Bi2O3 Nanoparticles Research Articles

A photoelectrochemical sensor for ultrasensitive dopamine detection based on composites of BiOI and Au-Ag nanoparticles

A photoelectrochemical dopamine sensor based on BiOI and AuAgNPs nanoparticles modified indium tin oxide (ITO) electrode was prepared successfully. The noble metal material AuAg significantly improved the shortcomings of poor surface conductivity and easy recombination of photogenerated electron holes in BiOI. The prepared electrode generated a significantly enhanced and stable photocurrent signal under Xe lamp irradiation. In addition, in weak acidic electrolyte solution, dopamine molecules were protonated and preferent existed in the form of cations, which were easily attracted by electrostatic and adsorbed on the surface of negatively charged AuAgNPs. As an electron donor, DA is vulnerable to oxidation to DA+ by BiOI holes, resulting in an increased anodic photocurrent. The detection limit was 0.3 pM (S/N = 3) and the dopamine concentration exhibited a nice linear relationship between 1 pM and 0.1 μM under ideal circumstances. The dopamine photoelectrochemical sensor shown strong sensitivity, a broad linearity range, and good selectivity against potential uric acid and ascorbic acid interference. This work provides a promising PEC detection platform for the detection of small and medium-sized molecules in biological analysis.

Structure-property behavior of polyethylene nanocomposites containing Bi2O3 and WO3 as an eco-friendly additive for radiation shielding

A new polymer based on nanocomposites was prepared to examine its radiation-shielding properties for potential industrial applications. Bismuth oxide (Bi2O3) nanoparticles and flower tungsten oxide nanostructures (FL-WO3) was hydrothermal synthesized. The Bi2O3 nanoparticles and WO3 nanostructure formation were confirmed using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy (TEM). The Bi2O3 nanospheres had an average diameter of approximately 30–68 nm. The WO3 nanostructure and Bi2O3 nanoparticles were incorporated into low density polyethylene (LDPE) to fabricate a nanocomposite. The radiation-shielding performance of different nanocomposites was investigated. The results showed that LDPE loaded with WO3, WO3/Bi2O3, and Bi2O3 displayed higher tensile strength and thermal stability than unloaded LDPE. The results showed that the LDPE loaded with 3% Bi2O3 performed better gamma attenuation at 662, 1173, and 1332 keV. Additionally, WO3, WO3/Bi2O3, and Bi2O3 as ecofriendly additive-reinforced LDPE materials have a gamma-ray-shielding performance. The results indicate that LDPE containing Bi2O3 have higher gamma-ray-shielding properties than other nanocomposites.

Gamma Attenuation Features of White Cement Mortars Reinforced by Micro/Nano Bi2O3 Particles.

This study aims to explore the radiation protection properties of white mortars based on white cement as a binder and Bi2O3 micro and nanoparticles in proportions of 15 and 30% by weight as replacement sand. The average particle size of micro- and nano-Bi2O3 was measured using a transmission electron microscope (TEM). The cross-sectional morphology and distribution of Bi2O3 within the samples can be obtained by scanning electron microscopy (SEM), showing that nanoscale Bi2O3 particles have a more homogeneous distribution within the samples than microscale Bi2O3 particles. The shielding parameters of the proposed mortars were measured using the HPGe detector at various γ-ray energies emitted by standard radioactive point sources 241Am, 133Ba, 60Co, 137Cs, and 152Eu. The experimental values of the prepared mortars' mass attenuation coefficients (MAC) match well with those determined theoretically from the XCOM database. Other shielding parameters, including half value layer (HVL), tenth value layer (TVL), mean free path (MFP), effective electron density (Neff), effective atomic number (Zeff), equivalent atomic number (Zeq), and exposure buildup factor (EBF), were also determined at different photon energies to provide more shielding information about the penetration of gamma radiation into the selected mortars. The obtained results indicated that the sample containing 30% by weight of nano Bi2O3 has the largest attenuation coefficient value. Furthermore, the results show that the sample with a high concentration of Bi2O3 has the highest equivalent atomic numbers and the lowest HVL, TVL, MFP, and EBF values. Finally, it can be concluded that Bi2O3 nanoparticles have higher efficiency and protection compared to microparticles, especially at lower gamma-ray energies.

