Lanthanum Oxide Nanoparticles Research Articles

Reinforcement of recycled polypropylene by nano lanthana with improved thermal, mechanical and antimicrobial properties

Abstract In this study, lanthanum oxide (La2O3) nanoparticles or lanthana were synthesized by the planetary ball milling method and then used as a filler for the preparation of the polypropylene (PP) based nanocomposites by solution mixing method. The PP used in the study was derived from the discarded saline bottles. The structural and the surface morphology of the synthesized lanthanum oxide nanoparticles were characterized by XRD, SEM and FTIR. The thermogravimetric analysis (TGA) study revealed that the thermal stability of the nano lanthana composites increased with the addition of the lanthanum oxide nanoparticles. The mechanical properties, such as Young’s modulus and tensile strength, were also improved by the addition of the lanthanum oxide nanoparticles to the PP matrix. The composites also showed antibacterial activity against Escherichia coli bacteria. This approach not only mitigates medical plastic waste and environmental impact but also paves the way for versatile polymer nanocomposites with extensive industrial applications, especially in biomedical packaging.

Lanthanum(III)-amino acid chelate mitigates copper(II) stress in rice (Oryza sativa)

Lanthanum (La(III)) is recognized for its ability to mitigate heavy metal stress in plants. However, the inorganic La(III) salts and lanthanum oxide nanoparticles (La2O3 NPs) extensively used in agriculture are prone to soil immobilization, thereby compromising their bioavailability and posing environmental risks. This study synthesized and characterized the lanthanum(III)-amino acid chelate (La(III)-AA) from soybean protein isolate (SPI) hydrolysates. Maximum chelating rate (94.95%) was achieved under the conditions of mole ratio 1:1.5, pH 8.0, 50 ℃ and 5 h. Glu, Asp and Pro represent the primary La(III)-binding ligands. UV-vis and FTIR demonstrated that amino nitrogen and carboxyl oxygen participate in metal-ligand recognition. Scanning and Transmission electron microscopy showed that La(III) chelates with amino acids in a core-shell structure of uniform size. Consequently, a proposed chemical structure for the La(III)-AA complex was presented. A concentration of 20 mg/L La(III)-AA outperforms inorganic La salts in growth promotion and Cu detoxification. La(III)-AA significantly reduces the content of Cu (II) in rice tissues and enhances seedling tolerance to Cu (II) stress. This study provides a novel La(III)-based candidate for crop protection and furthers our understanding of rare earth element-induced mitigation of heavy metal stress.

Synthesis and characterization of Lanthanum Oxide nanoparticles using Citrus aurantium and their effects on Citrus limon Germination and Callogenesis

The plant extract-mediated method is eco-friendly, simple, safe, and low-cost, using biomolecules as a reducing agent to separate nanoparticles. Lanthanum (La) is a rare earth metal that positively affects plant growth and agriculture. Citrus limon is a leading citrus fruit with many varieties. Conventional vegetative propagation methods depend on season, availability of plant material and are time-consuming. It is the main reason for limiting the acceptance of new varieties. So, In-vitro propagation of the lemon method is practiced overcoming all these problems. Lanthanum oxide nanoparticles (La2O3-NPs) were synthesized using plant extract of C. aurantium. Ultraviolet (UV)-Visible Spectroscopy, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Fourier Transform Infrared (FTIR) spectroscopy, and Thermal Gravimetric Analysis (TGA) were used to characterize the synthesized La2O3-NPs. Fabricated La2O3-NPs were oval and spherical, with an average size of 51.1 nm. UV-visible absorption spectra of La2O3-NPs were shown at a sharp single peak at 342 nm and FTIR showed stretching frequency at 455 cm−1-516 cm−1. In the TGA outcome, mass loss was 9.1%. In vitro experiments demonstrated that La2O3-NPs significantly enhanced the germination and growth of C. limon seeds, achieving an 83% germination rate at 5 mg/L concentration, with uncoated seeds showing root initiation at 10 days and shoot formation at 15 days. Furthermore, La2O3-NPs effectively stimulated callus induction and maturation, with optimal responses observed in media containing MS and 2 mg/L 2,4-D, resulting in a maximum callus frequency of 100% from leaves and 87.5% from shoots at 5 mg/L concentration. These findings underscore the potential of La2O3-NPs to improve seed germination rates, seedling vigor, and callogenesis efficiency, suggesting their promising integration into agricultural practices for sustainable crop production, especially in suboptimal growing conditions. Future research is recommended to explore the mechanisms and broader applications of La2O3-NPs across various plant species and environments.

