Peak Intensity Research Articles

Characterization of Silver Nanoparticles Synthesized With Fungi Isolated From Cocoa and Orange Plantation Soils

Green synthesis of nanoparticles with various metals is being interested among researchers globally attention for due to their safety, environmental friendliness and non-toxicity in contrast to chemical synthesis. Here, fungi were isolated from rhizosphere of cocoa and orange obtained from Federal University of Technology, Akure using standard mycological techniques with the aim of synthesizing silver nanoparticles. The silver nanoparticles synthesized by these fungal isolates were characterized using Ultraviolet-Visible (UV-Vis) and Fourier Transmission Infra- Red (FTIR) spectroscopy. Seven fungi isolated from the soil samples viz. Nigrospora sphaerica, Penicillium discolor, P. digitatum, Neurospora crassa, Alternarium infectoria, Trichophyton verrucosum and Mucor mucedo. The colour transformation from yellow to brown indicated the formation of silver nanoparticles. All the isolates showed an intense peak in the wavelength range of 410-440 nm. The FTIR analysis of silver nanoparticles synthesized by N. sphaerica, P. discolor, P. digitatum, N. crassa, A. infectoria, T. verrucosum and M. mucedo revealed the existence of a band at different stretches of bonds at different peaks of 3314.36 cm-1, 3310.47 cm-1, 2412.22 cm-1, 3912.33 cm-1 3614.52 cm-1, 3852.11 cm-1 and 2112.11 cm-1, respectively. The silver nanoparticles synthesized could have the potential application in agricultural, pharmaceutical and food industries as well as petrochemical industries for the clean - up of crude oil contaminated soils. J. Bio-Sci. 32(2): 31-44, 2024

Unforeseen advantage of looser focusing in vacuum laser acceleration

Acceleration of electrons in vacuum directly by intense laser fields holds great promise for the generation of high-charge, ultrashort, relativistic electron bunches. While the energy gain is expected to be higher with tighter focusing, this does not account for the reduced acceleration range, which is limited by diffraction. Here, we present the results of an experimental investigation that exposed nanotips to relativistic few-cycle laser pulses. We demonstrate the vacuum laser acceleration of electron beams with 100s pC charge and 15 MeV energy. Two different focusing geometries, with normalized vector potential a0 of 9.8 and 3.8, produced comparable overall charge and electron spectra, despite a factor of almost ten difference in peak intensity. Our results are in good agreement with 3D particle-in-cell simulations, which indicate the importance of dephasing.

Temperature Field Measurements in Swirl Spray Flames Using Two-Line Planar Laser Induced Fluorescence Thermometry

Abstract This paper investigates the temperature fields in a centrally staged swirl spray combustor using two-line OH planar laser induced fluorescence (PLIF) thermometry at elevated inlet pressures and temperatures up to 0.62 MPa and 650 K. The pilot and main stages of the combustor were supplied with RP-3 kerosene. OH radicals were excited using the Q1(5) and Q1(14) transitions within the A2Σ←X2Π (1,0) band. Two laser excitation systems were operated simultaneously, where the two beams were spatially combined and separated by a small interval in time. The PLIF signals excited at the two wavelengths were captured by two identical sets of imaging system. The calibration coefficient needed for quantitative conversion from fluorescence ratio to temperature was determined based on results from independent coherent anti-Stokes Raman scattering (CARS) measurements. A joint threshold mask was developed to remove the noise and weak signals in the raw PLIF images. The high temperature zones in the temperature field were then obtained, and the pilot and main stage flames were identified. In addition, the radial position of the pilot flame showed marked variations at a nominally fixed condition. By extracting the radial profiles, a consistency between the peaks of PLIF intensity and temperature was found, suggesting that PLIF images could be a qualitative substitute for the high temperature zones in the temperature fields of these swirl spray flames. This study demonstrates the feasibility of temperature field measurements using two-line OH PLIF in aero-engine model combustors.

N6-methyladenosine transcriptome-wide profiles of maize kernel development.

