Powder Diffraction Research Articles

Synthesis and Characterization of Iron–Sillenite for Application as an XRD/MRI Dual-Contrast Agent

In the present work, iron–sillenite (Bi25FeO40) was synthesized using a simple solid-state reaction method and characterized. The effects of the synthesis conditions on the phase purity of Bi2O3/Fe3O4, morphological features, and possible application as an XRD/MRI dual-contrast agent were investigated. For the synthesis, the stoichiometric amounts of Bi2O3 and Fe3O4 were mixed and subsequently milled in a planetary ball mill for 10 min with a speed of 300 rpm. The milled mixture was calcined at various temperatures (550 °C, 700 °C, 750 °C, 800 °C, and 850 °C) for 1 h in air at a heating rate of 5 °C/min. For phase identification, powder X-ray diffraction (XRD) analysis was performed and infrared (FTIR) spectra were recorded. The surface morphology of synthesized samples was studied by field-emission scanning electron microscopy (FE-SEM). For the radiopacity measurements, iron–sillenite specimens were synthesized at different temperatures and mixed with different amounts of BaSO4 and Laponite solution. It was demonstrated that iron–sillenite Bi25FeO40 possessed sufficient radiopacity and could be a potential candidate to meet the requirements of its application as an XRD/MRI dual-contrast agent.

Triple effective water treatment agent: P(AA/AMPS) capped sulfur quantum dots boast remarkable antiscale, antibacterial, and real-time tracking capabilities

Recent research has explored nanomaterials as sustainable scale inhibitors for water treatment. This research specifically delved into the development of environmentally benign antimicrobial sulfur quantum dot scale inhibitors (P(AA/AMPS)-SQDs) by capping P(AA/AMPS) with varying molecular weights. The synthesized P(AA/AMPS)-SQDs underwent thorough characterization employing high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and zeta potential analysis. The inhibitory efficacy of P(AA/AMPS)-SQDs on calcium carbonate (CaCO3) and calcium sulfate (CaSO4) scale formation was conducted under diverse conditions, including scale inhibitor concentration, reaction time, temperature, and pH using scanning electron microscopy and X-ray powder diffraction techniques. Remarkably, the water agent P(AA/AMPS)-SQDs showcased exceptional fluorescence, water solubility, and resilience to high temperatures. At specified concentrations, P(AA/AMPS)-SQDs demonstrated remarkable inhibition efficiencies, with over 98 % inhibition against the CaCO3 scale at 20 mg/L and over 97 % inhibition against the CaSO4 scale at 0.5 mg/L, significantly outperforming traditional scale inhibitors. Furthermore, P(AA/AMPS)-SQDs exhibited almost 100 % inhibition efficiency against Bacillus subtilis at a dosage of 150 mg/L. Furthermore, molecular dynamics simulation and quantum chemical calculations were employed to clarify the scale inhibition mechanisms of P(AA/AMPS)-SQDs. This multifunctional water treatment agent, integrating scale inhibition, antimicrobial properties, and online monitoring capabilities, lays a solid foundation for potential applications in engineering domains.

The thermal expansion of Ti-substituted CaAl12O19

CaAl12O19, which can incorporate Ti as both Ti3+ and Ti4+ (charge coupled substitution with Mg2+), is one of the first minerals to condense from a gas of solar composition and is used as a ceramic. It is variously known as hibonite, calcium hexaluminate (CaO.6Al2O3), and CA6. The lattice parameters and unit cell volumes of Ti-substituted hibonite (P63/mmc) with the formulae CaAl11.8Ti3+0.2O19 and CaAl9.8Ti3+0.54Mg0.83Ti4+0.83O19 were determined as a function of temperature from ~ 10 to 275 K by neutron powder diffraction. The thermal expansion is highly anisotropic with the expansion in c a factor of ~ 5 greater than that in a. The change in a is approximately equal for the two compounds whereas the change in c is almost 50% larger for CaAl11.8Ti3+0.2O19. CaAl11.8Ti3+0.2O19 also exhibits negative thermal expansion between 10 and 70 K. The change in unit cell volume with temperature of both compositions is well described by a two term Einstein expression. The large change in c is consistent with substitution of Ti onto the M2 and M4 sites of the R-block structural unit.

