X-ray Diffraction Spectroscopy Research Articles

Characterization and source identification of PM2.5 during intense haze episodes in an urban environment of Lahore

In the backdrop of persistent haze occurrences affecting Southeast Asia and Pakistan's environmental landscape, this study delves into an in-depth analysis of atmospheric Particulate Matter (PM2.5) during intense haze episodes prevalent in Lahore throughout October, November, and December 2019. Employing advanced analytical techniques encompassing Scanning Electron Microscopy (SEM) coupled with Energy-Dispersive Spectroscopy (EDX), X-ray Diffraction (XRD), and Raman Spectroscopy (RS), this investigation meticulously scrutinized PM2.5 samples. The findings showcased substantial variability in PM2.5 concentrations, peaking notably in December within the range of 43.2–301 μgm−3, averaging 168 ± 88.3 μgm−3, whereas lower concentrations ranging from 30.9 to 268 μgm−3, with an average of 106 ± 66.1 μgm−3, were observed in October. These concentrations displayed correlations with meteorological parameters, demonstrating a direct association with relative humidity and varying relationships with temperature and wind speed. The maximal PM2.5 concentrations aligned with lower temperatures (19.1 °C), while higher temperatures (26.1 °C) coincided with the lowest concentrations, illustrating distinct relationships with relative humidity percentages and wind speeds. Advanced spectroscopic analyses (RS and XRD) confirmed the presence of various minerals and elements within PM2.5 samples, encompassing calcite, calcium aluminosilicate, hematite, barite, quartz, gypsum, organic carbon, and nineteen elements identified by EDX. Morphological evaluations unveiled diverse particle shapes, from round, pointed, and irregular to rod-like, and agglomerate structures. SEM investigations delineated distinctive groups of anthropogenic and geogenic particles, emphasizing emission sources such as automobile emissions, crop residue burning, biomass burning, construction activities, soil dust, and industrial emissions. This comprehensive study lays the groundwork for source apportionment, vital for understanding consequential impacts on climate, visibility, and human health, fostering future investigations in this domain.

A Facile Synthesis and Characterisation of CdS Nanoparticles at Low Temperature Using Aegle Marmelos Extract

Abstract CdS NPs have become found applications across diverse domains in the field of nanobiotechnology because of their established biomedical characteristics. The dimensions and the materials used for coating CdS NPs are pivotal factors influencing their effectiveness in biomedical applications like cancer treatment, bacterial inhibition, bioimaging and biosensors. In this study, we succesfully produced CdS NPs by ecofriendly approach using aegle marmelos extract. The synthesized CdS NPs was subjected to characterization using X-Ray Diffraction spectroscopy (XRD), Ultraviolet-Visible spectroscopy (UV-VIS), Fourier Transform Infrared spectroscopy (FT-IR), Dynamic Light Scattering (DLS), Scanning Electron Microscope (SEM) with EDX and Transmission Electron Microscope (TEM). The research delineates a straightforward, economically viable environmentally friendly approach to synthesizing CdS nanoparticles, which is suitable for extensive production. Additionally, it presents a tactic to regulate both the size and distribution of nanoparticles using eco-friendly biomolecules, enhancing their potential for various applications. Based on the results obtained from the characterization studies, it was proposed to the further process for biological applications.

Synergistic photocatalysis and superior supercapacitor performance of cerium-enriched monodispersed nanoarchitectures: Dual excellence