Maize (Zea mays L.) kernel development is a complex and dynamic process involving cell division and differentiation, into a variety of cell types. Epigenetic modifications, including DNA methylation, play a pivotal role in regulating this process. N6-methyladenosine modification is a universal and dynamic post-transcriptional epigenetic modification that is involved in the regulation of plant development. However, the role of N6-methyladenosine in maize kernel development remains unknown. In this study, we have constructed transcriptome-wide profiles for maize kernels at various stages of early development. Utilizing a combination of MeRIP-seq and RNA-seq analysis, we identified a total of 11,170, 10,973, 11,094, 11,990, 12,203 and 10,893 N6-methyladenosine peaks in maize kernels at 0, 2, 4, 6, 8, and 12 days after pollination, respectively. These N6-methyladenosine modifications were primarily deposited at the 3'-UTRs and were associated with the conserved motif-UGUACA. Additionally, we found that conserved N6-methyladenosine modification are involved in the regulation of genes that are ubiquitously expressed during kernel development. Further analysis revealed that N6-methyladenosine peak intensity was negatively correlated with the mRNA abundance of these ubiquitously expressed genes. Meanwhile, we employed phylogenetic analysis to predict potential regulatory proteins involved in maize kernels development and identified several that participate in the regulation of N6-methyladenosine modifications. Collectively, our results suggest the existence of a novel post-transcriptional epigenetic modification mechanism involved in the regulation of maize kernels development, thereby providing a novel perspective for maize molecular breeding.

Nonlinear optical studies of Bismuth-doped Titanium di-oxide colloids achieved by femtosecond Z-Scan technique

In this paper, we explored the nonlinear optical (NLO) properties of Bismuth (Bi) doped titanium dioxide (TiO2) nanoparticle (NP) colloids in ethanol, with laser pulses of duration ∼ 150 femtoseconds (fs). The Bi-doped TiO2 NPs were synthesized via the chemical route, sol-gel method. The increased photo response of TiO2 upon doping it with metals has become a burning issue to extend the applications of metal-doped TiO2 NPs as integral parts in solar cells, catalysts, phototherapy, etc. The bandgap of anatase TiO2 NPs was observed to be reduced to 2.89 eV upon doping Bi. The modified band structure of the Bi-doped TiO2 NPs demonstrates novel chemical, mechanical, and optical properties. NLO studies were conducted on Bismuth-doped TiO2 NPs submerged in ethanol employing femtosecond laser input pulses with incoming wavelengths 700, 750, 800, 850, 900, and 950 nm. It has been detected that open aperture (OA) studies performed at an input peak intensity of 100 MW/cm2 on Bi-doped TiO2 NPs in ethanol were exhibiting complex NLO behavior, i.e., reverse saturable absorption (RSA) in saturable absorption (SA) and SA in RSA with mostly effective two-photon absorption (1 + 1) coefficients. Particularly, at ∼800 nm, the behavior observed was so complex, i.e., RSA in SA in RSA in SA, with an effective 3 PA (2 + 1) co-efficient (γ) ∼6.5 × 10−24 m3/W2. The closed aperture (CA) studies at ∼37 MW/cm2 exhibited self-defocusing effects, i.e., an intensity-dependent refractive index (n2) with a negative signature.

Dual‐mode sensing biopolymer membrane impregnated with molybdenum for ethylene detection and monitoring of fruits

AbstractIn this study, a dual‐mode sensing biopolymer membrane employing chitosan (CS), polyvinyl alcohol (PVA), and ammonium molybdate (AM) was developed for optical and electrochemical detection of ethylene. The biopolymer composite was characterized by X‐ray diffraction (XRD), Fourier transform infra‐red (FTIR), and scanning electron microscopy (SEM).The relationship between ethylene concentration and optical/electrochemical response was investigated. XRD analysis showed enhanced ionic conduction, supported by SEM images showing uniform pore distribution within the synthesized membrane, facilitating effective gas interaction with Molybdenum. The increased FTIR peak intensities with higher amount of molybdenum in the membrane indicates enhanced molecular interactions. Applied to a microelectrode chip, the membrane exhibits a measurable electrochemical response with oxidation peak appearing in cyclic voltammogram as Molybdenum ions undergo reduction upon ethylene exposure. Colorimetric measurements, based on CIELAB values, reveals visible color shift with increasing ethylene concentrations, particularly at 10% molybdenum impregnation. Ionic conductivity and total color difference exhibit parallel variation with ethylene concentrations. X‐ray photoelectron spectroscopy confirms molybdenum oxidation state shift from +6 to +5 in the membrane upon ethylene interaction. The inexpensive colorimetric method enables direct color change visualization in practical applications. The resulting dual‐functional biopolymer membrane shows adaptability and versatility by responding to both optical and electrochemical signals.

