Energy Dispersive X-ray Spectra Research Articles

The influence of the physicochemical processes on the electrical response of Al/p-Si structure with etched surface

In this paper, the electrochemical etching process is used for surface modification of the p-Si wafer, named as porous silicon (PS), in the metal–semiconductor (MS) type Schottky diode (SD) with a structure of Al/p-Si. Five regions of PS wafer with different etching rates are selected for comparison of them which are called P2, P3, P4, and P5 (P1 is the reference area without porosity). The morphological, structural, and electrical properties of the PS used in the MS-type SD are investigated using field-emission scanning electron microscope (FE-SEM) images, energy dispersive X-ray (EDX) analysis, and current–voltage (I–V) characteristics, respectively. The FE-SEM images show a meaningful effect on the porosity. The EDX spectrum demonstrates the importance of the chemical effects in addition to the physical changes in the porosity process of the p-Si wafer. The reverse-saturation current (I0), ideality factor (n), barrier height at zero-bias (ΦB0), and series/shunt electrical resistances are also computed and compared. Some of these parameters (n, Rs, BH) are determined using different methods, namely Thermionic emission (TE), Cheung functions, and modified Norde, and they exhibit strong agreement with each other. The energy-dependent profiles of surface states (Nss) are estimated from the I–V data by considering the voltage dependence of ΦB (V) and n(V). All the experimental findings indicate that the etching process of the p-Si wafer significantly influences the electrical performance of the Al/p-Si Schottky diode by increasing the extent of etching.

Electrochemical behaviour of sputter-coated titanium films on AZ31 magnesium alloy

Lightweight magnesium-based structural alloy AZ31 is normally prone to high corrosion in an aqueous environment. A detailed study is reported in this work on AZ31 Mg alloy coated with Ti thin films of different thicknesses by DC sputtering to investigate the capability of Ti coating to prevent corrosion of AZ31 under an aqueous environment similar to seawater. Ti films have been fabricated to 50, 100 and 150 nm thicknesses. Utilising grazing incidence-XRD and SEM, the films’ structure and microstructure were studied. The films were amorphous. Due to corrosion, interesting micro-structures evolved. Corrosion inhibition characteristics of the Ti films were characterised by electrochemical techniques such as potentiodynamic polarisation and impedance spectroscopy. Ti films with 100 nm and 150 nm thickness show a good inhibition capability. The corrosion mechanism was investigated using XPS and X-ray energy dispersive spectra.

Development of a Biodegradable, Cytocompatible, Antibacterial, and Biofilm-Controlling Chitosan Sulfobetaine Derivative Film as a Biological Material

The purpose of this research was to develop a chitosan sulfobetaine (CS-SNCC) film via the solution-casting method as a biodegradable antibacterial material for biomedical applications. Chitosan and monochloro-triazine sulfobetaine were used as the raw materials for CS-SNCC preparation, and Fourier-transform infrared (FTIR), ultraviolet–visible (UV-Vis), energy-dispersive X-ray (EDX), and X-ray photoelectron spectroscopy (XPS) spectra were used to characterize and analyze the structure of the synthesized CS-SNCC. Furthermore, the swelling property, thermal stability, biodegradability, cytocompatibility, and antibacterial properties of the CS-SNCC film were comprehensively investigated and compared with those of the chitosan film. The results for the film’s enzymatic biodegradation behavior show that the CS-SNCC film undergoes a weight loss of 45.54% after 21 days of incubation. In addition, the CS-SNCC film effectively resists bacterial adhesion, prevents the formation of bacteria biofilms, and exhibits high antibacterial activity, with inactivation rates of 93.43% for Escherichia coli and 91.00% for Staphylococcus aureus. Moreover, the CS-SNCC film shows good cellular activity and cytocompatibility according to the cytotoxicity results. Therefore, the prepared biodegradable, cytocompatible, antibacterial, and biofilm-controlling CS-SNCC film has potential for biomedical applications.