Researchers are being focused on designing sustainable and renewable energy storage systems, especially electronically tuned energy storage devices, due to increased electricity demand and fossil fuel depletion. Batteries and supercapacitors have substantially improved energy storage in recent years. In the course of developing nanomaterials with sustainable dual functionality, this study reviews the synthetic and dual applications of cerium-enriched copper oxide monodispersed nanomaterials, especially their synergic photocatalysis, which is much better than their superior supercapacitor storage. The sol-gel method was used for the preparation of nanoarchitectures, in which the crystalline structure and morphology were studied using X-Ray diffraction spectroscopy (XRD) and Scanning electron microscope (SEM) techniques. An important fact is that the nanoarchitectures with 10 % cerium showed their crystallite size, which was reported to be 17.30 nm, implying accuracy in the synthesis. The results of SEM indicate single-phase particles with slight agglomeration. The corresponding 10 % CeO2@CuO nanostructures were then comprehensively evaluated for both photocatalytic activities and energy storage purposes. In relation to photocatalysis, nanoarchitectures proved to be efficient for Rhodamine B (RhB) dye with 92 % degradation after 200 min of the reaction time. Moreover, the synthesized nanoparticles demonstrated excellent supercapacitor performance. The tailor-synthesized nanoarchitectures had a specific capacitance of 875 F/g and energy density achieved 78 Wh/g, which clearly shows the prospect for such materials used in high-energy storage devices. The10 % CeO2@CuO nanoarchitecture retained 88 % of capacitance for 2000 cycles, which made it possible to demonstrate the good robustness and durability of the materials for long-term utilization in energy storage. These findings contribute to the field of nanoscience and nanotechnology, offering a hopeful channel for the future development of advanced materials that have dual functionality.

Nanomechanical and microstructural properties of experimental bilayered zirconia ceramics after hydrothermal aging

Two experimental ceramic systems, 3Y-TZP/5Y-PSZ (3Y/5Y) and 4Y-PSZ/5Y-PSZ (4Y/5Y), underwent analysis before (3Y/5Yi or 4Y/5Yi) and after hydrothermal aging (3Y/5Ya or 4Y/5Ya) to simulate low-temperature degradation (LTD). The samples were sintered and characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Raman spectroscopy, alongside nanoindentation tests to measure elastic modulus (Em) and hardness (H). Assessments were conducted on the external surfaces and at individual layers on cross-sectioned samples at predetermined regions of interest (ROIs). Degraded superficial regions were observed in the cross-sectional SEM images of the 3Y and 4Y zirconia layers after aging. XRD indicated a tetragonal→monoclinic phase transformation in the aged groups for both 3Y (66 % m-ZrO2) and 4Y (29 % m-ZrO2). Raman spectroscopy revealed monoclinic phase amounts of 86 % for 3Y and 62 % for 4Y in the degradation regions observed in the SEM micrographs. Monoclinic phase peaks were virtually no longer detected in either material beyond a depth of 15 μm. Hydrothermal aging significantly diminished the H and Em values for the 3Y and 4Y zirconia surfaces. For the analysis of different zirconia surfaces within the same subgroup, all pairwise comparisons showed statistically significant differences, except for the values of H of 3Y/5Yi and Em for 4Y/5Yi. Regarding the nanoindentation results of cross-sectioned samples, the aging protocol did not affect the H and Em values of the equivalent ROIs (layers), regardless of the bilayered system. However, significant differences in H values were observed among the ROIs (layers) within the same bilayered system. Despite surface changes, nanomechanical properties remained preserved below the surface and at the interfaces of bilayered materials after aging. Nanoscale H values varied among some layers and interfaces, whereas the Em values exhibited differences across certain surfaces.

Novel 3D printing filaments: PLA and zinc carbonate basic composites for laser-assisted thermal decomposition

Additive manufacturing (AM), also known as 3D printing, has revolutionized the production of complex geometric structures across various industries. This study presents an innovative approach by integrating zinc carbonate basic (ZCB) precursor with polylactic acid (PLA) to develop composite filaments for fused deposition modeling (FDM) 3D printers. The resulting filaments undergo surface transformation into zinc oxide (ZnO) through high-power laser irradiation. Thermal analysis (TGA-DSC) and Fourier-transform infrared spectroscopy (FTIR) were used to confirm the decomposition of ZCB ([ZnCO₃]₂·[Zn(OH)₂]₃) into ZnO during the thermal decomposition stages. The study successfully extruded a composite filament containing 10% of ZCB, which worked adequately in 3D printing. The printed parts were analyzed through tensile tests (based on ASTM D638-5 standard), showing a notable difference in mechanical behavior between the commercial filament PLA and the composite filament (PLAC10). Laser irradiation of these samples facilitated a targeted conversion to ZnO, verified through scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The integration of zinc oxide within the printed structures enhances structural stability and provides surfaces enriched with ZnO, a metal oxide with widely reported applications. Furthermore, an irradiated 3D-printed sample demonstrated chemo-resistive properties upon carbon monoxide (CO) exposure, underlining its potential as a gas sensor and confirming its semiconductor nature. This approach provides a cost-effective and efficient way to develop innovative devices with integrated functional materials.

