Enhanced red luminescence in CaAl12O19:Mn4+via doping Ga3+ for plant growth lighting

Symmetrical Ligand's Fabricated Porous Silicon Surface Based Photoluminescence Sensor for Metal Detection and Entrapment

This study was based on the development of surface-based photoluminescence sensor for metal detection, quantification, and sample purification employing the solid sensory chip having the capability of metal entrapment. The Co(II), Cu(II) and Hg(II) sensitive fluorescence sensor (TP) was first synthesized and characterized its sensing abilities towards tested metal ions by using fluorescence spectral investigation while the synthesis and complexation of the receptor was confirmed by the chromogenic, optical, spectroscopic and spectrometric analysis. Under optical investigation, the ligand solution exhibited substantial chromogenic changes as well as spectral variations upon reacting with copper, cobalt, and mercuric ions, while these behaviors were not seen for the rest of tested metallic ions i.e., Na+, Ag+, Ni2+, Mn2+, Pd2+, Pb2+, Cd2+, Zn2+, Sn2+, Fe2+, Fe3+, Cr3+, and Al3+. These colorimetric alterations and spectral shifting could potentially be employed to detect and quantify these specific metal ions. After the establishment of the ligand's selective complexation ability towards selected metals, it was fabricated over the substituted porous silicon surface (FPS) keeping in view of the development of surface-based photoluminescence sensor (TP-FPS) for the selected metal sensation and entrapment to purify the sample just be putting off the metal entrapped sensory solid chip. Surface characterization and ligand fabrication was inspected by plan and cross sectional electron microscopic investigations, vibrational and electronic spectral analysis. The sensitivity of the ligand (TP) in the solution phase metal discrimination was determined by employing the fluorescence titration analysis of the ligand solution after progressive induction of Co2+, Cu2+, and Hg2+, which afford the detection limit values of 2.14 × 10- 8, 3.47 × 10- 8 and 3.13 × 10- 3, respectively. Concurrently, photoluminescence titration of the surface fabricated sensor (TP-FPS) revealed detection limit values of 3.14 × 10- 9, 7.43 × 10- 9, and 8.21 × 10- 4, respectively, for the selected metal ions.

Revealing the Structural, Elastic, Electronic, and Optical Properties of K2ScCuCl6 and K2YCuCl6: An In-Depth Exploration Using Density Functional Theory

The optoelectronic, structural, and elastic properties of K2ScCuCl6 and K2YCuCl6 double perovskite compounds were thoroughly investigated in this study using density functional theory. It is observed that both compounds exhibit exceptional structural and mechanical stability. The structural stability is assessed using Goldsmith's tolerance factor (tG), with values approaching unity indicating a reliable cubic perovskite structure. Phonon stability was ensured by the absence of negative energy formations and only real frequencies in the phonon calculations. Applying the finite displacement method also provided further evidence of the compounds' thermodynamic stability. The electronic properties analysis revealed that K2ScCuCl6 and K2YCuCl6 are narrow band gap semiconductors, with band gap values of 1.8 and 2.5 eV, respectively. This was confirmed by analyzing the density of states. Furthermore, the optical properties exhibited transparency at lower photon energies and significant absorption at higher energies. These exciting findings suggest that K2ScCuCl6 and K2YCuCl6 have promising applications in high-frequency UV devices.

A review of recent advancement in covalent organic framework (COFs) synthesis and characterization with a focus on their applications in antibacterial activity

The primary objective of this review is to present a comprehensive examination of the synthesis, characterization, and antibacterial applications of covalent organic frameworks (COFs). COFs represent a distinct category of porous materials characterized by a blend of advantageous features, including customizable pore dimensions, substantial surface area, and adaptable chemical properties. These attributes position COFs as promising contenders for various applications, notably in the realm of antibacterial activity. COFs exhibit considerable potential in the domain of antibacterial applications, owing to their amenability to functionalization with antibacterial agents. The scientific community is actively exploring COFs that have been imbued with metal ions, such as copper or silver, given their observed robust antibacterial properties. These investigations strongly suggest that COFs could be harnessed effectively as potent antibacterial agents across a diverse array of applications. Finally, COFs hold immense promise as a novel class of materials for antibacterial applications, shedding light on the synthesis, characterization, and functionalization of COFs tailored for specific purposes. The potential of COFs as effective antibacterial agents beckons further exploration and underscores their potential to revolutionize antibacterial strategies in various domains.

