Spectroscopy Analysis Research Articles

Sustainable catalytic pathways for biofuel precursors: quantitative conversion of glucose to gluconic acid using Pt-Zn biochar catalyst

Achieving quantitative conversion of biomass-derived feedstocks under ambient environmental conditions (20°C, atmospheric air, 0.1 MPa) is a critical milestone for sustainability in chemical processes. Herein, the quantitative conversion of glucose to gluconic acid was accomplished under ambient environmental conditions without any additives using a Pt-Zn intermetallic nanoparticle-supported biochar catalyst prepared from raw rice straw (Pt-Zn/strawC) via a straightforward one-pot solvothermal reaction with ethylene glycol solvent. Spectroscopic analyses verified the formation of the Pt-Zn intermetallic alloy and confirmed strong electronic metal-support interactions. The Pt-Zn/strawC catalyst (Pt:Zn molar ratio of 1:6) was highly selective for the conversion of glucose to gluconic acid, whereas yields as high as 99.9% (98.9% gluconic acid, 1.0% glucaric acid) were reached at 20 oC under base-free and additive-free conditions. Isotope measurements and density functional theory revealed synergistic interactions in the Pt-Zn alloy, wherein the alloy tended to absorb glucose and active O2 into superoxide radical (O2·). This work demonstrates a chemocatalytic method that is practical for environmental conditions and provides a new avenue for sustainable conversion of lignocellulosic biomass to chemical products.

Thermal studies on the Lower Carboniferous basins of Khenifra and Qasbat-Tadla, Morocco: what do they teach us about the pre-Variscan stages in NW Africa?

Within the Variscan Belt of Morocco, the Central Massif preserves Early Carboniferous rift basins. The Lower Carboniferous Khenifra and Qasbat-Tadla basins are aborted rifts, developed just before the Variscan orogenesis in Morocco that occurred during the Pennsylvanian-Cisuralian in NW Africa. Due to both weak inversion of these basins during the Variscan orogeny and limited burial afterwards, these basins offer the opportunity to study the Early Carboniferous pre-orogenic thermal regimes. In the Khenifra basin, 77 samples collected across the basin and its basement’s boundaries, allowed the determination of the maximal temperature reached during the rocks burial by means of Raman spectroscopic analyses. The Ordovician basement shows mean temperatures between 230 and 300°C whereas the upper Visean/Serpukhovian infill has a wide range, from temperatures < 160°C to 250-260°C. This thermal variation within the basinal series has been evidenced from west to east and cannot have been acquired during the Variscan events. The acquisition of these maximal temperatures occurred between Late Devonian to Upper Visean/Serpukhovian and is thought to result from the formation of an extended rift. In the Qasbat-Tadla basin, Rock-Eval data from Ordovician to Devonian source-rocks indicate significantly lower maximal temperatures reached by pre-Carboniferous samples that are within the oil window. Our results are in favor of a heterodox model for the Variscan belt in Morocco and NW African in general, suggesting that no pre-Variscan compressional events are needed. Instead, the development of the intraplate Variscan belt in NW Africa was permitted through the development of hot and weak Lower Carboniferous basins, subsequently inverted in a far-field stress field. The striking thermal differences between the Khenifra and Qasbat-Tadla basins suggest that important tectonic segmentation must have shaped the area during the Early Carboniferous extensional phase.

Visible/near-infrared luminescence and concentration effects of Pr3+-doped Sr2Al2GeO7 downconversion phosphors