Effect of carbonization methods on graphitization of soft and hard carbons

Pressurized carbonization is known to improve carbon content and create textural changes in resultant carbon compared to conventional (atmospheric) carbonization. However, further studies investigating the impact of these carbonization methods on the graphitic quality of the carbon precursors have not been explored extensively. This study investigates the influence of carbonization methods on the graphitization behavior of soft and hard carbons using a three-model system: phenolic resole (hard carbon), polyvinyl chloride (PVC) (soft carbon), and a 50:50 blend of resole and PVC. Carbonization was conducted under autogenic pressure (AGP) and atmospheric pressure (APP) at 500 °C for 5 h, followed by high-temperature treatment at varying temperatures. Various techniques, including X-ray diffraction and Raman spectroscopy showed hard carbon precursors exhibited improved properties under AGP carbonization such as larger crystallite size, sharp crystalline peaks, lower ID/IG ratio, and narrow G-full width half-maximum, an indication of improved crystallinity by lowering amorphous phase at high temperature. For soft carbon precursors, the method of carbonization did not impact the graphitization level. The most significant finding was the enhanced crystalline nature observed in hard carbon under AGP conditions, without the need for any catalyst. It shows the influence of pressure on improving the crystallinity of hard carbon precursors.

Preparation of Pt and bamboo charcoal co-modified TiO2 for formaldehyde sensing at room temperature.

Anatase TiO2 has evolved into one of the most attractive materials for gas sensing owing to its strong oxidation activity and excellent sensing properties. In this study, we prepared Pt and bamboo charcoal co-modified nano-TiO2 using a one-pot hydrothermal process and applied it to detect formaldehyde. The successful incorporation of the precious metal Pt and bamboo charcoal onto TiO2 was confirmed by scanning electron microscope, transmission electron microscopy, energy dispersive spectrometer, X-ray diffraction and X-ray photoelectron spectroscopy. Detailed analysis revealed a homogeneous distribution of Pt nanoparticles and bamboo charcoal on the TiO2 surface, which significantly improved the surface area and facilitated gas adsorption. These modifiers significantly enhanced the response of TiO2 to formaldehyde, for instance, the response signal increased fourfold, while the response time decreased from 91 to 68 s. The sample with 0.5@Pt and 0.5@C bamboo charcoal performed the best, showcasing the synergistic effect of metal nanoparticles and carbonaceous materials on gas-sensing properties. Our work highlighted the potential of using biomass-derived carbon to enhance the detection of formaldehyde and demonstrated the importance of material characteristics in designing effective gas sensors.

Highly stable mesoporous Ni-phyllosilicate particle under high temperature hydrothermal and base conditions towards industrial catalytic applications

Two mesoporous nickel phyllosilicate (Ni-PS) samples with Ni/Si ratios of 0.3 and 1 were used to compare high-temperature hydrothermal stability. The Ni-PS structures have well-developed porosity and pore size distributions mainly ranging from 2 to 20 nm. To assess their hydrothermal resistance as a reusable heterogeneous catalyst in high-temperature reactions, the samples were exposed to 800 °C for 7 days using steam-supplied muffle furnaces. Three types of mesoporous silica samples (i.e. MCM-41, SBA-15, and mesoporous benzene-silica) and two zeolites (i.e. ZSM-5 and zeolite-Y) were compared under the same conditions. The hydrothermal resistance was primarily confirmed based on changes in pore size distribution and surface area through nitrogen-sorption isotherm analysis. The crystal structure and the binding energy of each sample were investigated by X-ray diffraction and X-ray photoelectron spectroscopy measurements. The Ni-PS structures displayed excellent stability (i.e. BET surface area retained over 77 % and 65 % after 1-d and 7-d treatment, respectively.) compared with other mesoporous samples, and even higher stability than zeolite Y. In addition, structural stability at pH = 10 is much higher than that of ZSM-5. This suggests that it could be used for various catalytic chemical reactions including hydrogenation and cracking processes because NiO and Ni nanoparticles are uniformly distributed on the surface, maintaining their particle shape even after a reduction process.