Observation of Thermally Induced Piezomagnetic Switching in Cu2OSeO3 Polymorph Synthesized under High‐Pressure

AbstractA polymorph of Cu2OSeO3 with the distorted kagome lattice is successfully obtained using the high‐pressure synthesis technique (Cu2OSeO3‐HP). The structural analysis using X‐ray and neutron powder diffraction suggests that the tetrahedral Cu2+ clusters [similar to those in Cu2OSeO3 ambient‐pressure phase (Cu2OSeO3‐AP)] exist in Cu2OSeO3‐HP but with three symmetry inequivalent sites. No structural change is observed between 1.5 K and the room temperature. The complex magnetic H‐T phase diagram is established based on the temperature‐ and field‐dependent magnetization data, indicating two distinct antiferromagnetic phases at low and intermediate temperatures, in addition to the higher‐temperature spin‐glass‐like phase. The low temperature phase is identified by neutron powder diffraction refinements as a canted noncollinear antiferromagnetic order with a weak ferromagnetic component along the b‐axis. Size of the refined ordered moment is ≈1.00(4) µB in Cu2OSeO3‐HP, indicating a large enhancement compared to that of Cu2OSeO3‐AP (≈0.61 µB). By applying a uniaxial stress, finite enhancement of weak ferromagnetic component in the noncollinear antiferromagnetic phase in Cu2OSeO3‐HP is observed, which is the clear evidence of the piezomagnetic effect. Interestingly, the sign of the induced magnetization changes on heating from the low‐temperature to the intermediate‐temperature phases, indicating a novel piezomagnetic switching effect in this compound.

Wet-chemical synthesis of ‘snow stone’ chiolite Na5Al3F14:Ce3+,Gd3+ UVB emitting phosphors

Synthesis and characterization of Ultraviolet B (UVB) emitting phosphors based on hitherto unexplored Na5Al3F14 host activated with Ce3+ and/or Gd3+ are presented. These phosphors were easily synthesized by wet chemical process while the conventional solid-state procedures are known to fail in producing phase pure composition. Powder XRD confirms tetragonal structure with P 4/m n c space group. Both Ce3+ and Gd3+ yielded intense UVB emission. Further, Gd3+ emission was enhanced by Ce3+→Gd3+ energy transfer. Ease of synthesis, efficient emission in a narrow spectral region, broad excitation bands render Na5Al3F14 :Ce3+ , Gd3+ phosphors as promising materials for designing UVB light sources.

Effect of reagent addition and aging by microwave on the structure of layered double hydroxides

A series of MgAl-layered double hydroxides (MgAl-LDHs) were prepared by variable pH precipitation. The addition of the metal (M) containing solution to the base (B=NaOH) solution, either rapidly (r) or dropwise (d), led to the obtention of the MBr and MBd samples, respectively. In the other hand, by inverting the order of the added solution (pH increase methodology), BMr and BMd were obtained. The BMd sample was microwave aged at 80 °C, 150 °C and 220 °C for 45 min. The results of powder X-ray diffraction showed that rapid precipitation produces more crystalline LDHs than those obtained by dripping. The crystallinity of BMd was improved by microwave aging. All precipitation conditions produced nanoparticles with an average size of around 27.5 nm, which increased almost 5-fold with the microwave treatment. Precipitation by increasing pH gave LDHs with low pore volume, which increased during the heat treatment. Nevertheless, the specific surface area decreased significantly with aging temperature due to the increase in particle size.

Synergistically enhanced electromagnetic absorption in barium ferrite/hollow carbon spheres/epoxy composites

