VOLUME 47, NO4, AUG-2025

Quantitative Relationship Between the Ratio of Fe2+/Fe3+ in Fe3O4 and its Energy Gap in Photocatalytic Process

The energy gap of photocatalyst is important for photocatalytic processes. As a common substrate, the iron-based photocatalyst has attracted much attention due to its high catalytic activity. While, the basic functional relationship between the mole ratio of Fe2+/Fe3+ in Fe3O4 nanoparticles (NPs) and the energy gap (Eg) is still unknown. this quantitative relationship was built by equations in this study. A series of experiments are carried out and the functional relationship is summarized by UV-Vis diffuse reflectance spectra (DRS) based on Kubelka-Munk theory. Meanwhile, its application for removing the organic dye Congo Red (CR) is examined. Optimum reaction conditions are obtained by orthogonal experiments. This study supplies a basic quantitative relationship between the ratio of Fe2+/Fe3+ in Fe3O4 NPs and its energy gap. It is essential for designing all kinds of novel iron-based photocatalysts.read more

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Shijie Zhang

DFT Study on Mn-H Bond Dissociation Enthalpies of Manganese Hydrides in Manganese-Catalyzed Hydrogen Atom Transfer Reactions

In recent years, metal-catalyzed hydrogen atom transfer (MHAT) reactions have become integral to many catalytic reactions due to their stereoselectivity, chemical fidelity and selectivity. As the first transition metal element in abundant global reserves, manganese has the advantages of lower price and less toxicity, and a series of manganese complexes are used in MHAT reactions. In the reaction, the prominent catalytic intermediate manganese hydride formation is involved in the whole catalytic cycle, therefore the rupture of manganese-hydrogen bonds denoted by one of the thermodynamic parameter of the Mn-H bond dissociation enthalpy (BDE) is essential. In the present research, the Mn-H BDEs of some manganese hydrides which have experimental values were computed by using several DFT functionals, and the data showed that the B3P86 functional provided the highest precision, which has the least root mean square error (RMSE) of 3.3 kcal/mol. In the following, the BDEs and substituent effects of ten kinds of manganese hydrides involved in manganese-catalyzed hydrogen atom transfer reactions were further explored, and the calculations showed that the ligand has a significant effect on Mn-H BDEs, and the effect of substituents on Mn-H BDEs varies in different types of manganese hydrides. Moreover, the natural bond orbital (NBO) as well as the energies of frontier orbitals analyses aimed at revealing the intrinsic factors of different patterns of change of the Mn-H BDE were accomplished.read more

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Yan Que, Wenrui Zheng, Chenhao Wu, Shenghao Pan, Peilei Jiao

Fabrication of Cobalt-Doped Lignin Base Carbon Nanotubes Composite Material for Energy Storage Applications

The development of high-performance, sustainable, and economical electrodes with superior capacity and cyclic stability is crucial for the advancement of energy storage devices. Carbon nanotubes (CNTs) has garnered considerable interest as a potential electrode material for energy storage applications, owing to its high capacity, natural abundance, cost-effectiveness, and eco-friendliness. In the present study, lignin was combined with CNTs to synthesize a Co-CNTs/lignin composite electrode material via hydrothermal method, for enhance energy storage performance. The structure and surface morphology of the synthesized Co-CNTs/lignin composite is characterized by X-ray diffraction (XRD), RAMAN spectroscopy, X-ray Photoelectron Spectroscopy (XPS), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET). The thermal stability of the composite sample was also studied by thermogravimetric analysis (TGA). The Co-CNTs/lignin composite exhibit enhanced electrochemical kinetics and electrical conductivity compared to pristine Co-CNTs and Co-lignin. The Co-CNTs/lignin composite material has shown remarkable electrochemical performance, it exhibits high specific capacitance, an energy density, and a power density at a low current density. The composite material showed outstanding electrochemical stability, maintaining 98% of its original capacitance and exhibiting an impressive coulombic efficiency of 81% after 1000 charge-discharge cycles at a current density of 5 A g−1. The obtained data indicated that the composite materials exhibit superior performance in energy storage devices.read more