Synthesis of acetonitrile from NH3/syngas mixtures on molybdenum nitride: Insights into the reaction mechanism

Owing to their metallic-like surface electronic properties and their capacity to act as reservoirs and solid transfer agents for active nitrogen, transition metal nitrides are interesting as solid catalysts for C-C and C-N coupling reactions for the bottom-up production of higher (C2+) nitrogenated chemicals from unconventional carbon resources. The catalytically active state and reaction mechanism for the direct synthesis of acetonitrile from syngas/ammonia mixtures are studied on an unsupported Mo catalyst from complementary experimental and computational approaches. Temperature resolved X-ray diffraction and X-ray photoemission spectroscopy verify that an oxidic MoO3 catalyst precursor undergoes in situ (near-surface) nitridation, upon exposure to reaction conditions at 723 K, rendering Mo2N the actual working catalyst. Density Functional Theory mechanistic investigations on a γ-Mo2N(100) model surface point to a hydrogen-assisted CO dissociation on the nitride surface. Moreover, surface oxygen, evolved from CO dissociation, is predicted to play a central role as hydrogen acceptor, to enable the dehydrogenative NH3 dissociation. Direct condensation of CH and N adspecies proceeds with a low energy barrier of 33 kJ mol−1, which makes C-N coupling preferred over full hydrogenation of CHx species, in agreement with the experimental modest selectivity to methane (ca. 10 %). Both experimental and computational results indicate that HCN is a major intermediate product along the reaction pathway to acetonitrile. No energetically feasible associative reaction pathways could be identified for C-C coupling from HCN. The dissociation of the latter intermediate product is predicted to precede the reaction of CN adspecies to CHx. Similarly to NH3 dissociation, dehydrogenative HCN activation on the Mo2N surface is predicted to be facilitated through hydrogen abstraction by surface oxygen species, yet subjected to a comparatively higher energy barrier (>120 kJ mol−1), therefore likely to control the overall kinetics. These findings suggest that the enhancement of HCN dissociation is a central design objective towards Mo2N-based catalysts with advanced performance.

Simulation and experimental study of InN nanoparticles synthesized by ion implantation technology.

In order to synthesize InN nanoparticles (NPs), we have simulated the co-implantation of indium (In) and nitrogen (N) ions on silicon (Si) and silicon oxide (SiO2) substrates with flat-top profiles. The choice of flat-top profile is to increase the possibility of creating homogeneous zone with well-distributed InN nanoparticles over the entire implanted layer. In this view and to obtain these flat-top profiles, we must do several implantations with different doses and energies optimized by our program. The simulation results performed on a silicon substrate < 111 > , give an average dose of 4.30 × 1016 at./cm2 and the implantation energies were In (10, 46, and 180 keV) and N (13 and 35 keV). But for the SiO2 substrate, the total mean dose is about 5.20 × 1016at./cm2 for each Indium and nitrogen ion. The respective implantation energies were In (23, 63, and 120 keV) and N (12 and 28 keV) in an average depth of approximately 100 nm. The implantations were performed in a 206-nm-thick (SiO2) layer thermally grown on < 100 > silicon. Subsequent thermal treatments (500-900°C) lead to the formation of nanoparticles precipitates of the compound semiconductor (InN) and to cure the oxide defects during different periods of time. To verify that indium (In) and nitrogen (N) ions were located according to flat curves, we used RBS technical and study the formation (InN) stoichiometric compound several techniques, were used such as X-ray diffraction, UV-visible-IR, and photoluminescence (PL) spectroscopy. The simulated profiles have been chosen with the aim that the implanted element not exceeding 5-10 at %maximum concentration for each species. We have elaborated our program to simulate these profiles using data as input values from SRIM2008 code taking into account the sputtering factor. The optimal conditions are determined, which are the expected depth impact energies (Rp), the standard deviation (ΔRp) and the sputtering corrosion factor (Fs). Through these results, a simulation program has been created which allows building flat "distribution" curves for ion implantation for each element (In and N), so that each curve is obtained from three Gaussian functions whose values are carefully chosen in relation to the optimal experimental conditions.