Electrochromic films with better stability and rapid response are based on silane coupling agent linked lanthanum oxide/polyaniline composite

A fast response and stability enhanced electrochromic film based on a composite of polyaniline (PANI) with surface functionalized Lanthanum oxide (f-La2O3) nanoparticles has been prepared by in-situ polymerization. Scanning electron microscopy (SEM) and Fourier infrared spectroscopy (FTIR) confirmed that La2O3 was attached to the surface of PANI by silane coupling agent. Meanwhile, Electrochemical and electrochromic properties were investigated using cyclic volatammetry, chronoamperommetry, electrochemical impedance spectroscopy (EIS) and UV–vis spectroscopy. Compared with PANI, the f-La2O3/PANI composite showed excellent electrochromic performance, shorter response time and higher stability. As the mol ratio of La2O3 to aniline was 1:3.5, the composites exhibited best electrochromic behavior with superior coloration efficiency of 22.81 cm2 C−1 and fastest response time of 1.29 s/1.33 s for bleaching and coloration respectively. The result indicates that introduction of rare earth elements has great potential to improve the electrochromic properties of conducting polymers.

Facile green synthesis of lanthanum oxide nanoparticles: their photocatalytic and electrochemical applications

Facile green synthesis of lanthanum oxide nanoparticles: their photocatalytic and electrochemical applications

Excellent Adsorption of Lead (II) and Chromium (VI) from Water Using Zwitterions (-NH3+ and -COO-) Functionalized Nano Lanthanum Oxide: Kinetic, Isotherm, Thermodynamic, and Surface Mechanism.

Zwitterion amino acid l-cysteine functionalized lanthanum oxide nanoparticles (l-Cyst-La2O3 NPs) have been synthesized for the first time with lanthanum acetate as the precursor, NH4OH as the base, and l-cysteine as the in situ functionalized mediator. The typical size of l-Cyst-La2O3 NPs was obtained in the range of 15-20 nm from the TEM technique. A cytotoxicity test of l-Cyst-La2O3 NPs was performed in Raw 264.7 cell lines, which were shown to be highly biocompatible. The point zero charge pH (pHPZC) of bare and l-Cyst functionalized La2O3 NPs was obtained at pH 6 and 2. The maximum uptake capacities of l-Cyst-La2O3 NPs at temperatures 25-45 °C were obtained as 137-282 mg/g for Pb2+ and 186-256 mg/g for Cr6+. All of these values are much higher than those reported in the literature with other nanomaterials. The presence of -SH, -NH2, and -COOH functional groups in zwitterion l-cysteine provides multiple binding sites leading to the high adsorption of Pb2+ and Cr6+. Five-cycle desorption studies were successfully performed to regenerate the spent l-Cyst-La2O3 NPs.

Facile synthesis of lanthanum carbonate octahydrate and lanthanum oxide nanoparticles by sonochemical method: systematic characterizations