Room Temperature Ultrafast Oxidative Desulfurization with Sodium Hypochlorite in the Presence of Silica-Supported Catalysts

A series of silica-supported catalysts containing molybdenum, tungsten, and vanadium oxides as the active phase was investigated in the process of oxidative desulfurization with sodium hypochlorite. It was shown for the first time that catalysts containing vanadium oxide as the active phase are more stable under oxidation conditions with sodium hypochlorite and retain their effectiveness at increased dosages of the oxidant and at high initial sulfur contents. The catalysts were characterized in detail by a complex of methods: Fourier transform infrared, X-ray spectral fluorescence, transmission electron microscopy, scanning electron microscopy, and low-temperature nitrogen adsorption/desorption. Key factors affecting the oxidation of dibenzothiophene (DBT) were investigated: oxidant and catalyst amount, oxidation time, initial sulfur content, and acetonitrile amount. Under optimized conditions, the DBT conversion rate was 100% in 5 min at room temperature (25 °C), NaClO/S molar ratio 6:1, catalyst amount 2 wt %. In the real sample of the straight-run diesel fraction, the sulfur content was reduced from 10,100 to 3030 ppm. The V(10%)/SiO2 catalyst retains its activity for 5 oxidation-regeneration cycles.

An electrochemical sensor for the determination of environmentally hazardous fungicide pyrimethanil in water and fruit samples

We developed a facile electroanalytical system for the rapid and sensitive detection of pyrimethanil through the modification of carbon paste electrode surface using the as-fabricated europium doped feather-type CuO nanoflowers (FT-Eu3+-CuO NF sensor). The peak current of pyrimethanil oxidation was elevated by the sensor due to the integration of appreciable electrochemical features of the modifier, which indicates the high ability of the modified electrode to enhance the sensitivity of pyrimethanil detection. The pyrimethanil sensor under the optimized setting had a broad linear dynamic range (0.001-800.0 μM) and a narrow limit of detection (0.18 nM). The practical applicability of the as-fabricated electrode was verified by sensing pyrimethanil in real samples; it also exhibited commendable specificity, stability and reproducibility.

Preparation and characterization of sulphur and zinc oxide Co-doped graphitic carbon nitride for photo-assisted removal of Safranin-O dye

Recently, there has been significant interest in photocatalytic reactions involving graphitic carbon nitride (g-C3N4) due to its sp2-hybridized carbon and nitrogen content and it is an ideal candidate for blending with other materials to enhance performance. Here, we have synthesized and analyzed both doped and undoped g-C3N4 nanoparticles. Specifically, we co-doped sulfur (S) into g-C3N4, integrated it with ZnO particles, and investigated the photocatalytic potential of these nanocomposites to remove Safranin-O dye. The initial step involved the preparation of pure g-C3N4 through calcination of urea. Subsequently, S-g-C3N4 was synthesized by calcining a mixture of urea and thiourea with a 3 : 1 ratio. Finally, the ZnO-S-g-C3N4 composite was synthesized using the liquid exfoliation technique, with distilled water serving as the exfoliating solvent. These samples were characterized by advanced techniques, including UV-Vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), X-ray Diffraction (XRD), energy dispersive X-ray (EDX) and scanning electron microscopy (SEM), to assess their crystallinity, morphology, optical properties, and phase purity. Subsequently, these nanocomposites were employed in catalytic and photocatalytic processes to remove the Safranin-O dye (SO). The results highlighted the formation of Z-scheme junction responsible for ZnO-S-g-C3N4's significant performance improvement. The comparison of results demonstrated that S-g-C3N4 and ZnO-S-g-C3N4 composites revealed an effective removal of Safranin-O dye in the presence of UV-light as compared to pure g-C3N4, as it was attributed to the phenomenon of improved separation of photogenerated charge carriers as a result of heterojunction formation between S-g-C3N4 and ZnO interfaces. In addition to improving photocatalytic performance, this study presents a facile route for producing ZnO-S-g-C3N4 composite with superior adsorption capabilities and selectivity.