The Pr3+ ion has been widely doped into various materials as a red and near-infrared (NIR) emitting center for applications in lighting and solar spectrum downconversion. Herein, the preparation of a new library of Pr3+-doped Sr2Al2GeO7 phosphors was proved by powder x-ray diffraction patterns and Rietveld refinements and characterized by a scanning electron microscope with energy-dispersive x-ray spectrometry. The Sr2Al2GeO7:Pr3+ sample strongly absorbs blue photons over 420–500 nm and yields intense visible emissions with dominant peaks around 490 nm from the Pr3+ 3P0 → 3H4 transition, as well as robust NIR emission bands over 800–1200 nm. In addition to the typical transitions of 1D2 → 3F2 at 880 nm, 1G4 → 3H4 at 1000 nm, and 1D2 → 3F3,4 at 1070 nm, the distinguishable NIR emission at 929 nm was demonstrated from the 3P0 → 1G4 transition via static and dynamic spectroscopic analysis. Most interestingly, for the 3P0 blue-excited state, a considerably elevated concentration of about 10%Pr3+ was optimal for the visible/NIR emissions, in stark contrast to the diluted optimal 1%Pr3+ for the 1D2 state. The relevant cross-relaxation from the 3P0 and 1D2 states between Pr3+ was comprehensively treated by theoretical speculations and experimental results. Such concentrated Pr3+ blue activators would significantly facilitate the blue-to-NIR downconversion through a desired two-step sequential transition from the 3P0 initial state to the 1G4 intermediate level for quantum efficiency exceeding unity. The current results would consolidate the basis of concentrated Pr3+ donors to promote the novel Pr3+/Yb3+ codoping downconversion for greatly increasing Si solar cell efficiency.

Coprecipitation of nicotinic acid in PVP by gas antisolvent technique using Box-Behnken design

Nicotinic acid is a water-soluble compound recognized in the medical field for its ability to decrease low-density lipoprotein cholesterol levels. Additionally, nicotinic acid is used to alleviate the effects of heat stress in ruminant animals. The supercritical gas antisolvent technique was employed using carbon dioxide to encapsulate nicotinic acid in polyvinylpyrrolidone (PVP) using ethanol + acetone. Encapsulation efficiency, process yield and crystallite size data were evaluated using the Box-Behnken design. Gas chromatography-mass spectrometry quantified the encapsulation efficiency at (13.1 to 66.9)%, and the same technique was used to determine that the encapsulation of nicotinic acid increased the dissolution rate compared to the pure compound. A residual solvent level was quantified at least 33 times lower than the maximum permitted level. The encapsulation was shown to protect the active ingredient in thermal degradation tests in a climatic chamber. XRPD showed the stability of the crystalline structure of niacin after encapsulation, and the effects on its microstructure were evaluated using Rietveld analysis. Spectroscopic analysis showed evidence of intermolecular bonding between nicotinic acid particles and PVP. An average particle size of (80.4 to 238.9) µm was obtained by SEM analysis.

Sustainable and Cleaner Production of a Porous Geopolymer Support Based on Metakaolin and Natural Calcium Oxide

The field of engineering today, mainly civil engineering, given population growth and urbanization, is experiencing permanent changes, thereby implying the use of a sustainable and, above all, less polluting alternative. The present work deals with the study of the effects of the calcium-phosphate network in the geopolymeric matrix in an acidic environment (P2O5/H2O = 0.06 and 0.12) using metakaolin (MK) and calcined oyster shells (COs). Kaolin (K) and oyster shells (respectively heat treated at 700 and 900 °C), metakaolins and geopolymers (produced at room temperature according to the molar ratios P2O5/H2O = 0.06 and 0.12) have were characterized using chemical, thermal (TGA/DSC), mineralogical (XRD) analyzes and Fourier Transform Infrared Spectroscopic Analysis (FTIR). In addition, the physical and mechanical properties of the geopolymers (specimen appearance, setting time, linear shrinkage, water absorption and compressive strength) were determined. It was found that kaolin and oyster shells contain mostly kaolinite and calcium oxide respectively. However, the mineralogical analysis of MK shows a dome reflecting the presence of an amorphous phase favourable to geopolymerisation. From these results, we note that: the appearance of the geopolymer specimens is accentuated by the efflorescence and the presence of pores. The setting times of the pastes for the two solutions decreased with the addition of COs powder, due to the presence of calcium phosphate crystalline phases within the materials such as monetite and brushite which tend to accelerate network consolidation. Linear shrinkage also decreased with the addition of COs powder. On the other hand, with the addition of COs, the water absorption increase at the ratio 0.06 while they decrease at 0.12, due to the presence of pore within the geopolymers. As for the compressive strengths, they decrease with the addition of the COs powder, due to the weakening of the geopolymeric network by monetite and brushite. In conclusion, at high concentrations (P2O5/H2O = 0.12), COs (responsible for the formation of monetite and brushite in acidic environments) powder acts as a porogen. Given the presence of pores in the materials and their relatively high resistance compared to other studies, these materials could be used in engineering as sensors, insulators (thermal, electrical and acoustic).