Development of a novel sensor based on Bi2O3 and carbonized UIO-66-NH2 nanocomposite for efficient detection of Pb(Ⅱ) ion in water environment

Development of an efficient monitoring technology for rapid detection of toxic Pb(Ⅱ) ion in water environments is extremely important. Here, a novel and highly sensitive sensor was prepared using one-step calcination technique, based on Bi2O3 nanoparticles and carbonized metal–organic framework (MOF) nanocomposite. Scanning electron microscopy, transmission electron microscopy, contact angle and X-ray photoelectron spectroscopy characterization methods were used to analyze the morphology and structure of the prepared materials. Based on the electrical double-layer capacitance theory and Raman spectroscopy, changes to the active sites of different modified materials were investigated. Besides, differential charge densities and adsorption energies of the different modified materials in Zr-O clusters were calculated using density functional theory (DFT). A Bi2O3 and carbonized UIO-66-NH2 (Bi2O3/C-UIO-66-NH2) -modified glassy carbon electrode was used to detect Pb(Ⅱ) by differential pulse anodic stripping voltammetry. Under optimal experimental parameters, the developed electrochemical sensor has a wide linear range (2–130 μg/L) and a low detection limit (0.05 μg/L). Meanwhile, the sensor has excellent stability, repeatability, and anti-interference properties and has been successfully applied to detect Pb(Ⅱ) in actual water samples. The results of this paper show that our developed sensor an efficient and rapid sensor technology for monitoring lead in water environment.

Ti3C2@Bi2O3 nanoaccordion for electrochemical determination of miRNA-21.

Based on a dual signal amplification strategy of novel accordion-like Bi2O3-decorated Ti3C2 (Ti3C2@Bi2O3) nanocomposites and hybridization chain reaction (HCR), an ultra-sensitive electrochemical biosensor was constructed for miRNA-21 detection. By etching Ti3AlC2 with HF, Ti3C2 with an accordion-like structure was first obtained and subsequently covered by Bi2O3 nanoparticles (NPs), forming Ti3C2@Bi2O3. A layer of Au NPs was electrodeposited on the glassy carbon electrode coated with Ti3C2@Bi2O3, which not only significantly improved the electron transport capacity of the electrode but also greatly increased its surface active area. Upon the immobilization of the thiolated capture probe (SH-CP) on the electrode, the target miRNA-21 specifically hybridized with SH-CP and thus opened its hairpin structure, triggering HCR to form a long double strand with the primers H1 and H2. A large number of the electrochemical indicator molecules were thus embedded inside the long double strands to produce the desirable electrochemical signal at a potential of - 0.19V (vs. Ag/AgCl). Such dual signal amplification strategy successfully endowed the biosensor with ultra-highsensitivity for miRNA-21 detection in a wide linear range from 1fM to 100pM with adetection limit as low as 0.16fM. The excellent detection of miRNA-21 in human blood plasma displayed a broad prospect in clinical diagnosis. An ultra-sensitive electrochemical biosensor was successfully constructed for miRNA-21 detection in human blood plasma based on the dual signal amplification strategy of novel accordion-like Bi2O3 decorated Ti3C2 (Ti3C2@Bi2O3) nanocomposites and hybridization chain reaction.

Trade-off between breast dose and image quality using composite bismuth shields in computed tomography: A phantom study