Abstract This study could present the size and morphology of two synthesized nanoparticles (NPs) by observing their smallest possible dimensions. Lanthanum carbonate nanoparticles were synthesized by sonochemical method through the interaction of lanthanum acetate hydrate and sodium carbonate in an aqueous medium with a probe sonicator. After rigorous washing followed by drying, the La2(CO3)3·8H2O(S1) NPs were calcined at a temperature of 600 °C to obtain lanthanum oxide nanoparticles (S2). Both NPs were characterised through various instrumental techniques. PXRD study showed orthorhombic with space group of Pccn (56) and hexagonal phases with space group of P 3 ‾ m 1 $P\overline{3}m1$ (164) for S1 and S2 respectively whose morphology and elemental analysis were studied through FESEM and EDX. High resolution TEM image of La2(CO3)3·8H2O and La2O3 showed spherical shapes of the nanoparticles. Further study of XPS and FTIR conveyed detailed information of both nanoparticles whose TGA-DSC showed three step decomposition curves. The size and morphology of the synthesized nanoparticles have been found to have a distinct morphology and are found comparatively smaller in size than those observed in the earlier reported works (Table 1 Table 1: Comparative study of synthesized lanthanum carbonate and lanthanum oxide NPs with various techniques applied by other researchers. Sl. no. Name of NPs Methods Conditions Size of NP Reference 1 La2(CO3)3·8H2O Sonochemical method Time: 25 min XRD: Pccn (56) a = 8.9840 Å b = 9.5800 Å c = 17.0000 Å This work Temperature: 301 K Size: 24.102 nm Starting materials:(a) La(CH3COO)2: 0.050 M(b) Na2CO3:0.050 M TEM: Size: 4–30 nm La2(CO3)3 Reverse micelles Time: 1 h XRD: Size: nanoparticles absent [20] Temperature: 303 K Starting materials:(a) Triton X-100(b) Cyclohexane(c) n-butylalcohol(d) La(NO3)3(aq) e) NaCO3(aq) La2(CO3)3·8H2O Hydrothermal Time: 2–5 days XRD: Pccn a = 8.984 Å b = 9.580 Å c = 17.00 Å [21] Temperature: 773 K Size: nanoparticles absent Prepared by slow hydrolysis of La(CCl3COO)3 La2(CO3)3·1.4H2O Hydrothermal Time: 1 h 30 min Structure unknown [22] Temperature: 368 K Starting material:(a) La2O3 (b) HNO3 (c) Urea La2(CO3)3·1.7H2O Sonochemical Time: 30 min XRD: a = 8.990 Å c = 9.675 Å [23] Temperature: not specified Size: not specified (a) La(OAC)3 (b) Na2CO3 TEM: Size: 25–35 nm Concentration:(a) La(OAC)3: 0.051 M(b) Na2CO3: 0.251 M La2(CO3)3·5H2O Hydrothermal Time: XRD: Pbca a = 9.0167 Å b = 12.842 Å c = 9.6331 Å [24] Temperature: Size: not specified Starting materials:(a) La2O3 (b) HCl(c) Na2CO3 La2(CO3)3·3.4H2O Hydrothermal Time: 3–4 h XRD: P21212 a = 9.57 Å b = 12.65 Å c = 8.94 Å [25] Temperature: 298–308 K Size: not specified Starting materials:(a) LaCl3 (b) NH4HCO3 2 La2O3 Thermal decomposition Time: 2 h P3m1 a = 3.973 Å b = 3.9373 Å c = 6.129 Å [26] Temperature: 1073 K Size: 15 nm Starting material: La(OH)3 nanorods TEM: Size: 23 nm La2O3 Thermal decomposition Time: 2 h XRD: a = 11.347 Å [23] Temperature: 873 K Size: 30 nm Starting material:La2(CO3)3·1.7H2O TEM: Size: 30 nm La2O3 Thermal decomposition Time: not specified Not specified [27] Temperature: 1198 K Starting material:(a) La(NO3)3·9H2O(b) NH4HCO3 La2O3 Thermal decomposition Time: 4 h Not specified [28] Temperature: 1073 K Starting material: La(OH)3 La2O3 Thermal decomposition Time: 2 h P 3 ‾ m 1 $P\overline{3}m1$ a = 3.973 Å b = 3.9373 Å c = 6.129 Å This work Temperature: 873 K XRD: Size: 43.26 nm Starting material: La2(CO3)3·8H2O TEM: Size: 17–34 nm ).

Enhanced Photocatalytic Degradation of Organic Pollutants Using Iron Lanthanum Oxide Nanoparticles

This study investigates the synthesis, characterization, and photocatalytic performance of iron lanthanum oxide nanoparticles (FeLO NPs) tailored for environmental remediation applications. The nanoparticles were synthesized using a co-precipitation method involving ferrous and lanthanum nitrates, followed by pH adjustment and calcination. Characterization techniques including X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR) were employed to analyze the structural and morphological properties of the nanoparticles. XRD confirmed the crystalline nature of FeLO NPs with peaks corresponding to standard indices, while SEM images revealed a heterogeneous surface topology conducive to catalytic activity. FTIR analysis detected functional groups and bonding interactions indicative of the complex molecular composition of the nanoparticles. The Brunauer-Emmett-Teller (BET) method determined a surface area of 2.43 m²/g. Photocatalytic testing using methylene blue (MB) under UV and visible light showed that FeLO NPs achieved up to 90% degradation of the dye, highlighting their effectiveness in pollutant breakdown. The degradation mechanism involved the formation of electron-hole pairs, facilitating radical generation and subsequent pollutant decomposition. This study underscores the potential of FeLO NPs as efficient and sustainable photocatalysts for the treatment of dye-polluted wastewater.