Strength, plasticity, and spin transition of Fe-N compounds in planetary cores

Elastic and plastic properties of Fe-light element alloys and compounds are needed to determine the compositions and dynamics of planetary cores. Elastic strength and plastic deformation mechanisms and their relationship to electronic properties of ε-Fe7N3 and γ'-Fe4N mixture were investigated by x-ray diffraction and x-ray emission spectroscopy in the diamond anvil cell from 1 bar up to 60 GPa. X-ray diffraction shows that ε-Fe7N3 reaches a pressure of 15–20 GPa before undergoing bulk plasticity at a differential stress of 4.4–10.4 GPa. ε-Fe7N3 is stronger than γ'-Fe4N and hcp-Fe which achieve a flow stress of 1.5–3.6 GPa at 10–15 GPa and 2–3 GPa at ∼20 GPa, respectively. X-ray emission spectroscopy shows that a decrease in electronic spin moment begins before and completes after plastic flow onset for each nitride, suggesting that pressure-driven changes in electronic arrangement do not trigger a plastic response although they may modify the strength and plastic behavior of Fe-N compounds. Plastic deformation in ε-Fe7N3 and hcp-Fe results in a preferred orientation of (0001) normal to maximum compression, while γ'-Fe4N develops a maximum in the (110). These observations may be combined with measurements of elasticity to model seismic properties of cores of small planetary bodies such as Mars, Mercury, and the Moon.

Synthesis of iron loaded jackfruit peel biochar through microwave heating as a stable and active heterogenous Fenton catalyst for dye degradation

Iron-loaded biochar derived from jackfruit peels (Fe-JP) was synthesised by pyrolysis in a microwave furnace and iron was loaded onto the peels prior to pyrolysis, facilitated by sonication. The primary objective of the investigation was to examine the degradation process of methylene blue (MB) dye and Acid Red 1 (AR1) dye by the using Fe-JP biochar as a heterogeneous Fenton catalyst. The investigation encompassed an examination of the impact of different operating parameters, such as pH, catalyst dosage, and H2O2 concentration. The synthesised Fenton catalyst underwent characterization using Field Emission scanning electron microscopy (FESEM), Energy Dispersive X-ray (EDX), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) techniques, Fourier transform infrared (FTIR) spectra analysis, Raman spectroscopy, Brunauer-Emmet-Teller (BET) analysis. At a pH of 3, using an initial MB dye concentration of 20 mg/L and initial AR1 dye concentration of 50 mg/L, an 8 mM H2O2 concentration, and a catalyst dose of 2 g/L, the maximum dye removal efficiency reached 96.5 % and 98 % respectively, while the total organic carbon (TOC) removal efficiency reached 68.5 % and 75 % respectively. The observed reaction time under the given experimental conditions was 120 min. The thermal stability of the biochar catalyst was found to be excellent based on the Thermogravimetric analysis (TGA) and Differential Scanning Calorimeter (DSC) studies. The catalysts that were developed demonstrated remarkable durability and negligible leaching of iron, hence enabling their repeated usage in subsequent cycles. The findings of the investigation suggest that the primary mechanism responsible for the degradation of the dye was the surface-based heterogeneous Fenton activity. Additionally, the effect of adsorption on the elimination of colour under varying pH conditions was examined, which had a very low influence in dye degradation (<30 %). The conducted scavenging investigations in the research have indicated the major involvement of hydroxyl radicals (OH) in the degradation process, followed by surface-bound hydroxyl radicals (OHsurface), superoxide radicals (O2−) and ultimately by singlet oxygen radicals (1O2). The study's economic analysis demonstrated that using microwave mode of heating for catalyst synthesis is both green and cost-effective. This observation suggests the possibility of practical implications in the domain of dye degradation.