IntroductionMany researchers have suggested that bismuth composite shields (BCS) reduce breast dose remarkably; however, the level of this reduction and its impact on image quality has not been assessed. This study aimed to evaluate the efficiency of nano- and micro- BCS in reducing the dose and image quality during chest computed tomography (CT) scans. Materials and methodsBismuth shields composed of 15 weighting percentage (wt%) and 20 wt% bismuth oxide (Bi2O3) nano- and micro-particles mixed in silicon rubber polymer were constructed in 1 and 1.5 mm thicknesses. The physical properties of nanoparticles were assessed using a scanning electron microscope (SEM), X-ray diffraction (XRD), and energy-dispersive X-ray (EDX). Breast radiation doses were measured experimentally during chest CT using PMMA standard dosimetry phantom (body phantom, 76-419-4150, Fluke Biomedical) in the presence of the shields. The image quality was assessed by calculating signal and noise values in different regions. ResultsThe SEM images showed that the average size of Bi2O3 nano- and micro-particles was about 70 nm and 150 μm, respectively. The breast doses were reduced by increasing the shield thickness/bismuth weight percentage. The maximum dose reduction was related to the 20% weight of Bi2O3 nano-particles and a thickness of 1.5 mm. The minimum dose reduction was related to the 15% weight of Bi2O3 micro-particles with a thickness of 1 mm. The mean noise was higher in nano-particle bismuth shields than in micro-particles. ConclusionComposite shields containing bismuth nano- and micro-particles can reduce the breast dose during chest CT examinations while negatively impacting diagnostic image quality. Several critical factors, such as bismuth concentration, particle size, and shield thickness, directly affect the efficiency.

BIBLIOMETRIC COMPUTATIONAL MAPPING ANALYSIS OF PUBLICATION ON Bi2O3 NANOPARTICLES USING VOSVIEWER

This study examines the development of research on bismuth oxide (Bi2O3) nanoparticles through a bibliometric approach with computational mapping analysis using VOSviewer. Journal article data was obtained from the Google Scholar database using the Publish or Perish application. The keywords used to search related journals are Bi2O3, nanoparticles, chemistry, bismuth oxide. There were 998 journal articles related to keywords. The range of journal articles searched from the Google Scholar database is the last 10 years (2012 – 2022). The results show that research Bi2O3 nanoparticles can be separated into 3 terms: nanoparticle, Bi2O3, bismuth oxide. Nanoparticle term which is included in cluster 3 with 186 links total, 812 total link strength, and 163 occurrences. The second term is Bi2O3 which belongs to cluster 7 with a total of 213 links, a total link strength of 1550, and occurrences of 189 and a bismuth oxide term which belongs to cluster 4 with a total of 230 links, a total link strength of 2080, and 401 occurrences. The results of the analysis of research developments in the last 10 years show a slight fluctuation. In 2012 – 2013 there was an increase in the number of studies from 34 to 62 (28 studies). However, in 2013 – 2016 it decreased from 62 to 53 (9 studies). In 2016 – 2022 again experienced a significant increase from 53 to 152 (99 studies). With the results of this study, the development of research on Bi2O3 nanoparticles shows that this research has great opportunities that can be explored again.

Construction of novel g-C3N4 coupled efficient Bi2O3 nanoparticles for improved Z-scheme photocatalytic removal of environmental wastewater contaminant: Insight mechanism

Recently, the major environmental pollution produced by the release of wastewater in liquid type is one of the most extensive forms of foremost pollution in water ecosystems. In this article, the Bi2O3/g-C3N4 nanocomposite with a direct Z-scheme was effectively obtained by a facile hydrothermal system. The crystal structures, surface morphology, chemical composition, and the optical belongings of the as-obtained composite catalysts were examined by Power XRD, FT-IR spectra, High-resolution XPS spectra, FE-SEM images with EDX spectra, High-resolution TEM images, UV–Vis DRS, and PL spectra respectively. Furthermore, the photocatalytic performance was assessed by the degradation of aqueous Rhodamine B (Rh B) dye under visible-light exposure. The Bi2O3/g-C3N4 composite photocatalysts (PCs) showed the maximum photo-degradation efficiency through a rate constant value of 0.0149 min−1, which is 4.9 and 5.3 folds superior to Bi2O3, and GCN, respectively. The better GBO2 nanocomposite PCs showed a superior photocatalytic degradation performance (>82%) of aqueous Rh B dye after five successive recycles. Moreover, based on these outcomes of the radical scavenging test, a direct and effective Z-scheme photocatalytic charger transfer mechanism was also projected. Finally, the reusability of the as-obtained Bi2O3/g-C3N4 nanocomposite has better stability and reusability, which was a favourable applicant for wastewater handling.