Determination of dose- and time-dependent hepatotoxicity and apoptosis of Lanthanum oxide nanoparticles in female Swiss albino mice.

Nanosized lanthanum oxide particles (La2O3) are commonly utilized in various industries. The potential health risks associated with La2O3 nanoparticles, cytotoxic effects at varying doses and time intervals, and the mechanisms behind their induction of behavioral changes remain uncertain and necessitate further investigation. Therefore, this study examined in vivo hepatotoxicity, considering the quantity (60, 150, and 300mg/kg) and time-dependent induction of reactive oxygen species (ROS) over one week or 21days. The mice received intraperitoneal injections of three different concentrations in Milli-Q water. Throughout the experiments, no physical changes or weight loss were observed among the groups. However, after 21days, only the highest concentration showed signs of anxiety in the activity cage (p < 0.05). Subsequently, all animals treated with La2O3 NPs exhibited a significant loss of learning and memory recall using the Active Avoidances test, after 21days (p < 0.001). Markers for anti-reactive oxygen species (ROS) such as superoxide dismutase (SOD) were significantly upregulated in response to all concentrations of NPs after seven days compared to the control group. This was confirmed by a significant increase in glutathione peroxidase (Gpx1) and pro-apoptotic Caspase-3 expression at the lowest and highest doses. Additionally, both transcription and protein levels of the anti-apoptotic BCL-2 surpassed P53 protein in a dosage-dependent manner, indicating activation of the primary anti-apoptosis pathway. After 21days, P53 levels exceeded BCL-2 protein levels, confirming a significant loss of BCL-2 mRNA, particularly at the 300mg/kg concentration. Furthermore, a higher transcription level of Caspase-3, SOD, and Gpx1 was observed, with the highest values detected at the 300mg/kg concentration, indicating the activation of cell death. Histopathological analysis of the liver illustrated apoptotic bodies resulting from La2O3 NP concentration. The investigation revealed multiple inflammatory foci, cytoplasmic degeneration, steatosis, and DNA fragmentation consistent with increased damage over time due to higher concentrations. Blood samples were also analyzed to determine liver enzymatic changes, including alkaline phosphatase (ALP), alanine transaminase (ALT), aspartate aminotransferase (AST), and lipid profiles. The results showed significant differences among all La2O3 NP concentrations, with the most pronounced damage observed at the 300mg/kg dose even after 21days. Based on an animal model, this study suggests that La2O3 hepatotoxicity is likely caused by the size and shape of nanoparticles (NPs), following a dose and time-dependent mechanism that induces the production of reactive oxygen species and behavioral changes such as anxiety and memory loss.

Peepal (Ficus Religiosa) leaf extract mediated green synthesis of Lanthanum and Cerium oxide nanoparticles: Characterization and potential biological applications

Peepal (Ficus Religiosa) leaf extract mediated green synthesis of Lanthanum and Cerium oxide nanoparticles: Characterization and potential biological applications

Hydrothermal synthesis of lanthanum oxide nanoparticles modified pumice: High lanthanum oxide loading ratio and efficiency phosphate removal

Efficient and less restrictive phosphorus pollution treatment methods are required to treat water eutrophication. Lanthanum oxide nanoparticles modified pumice (LOMP) with a high loading ratio was prepared by a simple hydrothermal synthesis method which adjusted the synthesis conditions. The XRD, SEM, and TEM results show that the lanthanum oxide nanoparticles have successfully modified on the surface of the pumice, forming a disordered hierarchical structure. The adsorption kinetics results showed that phosphate adsorption was more consistent with the pseudo-second-order model. The adsorption isotherm was more consistent with the Sips model, and the theoretical adsorption capacity was 82.77 mg P/L. The results of the effects of the initial pH and the coexisting anions indicate that LOMP has a good phosphate removal efficiency in a wide range of pH and a strong ability to resist the competition of anions. The superior phosphate adsorption performance can be ascribed to the ligand exchange, which also can be promote by hydrogen ions.

Synthesis and application of lanthanum-doped magnetic biochar composite adsorbent for removal of fluoride from water.

