UV Intensity Research Articles

Investigation on Enhanced Machinability of SiC Ceramics through Photocatalytic Vibration Composite Polishing.

The problems of low polishing efficiency and serious surface damage in the processing of silicon carbide (SiC) ceramics are well-known. In view of the above problems, a new method of photocatalytic vibration composite polishing (PVCP) combined with a compound control strategy was proposed. A vibration-assisted device was developed, and a compound control system was designed for the device to improve the trajectory tracking accuracy. Experiments were carried out to verify the effectiveness of the vibration-assisted device and the compound control system. In addition, methyl orange degradation and fading experiments, redox potential measurement experiments, and SiC ceramic surface hardness characterization experiments were carried out to reveal the effects of vibration and photocatalytic parameters on polishing solution oxidation and SiC ceramic surface mechanical properties. Finally, the effects of photocatalysis, vibration frequency, amplitude, and the compound control system on the polishing effect were analyzed. The results show that when the UV intensity is 100%, the polishing force is 3-4N, the vibration frequency is 400 Hz, the amplitude is 15 μm, and the surface roughness of SiC ceramics is reduced by about 11 nm after the introduction of the compound control system, which verifies the effectiveness of the combination of the compound control system and PVCP.

Degradation of residual dyes in actual textile wastewater using UV/H<sub>2</sub>O<sub>2</sub>: Evaluation of the impact of operating variables through multi-layer perceptron analysis

UV/H<sub>2</sub>O<sub>2</sub> is a commonly used advanced oxidation process for removing non-biodegradable organic compounds. However, additional efforts are needed to understand the relative significance of operational factors during the UV/H<sub>2</sub>O<sub>2</sub>. Here, we investigated the effect and specific contribution of crucial factors such as H<sub>2</sub>O<sub>2</sub> concentration, UV intensity, and reaction time on the color and total organic carbon (TOC) removal efficiency in textile wastewater using the one-factor-at-a-time method and multi-layer perceptron (MLP) analysis. The results showed that color removal was enhanced with high H<sub>2</sub>O<sub>2</sub> concentration, high UV intensity, and long reaction time. Overall, more than 99% removal of color was achieved by the UV/H<sub>2</sub>O<sub>2</sub>, utilizing the following parameters: H<sub>2</sub>O<sub>2</sub> concentration of 5 mM, UV intensity of 26.6 W/m<sup>2</sup>, and reaction time of 180 min. On the other hand, the removal of TOC was increased by high H<sub>2</sub>O<sub>2</sub> concentration and long reaction time, but not by high UV intensity. In the MLP analysis, the H<sub>2</sub>O<sub>2</sub> concentration was identified as the primary factor affecting both color and TOC removal, accounting for 43% and 50% reduction of the color and TOC, respectively. Overall, this study helps to understand the relative importance of the most critical operating factors in treating actual textile wastewater by the UV/H<sub>2</sub>O<sub>2</sub>.

Removal of tetracycline by ultraviolet/sodium percarbonate (UV/SPC)advanced oxidation process in water

Tetracycline (TC) was widely used and frequently detected in various water bodies, where the presence of TC posed a significant threat to the health of aquatic organisms. Furthermore, antibiotics were hardly degraded by biological treatment. Thus, in order to enhance the removal of TC, we proposed the use of a novel ultraviolet/sodium percarbonate (UV/SPC) advanced oxidation process and initiated an in-depth study. The study investigated the influence of oxidant dosage, initial pH, UV intensity, and TC concentration on the removal of TC. The results demonstrated that the UV/SPC system efficiently removed TC, with removal efficiency increasing as the SPC concentration increased. Within the pH range of 3–11, TC degradation exhibited minimal variation, indicating the UV/SPC system's strong adaptability to pH variations. The research on the impact of the water matrix on TC removal revealed that HCO3− had an inhibitory effect on TC degradation, while NO3− promoted TC degradation. Additionally, the presence of free radical species (·OH, ·CO3−, ·O2−) were detected and rate constants for the secondary reactions (k·OH,TC = 6.3 × 109 L mol−1·s−1, k·CO3-,TC = 3.4 × 108 L mol−1·s−1) were calculated, indicating that ·OH exhibited a stronger oxidative performance compared to ·CO3−. This study did not only present a novel strategy via UV/SPC to remove TC but also uncovered the unique role of ·CO3− for contaminant removal.

