Search Results (8)

Nanoparticles of MgSb₂O₆ were synthesized using a microwave-assisted wet chemistry method, followed by calcination at 700 °C. Their ability to detect different concentrations of propane gas (C₃H₈) at various operating voltages was evaluated. The material’s crystalline phase was identified using X-ray powder diffraction (XRD). The morphology was analyzed by scanning electron microscopy (SEM), finding bar- and polyhedron-type geometries. Through transmission electron microscopy (TEM), we found particle sizes of 8.87–99.85 nm with an average of ~27.63 nm. Employing ultraviolet–visible (UV-Vis) spectroscopy, we found a band gap value of ~3.86 eV. Thick films made with MgSb₂O₆ powders were exposed to atmospheres containing 150, 300, 400, and 600 ppm of propane gas for dynamic testing. The time-dependent sensitivities were ~61.09, ~88.80, ~97.65, and ~112.81%. In addition, tests were carried out at different operating voltages (5–50 V), finding very short response and recovery times (~57.25 and ~18.45 s, respectively) at 50 V. The excellent dynamic response of the MgSb₂O₆ is attributed mainly to the synthesis method because it was possible to obtain nanometric-sized particles. Our results show that the trirutile-type oxide MgSb₂O₆ possesses the ability, efficiency, and thermal stability to be applied as a gas sensor for propane. Full article

Fabricating far-red light-emitting diodes (LEDs) with high emission efficiency is a change for the application in plant growth. In this work, a new type of far-red LED was fabricated for plant growth by encapsulating the Sr₃LiSbO₆:Mn⁴⁺, Mg²⁺ (SLSO:Mn⁴⁺, Mg²⁺) far-red phosphors with the gradient-refractive glass films. Under 365 nm excitation, the phosphors emitted the wide band in the 550–800 nm range, which overlapped with the absorption band of plants that absorb far-red light (PFR). The internal quantum efficiency (IQE) of the LED was 93.6%. Compared with the luminous efficacy of traditional (fluorescent silicone) LEDs (59 lm/W), the luminous efficacy of the new LED is increased by 62.7%, and reaches 96.74 lm/W. Thus, this far-red LED with high IQE has a long-term application prospect in plant growth. Full article

This study aimed to develop caffeine (CAF) orodispersible films (ODFs) and verify the effects of different percentages of film-forming agent and hydrotropic substances (citric acid—CA or sodium benzoate—SB) on various film properties. Hydroxypropyl methylcellulose E 5 (HPMC E 5) orodispersible films were prepared using the solvent casting method. Four CAF-ODF formulations were prepared and coded as CAF1 (8% HPMC E 5, CAF), CAF2 (8% HPMC E 5 and CAF:CA–1:1), CAF3 (9% HPMC E 5 and CAF:CA–1:1), and CAF4 (9% HPMC E 5 and CAF:SB–1:1). The CAF-ODFs were evaluated in terms of disintegration time, folding endurance, thickness, uniformity of mass, CAF content, thickness-normalized tensile strength, adhesiveness, dissolution, and pH. Thin, opaque, and slightly white CAF-ODFs were obtained. All the formulations developed exhibited disintegration times less than 3 min. The dissolution test revealed that CAF1, CAF2, and CAF3 exhibited concentrations of active pharmaceutical ingredients (APIs) released at 30 min that were close to 100%, whilst CAF4 showed a faster dissolution behaviour (100% of the CAF was released at 5 min). Thin polymeric films containing 10 mg of CAF/surface area (3.14 cm²) were prepared. Full article

Mg₃Sb₂-based compounds are one type of important room-temperature thermoelectric materials and the appropriate candidate of type-II nodal line semimetals. In Mg₃Sb₂-based films, compelling research topics such as dimensionality reduction and topological states rely on the controllable preparation of films with high crystallinity, which remains a big challenge. In this work, high quality Mg₃Sb₂ films are successfully grown on mismatched substrates of sapphire (000l), while the temperature-driven twin structure evolution and characteristics of the electronic structure are revealed in the as-grown Mg₃Sb₂ films by in situ and ex situ measurements. The transition of layer-to-island growth of Mg₃Sb₂ films is kinetically controlled by increasing the substrate temperature (T_sub), which is accompanied with the rational manipulation of twin structure and epitaxial strains. Twin-free structure could be acquired in the Mg₃Sb₂ film grown at a low T_sub of 573 K, while the formation of twin structure is significantly promoted by elevating the T_sub and annealing, in close relation to the processes of strain relaxation and enhanced mass transfer. Measurements of scanning tunneling spectroscopy (STS) and angle-resolved photoemission spectroscopy (ARPES) elucidate the intrinsic p-type conduction of Mg₃Sb₂ films and a bulk band gap of ~0.89 eV, and a prominent Fermi level downshift of ~0.2 eV could be achieved by controlling the film growth parameters. As elucidated in this work, the effective manipulation of the epitaxial strains, twin structure and Fermi level is instructive and beneficial for the further exploration and optimization of thermoelectric and topological properties of Mg₃Sb₂-based films. Full article