Fluoride levels greater than 1.5mg/L in drinking water are a global environmental issue that can seriously harm the health of humans. One of the most effective techniques for defluoridating water is adsorption. The main drawbacks of many adsorbent materials include their poor adsorption capabilities, prolonged contact times, excessively low or high pH levels, and high dosages. The biochar-based magnetic nanocomposite adsorbent was synthesized in the current study and used as an adsorbent for water defluoridation. Through slow pyrolysis, coffee husk waste was converted to biochar. The composite was created by chemically co-precipitating iron and lanthanum oxide nanoparticles onto the surface of biochar. By using X-ray diffraction analysis (XRD), Fourier transform infrared spectrometry (FTIR), Brunauer-Emmett-Teller (BET), and pHPZC values, researchers were able to describe the magnetic biochar nanocomposite material. The Central Composite Design (CCD), which uses four input variables including dosage (2-5g/L), solution pH (4-8), contact time (30-70min), and initial concentration (10-20mg/L), was used to design the experiments. The quadratic model indicated that the ideal conditions for removing 98.994% of the fluoride from water (adsorbent dosage of 5g L-1, pH 5.74, contact period of 60min, and initial concentration of 12.245mg/L) would be attained. The average triplicate value in ideal circumstances produced a removal effectiveness of 98.51%, demonstrating the proposed response surface's capacity for prediction. The findings of this investigation showed that the magnetic biochar nanocomposite that was created is an effective fluoride adsorbent.

Synthesis & characterization of Aluminium doped lanthanum oxide nanoparticles for adsorptive removal of Congo red from aqueous solution

Aluminium-doped nano lanthanum oxide (ALO NPs) were synthesized using sol–gel method. The structural characterization of the as-prepared nanoparticles were carried out using XRD, FT-IR, SEM-EDAX, HR-TEM, and XPS methods to study the effect of Al doping on the structural properties of lanthanum oxide. XRD analysis confirms the formation of hexagonal ALO NPs with an average crystallite size of 15–20 nm.The FTIR analysis gives an idea about the hygroscopic nature of the Aluminium doped La2O3 and its affinity towards carbon dioxide. SEM images reveal the agglomeration of nanoparticles. HR TEM -SAED characterization provides a deeper understanding of the material's polycrystalline nature. The presence of La in the 3d orbital, O in the 1 s orbital, and Al in the 2p orbital is explained by XPS spectra. The as-prepared ALO-NPs were used as an adsorbent for the removal of the toxic azo dye Congo red from water. The uptake of Congo red was found to increase with an increasing initial dye concentration. A maximum adsorption of 70.03 mgg−1 was obtained for 100 ppm Congo red concentration.

Synthesis, characterization and electrochemical detection of tartaric acid and grape juice using rGO doped La2O3 nanoparticles

The paper describes the synthesis of a reduced graphene oxide (rGO)/lanthanum oxide (La2O3) nanocomposite utilizing a simple reflux method. The presence of lanthanum oxide nanoparticles was confirmed by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-Ray analysis (EDAX), and Fourier-transform infrared spectroscopy (FTIR) analysis. rGO and La2O3/rGO had average crystallite sizes (D) of 14.96nm and 22.83 nm, respectively. Using cyclic voltammetry (CV) and Differential pulse voltammetry (DPV), electrochemical detection of tartaric acid (TA) and grape juice was done on synthesized material. The La2O3/rGO electrode was used to measure tartaric acid and grape juice concentrations, and the detection limits of both sensors were determined to be 151 μM and 127 μM respectively. The La2O3/rGO electrode also has a larger surface area.

A La2O3/MXene composite electrode for supercapacitors with improved capacitance and cycling performance

ABSTRACT Developing efficient electrode materials is a key towards high power electrochemical energy storage devices. Two-dimensional (2D) MXene shows excellent conductivity and electrochemical performance among other materials. However, the restacking of MXene layers may degrade their specific capacity and cycling performance. Considering this challenge, here we have designed a composite made of 2D MXene nanosheets and lanthanum oxide (La2O3) nanoparticles to overcome the limitations. The bifunctionality of La2O3 nanoparticles prevents the restacking of MXene layers and enhances the electrochemical properties of the electrode due to its good Faradic characteristics. The specific capacitance of the La2O3/MXene composite electrode is 366 F/g at 1 A/g, which is 4.5 and 3 times higher than those of the individual La2O3 and MXene. The composite electrode displays a capacitance retention of 96% after 1,000 cycles, which is due to synergistic effects between the two components and indicates the potential of La2O3/MXene composite for supercapacitors.