Detection of vanillin in food products over Cu - laser induced graphene nanocomposite using the combined electrochemistry and UV–Vis spectroscopy principles

Vanillin is the fragrant phenolic compound widely used as a food additive. However, an excessive consumption of vanillin can have adverse effects on human health. Therefore, the development of a sensor for the rapid and precise measurement of vanillin is essential. In this study, vanillin is successfully measured using the UV–Vis spectroelectrochemical (SEC) method. The method uses the laser induced graphene (LIG)-supported Cu nanoparticles coated over an indium tin oxide (ITO) as the electrode. The precursor material for Cu-LIG is synthesized using the suspension polymerization of phenol and formaldehyde, with the in-situ inclusion of Cu during gel formation step. The resulting polymeric film is subjected to calcination, hydrogen-reduction, and laser ablation to create a conductive Cu-LIG layer. The synthesized material exhibits a high electrochemical surface area of 0.907 cm2/cm2 and electrical conductance of 0.002 S, rendering it a suitable electrocatalyst for the oxidation of vanillin. The Cu-LIG/ITO electrode is used in detecting the oxidized species of vanillin at 370 nm-wavelength post two cyclic voltammetry (CV) cycles over 0–1.3 V potential. The sensor shows an excellent linear response (R2 value ∼ 0.993) over the concentration range 0.25–40 μg/mL, with 0.14 μg/mL limit of detection. Owing to the anti-interference ability of the SEC sensor, the intensity of UV–Vis absorbance at 370 nm remains unaffected against common interferents including glucose, fructose, ascorbic acid, and uric acid found in real food substances. This study has clearly shown the advantages of the combined electrochemistry and UV–Vis spectroscopy principles in quantitatively detecting oxidizable compounds in commercial food products.

Characterization and photocatalytic activity of TiO2 thin films prepared by sol-gel method for NOx degradation

Titanium dioxide (TiO2) thin film photocatalysts for the elimination of nitrogen oxides (NOx) were prepared by the dip-coating process using the sol–gel method. To prepare the sols, titanium (IV) butoxide (Ti(OBu)4), diethanolamine (DEA), butanol, and HCl were chosen. The TiO2 coatings were prepared using sols with varying volume ratios of Ti(OBu)4:DEA:Butanol. Additionally, three withdrawal speeds from the sol were employed. Subsequently, the TiO2 thin films were sintered at 500 and 700 °C. The obtained thin films were characterized using SEM to determine thickness, AFM to determine roughness, and the Step 500 platform for the adhesion test. NOx was found to be efficiently eliminated by TiO2 thin film photocatalyst. It is possible to obtain a TiO2 coating that is capable of degrading 300 ppb of NO in real time under specific conditions: a relative humidity of 30 %, a UV intensity of 20 W/m2, a gas flow rate of 1 dm3/min.

Insights into the efficient degradation of metformin - An emerging antidiabetic medicine by UV/Sulfite process

The growing utilization of metformin (MET) in diabetes treatment has resulted in its occurrence in wastewater treatment plants, where conventional techniques were proved inadequate in eliminating it. The present study evaluated the potential of UV/sulfite system in degrading MET and analyzed the influence of common factors (i.e UV intensity, dosage of reagent, the pH value of reaction solution) on the target contaminant removal. In comparison with both direct UV photolysis and merely sulfite reduction, the UV/sulfite process had a remarkable enhancement in MET removal, with 96.54% of MET (initial concentration of 15 mg/L) being degraded within 30 minutes. A strong linear relationship (R2 > 0.99) was observed between MET degradation kinetics and UV intensity. The increase of sulfite dosage and solution pH could promote MET degradation to a certain extent in the studied system. Additionally, the hydrated electron (eaq-) was found played the principle role in MET removal through scavenging reactions.

Ion imaging of spatially inhomogeneous nanoplasmas in NaCl particles.