Antidyslipidaemic evaluation of coagulin C and withacoagulin isolated from Withania coagulans (Stocks) dunal berries in hypertension induced secondary dyslipidemia in albino mice

Vascular diseases like hypertension has often been associated with dyslipidemia. Sustained elevated blood pressure for not less than four weeks develops gross irregularities inside arteriolar lumen. The pathological changes might be due to intimal arteriosclerotic thickening causing tapering of the structural narrowing along the arterioles. It might also be due to occurrence of irregular damage in the vascular structure from focal arteriolar constriction and lead to secondary dyslipidemia. The pharmacological intervention may lead to rectification and therapeutic benefit against dyslipidemia.The withanolides coagulin C and withacoagulin were isolated by flash chromatography from the extracts of Withania coagulans (Stocks) Dunal berries. The withanolides were characterized using 1H NMR and 13C NMR, UV and mass spectrometry and confirmed as coagulin C and withacoagulin. The oral toxicity of coagulin C and withacoagulin were investigated in albino mice followed by their antidyslipidemic activity with two dose levels i.e. 25 mg/kg and 50 mg/Kg p.o. This dyslipidemia was secondary to hypertension which was developed by DOCA salt model (25 mg/kg; s.c.+ 2% NaCl). Mice were administered dose of 10, 50 and 500 mg/kg coagulin C and withacoagulin orally for 28 days daily for sub-acute toxicity effect.Coagulin C and withacoagulin were found to be tolerated upto 2000 mg/kg p.o. during acute toxicity study in mice. Coagulin C and withacoagulin were claimed to possess No-Observed Adverse Effect Level (NOEL) at the dose of 500 mg/kg orally. The high dose (50 mg/Kg) withacoagulin has highly significant difference in total cholesterol, triglyceride, HDL, LDL and VLDL levels in comparison to disease control group along with highly significant difference in triglyceride and VLDL level compared to animals of vehicle control group. Coagulin C at both the low (25 mg/Kg) and high dose (50 mg/Kg) have highly significant difference in comparison to vehicle control, disease control and positive control in controlling total cholesterol, triglyceride, LDL and VLDL levels in the experimental animals indicating that coagulin C is not much as effective as withacoagulin in the normalization of altered lipid profile of the experimental animals.On the basis of spectroscopic analysis the isolated compounds from Withania coagulans (Stocks) Dunal berries were confirmed to be coagulin C and withacoagulin. Acute oral toxicity test in mice was found to have safe profile even at high dose for both the compounds. On development of secondary dyslipidemia due to DOCA salt induced hypertension in albino mice, both the isolated compounds showed different degree of correction in the altered lipid profile of the animals. Whereas withacoagulin has been found to have more significant and successful in controlling the altered lipid profile, coagulin C has only marginal effect. The docking studies also confirm the result and hence it can be suggested that withacoagulin is better than coagulin C in managing the alteration of lipid profile of the experimental mice.

Exploring Brominated Aromatic Butenolides from Aspergillus terreus EGF7-0-1 with Their Antifungal Activities.

Fungal diseases could severely harm agricultural productions. To develop new antifungal agents, based on the Global Natural Products Social Molecular Networking, typical bromine isotope peak ratios, and ultraviolet absorptions, cultivation of the soft coral-derived endophytic fungi Aspergillus terreus EGF7-0-1 with NaBr led to the targeted isolation of 14 new brominated aromatic butenolides (1-14) and six known analogues (15-20). Their structures were elucidated by extensive spectroscopic analysis and quantum chemical calculations. Compounds 1-14 exhibited wildly antifungal activities (against Colletotrichum gloeosporioides, Pestalotiopsis microspora, Fusarium oxysporum f. sp. cubense, Botrytis cinerea, and Diaporthe phoenicicola). The bioassay results showed that compounds 1-14 exhibited excellent antifungal activities against C. gloeosporioides, with concentration for 50% of maximal effect (EC50) values from 2.72 to 130.41 nM. The mechanistic study suggests that compound 1 may disrupt nutrient signaling pathways by reducing the levels of metabolites, such as carbohydrates, lipids, and amino acids, leading to an increase in low-density granules and a decrease in high-density granules in the cytoplasm, accompanied by numerous vacuoles, thereby inhibiting the growth of C. gloeosporioides. Monobrominated γ-butenolide 1 may be expected to exploit a novel agriculturally antifungal leading drug. Meanwhile, compound M1 has conformed antifugual activities against C. gloeosporioides by papayas in vivo.