The ongoing technological advancements have emphasized the importance of absorbent coatings, which are essential for effectively absorbing electromagnetic waves across various industries, including electronics, healthcare, and security systems. In this research, barium ferrite particles and hollow spherical carbon particles have been synthesized to investigate the synergistic effect of different compounds in absorbing electromagnetic waves in the epoxy coating. The barium ferrite particles were synthesized in two distinctive rod and spherical morphologies at 600 and 900 ºC, employing the sol-gel technique. Also, hollow spherical carbon particles were synthesized. Synthesized particles were analyzed structurally and chemically with an X-ray Powder Diffraction, Fourier infrared spectrometer, vibrating‐sample magnetometer, field emission Scanning Electron, and Raman spectroscopy.The absorption characteristics of a coating that contains rod and spherical morphologies of barium ferrite and hollow spherical carbon particles can be adjusted by controlling the amounts of synthetic compounds in the 8-12 GHz range. The results indicate that combining rod-shaped barium ferrite particles (900 ºC) and hollow spherical carbon particles in a thin epoxy coating improves impedance matching and wave attenuation. Notably, when the epoxy coating is 1.5-2 mm thick and contains 20% rod-shaped barium ferrite particles (900 ºC) and 1% hollow spherical carbon particles, reflection loss values of <-20 dB are observed at frequencies of 10-12 GHz.

Synthesis of ZnO nanoparticles from the medicinal plant Salvia fruticosa Mill.: Green approach for potential biomedical application against Zn deficiency in humans

We hypothesized that we could prepare ZnO nanoparticles (ZnO NPs) as a biomedical application treatment of zinc deficiency in human populations. In this study, we report a formulation prepared using a low-cost method for the green synthesis of ZnO NPs by utilizing the medicinal species Salvia fruticosa as natural raw material and Zn(NO3)2∙6H2O as a Zn source. The final product was identified and characterized by elemental analysis using X-ray energy-scattering spectroscopy (EDS), ultraviolet–visible spectroscopy (UV-VIS Spectroscopy), X-ray powder diffraction (XRD), and morphometric analysis using scanning electron microscopy (SEM). Finally, crystallization was studied using transmission electron microscopy (TEM). Afterward, ZnO NPs thus produced were utilized for foliar spraying on S. fruticosa open cultures, and Zn fortification in the foliage. Then, their effects on the biosynthesis of essential oils, and Zn bioavailability to humans were studied through different modes of consumption.ZnO NPs produced using our method were spherical while some were hexagonal, with an average size of approximately 22 nm, based on XRD results. The green synthesis method devised in this study afforded ZnO NPs from Zn(NO3)2∙6H2O with a 95 % yield, and consequently yielded economic benefits with respect to the current market prices. Foliage Zn fortification and the desired features were successfully achieved using ZnO NPs, and the proper mode of consumption of this medicinal plant has been recommended in this study.In conclusion, the methodology described in this study enables eco-friendly green synthesis of ZnO NPs at a low cost using S. fruticosa and puts forward a contemporary and integrated biomedical use of ZnO NPs to treat disorders resulting from or related to Zn deficiency.

Exploring Synthesis and Annealing Influence on WS2 (Tungsten disulfide): Structural, Morphological, Optical, and Magnetic Profiles

The resurgence of interest in Transition Metal Dichalcogenides (TMDCs) stems from their remarkable magnetic and optical properties, reminiscent of graphene. TMDCs like MoS2, MoSe2, WS2, and WSe2 exhibit substantial bandgaps that shift from indirect to direct in single layers. This characteristic enables diverse applications such as solar cells, transistors, photodetectors, and electroluminescent devices, without the direct use of graphene. In this study, polycrystalline WS2 powder was synthesized via the solid-state reaction method. We systematically investigated the structural, morphological, optical, and magnetic properties concerning the synthesized WS2 and its variants annealed at different temperatures. Through X-ray powder diffraction (XRD) analysis, we confirmed the hexagonal structure of the as-synthesized compound, with a space group of P 63/mmc. Interestingly, no structural transitions were observed in the annealed samples. Morphological examination revealed a plate-like structure across all samples. The determination of the optical bandgap was facilitated by UV-DRS absorption spectrum analysis. Our findings showcased the ferromagnetic behavior of the synthesized WS2, corroborated by magnetic measurements and electron paramagnetic resonance (EPR) analysis. These insights contribute to a deeper understanding of TMDCs and pave the way for their tailored utilization in advanced technological applications.