Effect of bismuth oxide nanoparticles on the radiation shielding of bentonite clay using Fluka modeling calculations and simulation studying

This research aims to evaluate the radiation shielding ability of fabricated bentonite clay doped with xBi2O3 nanoparticles (x = 0, 10, 20, 30, and 40 wt%). Gamma-ray shielding parameters for the newly designed bentonite/Bi2O3 nanocomposites were calculated with the help of the Monte Carlo software (FLUKA), for photon energies ranging from 0.015 to 15 MeV. Five shielding parameters were measured including the nanocomposites' mass attenuation coefficient, effective atomic number, electron density, mean free path, and half-value layer. X-ray diffraction analysis, Energy dispersive X-ray and the scanning electron microscope were used to investigate the characteristics of the developed nanocomposites (structural and morphological), as well as those of the as-prepared Bi2O3 nanoparticles. The findings demonstrated that an increase in the amount of Bi2O3 nanoparticles in the bentonite clay matrix enhances the predicted gamma-ray shielding characteristics of the resulting nanocomposites. As a result, the sample of bentonite clay including 40 wt% Bi2O3 nanoparticles had the highest value for mass attenuation, effective atomic number, and electron density, and the lowest value of mean free path and half-value layer, of all the developed nanocomposites.

Preparation of Bi2O3 modified ZSM-5 with photo-deposition method and its application in pyridine base synthesis

Bi2O3 modified ZSM-5 was prepared and used for synthesizing pyridine bases from ammonia and aldehydes. Bismuth was innovatively applied in the reaction of pyridine base synthesis. Photo-deposition method facilitated uniform dispersion of bismuth atomic clusters on the surface of ZSM-5. Bismuth atomic clusters were then oxidized to Bi2O3 nano-particles by O2 in the solution or air. The Lewis acid characteristics of Bi2O3 contributed to the formation of H+ during the reaction, and the properties of Bi2O3 facilitated the desorption of pyridine bases, therefore the prepared catalysts showed a better catalytic performance than the parent ZSM-5. The catalyst with 2.5 wt% bismuth had the best performance: the yield of pyridine bases was 1.8 times of that over parent ZSM-5, and the selectivity was as high as 91.0%. The catalyst also showed a good lifetime and regeneration performance.

Bi2S3/Bi2O3 nanocomposites as effective photocatalysts for photocatalytic degradation of tetracycline under visible-light exposure

A modified simple sol-gel process based on the nonionic surfactant Pluronic F-127 has synthesized bismuth oxide (Bi2O3). A series of Bi2S3/Bi2O3 nanocomposites with varying Bi2S3 content (1.0–4.0 wt%) have been prepared and used as efficacious photocatalysts for tetracycline (TC) photodegradation via visible-light illumination. The physicochemical characterization of the Bi2S3/Bi2O3 samples revealed that mesoporous Bi2S3 nanoparticles (NPs) were successfully incorporated onto the surface of Bi2O3, forming heterojunctions that promote both charge transfer and harvesting of visible light with decreasing the charge carriers' recombination. The amount of Bi2S3 determines the effectiveness of the heterojunctions in the Bi2S3/Bi2O3 nanocomposites, with 3.0 wt% of Bi2S3 achieving the best development by decreasing the bandgap to 1.9 eV while enhancing the absorption of visible light. After 90 min of light illumination, the 3 wt% Bi2S3/Bi2O3 nanocomposite demonstrated the highest photocatalytic activity towards TC degradation, with a 2-fold greater than bare Bi2O3 NPs. By optimizing the dose to 2.0 g/L, the 3 wt% Bi2S3/Bi2O3 accomplished a quick photocatalytic degradation of TC solution at a rate constant of 0.0466 min−1. Furthermore, it maintained notable reusability after five runs after 60 min of exposure. The boosted photocatalytic efficiency of the Bi2S3/Bi2O3 photocatalyst is suggested by a Z-scheme mechanism in which the photogenerated electrons in Bi2O3 prefer to associate with the photogenerated holes in Bi2S3 due to their matched band locations. This study reinforces the application of nanoheterojunction oxides in quickly eliminating antibiotic contamination under visible light.

