Ultrasound-assisted synthesis of V2O5 nanoparticles for photocatalytic and antibacterial studies

Nanomaterials Based Multifunctional Bioactivities of V2O5 and Mesoporous Carbon@V2O5 Composite: Preparation and Characterization

Nanocarriers have attracted considerable interest due to their prospective applications in the delivery of anticancer medications and their distinct bioactivities. Biogenic nanostructures can be effective nanocarriers for delivering drugs as a consequence of sustainable and biodegradable biomass-derived nanostructures that perform specific functions. In this case, a vanadium oxide (V2O5) and mesoporous carbon@V2O5 (C@V) composite was developed as a possible drug delivery system, and its bioactivities, including antioxidant, antibacterial, and anticancer, were investigated. Doxorubicin (DOX), an anticancer drug, was introduced to the nanoparticles, and the loading and release investigation was conducted. Strong interfacial interactions between mesoporous carbon (MC) and V2O5 nanostructures have been found to improve performance in drug loading and release studies and bioactivities. After incubation, the potent anticancer effectiveness was seen based on C@V nanocomposite. This sample was also utilized to research potential biomedical uses as an antioxidant, antibacterial, and anticancer. The most effective antioxidant, the C@V sample (61.2%), exhibited a higher antioxidant activity than the V-2 sample (44.61%). The C@V sample ultimately attained a high DOX loading efficacy of 88%, in comparison to a pure V2O5 sample (V-2) loading efficacy of 80%. Due to the combination of mesoporous carbon and V2O5, which increases specific surface area and surface sites of action as well as the morphology, it proved that the mesoporous carbon@V2O5 composite (C@V) sample demonstrated greater efficacy.

A review on green approaches utilizing phytochemicals in the synthesis of vanadium nano particles and their applications

In the modern era, inorganic nanoparticles have received profound attention as they possess boundless applications in various fields. Among these, vanadium-based nanoparticles (VNPs) are highly remarkable due to their inherent physiological and biological properties with many therapeutic and other applications, such as drug delivery systems for diseases like cancer, environmental remediation, energy storage, energy conversion, and photocatalysis. Moreover, physically, and chemically synthesized VNPs are very versatile, however, these synthesis routes cause concern to health and the environment due to the highly savage reaction conditions, using highly toxic and harsh chemicals, which compel the researchers to develop an eco-friendly, greener, and sustainable route for synthesis. In this outlook, to avoid the innumerable limitations, a bio approach is used over chemical and physical methods. This present review emphasis on the role of various biological components in the synthesis, especially Phyto-molecules that acts as capping and reducing agent, and solvent system for the nanoparticles synthesis. Furthermore, the influence of various factors on the biogenic synthesized nanoparticles has also been discussed. Finally, potential applications of as-synthesized VNPs, principally as an antimicrobial agent and their role as a nanomedicine, energy applications as a supercapacitor, and photocatalytic agents, have been discussed.

Design of V2O5 Blocks Decorated with Garlic Peel Biochar Nanoparticles: A Sustainable Catalyst for the Degradation of Methyl Orange and Its Antioxidant Activity

In this study, novel V2O5-decorated garlic peel biochar (VO/GPB) nanocomposites are prepared via the facile hydrothermal technique. As-synthesized VO/GPB is characterized by various spectroscopic and analytical techniques. The surface morphology of the as-prepared samples was predicted by SEM analysis, which shows that the block-like V2O5 was uniformly decorated on the stone-like GPB surface. The elemental mapping analysis confirms the VO/GPB composite is composed of the following elements: C, O, Na, Mg, Si, P, K, and V, without any other impurities. The photocatalytic activity of the VO/GPB nanocomposite was examined by the degradation of methyl orange (MO) under the irradiation of visible light; 84% degradation efficiency was achieved within 30 min. The reactive oxidative species (ROS) study reveals that hydroxyl and superoxide radicals play an essential role in MO degradation. Moreover, the antioxidant action of the VO/GPB nanocomposite was also investigated. From the results, the VO/GPB composite has higher antioxidant activity compared to ascorbic acid; the scavenging effect increased with increasing concentrations of VO/GPB composite until it reached 40 mg/L, where the scavenging effect was the highest at 93.86%. This study will afford innovative insights into other photocatalytic nanomaterials with effective applications in the field of photocatalytic studies with environmental compensation.

Sustainable Synthesis of Iron-Zinc Nanocomposites by Azadirachta indica Leaves Extract for RSM-Optimized Sono-Adsorptive Removal of Crystal Violet Dye