In-situ deposition of gold nanoparticles on screen-printed carbon electrode for rapid determination of Hg2+ in water samples

Herein, an electrochemical sensor for Hg2+ detection using in-situ deposited gold nanoparticles modified screen-printed carbon electrode (SPCE) was developed. The gold nanoparticles and Hg were co-deposited on the electrode during the enrichment process. Scanning electron microscope (SEM) and Energy dispersive X-ray (EDX) spectrum prove the successful modification of gold nanoparticles. After modification, the active surface area of the electrode enlarged, the electron transfer ability enhanced, and the detection of Hg2+ became possible. After comprehensive optimization of experimental parameters, the proposed sensor can achieve rapid detection of trace Hg2+ in drinking water through differential pulse stripping voltammetry (DPSV). The limit of detection reaches 0.33 μg/L, the linear range is 0.5–80 μg/L. The test can be completed within 5 min. This sensor does not require extra electrode modification before detection, which can simplify experimental steps and improve detection efficiency, holding great promise for the on-site detection of Hg2+ in environmental and food samples.

Development of Illite modified/Rh2O3 for electrochemical, sensor, photocatalysis and antioxidant studies

The present work revealed the development of illite modified/Rh2O3 nanocomposite through the reflux method. The modification of illite was achieved using CTAB (Cetyltrimethylammonium bromide) as a surfactant. The prepared nanocomposite was subjected to characterize X-ray diffractometer (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectrum (EDAX), thermogravimetric analysis (TGA) and UV–visible spectroscopy techniques. The results exhibit that illite modified/Rh2O3 can successfully facilitate the photocatalytic degradation of orange G (96%) with excellent performance. Cyclic voltammetry analysis of the synthesized material was conducted using a carbon paste electrode in 0.1 M KOH electrolyte, revealing its significant redox potential output as determined by the CV technique. The composite material was used to detect the green sensors like bee pollen and cow urine confirming better sensing performance. Illite modified/Rh2O3 nanocomposite is used for free radical scavenging of DPPH (2,2-diphenyl-1-picrylhydrazyl) showed high antioxidant activity and IC50 value compared with illite and illite modified.

The impact of methylene blue photosensitizer, aPDT and a calcium hydroxide-based paste on the physicochemical and mechanical characteristics of root canal dentin and the bonding interface of fiberglass posts

PurposeTo investigate the influence of methylene blue (MB)-mediated antimicrobial photodynamic therapy (aPDT) and calcium hydroxide (CH) medication on the mechanical characteristics, degree of conversion (DC), quantification, and volume of gaps at the adhesive interface of glass fiber posts (GFPs) luted to distinct thirds of root canal dentin. Additionally, the microhardness (MH), elastic modulus (Eit), morphology, and chemical structure of the intraradicular dentin were assessed. Materials and methods6 experimental groups were formed by sorting 102 bovine incisors. Canals receiving deionized water irrigation as a negative control; canals receiving deionized water irrigation and filled with CH as a positive control; groups treated with CH + MB at 50 and 100 mg/L without irradiation; and groups treated with CH + MB at 50 and 100 mg/L irradiated by red laser for 60 s (660 nm; 100 mW; 6.5 J; 72 J/cm2). MH, Eit, and DC properties were evaluated for both the resin cement layer and root dentin substrate (n = 8). Volume and quantification of gaps at the bonding interface (n = 6), and dentin morphology and chemical content were investigated (n = 3). Data were analyzed using a repeated-measures 2-way ANOVA followed by Tukey post hoc analysis (α = 0.05). ResultsThe distinct intraradicular thirds and treatment with MB-mediated aPDT, whether activated or not, in combination with CH, had a significant impact on the mechanical characteristics of the root dentin. This effect was also observed in the MH, Eit, DC, quantification, and volume of gaps at the luting interface (P < .05). In general, a higher concentration of MB, whether activated by a red laser or not, led to lower values in the mechanical properties of the root dentin, as well as in MH, Eit, and DC at the adhesive interface (P < .05). Additionally, these groups exhibited higher values for quantification and volume of gaps at the luting substrate (P < .05). Scanning electron micrographs and energy dispersive X-ray spectra showed qualitative similarity among all groups, except for the negative experimental control group. ConclusionsMB-mediated aPDT at 50 mg/L, in combination with CH, demonstrated favorable physico-chemical and mechanical characteristics in intraradicular dentin, along with satisfactory mechanical features and the adhesive interface integrity for GFPs at all intraradicular depths. Clinical significanceMB-mediated aPDT at a concentration of 50 mg/L combined to CH medication represents a suitable choice for photosensitization in the context of intracanal disinfection following the biomechanical procedure and prior to luting of intraradicular restorations.