Ratiometric Fluorescence and Chromogenic Probe for Trace Detection of Selected Transition Metals

The design and development of a fluorescence sensor aimed at detecting and quantifying trace amounts of toxic transition metal ions within environmental, biological, and aquatic samples has garnered significant attention from diagnostic and testing laboratories, driven by the imperative to mitigate the health risks associated with these contaminants. In this context, we present the utilization of a heterocyclic symmetrical Schiff Base derivative for the purpose of fluorogenic and chromogenic detection of Co2+, Cu2+ and Hg2+ ions. The characterization of the ligand involved a comprehensive array of techniques, including physical assessments, optical analyses, NMR, FT-IR, and mass spectrometric examinations. The mechanism of ligand-metal complexation was elucidated through the utilization of photophysical parameters and FT-IR spectroscopic analysis, both before and after the interaction between the ligand and the metal salt solution. The pronounced alterations observed in absorption and fluorescence spectra, along with the distinctive chromogenic changes, following treatment with Co2+, Cu2+ and Hg2+, affirm the successful formation of complexes between the ligands and the treated metal ions. Notably, the receptor's complexation response exhibited selectivity towards Co(II), Cu(II), and Hg(II), with no observed chromogenic changes, spectral variations, or band shifts for the various tested metal ions, including Na+, Ag+, Ni2+, Mn2+, Pd2+, Pb2+, Cd2+, Zn2+, Sn2+, Fe2+, Fe3+, Cr3+ and Al3+. This absence of interaction between these metal ions and the ligand could be attributed to their compact or inadequately conducive conduction bands for complexation with the ligand's structural composition. To quantify the sensor's efficacy, fluorescence titration spectra were employed to determine the detection limits for Co2+, Cu2+ and Hg2+, yielding values of 2.92 × 10-8, 8.91 × 10-8, and 4.39 × 10-3 M, respectively. The Benesi-Hildebrand plots provided association constant values for the ligand-cobalt, ligand-copper, and ligand-mercury complexes as 0.74, 2.52, and 13.89 M-1, respectively.

Microfluidic-based nanoemulsion of Ocimum basilicum extract: Constituents, stability, characterization, and potential biomedical applications for improved antimicrobial and anticancer properties

This paper reports on the findings from a study that aimed to identify and characterize the constituents of Ocimum basilicum extract using gas chromatography-mass spectrometry (GC-MS) analysis, as well as assess the physicochemical properties and stability of nanoemulsions formulated with O. basilicum extract. The GC-MS analysis revealed that the O. basilicum extract contained 22 components, with Caryophyllene and Naringenin identified as the primary active constituents. The nanoemulsion formulation demonstrated excellent potential for use in the biomedical field, with a small and uniform particle size distribution, a negative zeta potential, and high encapsulation efficiency for the O. basilicum extract. The nanoemulsions exhibited spherical morphology and remained physically stable for up to 6 months. In vitro release studies indicated sustained release of the extract from the nanoemulsion formulation compared to the free extract solution. Furthermore, the developed nanoformulation exhibited enhanced anticancer properties against K562 cells while demonstrating low toxicity in normal cells (HEK293). The O. basilicum extract demonstrated antimicrobial activity against Pseudomonas aeruginosa, Candida albicans, and Staphylococcus epidermidis, with a potential synergistic effect observed when combined with the nanoemulsion. These findings contribute to the understanding of the constituents and potential applications of O. basilicum extract and its nanoemulsion formulation in various fields, including healthcare and pharmaceutical industries. Further optimization and research are necessary to maximize the efficacy and antimicrobial activity of the extract and its nanoformulation. RESEARCH HIGHLIGHTS: This study characterized the constituents of O. basilicum extract and assessed the physicochemical properties and stability of its nanoemulsion formulation. The O. basilicum extract contained 22 components, with Caryophyllene and Naringenin identified as the primary active constituents. The nanoemulsion formulation demonstrated excellent potential for biomedical applications, with sustained release of the extract, low toxicity, and enhanced anticancer and antimicrobial properties. The findings contribute to the understanding of the potential applications of O. basilicum extract and its nanoemulsion formulation in healthcare and pharmaceutical industries, highlighting the need for further optimization and research.