Foliar spray of La2O3 nanoparticles regulates the growth, antioxidant parameters, and nitrogen metabolism of fragrant rice seedlings in wet and dry nurseries.

Nanoparticles (NPs) have been widely used in agriculture, and lanthanum oxidenanoparticles (La2O3) NPs can regulate plant growth. La2O3 NPs treatment was hypothesized to affect the accumulation and distribution of substances in rice seedlings under wet and dry nursery conditions. The objective of the present study was to ascertain the effects of La2O3 NPs foliar spray on the morphology and physiology of fragrant rice seedlings under wet and dry nursery conditions. Seedlings of two fragrant rice cultivars, namely 'Xiangyaxiangzhan' and 'Yuxiangyouzhan,' were grown under wet and dry nursery conditions with La2O3 NPs treatments at three concentrations (CK, La2O3 NPs 0mg L-1; T1, La2O3 NPs 20mg L-1; and T2, La2O3 NPs 40mg L-1). The results showed that the seedling-raising method was significantly associated with La2O3 NPs application (P < 0.05), affecting the leaf area of both cultivars. Changes in plant morphological parameters, such as dry weight and root-shoot ratio, were the reasons for the differences in cultivars in response to La2O3 NPs application. Changes were also observed in the plant morphological and physiological parameters of leaf area, specific leaf area, chlorophyll contents, antioxidant properties, and activities of nitrogen metabolism enzymes. The relationship between morphological and physiological processes in fragrant rice was investigated to test the hypothesis. In both wet and dry nursery methods, the T2 concentration of La2O3 NPs was beneficial for rice seedlings and significantly increased their leaf area due to changes in morphological and physiological parameters. Therefore, the results of this study provide a theoretical basis for expanding the research on La2O3 NPs application in rice, as well as relevant references for strengthening rice seedlings in the nursery, which has a positive effect on the grain yield improvement in fragrant rice.

Lanthanum Oxide Nanoparticles Reinforced Collagen ƙ-Carrageenan Hydroxyapatite Biocomposite as Angio-Osteogenic Biomaterial for In Vivo Osseointegration and Bone Repair.

A composite biomatrix fabricated with collagen, ƙ-carrageenan, hydroxyapatite reinforced with lanthanum oxide nanoparticles is explored as proangiogenic and osteogenic bone tissue repair biomaterial. The biomatrix shows increased physical and biological stability as observed from proteolytic degradation and thermal stability studies. The addition of lanthanum oxide nanoparticles facilitates good osseointegration coupled with simultaneous activation of proangiogenic properties to act as a bone mimicking material. The minimal level of reactive oxygen species and superior cytocompatibility help the as-synthesized biomatrix in achieving capillary migration into the bone micro environment. The composite biomatrix upregulates the expression of VEGF, VEGF-R2 genes in endothelial cells and osteopontin, osteocalcin in osteoblasts cells, respectively. The in vivo hard tissue repair experiment conducted in a rat model shows complete healing of the bone defect by eight weeks with the application of collagen-ƙ-carrageenan-hydroxyapatite-lanthanum oxide nanoparticle biomaterial when compared to the biomaterial made out of individual constituents alone. The biomaterial matrix gets biointegrated into the bone tissue and exerts its therapeutic value in bringing a faster osseo repair process. The study shows the feasibility of using rare-earth metal nanoparticles in combination with protein-polysaccharide biopolymers for bone regeneration.

Influence of nano additives on performance and emissions characteristics of a diesel engine fueled with watermelon methyl ester

Significant population and automobile expansion have resulted in a rapid rise in energy demand. Because of the high demand for energy and the rapid depletion of fossil fuels, experts are concentrating their efforts on developing a suitable alternative fuel for diesel. The performance and emission characteristics of biodiesel made from watermelon methyl ester were investigated using a lanthanum oxide (La2O3) nanoparticle addition. Through the transesterification meth od, biodiesel was produced from non-edible watermelon seed oil. Compared to B20, addition of 100 parts per million (ppm) of La2O3 nanoparticles to biodiesel emulsion fuel reduces CO and HC emissions by 4.75% and 6.67%, respectively. Compared to B20 at full load circumstances, the inclusion of La2O3 nanoparticles at 100 ppm enhances the brake thermal efficiency (BTE) and brake specific fuel consumption (BSFC) by 2% and 8.8%, respectively.