Mechanism regulation over dual-atom catalyst enables high-performance oxidative alcohol esterification

The development of heterogeneous catalysts with well-defined uniform isolated or multiple active sites is of great importance for understanding catalytic performances and studying reaction mechanisms. Herein, we present a CoCu dual-atom catalyst (CoCu-DAC) where bonded Co–Cu dual-atom sites are embedded in N-doped carbon matrix with a well-defined Co(OH)CuN6 structure. The CoCu-DAC exhibits higher catalytic activity and selectivity than the Co single-atom catalyst (Co-SAC) and Cu single-atom catalyst (Cu-SAC) counterparts in the catalytic oxidative esterification of alcohols and a variety of methyl and alkyl esters have been successfully synthesized. Kinetic studies reveal that the activation energy (29.7 kJ mol–1) over CoCu-DAC is much lower than that over Co-SAC (38.4 kJ mol–1) and density functional theory (DFT) studies disclose that two different mechanisms are regulated over CoCu-DAC and Co-SAC/Cu-SAC in three-step esterification of alcohols. The bonded Co–Cu and adjacent N species efficiently catalyze the elementary reactions of alcohol dehydrogenation, O2 activation and ester formation, respectively. The stepwise alkoxy pathway (O–H and C–H scissions) is preferred for both alcohol dehydrogenation and ester formation over CoCu-DAC, while the progressive hydroxylalkyl pathway (C–H and O–H scissions) for alcohol dehydrogenation and simultaneous hemiacetal dehydrogenation are favored over Co-SAC and Cu-SAC. Characteristic peaks in the Fourier transform infrared spectroscopy analysis may confirm the formation of the metal-C intermediate and the hydroxylalkyl pathway over Co-SAC.

Effect of Hydrogen on Oxidative Dissolution of Epsilon Particles-Doped UO2 Pellets under Carbonate Condition with Hydrogen Peroxide

The epsilon particles that result from UO2 fuel nuclear fission possess both advantages and disadvantages from a spent nuclear fuel (SNF) management perspective. In this study, the effect of epsilon particles, namely Ru, Mo, and Pd, inherent in simulated UO2 pellets is examined. Various analytical methods have been used to explore the changes in the structural, surface, and electrochemical properties of which contain epsilon particles. A notable finding is that the epsilon particles are not evenly distributed and tend to clump together, transforming into a metallic state after sintering, as detailed in the X-ray diffraction analyses. Energy-dispersive X-ray spectroscopy analyses highlight interesting aspects of the distribution of elements, especially the disappearance of Pd during sintering, which is likely due to its high vapor pressure. Although the lattice structure of UO2 remains unchanged, the sizes of the grains and pores visibly change, which may influence the tendency of UO2 pellet-cracking. Despite the addition of the epsilon particles, the electrical conductivity analyses show no significant changes, suggesting that they act as minor impurities without affecting the structural lattice. However, their possible role as catalysts in electrochemical reactions opens new and interesting areas that require thorough investigation. Moreover, examining the anodic dissolution under various conditions provides detailed insights into UO2 dissolution and oxidation, revealing how epsilon particles subtly influence the oxidative dissolution process. This study clarifies the basic interactions and effects of epsilon particles in UO2 pellets and broadens the path for a deeper understanding and improvement of nuclear fuel matrices and steering advancements in the safe and effective use of nuclear energy.