Reduction behaviour in neodymium doped ceria

Doped cerium oxides are technologically relevant materials and used as electrolytes in intermediate temperature solid oxide fuel cells. An important issue for these materials is the reduction of ceria at low oxygen partial pressures which leads to mixed ionic electronic conduction. In the present work, reduction behaviour in Ce0.8Nd0.2O1.9-δ is examined under inert and strongly reducing conditions. Even under inert conditions, ca. 3.5 % of the Ce is redox active up to around 800 °C, which appears to be correlated with non-linear behaviour in the Arrhenius plot of conductivity and thermal expansion of the lattice. Under more strongly reducing conditions, a secondary partial reduced phase is formed related to triclinic Ce11O20, which introduces significant electronic conductivity into the system. The dynamics of the re-oxidation process are examined using X-ray powder diffraction and electrochemical impedance spectroscopy.

Palladium fabricated on Fe3O4 as an organic-inorganic hybrid nanocatalyst for the Suzuki and Stille coupling reactions

The Fe3O4@L-Threonine-Pd complex, comprising palladium supported on modified Fe3O4 magnetic nanoparticles (MNPs), has been documented for its use in Stille and Suzuki coupling reactions. The catalyst's environmental friendliness was assessed through a range of techniques including vibrating sample magnetometry (VSM), Fourier-transform infrared spectroscopy (FTIR), inductively coupled plasma (ICP), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), energy dispersive X-ray photoelectron spectroscopy (XPS), and X-ray spectroscopy (EDS). Using an external magnet, it is easy to separate nanoparticles from the mixture. The nanocatalyst underwent Metal leaching and heterogeneity testing using the ICP-OES technique, demonstrating its ability to be recovered and reused multiple times without a significant loss of catalytic efficiency or palladium leaching.

Synthesis and annealing effect of structural, morphology, optical, and magnetic properties of tin telluride (SnTe)

This study explored the structural, vibrational, morphological, optical, and magnetic characteristics of both as-grown and annealed single crystals of tin telluride (SnTe), employing diverse analytical techniques. X-ray powder diffraction (XRD) analysis shows the cubic lattice structure of SnTe with consistent lattice parameters across different temperatures, along with the phase transition phenomenon. Fourier Transform Infrared Spectroscopy (FTIR) elucidates temperature-induced shifts in vibrational modes, indicating sensitivity to thermal stimuli. Scanning electron microscopy (SEM) reveals layer-by-layer growth patterns and temperature-dependent variations in crystal morphology. Energy-dispersive X-ray analysis (EDAX) confirms the synthesised crystals' high purity and slight tellurium-rich composition. Optical band gap measurements demonstrate an increase in band gap upon annealing, attributed to valence band convergence. Field-dependent magnetisation (M-H) curves exhibit ferromagnetic properties at ambient temperature, which escalate with increasing annealing temperature. Electron Paramagnetic Resonance (EPR) spectra reveal spin mobility and exchange coupling, with variations in the g-factor suggesting the presence of additional spin entropy. These observations offer significant insights into the complex properties of SnTe, which are crucial for its potential applications across various technological fields.

Larvicidal, bactericidal, antioxidant, hypoglycemic effects and anti-proliferative activity of phyto-synthesized Ag-ZnO nanocomposites using Eranthemum roseum (Vahl) R.Br. leaf extract against Aedes aegypti and Culex quinquefasciatus mosquito vectors

This research is conducted using zinc doped silver nanocomposite on Eranthemum roseum leaf extract. E. roseum has its own medicinal properties due its bioactive compounds. Silver and Zinc also has its own medicinal properties due to its microbial properties. Our work is aimed to combine nanoparticles with plant extract to explore the medicinal properties. The synthesized Ag-ZnO NCs is characterized using X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDAX) and Transmission Electron Microscopy (TEM) analysis. The XRD analysis confirms the crystal nature of the Ag-ZnO NCs. The average shape of the nanocomposite was obtained using SEM as spherical, EDAX analysis confirming the presence of Ag, Zn and Oxygen and TEM conforms the oval shape of nanoparticles Antibacterial activity shows highest level of activity against K. pneumoniae and B. subtilis. DPPH Activity of Ag-ZnO NCs highest inhibition of 52.56 % while the ABTS analysis of Ag-ZnO NCs shows 54.28 %. Hypoglycemic activity α-amylase and α- glucosidase assay of Ag-ZnO NCs obtained good activity with maximum level of inhibition 63 % and 60 %. Anti-proliferative assay shows good activity against cancer causing cells in HepG2 human liver cancer line with 67.11 %. Larvicidal potential of Ag-ZnO NCs recorded good mortality rate against Aedes aegypti and Culex quinquefasciatus. This study confirms the maximum activity of Ag-ZnO NCs and acts as Larvicidal, Anti-proliferative, Antioxidant, Hypoglycemic agents.