Studying photoemission from free, unsupported aerosol particles is a powerful method for gaining insight into light-matter interactions at the nanoscale. We used single-shot velocity map imaging to experimentally measure kinetic energy and angular distributions of ions emitted following interaction of sub-micrometer NaCl particles with femtosecond pulses of near infrared (NIR, 800 nm) and ultraviolet (UV, 266 nm) light. We combined this with time-dependent simulations of light propagation through the particles and a rate equation approach to computationally address the origin of the observed ion emission. For both NIR and UV pulses, ion emission is caused by the formation of an under-dense nanoplasma with similar densities, although using an order of magnitude weaker UV intensities. Such conditions result in remarkably similar ion fragments with similar kinetic energies, and no obvious influence of the plasma formation mechanism (photoionization or collisional ionization). Our data suggests that Coulomb explosion does not play a significant role for ion emission, and we discuss alternative mechanisms that can lead to material ablation from under-dense nanoplasma. Finally, we show how finite size effects play an important role in photoemission through generation of spatially inhomogeneous nanoplasmas, which result in asymmetric ion emission that depends on particle size and laser wavelength. By utilizing the single-particle information available from our experiments, we show how finite size effects and inhomogeneous nanoplasma formation can be exploited to retrieve the size and orientation of individual submicrometer aerosol particles.

Synthesis of rhodamine-helicin fluorescent probe for colorimetric detection of Cu2+ and fluorescent recognition of Fe3+

Fluorescent probes play a crucial role in analytical chemistry and biological imaging, offering selective detection of metal ions. Herein, we present the synthesis and characterization of a novel rhodamine-based fluorescent probe, RbHC (Rhodamine B Helicin), which was obtained through the condensation of rhodamine B hydrazide and helicin in ethanol. The probe demonstrates remarkable selectivity and anti-interference capabilities towards Cu2+ and Fe3+ ions in 80% acetonitrile solution. Spectral titration analysis revealed a linear relationship between the intensity and the concentration of Cu2+/Fe3+. The formation of complex between Cu2+/Fe3+ and RbHC was confirmed to be 1:1, and it was further confirmed by ESI mass spectroscopy and DFT calculations. The coordination with Cu2+/Fe3+ caused the opening of RbHC's spirolactam ring, resulting in distinct color change and red fluorescence emissions. Moreover, RbHC exhibits high stability and water solubility under both acidic and neutral conditions, enabling its application in the imaging of plant tissues. Besides, the absorption intensity of RbHC–Cu2+ increased significantly when exposed to sunshine and 365 nm UV radiation, indicating that it might be used as a potential indicator for measuring outdoor UV intensity.

Dual-stimuli-responsive, anti-freezing, and conductive ionic hydrogels for smart wearable and outdoor UV radiation monitoring devices

Many studies have shown that a certain amount of UV radiation can help the human body synthesize vitamin D. However, prolonged exposure of the skin can cause erythema, inflammation, and skin aging. In recent years, UV monitoring equipment has attracted extensive interest from researchers, and accurate monitoring of UV intensity is a core element of UV monitoring equipment. It is important to display outdoor UV intensity in a simple, convenient, and effective way. However, the development of UV/stress dual-responsive ion-conductive hydrogels with excellent conditioning capabilities for wearable devices remains a major challenge. In this work, we successfully fabricated a gelatin-glycerol-ammonium sulfate (GGS) ionic conductive hydrogel with excellent mechanical properties: high tensile strength of 330 kPa (elongation at break of 225%), high transparency of 90%, good frost resistance (−50 °C), heavy plasticity, and good conductivity. This GGS organic hydrogel has dual responsiveness to UV light and strain. Moreover, the GGS hydrogel has stable electrical signal output in different joint movements, which suggests that it can be used to monitor physiological signals and human movement. Photochromic-GGS hydrogel can achieve reversible color change in response to UV stimulus, and can be used as an outdoor UV intensity indication device. Other than that, the GGS hydrogel also exhibits good re-molding, recyclability, and reusability. Low-cost photochromic-GGS hydrogel's simultaneous stability and environmental friendliness allows GGS hydrogel to be used as a green and sustainable smart material. To the best of our knowledge, these combined features cannot be realized by conventional strategies. Thus, our design strategy for GGS ion-conducting hydrogels promises to be a new generation of "smart" multi-stimuli-responsive hydrogels for visualization of UV-responsive devices, interactive wearables, and visual display devices.