Pressure-Triggered Fluorescence Intensity Ratio Variations of YNbO4:Bi3+/Ln3+ (Ln = Eu or Sm) for High-Sensitivity Optical Pressure Sensing

Optical pressure sensing by phosphors is a growing area of research. However, the main pressure measurement methods rely on the movement of the central peak position, which has significant drawbacks for practical applications. This paper demonstrates the feasibility of using the fluorescence intensity ratio (FIR) of different emission peaks for pressure sensing. The FIR (IBi3+/ILn3+) values of the synthesized YNbO4:Bi3+/Ln3+ (Ln = Eu or Sm) phosphors are all first-order exponentially related to pressure, and YNbO4:Bi3+/Ln3+ (Ln = Eu or Sm) phosphors have high pressure-sensing sensitivities (Sp and Spr), which are 6 times higher than those from our previously reported work. In addition, the changes in FIR values during the decompression process were also calculated, and the trend was similar to that during the compression process. The YNbO4:Bi3+,Eu3+ phosphor has better pressure recovery performance. In summary, the YNbO4:Bi3+/Ln3+ (Ln = Eu or Sm) phosphors reported in this paper are expected to be applied in the field of optical pressure sensing, and this study provides a new approach and perspective for designing new phosphors for pressure measurement.

Statistical computational optimization approach for photocatalytic-ozonation decontamination of metronidazole in aqueous media using CuFe2O4/SiO2/ZnO nanocomposite

The increasing use of pharmaceuticals and the ongoing release of drug residues into the environment have resulted in significant threats to environmental sustainability and water safety. In this sense, developing a robust and easy-recovered magnetic nanocomposite with eminent photocatalytic activity is very imperative for detoxifying pharmaceutical compounds. Herein, a systematic study was conducted to investigate the photocatalytic ozonation for eliminating metronidazole (MET) from aqueous media utilizing the CuFe2O4/SiO2/ZnO heterojunction under simulated sunlight irradiation. The composite material was fabricated by a facile hydrothermal method and diagnosed by multiple advanced analytical techniques. Modelling and optimization of MET decontamination by adopting the central composite design (CCD) revealed that 90 % of MET decontamination can be achieved within 120 min of operating time at the optimized circumstance (photocatalyst dose: 1.17 g/L, MET dose: 33.20 mg/L, ozone concentration: 3.99 mg/min and pH: 8.99). In an attempt to scrutinize the practical application of the CuFe2O4/SiO2/ZnO/xenon/O3 system, roughly 56.18% TOC and 73% COD were removed under the optimized operational circumstances during 120 min of degradation time. According to the radical quenching experiments, hydroxyl radicals (HO•) were the major oxidative species responsible for the elimination of MET. The MET degradation rate maintained at 83% after seven consecutive runs, manifesting the efficiency of CuFe2O4/SiO2/ZnO material in the MET removal. Ultimately, the photocatalytic ozonation mechanism over the CuFe2O4/SiO2/ZnO heterojunction of the fabricated nanocomposites was rationally proposed for MET elimination. In extension, the results drawn in this work indicate that integrating photocatalyst and ozonation processes by the CuFe2O4/SiO2/ZnO material can be applied as an efficient and promising method to eliminate tenacious and non-biodegradable contaminants from aqueous environments.