Improved electrochemical performance of Fe3O4/TiO2 composite thin film electrode for energy storage applications

This study is the first attempt to examine the electrochemical properties of TiO2 composite with Fe3O4 thin film. In our analysis, X-Ray diffraction (XRD) confirms the formation of Fe3O4 on TiO2. Fourier Transform Infrared Spectroscopy (FT-IR) and Raman spectroscopy confirmed the functional groups. The UV–Vis spectroscopy analysis shows that the addition of Fe3O4 results in decrease in optical band gap. Our Cyclic Voltammetry (CV) results demonstrate that, under steady state conditions, the behaviors of TiO2 and Fe3O4/TiO2 electrodes regarding ion adsorption and charge transmission vary. Pseudocapacitive effects and charge transfer affects the functionality of the TiO2 electrode, whereas two-layer capacitance effects primarily control the response of the Fe3O4/TiO2 electrode. Numerous factors, including ion diffusion, rate capability, charge transfer, and series resistance, can be directly determined using electrochemical impedance spectroscopy (EIS). The experimental results and analysis presented in this work brings to light the significance of Fe3O4 in the electrochemical response of an electrode-electrolyte interface.

SYNTHESIS of P(N-ISOPROPYL ACRYLAMIDE - HYDROXYPROPYL METHACRYLATE) THERMO RESPONSIVE COPOLYMER FILMs BY INITIATED CHEMICAL VAPOR DEPOSITION METHOD

This study illustrates the deposition of thermo responsive p(N-isopropyl acrylamide-hydroxypropyl methacrylate) p(NIPAAm-HPMA) copolymer thin films by initiated chemical vapor deposition (iCVD) method using tert-butyl peroxide (TBPO) as the initiator. Copolymers were deposited at three different HPMA flow rates and the effects of NIPAAm/HPMA flow rate ratio on the deposition rate, structure and responsive properties of the as-deposited films were investigated. The highest deposition rate of 50 nm/min was observed for the copolymer deposited using lowest NIPAAm/HPMA monomer ratio studied. The deposition rate showed a significant increase with decreasing NIPAAm/HPMA flow ratio. Results of FTIR and XPS spectroscopy analyses revealed a significant preservation of structural retention in iCVD p(NIPAAm-HPMA) thermo-responsive films. Lower critical solution temperatures (LCST) of p(NIPAAm-HPMA) films were determined by carrying out a temperature-dependent contact angle analysis. Accordingly, it was shown that LCST was varied between 19 and 23 oC, which was observed to be dependent on the NIPAAm/HPMA monomer ratio. That LCST range is considerably below the literature- reported values for pNIPAAM, which makes the as-deposited copolymer suitable for applications that require thermos-responsive properties at lower temperatures.

Hydrothermal synthesis of La0.5Sr0.5MnO3 nanostructures for enhanced CO oxidation

This study focuses on the synthesis and characterization of La0.5Sr0.5MnO3 (LSMO) perovskite nanostructures via the hydrothermal method and their catalytic performance evaluation in CO oxidation. Structural analysis using techniques like XRD, FE-SEM, FTIR, and Raman spectroscopy analysis verified the development of LSMO nanostructures exhibiting a rhombohedral phase configuration. The catalytic activity of the annealed LSMO nanostructures was assessed, demonstrating significant CO conversion efficiency attributed to structural modifications enhancing catalytic performance. These findings highlight the potential of LSMO perovskite nanostructures as efficient catalysts for CO oxidation.

Preparation and Molecular Dynamic Simulation of Superfine CL−20/TNT Cocrystal Based on the Opposite Spray Method

In view of the current problems of slow crystallization rate, varying grain sizes, complex process conditions, and low safety in the preparation of CL−20/TNT cocrystal explosives in the laboratory, an opposite spray crystallization method is provided to quickly prepare ultrafine explosive cocrystal particles. CL−20/TNT cocrystal explosive was prepared using this method, and the obtained cocrystal samples were characterized by electron microscopy morphology, differential thermal analysis, infrared spectroscopy, and X-ray diffraction analysis. The effects of spray temperature, feed ratio, and preparation method on the formation of explosive cocrystal were studied, and the process conditions of the pneumatic atomization spray crystallization method were optimized. The crystal plane binding energy and molecular interaction forces between CL−20 and TNT were obtained through molecular dynamic simulation, and the optimal binding crystal plane and cocrystal mechanism were analyzed. The theoretical calculation temperature of the binding energy was preliminarily explored in relation to the preparation process temperature of cocrystal explosives. The mechanical sensitivity of ultrafine CL−20/TNT cocrystal samples was tested. The results showed that choosing acetone as the cosolvent, a spraying temperature of 30 °C, and a feeding ratio of 1:1 was beneficial for the formation and growth of cocrystal. The prepared CL−20/TNT cocrystal has a particle size of approximately 10 μm. The grain size is small, and the crystallization rate is fast. The impact and friction sensitivity of ultrafine CL−20/TNT cocrystal samples were significantly reduced. The experimental process conditions are simple and easy to control, and the safety of the preparation process is high, providing certain technical support for the preparation of high-quality cocrystal explosives.