Low-thermal-budget crystallization of ferroelectric Al:HfO2 films by millisecond flash lamp annealing

We report the use of a low-thermal-budget annealing technique; flash lamp annealing (FLA), which provides an extremely short annealing time in the millisecond range, on the ferroelectric properties of Al-doped HfO2 (HAO) films. HAO annealed at 1000 °C with 5 ms shows a higher remanent polarization value of 24.9 μC cm−2 compared to rapid thermal annealing (RTA), without degradation of endurance. GIXRD shows a stronger peak intensity originating from the orthorhombic (o-) phase and is observed when using FLA, indicating the formation of a larger amount of the o-phase. We believe that this is a consequence of the low thermal budget of FLA, and that specifically FLA can minimize the relaxation of the compressive stress in the TiN electrodes, inducing a high tensile stress to the HAO films and therefore an enhancement of o-phase formation. These results indicate that FLA is a promising annealing method for HAO crystallization due to the enhancement of o-phase formation.

Structural and Electrical Studies of Polycrystalline Pr𝑥Y1−𝑥FeO3 Materials Prepared Through Sol-Gel Route

Objectives: Investigations on structural, morphological and electrical studies of Pr substituted YFeO3 samples synthesized through sol-gel route are presented in this paper. Methods: PrxY1-xFeO3 (x=0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) samples are synthesized by sol-gel auto combustion method. Structural characterization of the samples is done by using X-ray diffraction (XRD), Field emission scanning electron microscope (FESEM) and Energy dispersive X-ray (EDX) techniques. Electrical properties are studied by J-E and Ln J-Ln E measurements. Findings: Rietveld refined XRD structural analysis shows sharp intense peaks indicating the crystalline nature of the samples and all the samples possess distorted orthorhombic structure with space group Pbnm. FESEM analysis shows non-uniform nature of grain size with increasing porosity. EDX data confirms elemental composition, weight and atomic percentage of the prepared samples which further confirms their purity. The leakage current density increases with increase in Pr doping. The slopes of Ln J-Ln E graphs of all the samples are in the range of 1.11 to 1.51 confirming that Ohmic conduction is predominant conduction mechanism. Novelty: Investigations on the effect of Pr substitution on electrical properties of single phase YFeO3­ samples reveal that the substitution of Pr in YFeO3 decreases the ferroelectric nature of the samples. Keywords: Sol-gel method, XRD, FESEM, EDX, Electrical Properties

Exploration of Laser-Assisted Chemical Bath for Enhancing Synthesis of Undoped and Nickel-Doped Zinc Oxide and Its Potential Applications in Water Purification and Mitigating Antimicrobial Resistance