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Zaib Ullah Khan, Jinghua Jiang, Zahid Ullah, Muhammad Yasir Ali Khan, Asifa Kusar

Synthesis and Study of a Novel Visualized Iron Ion Probe

In this study, we synthesized probe R using Rhodamine 6G as the chromophore. The structure of probe R was characterized, and its probe properties and reaction mechanism were studied. The experimental results could be observed with the naked eye, and probe R could detect iron ions effectively. The LOD of UV-vis absorption determination was 6.4 μM, which was significantly lower than the international sanitation standard for drinking water. Therefore, R could be used as a new visual metal ion probe to determine Fe3+ content. Job's plot experiment demonstrated that the response of probe R to Fe3+ was based on complex formation with a ratio between R and Fe3+ of 2:1.read more

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Rong Jiang, Sining Li, Jingwen Zhang, Haipeng Bi, Changjiang Li

Synthesis of Biodiesel from Waste Cooking Oil by Using Seashells as Catalyst

The basic aim of this research is to study the suitable conditions of the biodiesel by using waste refined cooking oil as a preliminary material with heat-treated seashells at 500°C, 800°C, and 1000°C as heterogeneous catalysts. It recorded at 800 °C a high level of CaO as catalyst 90.89 % under the following reaction conditions: catalyst is 0.5 g, temperature at 80 °C, reaction duration is 180 minutes, and the oil-to-alcohol ratio is 10:20%. The impact of energizing temperature on transesterification processes in the range of 500°C–1000°C proved that the calcination temperature at 800 °C of seashell-derived material raised biodiesel to 97% due to active sites on catalyst surfaces, converting rate linearly in comparison to other catalysts, and this tends to reduce the cost of purification procedures of biodiesel. It has been proved that the catalyst at 800°C possesses a density at 40°C of 0.850 g /cm3, an acid value of 0.6 mg KOH/g oil, a viscosity of 4.9 mm2/s, and a flash point of 165°C. It also contains high catalytic activity in the transesterification process of wasted cooking oil (WCO) for optimizing biodiesel characteristics in the future. As a result, the catalyst demonstrated high action in the transesterification effect. Scanning Electron Microscopy (SEM) illustrates calcined waste shells are irregular in shape, which means small, minute grains of pores accumulate, providing a large area of surface. Furthermore, the physical characteristics of CaO catalysts at 800 °C showed Brunauer- Emmett-Teller (BET) a significant surface area of 76.1888 m2/g and pore volume of 2.6539 cm3/g is considerably greater than other catalysts at temperatures of 500 °C–1000 °C. X-ray diffraction (XRD) data analysis demonstrate the main constituent of seashells is CaCO3, indicated by the diffraction peak at 2𝜃 approximately 28.48∘. However, carbon dioxide CO2 changes when the calcination temperature at 800 °C it transforms CaCO3 completely into CaO, which is the main component of the calcined catalyst. The CaO catalyst's well-crystallized structure is defined by the narrow, high-intensity peaks of catalyst. Eventually, the heterogeneous catalyst led to a significant rise in the active sites.read more

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Esraa Mohamed Musa and Norah A. Alsaiari

Interaction Activity of Metal-Free Phthalocyanine Compound Bearing Tetra -(2-(N-2´-Cyanoethyl)aminoethylsulfanyl) Units with DNA