Optimization and Transfollicular Delivery of Finasteride Loaded PLGA Nanoparticles Laden Carbopol Gel for Treatment of Hair Growth Stimulation

Background: One of the frequent side effects of cancer treatment is chemotherapyinduced alopecia (CIA). The psychological discomfort of hair loss may cause patients to stop receiving chemotherapy, lowering the therapy's effectiveness. Finasteride (FNS), a JAK inhibitor, has shown tremendous promise in therapeutic uses for treating baldness. Still, systemic side effects constrained its broad use in alopecia from oral treatment and a low absorption rate at the target site— PLGA-loaded nanoparticles (NPs) for topical delivery of FNS—to overcome these issues. Methods: The nano-precipitation process was used to make FNS-NPs. The independent variables (stabiliser and polymer) were PLGA (X1), P407 (X2), and sonication time (X3). Based on the point prediction method obtainable by the Box Behnken design software, the best FNS-NPs composition was selected. Entrapment efficiency, particle size, zeta potential, and polydispersity index were used to characterize the nanoparticles. Using Carbopol as a polymer, the ideal FNS-NPs composition was further transformed into a gel formulation. The prepared topical gel formulation (FNS-NPs gel) included gel characterization, Dynamic Light Scattering (DLS), Scanning Electron Microscopy (SEM), Powder X-ray Diffraction (PXRD), Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR), invitro and in vivo studies. Results: Optimized FNS-NPs (F13) had particle sizes of 175.26±3.85 nm, 0.241±0.11 PDI, 71.04±1.35 % EE, and -33.27±0.39 surface charges. There is no interaction between the drug and the excipients, according to FTIR studies. The FNS were visible in the X-ray diffractogram enclosed in a polymer matrix. The developed FNS-NPs gel formulation shows ideal drug content, viscosity, pH, and spreadability. According to the release and permeation investigation findings, FNS released slowly (68.73±0.94%) but significantly permeated the membrane more than before. In a dose- and time-dependent manner, the produced nanoparticles considerably (p≤0.05) increased FNS delivery compared to the FNS solution. The FNS-NPs gel therapy significantly increases the quantity and size of hair follicles dose-dependently. The effectiveness of the 1% FNSNPs gel and the 2% minoxidil solution were comparable. After 72 hours, the FNS-NPs gel showed no signs of skin irritation. The outcomes, therefore, showed that the trans follicular delivery mechanism of the FNS-NPs gel might stimulate hair growth. Conclusion: These findings imply that the innovative formulation that has been developed has several beneficial properties that make it suitable for FNS dermal delivery in the treatment of alopecia areata

The Effect of Layering Order of ZIF-8@PCL/PLA Composites in Electrospinning and Electrosprraying Process on Antibacterial Wound Healing

The imidazolate-zeolite framework-8 (ZIF-8), as a zinc-based metal-organic framework, can act as an antibacterial agent by releasing Zn2+ ions. In this project, utilizing this previously studied fact, a set of wound dressings has been prepared using polycaprolactam and polylactic acid. Electrospinning and electro-spraying processes have been employed to create these samples. In total, five samples were obtained with variations in the layering sequence, and all samples were tested against two bacteria: Staphylococcus aureus and Escherichia coli. The results indicated that all samples were effective against the Gram-positive bacterium S. aureus, with the sample produced by simultaneous electro-spraying and electrospinning exhibiting the highest lethality rate. However, only the sample with the sequence of polycaprolactam layer, polylactic acid, and then ZIF-8 succeeded in eliminating 99% of E. coli. The produced products were characterized using powder X-ray diffraction, IR spectroscopy, and scanning electron microscopy. The antibacterial effect of these wound dressings was evaluated using direct counting of bacterial colonies.