A systematic review on Nb2O5-based photocatalysts: Crystallography, synthetic methods, design strategies, and photocatalytic mechanisms

With the increasing popularity of photocatalytic technology and the highly growing issues of energy scarcity and environmental pollution, there is an increasing interest in extremely efficient photocatalytic systems. The widespread immense attention and applicability of Nb2O5 photocatalysts can be attributed to their multiple benefits, including strong redox potentials, non-toxicity, earth abundance, corrosion resistance, and efficient thermal and chemical stability. However, the large-scale application of Nb2O5 is currently impeded by the barriers of rapid recombination loss of photo-activated electron/hole pairs and the inadequacy of visible light absorption. To overcome these constraints, plentiful design strategies have been directed at modulating the morphology, electronic band structure, and optical properties of Nb2O5. The current review offers an extensive analysis of Nb2O5-based photocatalysts, with a particular emphasis on crystallography, synthetic methods, design strategies, and photocatalytic mechanisms. Finally, an outline of future research directions and challenges in developing Nb2O5-based materials with excellent photocatalytic performance is presented.

Preparation of polylactic acid reinforced with cellulose nanofibers toward photochromic self-healing adhesive for anti-counterfeiting applications

There are a number of drawbacks with photochromic adhesives, including their poor durability, high price tag, and lackluster performance. On the other hand, self-healable adhesives have shown to be durable and robust than conventional alternatives. Hydrogel adhesives that change color in response to ultraviolet light were created for usage in self-healable authenticating stamps. In this context, a combination of cellulose nanofibers (CNFs), polylactic acid (PLA) and nanoparticles of lanthanide aluminate (NLA) were prepared to generate an organic-inorganic hybrid hydrogel adhesive with self-healing properties. NLA agglomerates were avoided due to the use of CNFs as a nanofiller and dispersion agent. Colorless stamps require that NLA to be dispersed consistently in the CNFs/PLA hydrogel without clumping. This film becomes green when irradiated with ultraviolet, as indicated by luminescence spectra and CIE Lab coordinates. When illuminated at 365 nm, the paper sheets emitted light with a wavelength of 519 nm. The morphologies of prints were analyzed by different analytical methods. Diameter measurements from a transmission electron microscope (TEM) of the synthesized NLA ranged from 5 to 9 nm, whereas CNFs displayed diameters of 40-60 nm. The current NLA@CNFs/PLA hydrogel presents a reliable anti-counterfeiting solution for various authenticating products.

Copper (II) complex supported on magnetic nanoparticles as a novel nanocatalyst for the synthesis of imidazo[1,2-a]pyridines

Research on the synthesis of imidazo[1,2-a]pyridines has gained great importance among synthetic chemists because there have been numerous reports of their biological and medicinal activities. In this respect, we fabricated CuCl2 immobilized on Fe3O4 nanoparticles modified with 1,10-phenanthroline-5,6-diol [Fe3O4@Diol/Phen-CuCl2] and investigated its catalytic activity for the preparation of imidazo[1,2-a]pyridine derivatives through one-pot three-component reaction of 2-aminopyridines, aldehydes and terminal alkynes under ecofriendly conditions. FT-IR spectroscopy, EDX, SEM, TEM, XRD, TGA, VSM and ICP-OES techniques employed in order to identify the structure of the as-constructed Fe3O4@Diol/Phen-CuCl2 nanocatalyst. This catalytic system has a series of advantages such as the synthesis of imidazo[1,2-a]pyridine products with high yields in suitable time, performing the reactions in an environmentally friendly solvent (PEG), easy preparation of the catalyst with a simple method, and the recyclability of the Fe3O4@Diol/Phen-CuCl2 nanocatalyst.