Thermophysical &amp; photothermal characteristics of surfactant free graphene oxide, functionalized graphene oxide and reduced graphene oxide nanofluids

Graphene nanostructures-based dispersions, owing to their improved thermophysical and optical characteristics are being actively explored for use in thermal energy conversion and management. Here, thermophysical and photothermal characteristics of graphene oxide (GO), functionalized graphene oxide (f-GO), and reduced graphene oxide (rGO) based nanofluids (without surfactants) of various concentrations (0.05–0.23 wt.%) are evaluated. The structural, morphology and stability of the nanofluids are determined by XRD analysis, Transmission electron microscopy, UV- visible spectroscopy and zeta potential analysis. Subsequently, thermal conductivity and contact angle measurements are performed. Photothermal behaviour is investigated experimentally. Overall, it is found that among the prepared nanofluids, the f-GO nanofluids performed better compared to GO and rGO nanofluids. Maximum stability of f-GO nanofluids is obtained at 0.05 wt.% while the thermal conductivity and photothermal response is best obtained at 0.23 wt.% concentration.

Enhancing hydrovoltaic power generation with carbon spheres coated on nickel foam/polyethylene terephthalate substrate

The present study aims to assess the viability of hydrovoltaic impact as a potential method for energy generation. This methodology utilizes the capillary action of water in devices composed of nickel (Ni) foam/polyethylene terephthalate (PET) substrates coated with hydrothermally synthesized carbon spheres at various temperatures (180, 200, and 220 °C). The prepared materials and devices were analyzed using a range of analytical techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and Fourier transform infrared spectroscopy (FTIR). The SEM images revealed the spherical morphology of the carbon particles and their presence on Ni foam, whereas the XRD patterns indicated that the carbon spheres were amorphous. Spectroscopic analysis revealed the presence of hydroxyl functional groups in all the samples. The performance of the devices was assessed by electrochemical tests, including open-circuit potential (OCP), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The device coated with carbon spheres synthesized at 180 °C demonstrated enhanced performance with an elevated OCP value of 0.077 V, increased surface charge area, lower resistance to water, and reduced charge transfer resistance. These findings indicate the successful production of hydrovoltaic energy by utilizing the capillary action of water in carbon-sphere-coated Ni foam/PET devices.

Laser‐Induced Transformation of ZIF‐8 into Highly Luminescent N‐Doped Nanocarbons for Flexible Sensors

AbstractMetal–organic frameworks (MOFs) like the zeolitic imidazolate framework (ZIF‐8) have a high surface area, tunable porosity, and robust thermal and chemical stability, making them attractive candidates for various applications. Here, a strategy is shown that spans that functionality and provides strong photoluminescence (PL) emission, unlocking ZIF‐8‐based materials for chemical and temperature sensors based on PL. The approach is based on laser processing that dramatically boosts the PL response of laser‐irradiated ZIF‐8 (LI ZIF‐8), achieving a 70‐fold increase in intensity relative to the pristine material. The PL characteristics of the irradiated material can be easily tuned by varying the laser power and irradiation time with in situ and real‐time spectroscopic analysis providing insights into the process dynamics. It is found that the observed PL enhancement is primarily due to the laser‐induced transformation of ZIF‐8 into nitrogen‐doped nanocarbons and ZnO nanostructures. The versatility of this laser processing approach is leveraged to create flexible electronics by integrating the LI ZIF‐8/nanocarbon architectures into thermoplastic polyurethane (TPU). The multifunctional composite material shows excellent performance as flexible electrodes for human‐body monitoring applications, as well as both temperature and flexure sensors with remarkable mechanical resilience.