A terbium coordination polymer based on mixed rigid and flexible organic ligands as a luminescent sensor for the convenient visual detection of ascorbic acid

Ascorbic acid (AA) is an essential antioxidant in the human body, whose detection is of significance in many fields. In this study, a two-dimensional terbium coordination polymer [Tb (dlba) (phen)]n (Tb-CP) based on a rigid 1,10-phenanthroline (phen) and a flexible 2-(3,5-dicarboxybenzyloxy) benzoic acid unit (H3dlba) was prepared under the hydrothermal conditions and characterized by Powder X-ray diffraction, elemental analysis, thermogravimetric analysis, infrared spectroscopy and single crystal X-ray diffraction. The Tb-CP synthesized via the mixed ligand strategy exhibits excellent water stability and acid-alkali resistance. As a luminescent sensor, the Tb-CP showed bright green luminescence characteristics of Tb3+, which was quenched after the addition of AA, with a quenching efficiency of 95.3 %. Additionally, the sensor shows high sensitivity and a rapid response time of 30 s. The detection limit is as low as 55.4 nM. In the actual sample test, the recovery rate of AA was 95–105 % (RSD< 1 %), indicating that the sensor has the potential for practical application. Furthermore, an integrated system based on Tb-CP and a smartphone can be employed for the visual detection of AA.

Molecular spectroscopy, solvent effect, and DFT studies of azithromycin solvate

Azithromycin ethanol solvate monohydrate [C38H72N2O120.5(C2H6O)H2O], abbreviated by AZM-MH-EtOH, was synthesized by slow evaporation method and investigated by powder X-ray diffraction, Raman and infrared (IR) spectroscopy combined with density functional theory (DFT) studies. Electronic and vibrational properties were properly investigated based on a theoretical study of solvation effects, using implicit solvation and solute electron density models. The electronic and vibrational studies were evaluated under aqueous, ethanolic, and vacuum conditions. The electronic structure calculations indicated that the AZM-MH-EtOH is chemically more stable in solvents compared to vacuum condition. Ultraviolet–visible (UV–vis) measurements confirmed the stability of the material in ethanolic medium, due to higher absorbance values compared to the aqueous medium. Vibrational changes were observed in the Raman and IR bands, which have connection with hydrogen bonds. The experimental vibration modes showed better accordance with the predicted modes’ values under solvation effects, but a slight divergence is noticed when we compared to vibration modes obtained in vacuum. Furthermore, the results have revealed a greater affinity profile of AZM-MH-EtOH for water and ethanol solvents compared to theoretical data under vacuum condition.

Investigations on the synthesis, growth and physicochemical properties of nonlinear optical material: l-lysine monohydrochloride nickel bromide (LLMNB)

A good-quality single crystal of l-lysine monohydrochloride nickel bromide (LLMNB) with an optimum size of 7 mm × 3 mm x 2 mm was obtained within 40–45 days. SXRD examinations revealed the unit cell measurements and cell characteristics of l-lysine monohydrochloride nickel bromide (LLMNB) crystals. By using powder X-Ray diffraction (PXRD) studies, the grown crystal's crystalline nature was determined. The functional groups of the crystal were determined using Fourier transform infrared (FT-IR). The optical transmission of a LLMNB crystal was investigated to characterize the crystal. This illustrates the LLMNB crystal's broad transmission window spanning the whole visible range and its extremely low UV cut-off wavelength of 230 nm. According to the findings, the LLMNB crystal's SHG efficiency was 1.62 times higher than that of the reference crystal KDP. The dielectric property of the grown crystal was studied at various temperatures. The grown LLMNB crystal Vickers hardness number increases when a load is applied. Photoconductivity research looked into the nature of photoconductivity. Hence, all these investigations suggest that the grown LLMNB crystal can be used for nonlinear optical devices and it is a potential candidate for optoelectronic utilization.