Corrosion Evaluation and Inhibiting Effect of Chlorpheniramine Drug on Mild Steel in HCl Acid

The importance of non harmful inhibitors has informed the application of drugs as an agent to mitigate corrosion of metal materials. This research reveals the inhibitive reaction and adsorption mechanism of Chlorpheniramine drug (CD), on mild steel in an HCl solution using Potentiodynamic polarization, open circuit potential and weight loss method. The CD inhibitor was proportioned into 2.5, 5, 7.5, and 10ml while molarity of HCl was varied in the proportion of 0.1, 0.5, 1.0 and 1.5M at a temperature of 298 K. The reaction showed that as the CD concentration moves to higher concentration, the efficiency of the inhibitor increases, also the higher the concentration of the acid, the higher the corrosion rate. Observation from the result revealed that CD inhibitor protected the steel from corrosion destruction. The optimum efficiency occurred as 85.80% at 10ml CD concentration. CD inhibitor obeyed Freundlich law of isotherm with the average regression value of R2 = 0.9733, as R2 value gets close to unity. Scanning Electron Microscopy (SEM) and Energy-dispersive X-ray spectra (EDX) results also confirm strong adsorption mechanisms of CD inhibitor on the mild steel samples. Keywords: Chlorpheniramine Drug; Green Inhibitor; Open circuit potential; Potentiodynamic Polarization; Mild steel

Green synthesis and anti-tumor activity of curcumin @ ZnO/CuO nanoparticles

Both zinc oxide and copper oxide nanoparticles are promising biologically active materials. Green synthesis approach was used to prepare mixed ZnO/CuO nanoparticles loaded with curcumin extract. The isolated mixed oxides loaded with curcumin (curcumin @ ZnO/CuO) was characterized by UV–visible spectra, FTIR spectra, X-ray powder diffractions (XRD),Transmittance electron microscope (TEM), Energy dispersive x-ray (EDX) and x-ray photoelectron spectroscopy (XPS) spectra. X-ray powder diffractions indicated that ZnO has wurtzite structure and CuO crystallizes in a monoclinic system. XPS confirmed the existence of both CuO and ZnO nanoparticles. TEM results indicated the formation of quantum dots of curcumin @ ZnO/CuO with size in the range 6–10 nm. The optical band gaps of curcumin @ ZnO/CuO were determined and found to be 3.4 and 4.05 eV, which are higher than the bulk. The effects of curcumin @ ZnO/CuO on hepatocellular (HEPG-2) and colorectal (HCT-116) carcinoma were estimated by cell viability, cell cycle and anti-apoptotic factors (caspase-3/7, topoisomerase 2beta and annexin). Strong cytotoxicity activity and apoptosis of tumor cells were observed for curcumin @ ZnO/CuO. The cytotoxicity of the current compounds showed higher activity in comparison with other compounds that were previously studied.

Thermal and mechanical properties of a sustainable bio-flax fibre-based lightweight aggregate concrete

A novel lightweight aggregate concrete (LWAC) or lightweight concrete (LWC) is developed using expanded perlite powder and lightweight expanded clay aggregate as a replacement for conventional fine and coarse aggregates, respectively. Furthermore, the natural plant-based flax fibre in treated form was added to the LWC mix at three different volume fractions. The mechanical and thermal characterisation of LWC was carried out using the compressive strength test, split tensile test, modulus of rupture, thermal conductivity and thermal resistance test. Moreover, the microstructural and durability properties were obtained using scanning electron microscopy/energy dispersive X-ray spectrum analysis, rapid chloride penetration test, sorptivity test and water absorption test. Test results reveal that the addition of 2.0% flax fibre resulted in improved mechanical, thermal and durability properties when compared to LWC with no fibres. Moreover, the microstructural analysis using SEM revealed the formation of ettringite which is responsible for the strength development in the LWAC mix.