Driving up the Electrocatalytic Performance for Carbon Dioxide Conversion through Interface Tuning in Graphene Oxide-Bismuth Oxide Nanocomposites.

The integration of graphene oxide (GO) into nanostructured Bi2O3 electrocatalysts for CO2 reduction (CO2RR) brings up remarkable improvements in terms of performance toward formic acid (HCOOH) production. The GO scaffold is able to facilitate electron transfers toward the active Bi2O3 phase, amending for the high metal oxide (MO) intrinsic electric resistance, resulting in activation of the CO2 with smaller overpotential. Herein, the structure of the GO-MO nanocomposite is tailored according to two synthetic protocols, giving rise to two different nanostructures, one featuring reduced GO (rGO) supporting Bi@Bi2O3 core-shell nanoparticles (NP) and the other GO supporting fully oxidized Bi2O3 NP. The two structures differentiate in terms of electrocatalytic behavior, suggesting the importance of constructing a suitable interface between the nanocarbon and the MO, as well as between MO and metal.

Efficient application of newly synthesized green Bi2O3 nanoparticles for sustainable biodiesel production via membrane reactor

Introduction of waste and non-edible oil seeds coupled with green nanotechnology offered a pushover to sustainable and economical biofuels and bio refinery production globally. The current study encompasses the synthesis and application of novel green, highly reactive and recyclable bismuth oxide nanocatalyst derived from Euphorbia royealeana (Falc.) Boiss. leaves extract via biological method for sustainable biofuel synthesis from highly potent Cannabis sativa seed oil (34% w/w) via membrane reactors. Advanced techniques such as X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Diffraction X-Ray (EDX), and FT-IR were employed to illustrate the newly synthesized green bismuth oxide nanoparticles. 92% of FAMEs were produced under optimal reaction conditions such as a 1.5% w/w catalyst weight, 1:12 oil to methanol molar ratio, and a reaction temperature of 92 ⸰C for 3.5 h via membrane reactor. The synthesized Cannabis biodiesel was identified using the FT-IR and GC-MS techniques. The fuel properties of synthesized biofuels (acid number 0.203 mg KOH/g, density 0.8623 kg/L, kinematic viscosity 5.32 cSt, flash point 80 °C, pour point −11 °C, cloud point −11 °C, and Sulfur 0.00047 wt %, and carbon residues 0.2) were studied and established to be comparable with internationally set parameters. The experimental data (R2 = 0.997) shows that this reaction follow pseudo first-order kinetics. These findings affirm the application of green bismuth oxide nanoparticles as economical, highly reactive and eco-friendly candidate for industrial scale biodiesel production from non-edible oil seeds.

Bismuth (III) oxide decorated graphene oxide filled epoxy nanocomposites: thermo-mechanical and photon attenuation properties

In this study, bismuth (III) oxide (Bi2O3) decorated graphene oxide (GO) nanocomposites were employed as novel radioprotective fillers in the epoxy matrix. Decoration of GO with Bi2O3 would transform it as carrier for Bi2O3 particles, thereby enhancing the thermo-mechanical and radiation shielding properties of the epoxy composites through effective filler distribution. Structural and compositional studies confirmed the successful decoration of Bi2O3 on the surface of GO. Thereupon, epoxy composites containing decorated fillers at different loadings (5, 10 and 15 wt%) were synthesized using solution casting technique. The correlation between surface decoration and filler loading was systematically examined as function of thermo-mechanical, viscoelastic and radiation shielding properties of the composites. These nanocomposites displayed good thermal resistance (~ 450 °C), high glass transition temperature (~ 136 °C), elastic modulus (~ 4.36 GPa) and storage modulus, thereby confirming the improved dispersion and better interfacial adhesion in the composites. The formation of continuous filler network across epoxy matrix formed by decorated fillers significantly improved X-ray and γ-ray shielding properties of epoxy composites in the wide energy range of medical interest (30 – 1332 keV). Shielding efficiency of these lowly loaded BGO/epoxy composites were comparable with the composites containing Bi2O3 nanoparticles alone and highly loaded microcomposites.