Chromoionophoric molecular probe infused bimodal porous polymer rostrum as solid-state ocular sensor for the selective and expeditious optical sensing of ultra-trace toxic mercury ions

This study presents a distinctive solid-state naked-eye colorimetric sensing approach by encapsulating a chromoionophoric probe onto a hybrid macro-/meso-pore polymer scaffold for fast and selective sensing of ultra-trace Hg(II). The customized structural/surface properties of the poly(VPy-co-TM) monolith are attained by specific proportions of 2-vinylpyridine (VPy), trimethylolpropane trimethacrylate (TM), and pore-tuning solvents. The interconnected porous network of poly(VPy-co-TM), inherent superior surface area and porosity, is captivating for the homogeneous/voluminous incorporation of probe molecules, i.e., 7-((4-methoxyphenyl)diazenyl)quinoline-8-ol (MPDQ), for the target-specific colorimetric detection. The structural morphology, surface topography, and phase characteristics of the bare poly(VPy-co-TM) monolith and MPDQ@poly(VPy-co-TM) sensor are examined using HR-TEM-SAED (High-Resolution Transmission Electron Microscopy - Selected Area Electron Diffraction), FE-SEM-EDAX (Field Emission Scanning Electron Microscopy - Energy Dispersive X-ray Spectroscopy), XPS (X-ray Photoelectron Spectroscopy), p-XRD (Powder X-Ray Diffraction), FT-IR (Fourier Transform Infrared Spectroscopy), UV-Vis-DRS (Ultraviolet-Visible Diffuse Reflectance Spectroscopy), and BET/BJH (Brunauer-Emmett-Teller / Barrett-Joyner-Halenda) analysis. The distinctive properties of the sensor reveal a constrained geometrical orientation of the MPDQ probe onto the long-range continuous monolithic network of meso-/-macropore template, enabling selective interaction with Hg(II) with peculiar color transfiguration from pale yellow to deep brown. The sensor demonstrates a linear spectral-color alliance in the 0–200 ppb concentration range for Hg(II), with quantification and detection limits of 0.63 and 0.19 ppb. The sensor efficacy is verified using certified contaminated water and tobacco samples, with excellent reusability, reliability, and reproducibility of ≥ 99.23 % (RSD ≤1.89 %) and ≥ 99.19 % (RSD ≤1.94 %) of Hg(II), respectively.

An Insight into Synergistic Effects of Cu and Ag Co-Doping in Nanocrystalline MgFe2O4 for Enhancing the Photocatalytic Degradation of Crystal Violet and Benzimidazole

Herein, the optical bandgap of magnetically separable, reusable and visible light active photocatalyst i.e. soft and n- type spinel ferrite MgFe2O4 is tailored to enhance its catalytic efficacy. The un-doped spinel ferrite MgFe2O4, and doped spinel MgFe2O4 i.e. Cu@MgFe2O4 (Cu0.05Mg0.95Fe2O4), Ag@MgFe2O4 (Ag0.1MgFe1.9O4), and Cu/Ag@MgFe2O4 (Cu0.05Ag0.1Mg0.95Fe1.9O4) were prepared by facile co-precipitation technique. Powder X-ray Diffraction (PXRD) and Fourier Transform Infrared (FTIR) spectroscopy were performed to confirm the successful synthesis of all prepared materials. The fabricated samples were used as photocatalysts for the degradation of Crystal violet (azo dye) and Benzimidazole (colorless pollutant). The results of photocatalytic experiment obtained from UV-Visible analysis showed about 71%, 82%, 85%, and 93% degradation of crystal violet by MgFe2O4, Cu@MgFe2O4, Ag@MgFe2O4, and Cu/Ag@MgFe2O4 respectively. Hence, the transition metal (Cu) and noble metal (Ag) co-doped MgFe2O4 exhibited about 22% increase in its catalytic activity against crystal violet as compared to pure MgFe2O4. The highest catalytic performance of Cu/Ag@MgFe2O4 could be assigned to its decreased crystallite size (18nm) and moderate band gap (2.17eV) as compared to its counter parts i.e. MgFe2O4 (26nm, 2.0eV), Cu@MgFe2O4 (22.5nm, 2.03eV), and Ag@MgFe2O4 (21nm, 2.05eV). Furthermore, ~84% degradation of benzimidazole was observed using Cu/Ag@MgFe2O4 as catalyst. The enhanced degradation activity of Cu/Ag@MgFe2O4 (Cu0.05Ag0.1Mg0.95Fe1.9O4) photocatalyst for both dye and colorless compound could be accredited to the synergistic effects of structural engineering and optical bandgap tuning by the co-doping of Cu and Ag in MgFe2O4. Hence, Cu0.05Ag0.1Mg0.95Fe1.9O4 could be a remarkable photocatalyst in future for the removal of harmful industrial pollutants.