Near-Infrared Reflective Polymer Films Based on UV-327-Doped Zinc Oxide Nanoparticles.

We prepared cholesteric liquid crystal (CLC) films with broadband reflective properties by admixing organic dye UV-327 into inorganic zinc oxide nanoparticles (ZnO NPs), utilizing the principle of pitch distribution from a large to a small gradient along the film thickness direction, leading to broadband reflection. ZnO NPs are poorly dispersed and easy to gather, but they do not decompose easily. The addition of UV-327 makes up for the above shortcomings. UV-327 is an organic compound with good compatibility and dispersion with liquid crystal systems. Therefore, we used the method of mixing two UV-absorbing dyes (UV-327 and ZnO NPs) to obtain CLC films. UV-absorbing dyes (UV-327 and ZnO NPs) made the liquid crystal films form a UV intensity gradient in the direction of thickness, prompting the polymerizable monomers to polymerize faster on the stronger side of the light, leading to the relative diffusion of chiral molecules and polymerizable monomers, forming the concentration gradient of chiral molecules in the direction of thickness. The pitch has a gradient distribution as the chiral concentration varies. Then, anchored by the polymer network, the pitch gradient distribution no longer changes. Broadened reflective bandwidth can reach up to 881 nm. Furthermore, the film covers the near-infrared wavelength band well, which can be applied to future smart windows or laser shielding for medical and military applications. It is also believed that this achievement will optimize the preparation technology of broadband reflective CLC films in the future.

The novel n-channel liquid crystal organic field effect transistor (LC-n-OFET): A promising technology for low-power electronics

In this study, a novel n-channel liquid crystal organic field effect transistor (LC-n-OFET) was fabricated using a mixture of E7 nematic liquid crystal (NLC) and [6,6]-phenyl C61 butyric acid methyl ester (PCBM) in an OFET cell. The LC-n-OFET performance was investigated regarding dielectric properties, UV illumination sensitivity, and channel length dependence. Output and transfer current-voltage (I–V) characteristics were measured to evaluate the electrical properties in dark and under UV illumination for varying channel lengths. Additionally, the dielectric characteristics of the LC-n-OFET were determined along with the capacitance-frequency response (Ci-f), threshold voltage (VTh), field-effect mobility (μFET), and on/off current ratio (Ion/off) as a function of UV illumination intensity and channel length changes. Electrical measurements showed the Ion/off current ratio is inversely proportional to channel length but directly proportional to UV intensity. Meanwhile, the threshold voltage (VTh) and mobility (μFET) increased with longer channel length and higher light intensity. Overall, the novel LC-n-OFET exhibited promising performance with low VTh, high μFET, and large Ion/off.

Effect of phlorotannins modification on the physicochemical, structural and functional properties of soybean protein isolate and controlled hydrolysates: Covalent and non-covalent interactions

In this research, the physicochemical, structural and functional properties of soybean protein isolate (SPI) as well as controlled hydrolysates (HSPI) were investigated by treatment with different concentrations of phlorotannins (PT) (0, 0.2, 0.5, 1.0, 2.0, mg/mL) through covalent and non-covalent interactions. Native/SDS-PAGE confirmed the formation of covalent and non-covalent complexes between PT and SPI/HSPI, and the presence of covalent bonds other than disulfide bonds in the covalent complexes (C–N, C–S bonds). After binding to PT, the secondary and tertiary structures of SPI/HSPI were changed. The secondary structure of complexes was transformed from β-sheet and β-turn to α-helix and random coil, and higher rates of transformation for covalent complexes. With the increase of PT concentration, the fluorescence and UV intensity of covalent/non-covalent complexes gradually reduced and rose, respectively; covalent complexes had lower fluorescence and higher UV intensity at equal concentrations. The particle size and ζ-potential of covalent/non-covalent complexes rose with PT concentration, and the PDI decreased and then rose, reaching a minimum value of 0.21 (HSPI-PT covalent) at PT of 0.5 mg/mL. TEM showed PT addition induced the aggregation of the complexes to increase. Meanwhile, surface hydrophobicity reduced while the antioxidant activity rose. Solubility, foaming activity and emulsifying activity of HSPI-PT covalent complexes first rose and then declined, and were optimal at PT of 0.5 mg/mL, with 78%, 250% and 97 m2/g, respectively. These will provide references for the improvement of soy protein properties and the application of complexes in formulated foods.