Structural, vibrational, optical, and anticancer properties of Hyphaene thebaica‐reduced nano‐lanthanum oxide (La2O3)

Phytoextracts modulated synthesis of nano‐scaled spherical lanthanum oxide nanoparticles (La2O3 NPs) are reported using the aqueous extracts of Hyphaene thebaica as a bioreducing and chelating agent. X‐ray diffraction (XRD) pattern revealed sharp peaks and single‐phase purity. The Debye–Scherrer approximation indicated an average crystallite size of 37 nm, whereas W‐H plot revealed a crystallite size of 59 nm, complemented by the high‐resolution transmission electron microscopy (HR‐TEM). The infrared spectroscopy revealed characteristic La‐O band at 426 and 648 cm−1. K‐M function revealed the bandgap of 5.6 eV, whereas broad intense emission peaks between 345 and 750 nm. The Raman spectra revealed peaks at 182, 325, 384, and 491 cm−1. Elemental composition was confirmed using energy‐dispersive X‐ray spectroscopy (EDS) spectrum, and the spotty rings from selected area electron diffraction (SAED) indicated the crystalline nature of the HT‐La2O3 NPs. In addition, the HT‐La2O3 NPs were investigated for in vitro antioxidant, anticancer, antiangiogenic, and cytotoxic potentials. DPPH free radical scavenging activity was highest, that is, 49.54 ± 0.88% at 1000 μg/mL. MTT assay on MCF‐7 and 3T3 cell lines revealed a median lethal concentration of 114 and 43 μg/mL, respectively. The antiangiogenic effect examined by chick chorioallantoic membrane (CAM) assay indicated inhibition of 57.14 ± 0.96% at 1000‐μg/mL concentration with an IC50 of 551 μg/mL. IC50 for the brine shrimp lethality assay was 314.2 μg/mL. Our study indicates cytotoxicity of HT‐La2O3 NPs, and it further concluded that HT‐La2O3 NPs were more potent against 3T3 cells as compared with MCF‐7 cells. Further research on the biological synthesis and anticancer studies are recommended for the large‐scale applications of the La2O3 NPs.

Lanthanum Oxide Nanoparticles Distribution in Wistar Rats after Oral Exposure and Respective Effects

Adult Wistar rats were exposed to lanthanum oxide nanoparticles (La2O3-NPs). Animals were initially treated with single doses of La2O3-NPs suspensions at 5.0, 50, 300 and 2000 mg kg-1 per body weight (bw), which were orally administered. Behavior changes, symptoms of intoxication and mortality were not observed for individuals treated with the La2O3-NPs. However, the histological analysis of different organs of the treated rats revealed that 300 mg kg-1 and 2000 mg kg-1 bw La2O3-NPs caused hepatic lesions. Subsequently, 40 individuals were divided in four groups with 10 individuals in each group and daily treated with water only (control) and with 1.0, 10 and 100 mg kg-1 bw La2O3-NPs. After 30 days, it was observed that the La2O3-NPs did not affect the body weight and organs weight of the animals. The La2O3-NPs also did not change the levels of creatinine, urea, glutamyl transferase (γ-GT), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and thiobarbituric acid reactive substances (TBARS) in blood serum. Neurotoxicity, evaluated by the acetylcholinesterase (AChE) activity, was not observed as well. An increase of reactive oxygen species (ROS) was found in kidney of rats treated with 100 mg kg-1 bw La2O3-NPs. Conversely, protein oxidation decreased in the liver of those animals. The catalase (CAT) activity was not affected by La2O3-NPs and that of superoxide dismutase (SOD) was in the liver of animals treated with 10 mg kg-1 bw La2O3-NPs. Lanthanum was determined in organs and blood of the treated animals. The element was not detected in the blood but was in the organs, in higher concentration in liver, kidneys, and heart. Lanthanum present in the form of NPs or as free ion could not be detected. As such, it is worth investigating possible transformation of La2O3-NPs in the organism, their elimination routes, and effects of longer exposure times.