Study of structural, dielectric, transport and optical properties of the CaMn0.94Ce0.06 O3 Ceramic

We report the structure, microstructure, dielectric, transport, and optical properties of the CaMn0.94Ce0.06O3 ceramic synthesized by the solid-state reaction method. Analysis of the X-ray diffraction (XRD) pattern of the sample adopts an orthorhombic crystal symmetry. A study of scanning electron microscope (SEM) micrograph shows the homogeneous distribution of the well-grown grains over the entire surface of the sample. The well-defined and distinct grain boundaries surrounding the compact grains may be a possible reason for a better conductivity mechanism in the sample. The study of the energy dispersive x-ray (EDX) spectrum provides information about the formation of high-purity samples and also confirms the presence of Ca, Mn, Ce and O in both weight and atomic percentages. The agglomeration rate during the sintering process may be a possible reason for a better dielectric and conductivity mechanism. Fourier-transform infrared spectroscopy (FTIR) study strongly supports the presence of all constituent element’s atomic vibration bands. The study of the UV visible spectra provides the idea of semiconducting nature and bandgap energy of 4.89 eV. At a low range of frequency, the presence of the Maxwell-Winger type of dielectric dispersion is confirmed. Dielectric properties were investigated, including conductivity, dielectric constant, dielectric loss, and complex modulus. According to impedance analysis, primarily the charge carriers’ long-range movement controls the conduction process. The semiconducting nature of the sample is confirmed by analysis of the Cole-Cole plots.

Photocatalytic degradation of acid blue 74 by Co: WO3 nanoparticles: Kinetics and response surface methodology studies

Energy-efficient sol-gel synthesis was achieved through the microwave assisted self-combustion route to produce hexagonal Tungsten oxide semiconductor (WO3). The photocatalytic activity was enhanced by doping Cobalt (Co) into the crystalline structure of the nanoparticle, which were subsequently sintered at 400 °C for an hour. The structural and morphological properties of the Co-doped WO3 were revealed using X-ray diffraction (XRD) characterization. The nanoparticles exhibited an amorphous structure before annealing, due to the short heating time during combustion synthesis. Sintering the nanoparticle transformed the nanoparticle from a monoclinic phase to orthorhombic phase structure. Additional analysis techniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray spectrum analysis (EDS).To assess the photocatalytic performance of these particles, Acid Blue 74 (AB 74) was employed in photodegradation experiments under UV light irradiation within a semi-continuous reactor.The photodegradation of dye molecules was evaluated utilizing a UV–Vis spectrophotometer, and the mineralization efficiency of the dye was determined through total organic carbon analysis (TOC). The results indicated that the dimension of the synthesized nano catalyst fell within the range of 70–120 nm, and it exhibited the ability to completely degrade a solution with an initial dye concentration of 20 ppm within 60 min. Various parameters affecting the photocatalytic reaction, including the photocatalyst dosage, initial dye concentration, pH and temperature of the dye solution were also investigated. The experiments were designed using Response surface methodology (RSM), through which a mathematical model for the dye removal process was developed.

Enhancement in the Electrocatalytic and Optoelectronic Performance of Cost-Effective Counter Electrode VO2 for Dye-Sensitized Solar Cell (DSSC)