This study aims to explore the antimicrobial and photocatalytic efficiencies of pure and Ni-doped ZnO nanostructures produced via Laser-assisted Chemical Bath Synthesis (LACBS) to develop sustainable solutions for water treatment and pathogen control amid the global water crisis exacerbated by climate change and environmental pollution. Utilizing zinc acetate dihydrate and hexamethylenetetramine, the nanostructures were synthesized with Ni doping levels of 0.0%, 1.5%, 3.0%, and 4.5%, targeting their promising photocatalytic and antimicrobial properties to combat contaminants from pharmaceuticals, agriculture, and industries. Morphological analyses using Scanning Electron Microscopy showed a transition from hexagonal particles to nanoflowers, enhancing photocatalytic activity due to increased surface-to-volume ratio. X-ray Diffraction confirmed the hexagonal wurtzite structure, with variations in peak intensities indicating improved crystallinity with Ni doping. Energy Dispersive X-ray analysis verified the purity and successful incorporation of Ni. Photocatalytic assessments indicated up to 99.24% degradation of Methylene Orange dye under blue laser irradiation within 60minutes, correlating with Ni content. Antimicrobial tests demonstrated effective inhibition of pathogens such as Escherichia coli, Staphylococcus aureus, and additional strains like Candida albicans and Klebsiella pneumonia, with increasing zones of inhibition corresponding to higher Ni levels, extending up to 37mm. The results underscore the dual functionality of ZnO nanostructures for applications in sustainable water treatment and antimicrobial controls, highlighting the need for future studies to examine the impacts of further increased doping concentrations on the material properties and efficacy.

STUDY OF THERMOLUMINESCENCE CHARACTERISTICS OF QUARTZ FOR HIGH RADIATION DOSES (>1KGY): IMPLICATIONS FOR EXTENDING THE LUMINESCENCE DATING RANGE

Quartz is an omnipresent abundant natural mineral, used for luminescence dating. Lately, quartz optically stimulated luminescence (OSL) technique is widely used to estimate the equivalent doses (De) for dating geological events (up to 250 Gy, limited by saturation). Some works report thermoluminescence (TL) saturation around ∼ (10-40) kGy. Still dose estimates for such high radiation dose (HRD) range are not achieved. Significant research exists about luminescence response for low dose ranges (<250 Gy) but limited studies are done for HRDs (>1 kGy). This work characterizes the luminescence response of quartz for HRDs (1-21 kGy) to improve existing understanding of luminescence mechanism. Results show that the characteristics of the trap (<200°C) differ significantly at HRDs than low doses. TL in multi-spectral detection (UV-Visible) band suggest an increase in 340-380°C peak intensity up to 11 kGy dose. The measurements of saturation dose suggest that it depends on the trapping centres but is independent of recombination centres for the samples used for study. The traps are found bleachable by sunlight, reducing TL signal to residual levels in 1 hour. Further, the bleachability is found to be anti-correlated with luminescence emission wavelength. At HRDs luminescence sensitivity is influenced by dose given in previous cycle which is difficult to correct by routine normalization procedures. The work also explores the various normalization methods to find appropriate method for HRD estimation and recommends the use of mass normalization as other normalization methods do not correct the sensitivity changes at HRDs adequately.

Investigating Nanoindentation and Wear Properties of Spark Plasma Sintered Ti48Al48Cr2Nb2 Alloy

This work studied spark plasma sintered Ti48Al48Cr2Nb2 alloy for their nanoindentation and wear properties. Results showed an improvement in nanoindentation properties of the compacts with an increase in holding time from 5min to 7.5min for the heating rate of 50°C/min and 100°C/min. X-ray diffraction (XRD) analysis showed the intensity of diffraction peaks of two major crystalline phases of Ti3Al2.25Nb0.75 and γ-TiAl. Scanning electron microscopy (SEM) images of sintered compacts possessed varied microstructures due to different sintering parameters. The nearly lamellar structure showed a good balance of yield stress and fracture toughness. Wear tracks SEM analysis revealed the worn surface morphologies and the sample sintered for 7.5 min at the eating rate of 50°C/min sustained the least damage evident by the shallow grooves and narrow wear track. Profilometer measurements revealed the wear track depth and width, confirming the degree of wear for the samples sintered at varied conditions.