Aluminum antimonide (AlSb), a semiconductor compound, finds its applications in optoelectronics because of its tunable bandgap and promising properties achieved by tailoring suitable dopants. To explore the effects of doping, thin films of pure AlSb and 10% magnesium (Mg)-doped aluminum antimonide (MgAlSb) were synthesized through compound solution deposition on a glass substrate using a low-cost chemical bath deposition (CBD) technique at varying bath temperatures with deposition time intervals ranging from 60 to 180 min. Optical microscopy was used to evaluate the surface roughness and morphology of the synthesized films, revealing the surface roughness and thin film uniformity at different deposition times. The structural characteristics of AlSb and Mg-doped AlSb thin films were further examined using the X-ray diffraction technique, which validated the formation of AlSb and Mg-doped AlSb thin films. This research enables large-scale low-temperature deposition for a variety of conceivable applications in the coatings, materials penetration, energy, and photonic sectors due to the novel properties of this material. Full article

In this study, polymer solar cells were synthesized by adding Sb₂S₃ nanocrystals (NCs) to thin blended films with polymer poly(3-hexylthiophene)(P₃HT) and [6,6]-phenyl-C61-butyric-acid-methyl-ester (PCBM) as the p-type material prepared via the spin-coating method. The purpose of this study is to investigate the dependence of polymer solar cells’ performance on the concentration of Sb₂S₃ nanocrystals. The effect of the Sb₂S₃ nanocrystal concentrations (0.01, 0.02, 0.03, and 0.04 mg/mL) in the polymer’s active layer was determined using different characterization techniques. X-ray diffraction (XRD) displayed doped ratio dependences of P₃HT crystallite orientations of P₃HT crystallites inside a block polymer film. Introducing Sb₂S₃ NCs increased the light harvesting and regulated the energy levels, improving the electronic parameters. Considerable photoluminescence quenching was observed due to additional excited electron pathways through the Sb₂S₃ NCs. A UV–visible absorption spectra measurement showed the relationship between the optoelectronic properties and improved surface morphology, and this enhancement was detected by a red shift in the absorption spectrum. The absorber layer’s doping concentration played a definitive role in improving the device’s performance. Using a 0.04 mg/mL doping concentration, a solar cell device with a glass /ITO/PEDOT:PSS/P₃HT-PCBM: Sb₂S₃:NC/MoO₃/Ag structure achieved a maximum power conversion efficiency of 2.72%. These Sb₂S₃ NCs obtained by solvothermal fabrication blended with a P₃HT: PCBM polymer, would pave the way for a more effective design of organic photovoltaic devices. Full article

The present work shows, for the first time, the application of laser ablation connected to inductively coupled plasma mass spectrometry (LA-ICP-MS) to the localized quantitative analysis of inclusions in polymeric industrial films. The multielemental mapping capabilities of LA-ICP-MS has allowed to chemically examine unique defects appeared during the plastic processing. This analytical tool is perfectly suited to detect elements such as Al, Mg, Zr, Ti, Cr, P, Pb, Sb, Zn, and Si in those inclusions. A method for multielemental quantitative analysis of these defects has been developed in the present work. The profiling for more than 100 different defects in three samples has demonstrated that more than 50% of these inclusions contain aggregates of some of the aforementioned elements. Therefore, the distribution of elements used as additives or present in catalysts must be carefully controlled during the production of polymeric films in order to avoid degradation in their performance. Full article

In this work, unmodified screen-printed electrode (bare SPE) and Sb-film modified SPE (SbFSPE) sensors were employed for the analysis of trace amounts of Pb(II) in non-deaerated water solutions. The modified electrode was performed in situ in 0.5 mg/L Sb(III) and 0.01 M HCl. The methodology was validated for an accumulation potential of –1.1 V vs. Ag/AgCl and an accumulation time of 60 s. A comparative analysis of bare SPE and SbFSPE showed that the detection and quantification limits decrease for the bare SPE. The method with the bare SPE showed a linear response in the 69.8–368.4 µg/L concentration range, whereas linearity for the SbFSPE was in the 24.0–319.1 µg/L concentration range. This work also reports the reason why the multiple standard addition method instead of a linear calibration curve for Pb(II) analysis should be employed. Furthermore, the analytical method employing SbFSPE was found to be more accurate and precise compared to the use of bare SPE when sensors were employed for the first time, however this performance changed significantly when these sensors were reused in the same manner. Furthermore, electrochemical impedance spectroscopy was used for the first time to analyse the electrochemical response of sensors after being used for multiple successive analyses. Surface characterisation before and after multiple successive uses of bare SPE and SbFSPE sensors, with atomic force microscopy and field emission scanning electron microscopy, showed sensor degradation. The interference effect of Cd(II), Zn(II), As(III), Fe(II), Na(I), K(I), Ca(II), Mg(II), NO₃^–, Bi(III), Cu(II), Sn(II), and Hg(II) on the Pb(II) stripping signal was also studied. Finally, the application of SbFSPE was tested on a real water sample (from a local river), which showed high precision (RSD = 8.1%, n = 5) and accurate results. Full article