The phthalocyanine having 4-(2-(N-2´-cyanoethyl)aminoethylsulfanyl) group had been reported earlier in the literature. In this current studying, DNA binding activity of 1Pc phthalocyanine bearing 4-(2-(N-2´-cyanoethyl)aminoethylsulfanyl units was examined spectroscopically via elctronic absoption, fluorescence titration, melting point profile, electrophoresis and viscosity methods. The interaction activity of 1Pc compound was examined at differing concentrations. UV/Vis spectrometer, viscosity, fluorescence spectroscopy and thermal melting temperature confirmed that 1Pc binds to the DNA. The Kb of 1Pc is also estimated via UV/Vis titration and Kb of 1Pc was computed as 2.1394 x 106 M-1. The Kb value demonstrated that 1Pc reacts with DNA by an intercalative mechanism. Alongside this research, the mechanism by which the compound binds to DNA was investigated by determining Tm. The Tm of DNA + 1Pc complex was identified as 74.31. This data confirmed that 1Pc binds to DNA intercalatively. All the results obtained from the used methods demonstrated that 1Pc phthalocyanine compound has an efficient DNA interaction activity and 1Pc phthalocyanine compound interacts with DNA via an intercalative mechanism. As a result, the compound may be a therapeutic agent due to its DNA interaction property.read more

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Ali Arslantaş and Mehmet Salih Ağırtaş

Green Synthesis and Characterization of Moringa Extract Fe-TiO2 Nanocomposites for Efficient Photodegradation of Methylene Blue from Wastewater

In this study, iron-doped titanium dioxide (TiO2) nanocomposites were synthesized using Moringa oleifera leaf extract via a green two-step sol-gel method, aiming to enhance photocatalytic degradation performance under sunlight. The Moringa-mediated synthesis provided an eco-friendly and cost-effective route for obtaining Fe-doped TiO2 nanomaterials (MFTNc) with improved structural and optical characteristics. X-ray diffraction (XRD) confirmed the anatase phase and revealed a reduction in crystallite size with increasing Fe content, while FTIR analysis validated the presence of key functional groups and Fe–O–Ti bonding. UV–Vis spectroscopy demonstrated a significant redshift in absorption and narrowing of the band gap from 3.21 eV (pure TiO2) to 2.98 eV (0.9% Fe-doped TiO2), enabling visible light activation. The photocatalytic activity was evaluated through the degradation of methylene blue (MB) under solar irradiation. The 0.9% Fe-doped TiO2 sample exhibited the highest degradation efficiency (22.5%), significantly outperforming pure TiO2 (9.25%) due to enhanced charge carrier separation and reactive oxygen species (ROS) generation. These results highlight the potential of MFTNc as a sustainable and efficient photocatalyst for environmental remediation applications.read more

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Ayesha Noor, Muhammad Irfan, Alishba Qureshi, Somia Bibi, M. Naziruddin Khan, Fatimah M. Alzahrani, Wissem Mnif

Prussian Blue: History, Miscellaneous Uses and Analytical Applications-A Review

Since the accidental discovery of Prussian Blue in 1706, the blue chemical has been extensively employed in a number of commercial applications. It has been used as a color for paintings, dye for textile, antidote for heavy metal toxicity, staining agent in histopathology, and by machinists and toolmakers for spotting metal surfaces. In addition, due to its unique electrochemical properties, Prussian Blue has been vastly studied as storage of electric energy and used as a battery material. The electroanalytical applications of Prussian Blue and its different analogs have also been thoroughly investigated and used as sensors and biosensor for last few decades. Very recently the investigations have been made on the use of nanoparticles of Prussian Blue in biomedicine. The deep blue color and easy formation of Prussian Blue as a result of redox properties of iron ions, made it an excellent coloring reagent, which shows absorption around 700nm, for the spectrophotometric determination of a large variety of materials like phenols, sugars, drugs, ascorbic acid, antibiotics, adrenaline, hydroxy urea, dopamine, and penems in a vast range of substances such as soil, fruit, vegetables, pharmaceutical preparations and tobacco. Similarly, on the basis of Prussian Blue, a number of sensors and biosensor schemes have been developed for the detection and determination of a number of substances. Prussian Blue has a fascinating and interesting history along with its miscellaneous uses since the start of 18th century. In this review an attempt has been made to cover the history, miscellaneous uses and analytical applications of Prussian Blue employed as spectrophotometric reagent and a biosensor.read more

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Rimsha Rey Khan and Jamil Anwar