Physical Properties Studies of Magnesium Phthalocyanine (MgPc) Thin Films of Different Annealing Temperatures Prepared by Pulsed Laser Deposition Technique

Magnesium Phthalocyanine (MgPc) was deposited on a glass substrate by pulsed laser deposition (PLD) using Q-Switching Nd:YAG laser with wavelength 1064 nm, repetition rate 6 Hz, at room temperature (300K) and different annealing temperatures (373, 473, and 573)K under vacuum condition of 10-3 torr. All films were annealed for one hour to attain crystallinity. X-ray diffraction (XRD) of MgPc powder indicated that MgPc crystallizes in polycrystalline with a monoclinic structure. While comparing the MgPc films, it was observed that the intensity of the characteristic peak increases with temperature, and the crystallization exhibited a monoclinic structure typical of the β-form. The Miller indices, hkl, values for each diffraction peak in the XRD spectrum were calculated. The characteristic peak of Phthalocyanine (MgPc) was found at 2θ value 6.9137ᵒ with the hkl value of (100) for both MgPc powder and deposited thin films. Field emission scanning electron microscopy (FESEM) and energy-dispersive X-ray spectroscopy (EDX) analyses indicated that crystallinity improved and surface morphology was enhanced with the rise in annealing temperature and showed uniform-sized grains. They also assisted in identifying the optimal parameters that yielded the best structural properties for the film. The optical properties of MgPc thin film showed two absorption bands. The MgPc thin films exhibit transport and onset direct energy gaps (Eg) for all samples. Additionally, the absorption coefficient (α) was calculated using Lambert Law, revealing a slight dependence on the annealing temperature.

Resolving a Candidate Dual Active Galactic Nucleus with ∼100 pc Separation in MCG-03-34-64

We report the serendipitous multiwavelength discovery of a candidate dual black hole system with a separation of ∼100 pc, in the gas-rich luminous infrared galaxy MCG-03-34-64 (z = 0.016). Hubble Space Telescope/Advanced Camera for Surveys observations show three distinct optical centroids in the [O iii] narrow-band and F814W images. Subsequent analysis of Chandra/ACIS data shows two spatially resolved peaks of equal intensity in the neutral Fe Kα (6.2–6.6 keV) band, while high-resolution radio continuum observations with the Very Large Array at 8.46 GHz (3.6 cm band) show two spatially coincident radio peaks. Fast shocks as the ionizing source seem unlikely, given the energies required for the production of Fe Kα. If confirmed, the separation of ∼100 pc would represent the closest dual active galactic nuclei reported to date with spatially resolved, multiwavelength observations.

Green synthesis of ZIF-67 nanoparticles via microfluidics: Towards sustainable nanomaterial production

This study explored the synthesis of zeolitic imidazolate framework-67 (ZIF-67) nanoparticles using a microfluidic reactor, focusing on the effects of reactant concentration, temperature, and flow rate on the material’s properties. Design Expert software was utilized to optimize these variables to enhance the synthesis process while preventing reactor clogging due to precipitate formation. The experiments varied concentrations of cobalt (II) nitrate hexahydrate and 2-methylimidazole, along with temperature and flow rates. After synthesis, the samples underwent extensive characterization, including FTIR, NMR, TEM, SAED, and XRD analyses. FTIR results confirmed the successful formation of ZIF-67, with varying conditions leading to shifts in peak positions and intensities, indicating changes in bonding and molecular structure. NMR spectra provided insights into the hydrogen environments within the nanoparticles. TEM and SAED analyses revealed that the nanoparticles predominantly exhibited a uniform rhombic dodecahedral morphology with diameters ranging from 5 to 10 nm. XRD patterns were consistent with simulated data, showing variations in peak positions and crystallinity with changes in synthesis conditions. The study highlighted that increasing reactant concentrations, temperature, and flow rate generally enhanced the production rate and crystallinity of ZIF-67, with 2-methylimidazole concentration having the most significant impact. The findings contributed to optimizing ZIF-67 synthesis, demonstrating the feasibility of using microfluidic reactors and green solvents for producing high-quality nanoparticles with controlled properties.

Optoelectronic Properties of Chemical Vapor Deposition Grown Monolayer MoS2 Nanowires

Monolayer (1L) MoS2 nanowire possesses large amount of exposed edges, resulting in unique physical properties differing to the large size flake. Preparation of high quality 1L MoS2 nanowire using chemical vapor deposition (CVD) is still challenging to the best of our knowledge. Herein, by employing space-confined CVD method using Mo foil as Mo source, 1L MoS2 nanowires with width of ~70nm can be deposited on the surface of 1L MoS2 flake. Tip-enhanced photoluminescence (TEPL) measurements indicate different PL peak position and intensity distribution across the nanowires. Photosensitive Kelvin probe force microscopy (KPFM) measurements further reveal that these nanowires exhibit lower Fermi level than the 1L MoS2 flake, resulting in tunable optosensitive charge transfer under different excitation photon energies form 1.58eV to 2.33eV.