Room-temperature mL-to-μL quantitative liquid concentration device for cyclone flow.

Highly sensitive quantitative analysis of liquids is required in various fields. Analytical instruments and devices such as chromatography, spectroscopic analysis, DNA sequencers, immunoassay, mass spectrometry, and microfluidic devices are utilized for this purpose. Typically, the sample volume is at the milliliter scale, while the analysis volume is at the microliter scale. Consequently, most of the sample is discarded. Therefore, a universal volume interface is required to quantitatively concentrate samples from milliliter to microliter volume. This study introduces a liquid quantitative function to the cyclone concentration method using a millimeter-scale channel, which is highly suitable for controlling liquids at the microliter scale due to its high fluidic resistance against cyclone flow. This method enables the effective control of liquid concentration by cyclone flow. The optimum channel structure is investigated, and a 33-fold concentration of aqueous solutions is demonstrated. Finally, the concentration device is applied to measure molybdenum ions in a river.

Ecofriendly Synthesis, Spectroscopic Analysis and in silico Study of Coumarin Hydrazide-Hydrazone Derivative Targeted against HIV and SARS-CoV-2

Ecofriendly Synthesis, Spectroscopic Analysis and in silico Study of Coumarin Hydrazide-Hydrazone Derivative Targeted against HIV and SARS-CoV-2

Alumina-supported multi-metal catalyst for e-waste management for reclamation of valuable products

ABSTRACT Electronic and electrical waste (e-waste) has increased exponentially due to the humungous growth in the information technology and communication sector. Many multi-metal catalysts are developed by researchers for electronic waste plastic conversion into fuel products and recovery of valuable metals. In the present study, an Alumina-supported catalyst powder with selected transition metals metal oxides was prepared to improve the yield of hydrocarbon liquids. FESEM with energy-dispersive spectroscopy, XRD and laser diffraction particle size analysis were used to characterise catalysts. The shredded e-waste chips to catalyst weight ratio was maintained from 2:1 to 10:1 and studied. The experiments were conducted with a reaction temperature range from 300°C to 500°C. The produced fuel density was 0.88 kg/L, with 0.75 liquid fuel conversion and 71.7% overall liquid fuel yield. The light gas percentage was 4–6%. NMR analysis, bomb calorimetric study and gas chromatography-mass spectroscopy of liquid fuel analysis suggest carbon chain compounds of C3–C20 hydrocarbon, indicating a mixture of petrol and diesel-like liquid products. The catalyst can be tuned to improve liquid fuel conversion. The liquid fuel product is promising for fuel use, however, upgrading treatments are needed to meet standard product specifications.

Harnessing wood bottom ash for efficient arsenic removal from wastewater: Adsorption mechanisms and process optimisation

This study explored the innovative application of wood bottom ash (WBA) as an adsorbent for arsenic (As) removal from wastewater, focusing on the adsorption mechanism and optimisation of the operational conditions. Comprehensive spectroscopic analyses, including FE-SEM/EDS, BET, XRF, XRD, FT-IR, and XPS, were performed to examine the elemental and mineralogical changes in WBA before and after As adsorption. The study assessed the adsorption kinetics and isotherms, revealing that As adsorption reached equilibrium within 48 h, with a maximum capacity of 121.13 mg/g. The adsorption process followed a pseudo-second-order kinetic model and aligned well with the Langmuir isotherm, indicating that the process is governed by chemisorption and occurs as monolayer adsorption. The primary removal mechanism was the surface precipitation of amorphous calcium arsenate. Response surface methodology was employed to analyse and optimise the factors influencing As removal, including solution pH, ionic strength, adsorbent dose and reaction time. The optimal conditions for maximum As removal were pH 7.11, 8.37 mM ionic strength, 9.08 g/L WBA dose, and 2.58 h reaction time. This study offers novel insights into the efficient and cost-effective use of WBA for As removal, highlighting its potential as a sustainable solution for wastewater treatment in developing countries.