Spindle-like MIL101(Fe) decorated with Bi2O3 nanoparticles for enhanced degradation of chlortetracycline under visible-light irradiation.

Improving the photocatalytic performance of metal–organic frameworks (MOFs) is an important way to expand its potential applications. In this work, zero-dimensional (0D) Bi2O3 nanoparticles were anchored to the surface of tridimensional (3D) MIL101(Fe) by a facile solvothermal method to obtain a novel 0D/3D heterojunction Bi2O3/MIL101(Fe) (BOM). The morphology and optical properties of the as-prepared Bi2O3/MIL101(Fe) composite were characterized. The photocatalytic activity of the synthesized samples was evaluated by degrading chlortetracycline (CTC) under visible-light irradiation. The obtained BOM-20 composite (20 wt % Bi2O3/MIL101(Fe)) exhibits the highest photocatalytic activity with CTC degradation efficiency of 88.2% within 120 min. The degradation rate constant of BOM-20 toward CTC is 0.01348 min−1, which is 5.9 and 4.3 times higher than that of pristine Bi2O3 and MIL101(Fe), respectively. The enhanced photocatalytic activity is attributed to the formation of a Z-scheme heterojunction between Bi2O3 and MIL101(Fe), which is conducive to the rapid separation of photogenerated carriers and the enhancement of photogenerated electron and hole redox capacity. The intermediate products were analyzed by liquid chromatography–mass spectrometry (LC–MS), and a possible photocatalytic degradation path of CTC was proposed. This work provides a new perspective for the preparation of efficient MOF-based photocatalysts.

Polyethylene oxide-engineered graphene with rich mesopores anchoring Bi2O3 nanoparticles for boosting CO2 electroreduction to formate

Nanostructured Bi2O3 electrocatalysts for electrochemical reduction of CO2 (CO2ER) into formic acid (HCOOH) hold great promise due to low toxicity and inexpensive cost, but are still confronted with poor catalytic performance in the high overpotential region. Herein, the polyethylene oxide-engineered reduced graphene oxide (p-rGO) with rich mesopores was designed as the support of Bi2O3 nanoparticles for the efficient CO2ER to HCOOH. The resultant Bi2O3/p-rGO electrocatalyst delivered an outstanding faradaic efficiency of 94.3% with a competitive current density of -16.8 mA cm−2 at -1.09 VRHE, and maintained the faradaic efficiency above 90% over a wide potential range (-0.99 to -1.29 VRHE). The advanced performance of Bi2O3/p-rGO could be attributed to the integrated contributions of the unique mesoporous structure and the favorable support effect between p-rGO and Bi2O3. This work may provide a new design for the construction of metal/metal oxide on mesoporous reduced graphene to develop high-performance electrocatalysts for CO2ER.

Enhanced electrochemical performance of mixed metal oxide (Bi2O3/ZnO) loaded multiwalled carbon nanotube for high-performance asymmetric supercapacitors

Bismuth oxide/Zinc oxide (Bi2O3/ZnO-BZ) and Bismuth Oxide/Zinc Oxide loaded Multi-Walled Carbon Nanotube (Bi2O3/ZnO@MWCNT-BZM) nanocomposites (NCs) were successfully synthesized through the one-pot hydrothermal method. The prepared samples were analytically characterized to reveal their structural, morphological and functional group characteristics. The presence of Bi2O3 nanoparticles with mixed crystalline phases (Cubic and Monoclinic) and hexagonally structured ZnO nanoparticles in BZM NCs were confirmed by XRD analysis. The electrochemical performances of the prepared NCs were investigated using 1 M KOH electrolyte in an electrochemical workstation under two and three-electrode configurations. The asymmetric supercapacitor fabricated by using BZM NCs modified working electrode possessed the maximum of 204.92 Fg−1 specific capacitance, whereas BZ NCs modified working electrode showed only 145.90 Fg−1 at the scan rate of 5 mVs−1. BZ NCs retained their electrochemical behaviour of about 78.45 % after 5000 charge-discharge cycles and it was further extended up to 84.62 % by the incorporation of MWCNT. Through the fabrication of supercapacitors using BZM NCs, a maximum of 1800 Wkg−1 power density and 9.433 Whkg−1 energy density were achieved. The proposed BZM NCs-based electrodes with superior power and energy densities with high cyclic stability provided vital advantages for long-term commercial applications.