A comparative study of optical property on unintentionally doped and Sn-Doped β-Ga2O3 crystals by EFG method with a cylindrical Ir die

In this work, we carried out a comparative study of optical property on unintentionally doped and Sn-doped β-Ga2O3 crystals by edge-defined film-fed growth (EFG) method with a cylindrical iridium (Ir) die. The non-polarized Raman spectra showed the anisotropy in Raman peak position and intensity for three different planes (i.e., (100), (010) and (001)) of β-Ga2O3 crystals, independent of the Sn dopant. A difference in the Raman spectra between the unintentionally doped and Sn-doped β-Ga2O3 crystals was observed in the (001) plane. The strong in-plane anisotropy of the monoclinic β-Ga2O3 crystal related to the crystallographic orientation was demonstrated by the angle-resolved polarized Raman spectroscopy. The Sn dopant cannot change the optical transmittance and bandgap values of the unintentionally doped and Sn-doped β-Ga2O3 crystals with the (100), (010) and (001) orientations. However, the Sn-doped β-Ga2O3 crystal with the (010) orientation showed the higher valence band maximum and lower surface barrier height values. The X-ray photoelectron spectroscopy of the unintentionally doped and Sn-doped β-Ga2O3 crystals with the (010) orientation was also measured, which showed no obvious difference. The different luminescence centers and level of electron ionization of the unintentionally doped and Sn-doped β-Ga2O3 crystals were observed by the cathodoluminescence spectroscopy and electron paramagnetic resonance, respectively. Based on the comprehensive comparison, it can be concluded that the anisotropy in optical property of the unintentionally doped and Sn-doped β-Ga2O3 crystals with (100), (010) and (001) orientations apparently exist.

The effect of seed layer cycles on the structural, optical, and morphological properties of ZnO nanorods.

In this study, ZnO seed layers with different cycles were formed on glass substrates by the sol-gel technique, and ZnO nanorods were grown on them by the hydrothermal method. Morphology and the structural characterization of the seed films and the ZnO nanorods are carried out by field emission scanning electron microscopy (FE-SEM) and x-ray diffraction techniques. In addition, to investigate the effect of seed layer deposition cycles on the optical properties of the ZnO nanorod arrays, UV/visible spectrophotometer and photoluminescence (PL) measurements were performed. The changes in structural and optical parameters such as dislocation density, strain, crystallite size, and optical band gap values on each seed layer deposition cycle were examined. The highest optical band gap and crystallite size were obtained for ZnO nanorods with 4 cycles seed layer as 3.22 eV and 63.6 nm, respectively. Also, in the PL spectrum, the largest ratio of UV-emission region to weak-visible emission region was obtained in ZnO nanorods having 4 cycles. In addition, the glucose detection properties of ZnO nanorods having 4 cycles were investigated using the PL measurements and it was found that UV-emission peak intensity of ZnO nanorods decreased as the glucose concentration increased from 8 to 40 mM. The results show that the number of deposition cycles of the seed layer has a strong influence on the orientation, crystal quality, and optical band gap of the growing ZnO nanorods, as well as significantly affecting their morphological properties. RESEARCH HIGHLIGHTS: High quality ZnO nanorods were grown on glass substrates by hydrothermal method. The effect of ZnO seed layer cycles on the structural, optical, and morphological characteristics of ZnO nanorods grown on were examined. It was found that the number of cycles of the seed layer is a critical parameter for growing quality and well-aligned ZnO nanorods.