Polymer based Carbon Aerogels for Methylene blue and indigo carmine dyes removal

Abstract Herein we prepared the polymer-based carbon aerogel (CAs) from resorcinol and thiophene-2-carboxyaldehyde. The prepared CAs was characterized using the powder X-Ray diffraction (PXRD) spectroscopy and Fourier Transform Infra-Red (FT-IR) spectroscopy. The above characterization techniques confirmed the formation of CA’s. As we know the CA’s possess good surface area. Hence, we used the CAs for the purpose of removing the organic dyes from the water. In the application purpose we removed Methylene Blue (MB) dye and Indigo Carmine (IC) dye from the water. Initial results confirmed that CAs actively removes 100% dyes in 3.5 and 4 h for MB and IC dyes respectively.

Unveiling the potential of high-temperature chemical vapour deposition growth of boron carbide: Investigating physicochemical, mechanical and electrical properties

Chemical vapour deposition (CVD) is a widely utilized technique in industry, particularly venerated for its precision and reliability in producing hard ceramic materials. In this study, a gas mixture comprising BCl3-CH4-H2 was employed to deposit boron carbide (B4C) onto a graphite substrate to investigate the substrate temperature-dependent physicochemical, mechanical, and electrical properties of the B4C. The phase compositional and vibrational characteristics of the B4C were thoroughly assessed using X-ray diffraction (XRD) and micro-Raman spectroscopy techniques, respectively. The field-emission scanning electron microscopy (FE-SEM) images reveal a morphological transition from murataite to triangular flakes, accompanied by noticeable grain expansion with growing substrate temperature. Additionally, energy-dispersive X-ray spectroscopy (EDS) indicates a consistent trend of increasing boron concentration and decreasing carbon concentration with rising substrate temperature. Consequently, variations in substrate temperature notably tune the deposition rate, mechanical and electrical properties of B4C. The deposition rate at 1200 °C was 1476 μm/h. Whereas, the material hardness and electrical conductivity of the CVD deposited B4C were found to be 3166 HV and 18.358 Ω-1cm-1, respectively. The present study highlights the importance of high-temperature CVD growth of the B4C for industrial applications.

Impact of electrolyte solutions on carbon dioxide fixation in single chamber Al–CO2 battery

Governments and research & development (R&D) organizations are actively initiating various programs and research strategies for CO2 capture, its utilization, and integration with long duration energy storage from renewable sources worldwide. In line with the carbon capture goals, here we report a novel electrochemical Al-CO2 battery cell, that can simultaneously capture CO2 and convert it into value-added products, in addition to long-duration energy generation and storage. This innovative approach employs cost-effective Al metal as an anode and an in-house synthesized Ni–Fe based bimetallic double hydroxide catalyst as the cathode, with meticulously optimized compositions and morphologies. We explore the impact of different aqueous electrolyte solutions compositions on the cell performance, demonstrating up to 10 h of stable long duration energy storage with a stable voltage profile. The cell exhibits low polarization even at high current densities of up to 12 mA cm−2 and maintains stable cycling over 500 h. Through Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray Diffraction and X-ray photoelectron spectroscopy (XPS) analysis, we determined that the discharge product is either NaAlCO3(OH)2 or KAlCO3(OH)2, distinct from the Al2(CO3)3 typically reported in conventional Al–CO2 batteries.

An EPR study of point defects in zinc oxide thin films

We studied ZnO thin films deposited on glass slides by thermal evaporation in vacuum followed by heat treatment in open air or Ar flow. The samples were characterized using x-ray diffraction, Raman scattering, photoluminescence (PL), and electron paramagnetic resonance (EPR) spectroscopy. We observed a broad PL band in the visible region at spectral positions of 504 and 560 nm and a low-intensity band in the UV region at 390 nm. The EPR spectra display a clear first derivative structure at g=1.96 at temperatures below 200 K. The PL spectrum shows red-shifted valence to conduction band emission due to electron hole recombination through shallow surface states. We found an activation energy of E a = 4.2 meV using the Arrhenius plot and estimated concentrations of paramagnetic defects and spin–spin relaxation time constants of 1016 m−3 and 10–14 s, respectively.