Light-adaptable artificial iris with dynamically scalable pupil-aperture function by radially patterned photochromic transition control

The iris is an ocular organ that actively controls the size of the pupil-aperture in response to external light, thereby regulating the amount of light reaching the retina for better visual acquisition. Herein, we propose a light-adaptive pupil-scalable artificial iris for addressing human iris defects with biomimetic self-regulating light control similar to human iris actuation, which is realized by a radially gradient and reversible photoswitching of photochromic dyes doped within a biocompatible hydrogel matrix. The radial photochromic switching of light transmissions was achieved by the gradient patterning of the crosslinking density of the hydrogel matrix using a near-infrared light-absorbing photomask that generated radially thermal gradience during hydrogel matrix polymerization. With the effective pupil-aperture control, the proposed artificial iris exhibited a variation in the visible-light transmittance from ∼82 % at the ultraviolet light (UV) intensity of 0.5 mW/cm2 to ∼43 % at 3.0 mW/cm2 representing the transparent and colored states, respectively. The switching times for the transitions to the colored and transparent states were 27.42 and 112.25 s, respectively, at a UV intensity of 3.0 mW/cm2, which can be faster under the hydrated state. The artificial iris demonstrated potential in biomedical applications by offering reliable light-adaptive attenuation control through human-like pupil-aperture adjustments.

Zinc phthalocyanine compound-based photo-electric organic shock-proof disposable flexible sensors

This research study introduces a multifunctional photo-electric sensor that utilises a semiconductor composite material and is implemented on a cellulose substrate. The flex electronic devices were manufactured using a rubbing-in technique that does not require energy. The investigation focused on using a compound consisting of zinc phthalocyanine and multi-walled carbon nanotubes (MWCNTs) as an active layer. However, aluminium top electrodes were utilized for photo-electric characterization, respectively. The surface type symmetry was designed to achieve disposable organic, shock-proof, and vibration-free electronic devices. They are then analyzed and characterized for their morphological and electrical parameters. The material structural analysis was performed with x-ray diffraction of materials, UV–Vis, photo luminance, Fourier-transform infrared spectroscopy, and for electrical characterization, the capacitance and impedance at varying ultra-violet (0–1300 W/cm), infrared (0–1580 W/m2), and frequency (0.1–200 kHz) were performed. Each parameter's influence is broken out in detail to illuminate the underlying physics of the results further. The results show that when Infrared intensity rises, impedance falls, whereas UV intensity increases. In the context of capacitance, it is observed that exposure to ultraviolet radiation leads to a decrease or increase in capacitance, while intensification of infrared light also results in a corresponding change in capacitance.Moreover, it can be observed that the sensitivity of electronic equipment exhibits a reduction when the frequency is increased. These devices have a wide range of applications, such as their use in food supply chains to safeguard food from the detrimental impact of high ultraviolet and infrared radiation on public health. They can also be employed in the medical industry for optical physiotherapy treatments and in universities for research purposes in countries that fall below the international poverty line, owing to their cost-effective fabrication technique.