Physiological response of Bidens pilosa to cadmium stress monitored by Fourier Transform Infrared Spectroscopy

The cadmium (Cd) pollution of soil causes serious environmental problems. The present paper deals with the physiological response of the changes in chemical components in the root, stem and leaf of Bidens pilosa seedlings stressed by excess cadmium ions (Cd2+) using Fourier transform infrared spectroscopy technique (FTIR). Cadmium accumulation in plant and distribution in subcellular by atomic absorption spectroscopy were tested under different concentrations cadmium stress. Results indicated that at a Cd concentration of 7 mg·L-1, B. pilosa maintained normal growth without visible Cd toxicity symptoms, though biomass was reduced compared to controls. FTIR analysis revealed that the overall peak shapes of roots, stems, and leaves remained largely unchanged before and after heavy metal treatment, suggesting that the structural integrity of plant organs was not compromised. However, shifts in specific functional group absorption peaks, including hydroxy (3387-3417 cm-1), carboxyl (1411-1419 cm-1), and amide groups (1635 cm-1), were observed, indicating their involvement in the heavy metal absorption process. The characteristic peak intensity of leaves was higher at high Cd concentration than at medium-low Cd concentration, while peaks in stems and roots remained consistent with or exceeded those of the control group. Cd predominantly accumulated in cell walls (46.21%-55.32%) and was minimally distributed in chloroplasts and mitochondria (4.11%-8.43%). These findings suggest that B. pilosa exhibits strong tolerance to Cd-contaminated soil and has significant potential for phytoremediation. The FTIR method offers strong evidence supporting the development of phytoremediation technology.

Photocatalytic Activity of Self-Heterojunctioned Intermediate Phases in HCl Protonated and HNO3 Deconjugated g-C3N4 Nanostructures

This research involved the different acid-treatment conditions of graphitic carbon nitride and its modified nanostructures through thermal polycondensation of urea at various temperatures. X-ray diffraction patterns revealed that processing at a lower temperature of 500 °C resulted in the presence of melem and its derivatives, indicating incomplete transformation of urea to g-C3N4. However, treatment at higher temperatures and the HCl acid treatment led to the formation and expansion of g-C3N4 networks, as evidenced by notable differences in peak intensities observed in their Fourier-transform infrared and Raman spectra. Scanning electron microscopy analysis illustrated a transition from the granular morphology of melamine to the layered structure characteristic of g-C3N4. The nanoparticle morphology observed in the HNO3 acid treatment sample was attributed to the deconjugation of nanosheets through the highly oxidative acid medium. The most suitable photocatalytic activity for Methylene Blue (MB) reduction under UV and visible light illumination was observed in the samples prepared at 550 °C and HCl post-processed nanostructures. It is proposed that the enhanced photocatalytic activity observed in these samples may be attributed to the reduced recombination of photogenerated charge carriers facilitated by heterojunctions formed between different intermediate phases. These findings highlight the potential of modified g-C3N4 and its derivatives as promising photocatalytic materials for water purification applications.

Clove Oil mediated combustion method synthesised Dy stabilized Lanthanum Ferrite its application as Photocatalyst and Antibacterial agent

The work gives the details about the influence of (Dy) substitution in the Lanthanum ferrite (x = 1mol%, 3mol%, 5mol%, 7mol%) nanoparticles prepared by biofuel mediated combustion method. The studies of PXRD, SEM, UV-DRS, FTIR, TEM were carried out to understand the structural characteristics. The PXRD shows the high crystalline peak of lanthanum ferrites. From Rietveld refinement analysis confirms orthorhombic structure. The estimated crystal size is 31-43nm. The band gap from UV -DRS studies was in the 2.4-2.8eV range. The morphological studies SEM and TEM shows the agglomerated structure. The variation of peak intensity (PXRD), the band gap and the force constant calculated from FTIR confirms the presence of dopant in the host disturbed the crystal lattice. The Photocatalytic degradation for the Eosin Y dye were done under visible light. The 3mol% Dy doped Lanthanum ferrite shows enhanced results of about 85.09% in 60minutes. The crystallinity nature from XRD and band gap of about 2.4eV could more most supportive parameters for the nanomaterial for photodegradation. The antibacterial activities for E.coli and P. aeruginosa shown effective activity, which could make the sample to be more applicable towards biomedical field.