Optical and structural properties of Europium-doped hydroxyapatite

Europium-doped hydroxyapatite (0 ≤ x ≤ 0.3) was synthesized using the hydrothermal method and thermally treated from 200 to 800 °C. Our results revealed the formation of Europium phosphate (EuPO4) as a second phase above 0.05%, leading to improved emission properties. The samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Energy-dispersive X-ray spectroscopy (EDX), Fourier-transform infrared spectroscopy (FTIR), X-ray Diffraction (XRD), and Raman spectroscopy. The optical properties were measured with diffuse reflectance and luminescence spectroscopy, showing that the combination of Europium-doped hydroxyapatite and EuPO4 enhanced the emission properties. The highest emission intensity was observed at 800 °C and HA: 0.2Eu. These results have potential applications for biomedical imaging and sensing.

MOLECULAR BEAM EPITAXY GROWTH OF HIGH-QUALITY InN NANORODS ON Si (111) SUBSTRATE

The growth of high-quality InN nanorods (NRs) on Si (111) by plasma-assisted molecular beam epitaxy (PAMBE) is reported. X-ray diffraction and Raman spectroscopy investigations indicates that the NRs are wurtzite, c-axis oriented and single crystalline. Low temperature photoluminescence emissions with peak energy of ~ 0.75eV was observed indicating the high quality of the nanostructures. This study unravels a novel strategy for the successful growth of high-quality InN NRs on Silicon which is highly promising for applications in next generation nanodevices.

Enhanced photocatalytic activity of Sn-doped TiO2 nanoparticles: Microstructural-photoelectrochemical synergy

The material prepared by synthesizing titanium dioxide (TiO2) powder via sol-gel refluxing using titanium tetraisopropoxide (TTIP) as a precursor was doped with varying concentrations of tin (Sn) at 0.25 %, 0.50 %, and 0.75 %. Characterization techniques including scanning electron microscopy (SEM) were employed to analyse particle sizes, revealing dimensions ranging between 12 and 20 nm. Subsequent X-ray diffraction (XRD) and Raman spectroscopy confirmed the formation of phase-pure nanocrystalline anatase, corroborated by Fourier transform infrared spectroscopy (FTIR) that identified Ti–O–Ti bonding in anatase titania. Surface area analysis using Brunauer-Emmett-Teller (BET) analysis showed a gradual increase in surface area with increasing Sn doping levels, from 100.5 m2/g for pure TiO2 to 116.9 m2/g for 0.75 % Sn-doped TiO2. UV–Vis spectroscopy demonstrated distinct absorption peaks and corresponding band gaps, with 0.75 % Sn-doped TiO2 exhibiting the broadest absorption in the range of 400 –800 nm. Photocatalytic decomposition of methylene blue was then evaluated, revealing enhanced performance with Sn-doped titania, particularly with 0.75 % Sn doping, suggesting its superiority in organic pollutant degradation. This observation underscores the potential of Sn-doped TiO2 as an effective photocatalyst.

Nanostructural modulation of Schottky barrier in Au/α-MoO3 heterojunction via Au nanoparticle size control

Metal-semiconductor systems, particularly those incorporating metallic nanoparticles, have garnered significant attention due to their charge transport properties and potential in solid-state applications. Thus, this study focuses on the synthesis of MoO3 microstructures through thermal oxidation, followed by the synthesis of gold nanoparticles (AuNPs) via post-thermal treatment of an Au-coated film. We systematically investigated the effect of annealing temperatures ranging from 400 °C to 700 °C on the size of the AuNPs. Utilizing techniques such as X-ray diffraction, electron microscopy, reflectance, and X-ray photoelectron spectroscopy (XPS), the physical and chemical properties of the AuNPs/MoO3 heterojunction were characterized. Findings reveal a direct correlation between the size of AuNPs and the Schottky barrier height (SBH) in the Au/MoO3 system. By considering factors such as defects, impurities, lattice mismatch, and Au diffusion—referred to as the alpha adjustment—we established that smaller AuNPs foster lower SBH values in the heterostructures. The adjusted SBH for AuNPs with diameters of 81.90 nm ± 7.21 nm, 99.44 nm ± 9.47 nm, 134.96 nm ± 15.40 nm, and 459.99 nm ± 42.63 nm resulted in a value of 0.2 eV, 0.37 eV, 1.26 eV, and 3.61 eV, respectively.