Preparation of ZnO/Bi2O3 Composites as Heterogeneous Thin Film Materials with High Photoelectric Performance on FTO Base

In recent years, ZnO nanomaterials have achieved great performance in solar energy applications. How to synthesize a ZnO nanocomposite structure with high photoelectric conversion efficiency has become an urgent problem to solved. In this paper, a narrow band gap bismuth trioxide (Bi2O3) coated on a ZnO nanoarray by magnetron sputtering was used to prepare a composite heterojunction ZnO/Bi2O3. Studies have found that ZnO/Bi2O3 exhibits excellent photoelectric conversion performance. By preparing a composite heterostructure of ZnO/Bi2O3, it can effectively compensate for the insufficient absorption of ZnO in the visible light range and inhibit the recombination of carriers within the material. The influence of Bi2O3 thickness on the microstructure and electronic structure of the ZnO/Bi2O3 composite structure was explored and analyzed. The energy gap width of the composite heterostructure decreases with the increase in the Bi2O3 thickness on the surface of the ZnO nanorod array. At the same time, the conductive glass composite film structure is simple to prepare and is very environmentally friendly. The ZnO/Bi2O3 composite heterogeneous material prepared this time is suitable for solar cells, photodetectors, photocatalysis and other fields.

Bismuth Trioxide Doped Polyamide 6.6 Nanocomposites for Electrically Insulating Materials

Polymer-based insulators have attracted much attention amongst researchers due to their various advantages such as light weightness, lower cost and ease of production. In this study, it is aimed to manufacture lightweight and thin insulator by electrospun composite fibers and to observe the effect of bismuth oxide (Bi2O3) on insulating property of polymer-based composite structure. For that purpose, polyamide 6.6 polymer (PA6.6) with high dielectric constant was doped with bismuth trioxide micro particles and it was used for coating polyester spunbonds by electrospinning technique. Morphological properties, thermal behaviours and electrical resistance of coated spunbonds were investigated. Scanning electron microscopy (SEM) and electron dispersive X-ray spectroscopy (EDX) showed that Bi2O3 was succesfully adapted into fiber structure and nano-scale PA6.6/Bi2O3 composite fibers were obtained. Thermal behaviours of coated samples were developed by increasing Bi2O3 loading according to differential scanning calorimetry (DSC) and thermogravimetic analysis (TGA) results. Addition of Bi2O3 caused remarkable increase on electrical resistance of PA6.6 electrospun surfaces. Bi2O3/PA6.6. nanocomposite fibers are promising and good candidates for thin electrically insulating polymer-based structures for micro- or nanodimensional devices.

Synthesis, Characterization, and Antibacterial Evaluation of a Cost-Effective Endodontic Sealer Based on Tricalcium Silicate-White Portland Cement

Mineral trioxide aggregate (MTA) is an ideal yet costly endodontic sealer material. Tricalcium silicate-white Portland cement (TS-WPC) seems to have similar characteristics to those of MTA. This work aims to characterize a modified TS-WPC and evaluate its antibacterial properties as a potential endodontic sealer material. The modified TS-WPC was synthesized from a 4:1 mixture of sterilized Indocement TS-WPC and bismuth trioxide using a simple solution method with 99.9% isopropanol. The mixture was stirred until it was homogenous, centrifuged, and dried. The material was then characterized using infrared spectroscopy, X-ray diffraction, and electron microscopy and subjected to antibacterial evaluation against Enterococcus faecalis using a Mueller–Hinton agar inhibition test. The results showed that the material was characterized by main functional groups of hydroxyls, silicate, bismuth trioxide, and tricalcium silicate, like those of a commercial MTA-based sealer, both tested after hydration. Modified TS-WPC before hydration showed similar powder morphology and size to the commercial one, indicating the ease of manipulation. Both materials exhibited antibacterial activity due to calcium dihydroxide’s ability to absorb carbon dioxide, which is essential for the anaerobic E. faecalis, with minimum inhibitory effect and bactericidal concentrations of 12,500 ppm and 25,000 ppm, respectively. The modified TS-WPC has the potential to become a cost-effective alternative endodontic sealer material.

Impact-Induced Reaction Characteristic and the Enhanced Sensitivity of PTFE/Al/Bi2O3 Composites

In this paper, the reaction characteristic of a novel reactive material, which introduced bismuth trioxide (Bi2O3) into traditional polytetrafluoroethylene/aluminum (PTFE/Al), is studied. The effect of Bi2O3 with different content and particle size on the reaction behaviors of PTFE/Al/Bi2O3 are investigated by drop-weight test and X-ray diffractometer (XRD), including impact sensitivity, energy release performance under a certain impact, and reaction mechanism. The experimental results show that the content of Bi2O3 increased from 0% to 35.616%, the characteristic drop height of impact sensitivity (H50) of PTFE/Al/Bi2O3 reactive materials decreased first and then increased, and the minimum H50 of all types of materials in the experiment is 0.74 times that of PTFE/Al, and the particle size of Bi2O3 affects the rate of H50 change with Bi2O3 content. Besides, with the increase of Bi2O3 content, both the reaction intensity and duration first increase and then decrease, and there is optimum content of Bi2O3 maximizing the reaction degree of the PTFE/Al/Bi2O3. Furthermore, a prediction model for the impact sensitivity of PTFE-based reactive material is developed. The main reaction products include AlF3, xBi2O3·Al2O3, and Bi.

Remarkably Facile Preparation of Superhydrophobic Functionalized Bismuth Trioxide (Bi2O3) Coatings

Herein, a novel superhydrophobic functionalized nano-Bi2O3 coating is designed and fabricated using electrophoretic assembly deposition (EAD) in the optimal suspension of polyethylene glycol, ethanol, acetylacetone, and surface functionalization. The small size (70 nm, nano-scale) of Bi2O3 particles and uniform distribution make the target film possessing a promising structure for realizing hydrophobic functionalization. Moreover, the hydrophobicity and stability results indicate that the product has a high-water contact angle (CA) of ca. 167° and is kept almost stable after 180 days exposure in the natural environment. These findings will provide new insight into a better design of superhydrophobic functional coatings via this facile method, holding great promise for future various applications.