Environmental pollution has exacerbated the availability of clean water to mankind. In this study, Azadirachta indica leaf extract was used for sustainable synthesis of Fe-Zn nanocomposites (IZNC). The instrumental techniques of Fourier transformed infrared (FTIR) spectroscopy, energy dispersive X-ray spectroscopy (EDS), and scanning electron microscopy (SEM) were used to determine the structural and chemical composition. The overall surface was mildly acidic in nature, as the pH_PZC was observed to be 6.00. The ultrasonicated adsorption experiments were designed by central composite design (CCD). The best responses, which proposed a contaminants removal of 80.39%, were assessed using the response surface methodology (RSM). By repeating experimental runs at the expected optimum operating parameters (OOP), the method was experimentally affirmed with the %mean error and %RSD₉ being 2.695% and 1.648%, respectively. The interaction of CV dye and the nanocomposite showed tremendous adsorption efficiency towards crystal violet (CV) dye, as revealed by isotherm studies. Fitting kinetics and isotherm models were affirmed by root mean square error (RMSE), χ2, and a Pearson regression coefficient. Thermodynamic studies proved spontaneity of the CV dye adsorption over the nanocomposites. The values for ΔG^o, ΔH^o, and ΔS^o were observed to be -1.089 kJ/mol, 28.59 kJ/mol, and -3.546 kJ/mol, respectively. Recovery of CV dye was carried out in a variety of media, including NaOH, NaCl, and CH₃COOH. The maximum CV recovery was achieved in an acidic media. The robustness of adsorption was affirmed by the interference of various matrix ions, including KCl, LiCl, NaCl, and MgCl₂, which did not significantly affect the adsorption process. The maximum adsorption capacity was obtained at a low concentration of LiCl. The results show that a green synthesis approach for nanocomposite synthesis might be an effective and economical way to remove organic contaminants from wastewater. Moreover, it is also effective for effluent treatment plants (ETP) for waste management purposes, in which it may be coupled with chlorine as a disinfectant to purify water that can be used for domestic and irrigation purposes.

Photocatalytic Activity of the V2O5 Catalyst toward Selected Pharmaceuticals and Their Mixture: Influence of the Molecular Structure on the Efficiency of the Process

Due to the inability of conventional wastewater treatment procedures to remove organic pharmaceutical pollutants, active pharmaceutical components remain in wastewater and even reach tap water. In terms of pharmaceutical pollutants, the scientific community focuses on β-blockers due to their extensive (over)usage and moderately high solubility. In this study, the photocatalytic activity of V2O5 was investigated through the degradation of nadolol (NAD), pindolol (PIN), metoprolol (MET), and their mixture under ultraviolet (UV) irradiation in water. For the preparation of V2O5, facile hydrothermal synthesis was used. The structural, morphological, and surface properties and purity of synthesized V2O5 powder were investigated by scanning electron microscopy (SEM), X-ray, and Raman spectroscopy. SEM micrographs showed hexagonal-shaped platelets with well-defined morphology of materials with diameters in the range of 10−65 µm and thickness of around a few microns. X-ray diffraction identified only one crystalline phase in the sample. The Raman scattering measurements taken on the catalyst confirmed the result of XRPD. Degradation kinetics were monitored by ultra-fast liquid chromatography with diode array detection. The results showed that in individual solutions, photocatalytic degradation of MET and NAD was relatively insignificant (<10%). However, in the PIN case, the degradation was significant (64%). In the mixture, the photodegradation efficiency of MET and NAD slightly increased (15% and 13%). Conversely, it reduced the PIN to the still satisfactory value of 40%. Computational analysis based on molecular and periodic density functional theory calculations was used to complement our experimental findings. Calculations of the average local ionization energy indicate that the PIN is the most reactive of all three considered molecules in terms of removing an electron from it.

Copper oxide nanoparticles doped with lanthanum, magnesium and manganese: optical and structural characterization

Copper oxide (Cu₂O) is a promising semiconductor for photovoltaic and photocatalytic applications since this material has a high optical absorption coefficient and lower band gap (2.17 eV). Doped lanthanum (La), magnesium (Mg) and manganese (Mn) Cu₂O nanoparticles (Cu₂O Nps) were prepared by a displacement reaction. The doped and undoped Cu₂O Nps were characterized with scanning electron microscopy-energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), transmission electron microscopy (TEM) and ultraviolet-visible spectroscopy. The EDS results confirm the presence of La, Mg and Mn in the Cu₂O Nps. The XRD results confirm the formation a single cubic phase of Cu₂O with a cuprite structure. TEM images confirm the formation of Nps with mean diameters between 12.0 ± 6.1 and 30.8 ± 11.0 nm. Doped and undoped Nps present a narrow band gap (2.40 eV), blue shifted with respect to bulk Cu₂O.

Graphitic carbon-encapsulated V2O5 nanocomposites as a superb photocatalyst for crystal violet degradation

To materialize the excellent photocatalyst for crystal violet dye-degradation, the graphitic carbon-encapsulated vanadium pentoxide (GC-V₂O₅) nanocomposites were synthesized through the simple sonication method by using the green tea waste-derived GC nanoflakes and the sonochemically synthesized V₂O₅ nanorods. The nanocomposites were confirmed to comprise an aggregated morphology, in which the orthorhombic V₂O₅ nanorods were well anchored with the intertwingled GC nanoflakes. Owing to the encapsulation of defective V₂O₅ by conductive GC, the GC-V₂O₅ nanocomposites exhibited the enhanced photocatalytic dye-degradation efficiency up to 98.4% within 105 min. Namely, the encapsulated GC nanosheets might compensate the native defects (i.e., charge traps) on the V₂O₅ surface; hence, the charge transport could be enhanced during the dye-degradation process while the photocarrier recombination could be suppressed. The results suggest the conducting layer-encapsulated semiconducting oxide nanocomposites (e.g., GC-V₂O₅) to be of good use for future green environmental technology, particularly, as a superb photocatalyst for dye degradation.

