is characterized by particle-like morphology. Then the growth of spheroid species in three-dimension plays better compatibility and bioactivity behavior than that of the other types of morphology. This is may because the spherical shape has a higher surface area than that of the needle-like morphology. Accumulation and aggregation of small-sized spheres from cerium borate phases played the role of enhancing the hardness of the studied materials.

Effect of nanoparticles on the mechanical properties of kenaf fiber-reinforced bio-based epoxy resin

Ecological composites materials have become a topic of interest in materials science and engineering in recent years because of the growing need for environment-friendly composites that maintain properties like light weight, but gain biodegradability and renewability. Bio-composites of kenaf fiber-reinforced bio-based epoxy resin filled with different kind of nanoparticles were prepared in this work using a hybrid manufacturing process combining vacuum-assisted resin infusion and an autoclave. Nanoparticles of carbon, metal oxides and layered silicates were employed in this work to analyze their effect on the mechanical properties of bio-kenaf composites. Nanoparticles were synthesized and heat-treated according to their nature, and Fourier transform infrared spectra confirmed the presence of functional groups. Laminar structures, such as graphene or layered silicates, had more influence on the bio-kenaf composite toughness than the particle-like morphology of metal oxides. However, the nanoparticles influenced the strength because of their effective stress transfer mechanism. Despite voids of different sizes, which were detected using scanning tomography, they did not influence the mechanical properties of the bio-kenaf composites, showing that the filler effect of the nanoparticles is the dominant mechanism.

Realization of Inverted Organic Solar Cells by Using Sol-Gel Synthesized ZnO/Y2O3 Core/Shell Nanoparticles as Electron Transport Layer

In this article, we describe a simple, low-cost, and environment friendly sol-gel technique to form an effective protective Y2O3 layer over the core ZnO surface. The synthesized ZnO/Y2O3 core/shell nanoparticles have been studied for the investigation of morphology, purity, structure, luminescence, and electronic properties using different characterization techniques. The average particle size has been calculated to be 40 nm (approx). Scanning electron microscopy images show that the synthesized nanomaterials have particle-like morphology with spherical shape while high-resolution transmission electron microscopy analysis confirms their core/shell structure. Furthermore, ZnO/Y2O3 sample has been investigated as an electron transport layer (ETL) in inverted organic solar cell (OSC) with a blend of poly{4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b’]dithio phene-2,6-diyl-alt-3-fluoro-2-[(2ethylhexyl)carbonyl]thieno [3,4-b]thiophene-4,6-diyl} (PTB7), and [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) as an active layer. On comparing with the standard device having pure ZnO as ETL, the power conversion efficiency of PTB7:PC71BM based device with ZnO/Y2O3 as ETL is efficiently improved from 5.77% to 6.22%. This study provides an economical method to increase the efficiency of OSCs.

Pb-doped SnS nano-powders: Comprehensive physical characterizations

Un- and Pb-doped SnS nano-powders (NPs) prepared using the co-precipitation method. The elemental composition of obtaining NPs was investigated by energy-dispersive X-ray spectroscopy (EDX) that showed the presence of Sn and S elements in undoped SnS sample. The inclusion of Pb-dopant in the EDX spectra of Pb-doped SnS samples was observed. X-ray diffraction (XRD) patterns indicated the production of orthorhombic SnS for all samples. The crystalline quality of SnS NPs was improved after Pb-doping. The crystallite size was increased and the lattice strain of SnS NPs was decreased after Pb-doping. Field emission scanning electron microscopy (FESEM) images exhibited the particle-like morphology that increased the size of SnS nanoparticles after Pb-doping from 22.98 nm to 24.39 nm. The FESEM outcomes were verified by the transmission electron microscopy (TEM) images. Photoluminescence (PL) spectra displayed two emission peaks for all samples that linked to lattice defects including Sn interstitials and/or Sn vacancies, comprising a blue and a green emission peak. Absorption spectra were obtained for Pb-doped SnS NPs relative to the undoped SnS NPs. The Eg of SnS NPs was reduced from 1.71 eV to 1.44 eV after Pb-doping. The resistivity of SnS NPs initially decreased and then increased after Pb-doping. Mott-Schottky plots revealed that the Pb-dopant changed the conductivity type of SnS NPs. Due to the inclusion of Pb-doping, the dielectric constant of SnS NPs has been improved. The results of ac-conductivity are verified by the I–V characteristic.