Nontoxic flexible PVC nanocomposites with Ta2O5 and Bi2O3 nanoparticles for shielding diagnostic X-rays

Plasticized polyvinyl chloride (PVC) composites were prepared with tantalum oxide V (Ta2O5) and/or bismuth oxide III (Bi2O3) nanoparticles (NPs) at different concentrations and further cross-linked with a dose of 75 kGy of gamma rays. The materials obtained are light, flexible and nontoxic, to be used as radiation attenuators in the medical area for replacing the traditional lead which is toxic and dense. Mechanical tests through mechanical dynamic analysis (DMA) show an enhanced tenacity for composites and lightness, according to density measurements. By means of scanning electron microscope images (SEM), an adequate dispersion of the nanoparticles (NPs) was observed. The X-ray attenuation property was evaluated at radiodiagnosis energies (50–129 kV) using a conventional X-ray equipment, observing values of mass attenuation coefficients greater than those of lead, when PVC composites were loaded with 50 wt percent (% wt) of a combination of Ta2O5 and Bi2O3 NPs. Half and tenth value layers of 0.77 and 2.20 mm respectively, for 129 kV X-Rays were also obtained. Non-toxicity of the composites was observed by means of a cell viability test. Therefore, the investigated materials are promising for the fabrication of medical diagnostic X-ray shielding attachments.

Constructing TiO2@Bi2O3 multi-heterojunction hollow structure for enhanced visible-light photocatalytic performance

Combining heterojunction with advanced structures is a promising tool to enhance the photoelectrochemical performance of semiconductor photocatalysts for environmental remediation. Herein, a novel multi-heterojunction TiO2@Bi2O3 (MHTB) hollow photocatalyst is successfully constructed by loading Bi2O3 nanoparticles on the surface of inner TiO2 and outside of TiO2 shell. Photoelectrochemical characterizations show that the formation of multiple heterojunctions at the TiO2@Bi2O3 interfaces facilitates faster separation and transfer of photoinduced charge carriers than that of conventionally reported p-n heterojunction photocatalysts. Because of the separated two layers of Bi2O3 and unique hollow structure, the photocatalytic performance of MHTB is significantly improved, leading to excellent photo-degradation rate constant (k = 0.0165 min−1) for the degradation of levofloxacin, which approaches 1.5-fold and 2.6-fold increase than that of TiO2@Bi2O3@TiO2 (n-p-n heterojunction) and TiO2@Bi2O3 (n-p heterojunction), respectively. Notably, the MHTB photocatalyst exhibits an excellent anti-interference capability for the interference of environmental factors. Moreover, the photocatalytic activity, crystal structure, and bonding energy of MHTB photocatalyst remain unchanged after being used several times, indicating an excellent stability. Therefore, this finding opens a new door to develop highly active photocatalysts with multiple heterojunctions for efficient pollutant removal and environmental remediation.

Cotton-derived 3D carbon fiber aerogel to in situ support Bi2O3 nanoparticles as a separation-free photocatalyst for antibiotic removal

Because of abundant oxygen-based groups, natural cotton is adopted as the precursor to in situ fabricate a three-dimensional (3D) Bi2O3-supported carbon fiber aerogel (Bi2O3/CF). The calcination temperature plays an important role in the crystal composition of Bi species and the specific surface area of the aerogel. When the calcination temperature is 800 °C, the Bi2O3/CF product exhibits the highest tetracycline (TC) removal efficiency, including large adsorbability and superior photocatalytic activity. Furthermore, its 3D porous network architecture provides a multidimensional open framework for the free mobility of solution and rapid diffusion of reactants and products. In the flowing system, the 3D Bi2O3/CF aerogel can implement the continuous and stable elimination of pollutants for a long time, and it does not require any separation operation. Consequently, the 3D Bi2O3/CF aerogel is expected as a promising functional material to massively remove organic pollutants from industrial wastewater.