Dye-sensitized solar cells (DSSCs) have garnered significant attention in the scientific community for more than two decades due to their cost-effectiveness, convenient manufacturability, little toxicity, and straightforward preparation methodology. In this study, we present a cost-effective alternative to the platinum electrode for DSSCs, which serves as the counter electrode. The utilization of vanadium oxide nanoparticles as counter electrodes (CEs) in DSSCs has been the subject of research due to its enhanced stability, cost-effectiveness, and favorable photovoltaic characteristics. The device has been fabricated in configuration of fluorine-doped tin oxide (FTO)||TiO2||ruthenium (II) dye (N719)||iodide—triiodide electrolyte||VO2 (counter electrode)||FTO and investigate their photovoltaic performance. The utilization of X-ray diffraction (XRD) analysis has provided insights into the crystalline properties of VO2, indicating that it exists in a crystalline phase with a crystalline size measuring 43.19 nm and a lattice strain of 1.68 × 10−3. The utilization of a field emission scanning electron microscope (FESEM) that is equipped with an energy dispersive X-ray spectrum reveals a dense microstructure characterized by a uniform distribution of vanadium (V) and oxygen (O) across the whole surface. The Raman spectroscopic examination of VO2 reveals the existence of many Raman bands, thereby confirming the presence of the monoclinic phase. Cyclic voltammetry measurements were employed to investigate the catalytic activity of the CE toward the electrolyte. The photovoltaic performance of the manufactured device was examined by I–V measurement, revealing a notable open circuit voltage (Voc) and efficient power conversion efficiency when compared to the other materials that were evaluated.

Study on triphase of polymorphs TiO2 (anatase/rutile/brookite) for boosting photocatalytic activity of metformin degradation

The elution of pharmaceutical products such as metformin at higher concentrations than the safe level in aquatic systems is a serious threat to human health and the ecosystem. Photocatalytic technology using TiO2 semiconductors potentially fixes this problem. This study aims to synthesize triphasic anatase–rutile–brookite TiO2 using ultrasound assisted sol–gel technique in the presence of acid and its application to photodegradation of metformin under UV light irradiation. Based on X-ray diffraction analysis, a TiO2 sample consisted of anatase (76%), rutile (7%), and brookite (17%) polymorph (A76R7B17) that was fully crystallized. Scanning electron microscopy (EM)–energy dispersive X-ray spectra results showed agglomerated triphasic A76R7B17 with irregular spherical clusters. Transmission EM results revealed that the crystal size of A76R7B17 was 4–14 nm. The Brunauer–Emmett–Teller analysis showed the sample's specific surface area of 149 m2 g−1. The degradation test of metformin demonstrated that the A76R7B17 exhibited a 75.4% degradation efficiency after 120 min under UV light irradiation, significantly higher than using biphasic and single-phase TiO2 photocatalysts. This difference could be attributed to the heterojunction effect of triphasic materials that effectively reduced electron–hole recombination rate as well as the combination of effective electron transfer from conduction band of brookite and anatase and the utilization of wider range of UV–visible light using rutile.

Plant phytochemicals-mediated synthesis of zinc oxide nanoparticles with antimicrobial, pharmacological, and environmental applications.

Nanotechnology is a fast-growing field with large number of applications. Therefore, the current study, was designed to prepare Zinc Oxide nanoparticles (ZnO NPs) from A. modesta leaves extract through a cost-effective method. The prepared NPs were characterized through UV-Vis Spectroscopy (UV-Vis), Dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), scanning electron microscope (SEM), and energy dispersive X-ray (EDX). The XRD and DLS analysis revealed the hexagonal nanocrystalline nature of ZnO NPs. The FTIR results displayed multiple fictional groups and UV results confirmed its optical properties. The average size of the NPs was 68.3 nm with a band gap of 2.71 eV. The SEM images divulge a clover leaf shape of ZnO NPs. The EDX spectrum revealed the presence of zinc and oxygen. The prepared NPs showed excellent biomedical application. The highest antileishmanial activity was 68%, anti-inflammatory activity was 78%, total antioxidant capacity (TAC) was 79.1%, antibacterial potential (ZOI) 22.1 mm, and highest growth inhibition of 85 ± 2.1% against A. rabiei. The adsorption efficiency of 85.3% within 120 min was obtained. Conclusively ZnO NPs have shown potential biomedical and environmental applications and ought to be the more investigated to enhance their practical use.