Formation of halonitromethanes from glycine during LED-UV265/chlorine disinfection

LED-UV265/chlorine is a promising alternative disinfection technology that emits mono-wavelength light for high germicidal efficiency. Halonitromethanes (HNMs) are highly cytotoxic and genotoxic disinfection byproducts that can be formed during LED-UV265/chlorine disinfection. Thus, this work aimed to investigate the HNMs formation from glycine (Gly) during LED-UV265/chlorine disinfection. The results indicated that the concentrations of chlorinated-HNMs (Cl-HNMs) increased first and then decreased as the reaction proceeded. Besides, the effects of operating parameters (UV intensity, free chlorine dosage, and pH) and coexisting ions (Cu2+ and Br−) on HNMs formation were investigated. It was found that the formation concentrations of Cl-HNMs increased with the increase of LED-UV265 intensity and free chlorine dosage but decreased with increased pH. The presence of Cu2+ promoted the formation of Cl-HNMs. The total concentration of HNMs (at 3 min) with adding 1.5 mg/L Cu2+ was 30.90% higher than that without Cu2+. Notably, nine species of HNMs were detected after adding Br−, and the total concentrations of HNMs were enhanced. Moreover, Cl-HNMs were gradually transformed into brominated (chlorinated)-HNMs and brominated-HNMs as Br− concentration increased. According to the findings, the possible formation mechanism of HNMs from Gly during LED-UV265/chlorine disinfection was deduced. Finally, it was demonstrated that the formation laws of HNMs from Gly in real water samples were basically consistent with those in simulated water. Insights obtained in this study help to comprehend the HNMs formation from Gly and provide strategies for controlling the production of HNMs during LED-UV265/chlorine disinfection.

Preparation of triple-layer polymer dispersed liquid crystal films with progressive driving functionality

ABSTRACT In this paper, three single-layer polymer dispersed liquid crystal (PDLC) films with different electro-optical properties were prepared by the polymerisation-induced phase separation (PIPS) method firstly. The triple-layer PDLC film with progressive drive function was obtained by integrating three single-layer PDLC films. In contrast to the single-layer PDLC film, it is possible to make the triple-layer PDLC film enter the intermediate state between the on-state and off-state, while its transmittance can be controlled in low voltage by adjusting the applied voltage. It was found that the polymerisation temperature, time and UV intensity had significant effects on the electro-optical properties of the triple-layer PDLC films by comparing the electro-optical curves at various temperatures, times and UV intensities. The sample obtained under the optimal polymerisation condition showed a 31% reduction in threshold voltage, a 56% reduction in saturation voltage, a 20% reduction in off-state response time, and a 21% increase in contrast ratio than the original condition. The possibility to broaden the application area of PDLC is offered.

Dynamics of Photospheric Magnetic Flux Distribution and Variations in Solar RVs: A Study Using HARPS-N Solar and SDO Observations

The distribution and evolution of photospheric magnetic fields in sunspots, plages, and network, and variations in their relative flux content, play key roles in radial velocity (RV) fluctuations observed in Sun-as-a-star spectra. Differentiating and disentangling such magnetic contributions to RVs help in building models to account for stellar activity signals in high-precision RV exoplanet searches. In this work, as earlier authors, we employ high-resolution images of the solar magnetic field and continuum intensities from SDO/HMI to understand the activity contributions to RVs from HARPS-N solar observations. Using well-observed physical relationships between strengths and fluxes of photospheric magnetic fields, we show that the strong fields (spots, plages, and network) and the weak inter-network fields leave distinguishing features in their contributions to the RV variability. We also find that the fill factors and average unsigned magnetic fluxes of different features correlate differently with the RVs and hence warrant care in employing either of them as a proxy for RV variations. In addition, we examine disk-averaged UV intensities at 1600 and 1700 Å wavelength bands imaged by SDO/AIA and their performances as proxies for variations in different magnetic features. We find that the UV intensities provide a better measure of contributions of plage fields to RVs than the Ca ii H-K emission indices, especially during high activity levels when the latter tend to saturate.