A Review of Green Synthesis of Metal Nanoparticles Using Algae

The ability of algae to accumulate metals and reduce metal ions make them a superior contender for the biosynthesis of nanoparticles and hence they are called bio-nano factories as both the live and dead dried biomass are used for the synthesis of metallic nanoparticles. Microalgae, forming a substantial part of the planet's biodiversity, are usually single-celled colony-forming or filamentous photosynthetic microorganisms, including several legal divisions like Chlorophyta, Charophyta, and Bacillariophyta. Whole cells of Plectonema boryanum (filamentous cyanobacteria) proved efficient in promoting the production of Au, Ag, and Pt nanoparticles. The cyanobacterial strains of Anabaena flos-aquae and Calothrix pulvinate were used to implement the biosynthesis of Au, Ag, and Pt nanoparticles. Once synthesized within the cells, the nanoparticles were released into the culture media where they formed stable colloids easing their recovery. Lyngbya majuscule and Chlorella vulgaris have been reported to be used as a cost-effective method for Ag nanoparticle synthesis. Dried edible algae (Spirulina platensis) was reported to be used for the extracellular synthesis of Au, Ag, and Au/Ag bimetallic nanoparticles. Synthesis of extracellular metal bio-nanoparticles using Sargassum wightii and Kappaphycus alvarezi has also been reported. Bioreduction of Au (III)-Au (0) using the biomass of brown alga, Fucus vesiculosus, and biosynthesis of Au nanoparticles using red algal (Chondrus crispus) and green algal (Spyrogira insignis) biomass have also been reported. Algae are relatively convenient to handle, less toxic, and less harmful to the environment; synthesis can be carried out at ambient temperature and pressure and in simple aqueous media at a normal pH value. Therefore, the study of algae-mediated biosynthesis of metallic nanoparticles can be taken toward a new branch, termed phyco-nanotechnology.

Hydrated vanadium pentoxide/reduced graphene oxide composite cathode material for high-rate lithium ion batteries

As well-known, hydrated vanadium pentoxide (V₂O₅·nH₂O) has a larger layer spacing than orthogonal V₂O₅, which could offer more active sites to accommodate lithium ions, ensuring a high specific capacity. However, the exploration of V₂O₅·nH₂O cathode is limited by its inherently low conductivity and slow electrochemical kinetics, leading to a significant decrease in capability. Herein, we prepared V₂O₅·nH₂O/reduced graphene oxide (rGO) composite with low rGO content (8 wt%) via a simple yet effective dual electrostatic assembly strategy. When used as the cathode material for lithium-ion batteries (LIBs), V₂O₅·nH₂O/rGO manifests a high reversible capacity of 268 mAh g^-1 at 100 mA g^-1 and especially an excellent rate capability (196 mAh g^-1 at 1000 mA g^-1 and 129 mA h g^-1 at 2000 mA g^-1), surpassing those of the V₂O₅/carbon composites reported in the literatures. Notably, the remarkable performance should be referable to the synergetic effects between one-dimensional V₂O₅·nH₂O nanobelts and two-dimensional rGO nanosheets, which provide a short transport pathway and enhanced electrical conductivity. This strategy opens a new opportunity for designing high-performance cathode material with excellent rate performance for advanced LIBs.

Synthesis and characterization of microbial mediated cadmium oxide nanoparticles

Microbial mediated synthesis of metallic nanoparticles constitutes as effective and promising approach for the development of antibacterial materials in the field of bioengineering and biomedicine. We prepared Cadmium oxide nanoaprticles (CdO NPs) utilizing Penicillium oxalicum, and cadmium acetate solution via coprecipitate method. The elemental composition and morphology of these synthesized CdO NPs were examined through X-ray diffraction (XRD), UV-Vis absorption spectroscopy, Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), and Energy dispersive spectroscopy (EDS). Furthermore, we evaluated the bactericidal potential of prepared CdO NPs using Escherichia coli (E.coli), Staphylococcus aureus (S.aureus), Bacillus cereus (B.cereus), and Pseudomonas aeruginosa (P. aeruginosa). Dimethyl sulfoxide was used as negative control while erythromycin was used as positive control. The XRD spectrum revealed cubic crystalline nanoparticles with 22.94 nm size and UV showed absorbance peak at 297 nm with 2.5 eV band gap energy. FTIR depicted O─H and carboxylic groups along with CdO stretching vibration. EDS showed the presence of organic compounds on Cd and O over NPs surface. SEM results revealed the spherical shape of the CdO NPs. The synthesized NPs exhibited highly potent bactericidal activity against selected strains and demonstrated less optical density of 0.086 after 24 hr. Owing to the significant antibacterial activity of CdO NPs, the broad application prospects of these nanoparticles CdO NPs in extensive biomedical applications is indicated.