Sensor properties of heterocyclic compound with nanoparticles – molecular docking studies

Quenching and enhancing behaviour of 1-(4-methoxyphenyl)-2-(4-methylnaphthalen-1-yl)-1H-phenanthro[9,10-d]imidazole (MMPI) with Cu –doped ZnO nanoparticle has been studied. MMPI has been characterized by 1H, 13C NMR and mass spectral analysis. Cu –doped ZnO nanoparticle have been synthesised by sol-gel method and characterized by powder X-ray diffraction (XRD), Scanning Electron Microscope (SEM) and Energy Dispersive X-ray Spectra (EDS). Quenching and enhancing behaviour were confirmed by the MMPI strongly binding on the surface of Cu –doped ZnO nanoparticle. Increasing concentration of nanoparticle into MMPI results in enhances absorbance and quenching fluorescence was observed. Fluorescence quenching was confirmed electron transfer from excited state of MMPI to nanoparticle. Theoretical calculations were performed by Gaussian -03 package. In order to understand the binding interaction with DNA docking study has been carried out.

Ferromagnetic Enhancement of Microcrystalline Cellulose via Chemical Reduction Method

Iron oxide nanoparticles (NPs) have potential in biological, biomedical, and environmental applications because of their magnetic susceptibility, stability, and biocompatibility characteristics. However, it also has limitations, such as the aggregation of magnetic NP. Thus, the outer surface of the particles should be modified by coating materials. This paper focused on synthesizing iron oxide by chemical reduction method and coating it with Fe(III) nitrate, PVP, and hydrazine. The coating solution at two different concentrations was prepared to determine effective and economical usage conditions. The effect of coating iron oxide with microcrystalline cellulose (MCC) was conducted at different concentrations of iron oxide on the nanomaterials with respect to morphological, thermal, and magnetic susceptibility. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) indicated good morphology images of FeNp-MCC. Energy dispersive X-ray (EDX) spectra reveal the presence of carbon, oxygen, and iron in the synthesized microparticles.TGA analysis showed iron material was succesfully formed into the surface of microcrystalline cellulose. Lastly,the magnetism results proved that cellulose is strongly interacting with magnetite nanoparticles.

Design, Spectral and Biological Evaluation of Benzohydrazide Derivatives

The TiO2(R) Nanoparticles were synthesised by the sol–gel method and characterized by powder X-ray diffraction(XRD) scanning electron microscopy (SEM) and energy dispersive X-ray (EDS) spectra. The benzohydrazide derivatives (1-4) have been synthesized by using sol-gel prepared TiO2 (R) acting as a catalyst under solvent conditions and characterized by FT-IR, NMR and mass spectral studies. Antimicrobial studies were carried out against the bacterial strains viz., Escherichia coli, Salmonella typhi, Staphylococcus aureus and Pseudomonasaeruginosa and fungal strains viz., Candida albicans, Aspergillus niger, Mucor and Rhizopus sp.

Tailoring the structural, optical, electrical and multiferroic properties of Sm1-xRxFeO3 (x = 0.0 and 0.5; R = Pr, Nd, and Gd) and their synergistic photocatalytic activity

In this work, nanocrystalline Sm1-xRxFeO3 (x = 0.0 and 0.5; RPr, Nd, and Gd) samples have been synthesized via auto-combustion method and characterized to understand their microstructural, optical, electrical and multiferroic properties. X-ray diffraction data in combination with the FTIR spectra revealed the monophase and distorted orthorhombic configuration of all the samples with Pbnm space group. Rietveld refinement displayed a reduction in the bond length as well as the bond angle in the Sm0.5Gd0.5FeO3 sample. Raman spectra exhibit compressive strain in Sm0.5Gd0.5FeO3 nanoparticles; this finding is further supported by the XRD analysis. UV–visible spectroscopy manifests a reduction in the optical energy bandgap on moving Gd to Pr in Sm0.5R0.5FeO3 system. Transmission electron microscopy (TEM) images in combination with energy dispersive x-ray (EDX) spectra reveal the non-uniform surface morphology with the agglomerated nature of nanoparticles and affirm the elemental compositions of all the samples. The room temperature P-E and M − H loops infer the multiferroic nature of all samples. Electron paramagnetic resonance (EPR) analysis divulges the weakening of the super-exchange interactions in Sm0.5R0.5FeO3 system. DC electrical resistivity measurements reflect semiconductor-like behaviour in all prepared samples. The dielectric behaviour of the samples is in accordance with the “universal dielectric response” model. The temperature-dependent dielectric measurements of all prepared samples have been performed at 1 kHz to determine the Néel temperature (TN). The photocatalytic investigation depicts the superior photocatalytic response of Sm0.5Pr0.5FeO3 nanoparticles under solar-light irradiation through the synergism of semiconductor-photocatalyzed oxidation and heterogeneous Fenton-like reaction.