Experimental study of the removal NO x and SO2 from flue gas using the O3/H2O2, and O3/UV processes

ABSTRACT The study investigates the effect of different parameters for the removal of SO2 and NO x through a wet process concurrently. Two separate processes have been compared for the removal of flue gases, that is, Ozone/UV and H2O2/UV. The research aims to develop a comparative study for the removal of SO2 and NO x simultaneously using Ozone/H2O2 and UV light and find the energy consumption (also known as E EO) for each process. Combining UV with O3 and H2O2 play a crucial role in generating hydroxyl radicals. Different combinations of Ozone/H2O2, flue gas, and UV intensity were studied at different pH and temperatures of the solution to achieve maximum removal of the flue gases. For, the ozonation process it was observed that the removal% of flue gases increases with increasing UV intensity, and at higher UV intensity (250 W), the removal% for NO x is 92% and SO2 is 95% simultaneously at optimum temperature 308 K. For H2O2/UV process (250 W UV intensity), removal% for NO x is 95% and SO2 is 100% at 313 K, 0.3 LPM flow rate of flue gases. The E EO values obtained for both processes were less than 1 for 95% NO x /SO2 removal efficiency.

Enhanced sonophotocatalytic degradation of amoxicillin antibiotics using Fe3O4@SiO2/PAEDTC surrounded by MIL-101(Fe) in aquatic environment under the COVID-19 pandemic

In the conditions of corona disease, the need for antibiotics in the world has quadrupled, so it is required to remove their residues from the environment. A core–shell metal–organic framework (MOF) composed of Fe3O4, SiO2, and MIL-101 was synthesized by hydrothermal method and used as a sonophotocatalyst for the amoxicillin (AMX) degradation from aqueous solution. The features of the new MOF were determined by SEM, TEM, XRD, FTIR, and BET techniques. The specific area of core–shell magnetic particles was 992 m2/g, which was indicative of its usability to adsorb pollutants and photons. Complete degradation of AMX was achieved by sonophotocatalysis process based on prepared nanocomposite at pH of 5, UV intensity of 36 W, AMX concentration of 50 mg/L, US frequency of 36 kHz, and time of 25 min. Kinetic study with pseudo-first order reaction for the decomposition of AMX showed the order of kinetic constant rate as Ksonophotocatalytic > Kphotocatalytic > Ksonocatalytic > Kadsorption. Hydroxyl radicals (•OH) and holes (h+) were respectively determined as the main species in the decomposition of AMX by performing quenching experiments. Less than an 8% reduction in AMX degradation rate was observed by the sonophotocatalytic process in the presence of prepared nanocomposite during six consecutive reaction cycles. Removal rates of TOC > 77% and BOD5/COD ratio > 0.4 showed that AMX was converted to CO2, H2O, and simple degradable compounds during the sonophotocatalysis process. A toxicity study with the microbial culture of Escherichia coli (E. coli) demonstrated a lower inhibition rate in the sonophotocatalytic process compared to photolysis and photocatalytic processes. All the laboratory results proved that the Fe3O4@SiO2@MIL-101(Fe) is an encouraging candidate for AMX degradation to preserve the ecosystem.

Investigating the use of Moringa Oleifera leaf extract as an environment-friendly corrosion inhibitor for API 5L X52 steel in 1 M HCl

This work studied the potential of using moringa oleifera leaf extract (MOLE) as an eco-friendly inhibitor for API 5L X52 steel in acidic media at 0.1 g/L–0.5 g/L concentration and 25 °C–60 °C. The study also evaluated the impact of adding potassium iodide (KI) to the corrosion-inhibiting properties of MOLE. Results from electrochemical testing showed that MOLE exhibited a high inhibition efficacy of 99% at 0.5 g/L concentration and 60 °C. The findings indicated that MOLE functions as a mixed-type corrosion inhibitor. Its efficiency increases with higher inhibitor concentrations following a Langmuir adsorption isotherm, and it is physically adsorbed on the steel surface. FT-IR spectra analysis revealed the presence of hydroxyl, carbonyl, saturated, and unsaturated aliphatic functionalities in the MOLE. The decreased absorption intensity in UV–vis spectra after 2 and 4 h of corrosive acid environment exposure indicates that MOLE was well adsorbed onto the metal surface. Hence, adding KI to the MOLE-containing samples enhanced the inhibitor's adsorption. The SEM-EDX observations supported the findings from electrochemical characterization and confirmed MOLE’s high inhibition performance. Hence, this study suggests that MOLE has promising potential as a green corrosion inhibitor for the API 5L X52 steel in acidic media.