Exploring the Potential of Nickel Oxide Nanoparticles Synthesized from Dictyota bartayresiana and its Biological Applications.

The present study validates the impact of nickel oxide nanoparticles (NiONPs) biosynthesized from the brown seaweed Dictyota bartayresiana (DB) and its biological applications. The phytochemicals analyzed in the seaweed extract served as a reducing, capping or stabilizing agent in the formation of nanoparticles. UV visible spectrum of nickel oxide nanoparticles synthesized from DB (DB-NiONPs) represented a prominent peak at 392nm which validates its formation. Fourier Transmission Infrared Spectroscopy (FT-IR) showcased the presence of functional groups in the biomolecules which aids in the stabilization of DB-NiONPs. The X-ray diffractometry (XRD) revealed the crystalline nature of DB-NiONPs and the particle size was calculated as 18.26nm. The Scanning electron microscope (SEM) illustrates the irregularly shaped DB-NiONPs and the desired elements were depicted in energy dispersive X-ray (EDX) spectrum which confirms the purity of DB-NiONPs. The DB-NiONPs efficiently decolorised the Black B133 (BB133) dye to 86% in 25min. The data of adsorption studies well fitted into Langmuir isotherm and pseudo-second order kinetic model. The thermodynamic study substantiated the spontaneous, feasible and endothermic process of adsorption. DB-NiONPs revealed enhanced antimicrobial, larvicidal and nematicidal activities against the selected microbes, larva of Culex pipens and juveniles of Meloidogyne incognita respectively. The phytotoxicity studies revealed the DB-NiONPs had a positive impact on the germination and growth of green gram seedlings.

Oxygen vacancies mediated changes in ferromagnetic, optical, Photoluminescent and electronic structure properties of Ho-doped CeO2 nanoparticles

The undoped CeO2 and Ce1-xHoxO2 (x = 0.03, 0.05 and 0.07) nanoparticles prepared using microwave assisted co-precipitation route are investigated using X-Ray Diffraction (XRD), UV–Vis–NIR, Raman, photoluminescence, X-ray Photoelectron Spectroscopy (XPS) and SQUID-VSM magnetometer. The XRD validates the inclusion of Ho3+ at the Ce3+/Ce4+ site while maintaining the crystal structure with development of defects and oxygen vacancies with expansion of the CeO2 nanolattice. The composition of the elements with desired stoichiometry is confirmed by Energy Dispersive X-ray spectra analysis. The absorption spectroscopy analysis reports the Urbach energy along with refractive index increases with Ho3+ doping and the optical band gap is decreased indicating red shift. All the nanoparticles are subjected to PL investigations to ascertain the oxygen vacancy and defect structure of nanoparticles. Raman active modes at ∼500 - 630 cm−1 verifies the existence of oxygen vacancies (Vo)., which are seen to rise with concentration of Ho-doping in the CeO2 lattice. When Ce4+ transforms into Ce3+, oxygen vacancies are generated in the lattice to maintain the charge neutrality, as can be seen by the Ce-3d, O-1s, and Ho-4d core level XPS spectra. To demonstrate that Ho3+ doping favours ferromagnetic ordering in the CeO2 lattice, the magnetic properties using the Bound Magnetic Polaron model and F centre exchange mechanism are discussed. The development of various complexes that involve host and doped cations are mediated by Vo suggests the existence of F0, F+, and F2+ centres. The weak ferromagnetic behaviour in Ho3+-doped CeO2 nanoparticles reinforce the relationship between Vo to explain the observed magnetic properties of nanoparticles.