Synthesis, characterization, Hirshfeld surface analysis, antioxidant and selective β-glucuronidase inhibitory studies of transition metal complexes of hydrazide based Schiff base ligand

The synthesis of N'-[(4-hydroxy-3-methoxyphenyl)methylidene] 2-aminobenzohydrazide (H-AHMB) was performed by condensing O-vanillin with 2-aminobenzohydrazide and was characterized by FTIR, high resolution ESI(+) mass spectral analysis, 1H and 13C-NMR. The compound H-AHMB was crystallized in orthorhombic Pbca space group and studied for single crystal diffraction analysis. Hirshfeld surface analysis was also carried out for identifying short interatomic interactions. The major interactions H…H, O…H and C…H cover the Hirshfeld surface of H-AHMB. The metal complexes [M(AHMB)n] where M = Co(II), Ni(II), Cu(II) and Zn(II) were prepared from metal chlorides and H-AHMB ligand. The bonding was unambigously assigned using FTIR and UV/vis analysis. The synthesized ligand H-AHMB and its metal complexes were studied for β-glucuronidase enzyme inhibition. Surprisingly the metal complexes were found more active than the parent ligand and even the standard drug. Zn-AHMB shown IC50 = 17.3 ± 0.68 µM compared to IC50 = 45.75 ± 2.16 µM shown by D-saccharic acid-1,4-lactone used as standard. The better activity by Zn-AHMB implying zinc based metallodrug for the treatment of diseases associated with β-glucuronidase enzyme. The DPPH radical scavenging activities were also studied for all the synthesized compounds. The Co-AHMB complex with IC50 = 98.2 ± 1.78 µM was the only candidate to scavenge the DPPH free radicals.

Construction and characterization of a magnetic nanoparticle-supported Cu complex: a stable and active nanocatalyst for synthesis of heteroaryl-aryl and di-heteroaryl sulfides

Diaryl and di-heteroaryl sulfides exist in the structure of many drugs and important biological compounds, also these compounds are well-known in medicinal chemistry due to important biological and pharmaceutical activities. Therefore, the development of novel, ecofriendly and efficient catalytic systems for the preparation of diaryl and di-heteroaryl sulfides is a very attractive and important challenge in organic synthesis. In this attractive methodology, we wish to introduce Fe3O4-supported 3-amino-4-mercaptobenzoic acid copper complex (Fe3O4@AMBA-CuI) nanomaterials as a novel and efficient magnetically recoverable catalyst for the preparation of heteroaryl-aryl and di-heteroaryl sulfides with high yields through reaction of heteroaryl halides with aryl or heteroaryl boronic acids and S8 as the sulfur source under ecofriendly conditions. This catalytic system was very efficient and practical for a diverse range of heteroaryl substrates including benzothiazole, benzoxazole, benzimidazole, oxadiazole, benzofuran, and imidazo[1,2-a]pyridine, because the desired diaryl and di-heteroaryl sulfides were prepared with high yields. The reusability-experiments revealed that the Fe3O4@AMBA-CuI nanocatalyst can be magnetically separated and reused at least six times without a significant decrease in its catalytic activity. VSM and ICP-OES analyses confirmed that despite using the Fe3O4@AMBA-CuI nanocatalyst 6 times, the magnetic properties and stability of the catalyst were still maintained. Although all the obtained heteroaryl-aryl and di-heteroaryl sulfide products are known and previously reported, the synthesis of this number of heteroaryl-aryl and di-heteroaryl sulfides has never been reported by any previouse methods.

Synthesis and characterizations of super adsorbent hydrogel based on biopolymer, Guar Gum-grafted-Poly (hydroxyethyl methacrylate) (Gg-g-Poly (HEMA)) for the removal of Bismarck brown Y dye from aqueous solution

Chemical modification of guar gum was done by graft copolymerization of monomer hydroxyethyl methacrylate (HEMA) using azobisisobutyronitrile (AIBN) as initiator. Optimal reaction parameters were settled by varying one reaction condition and keeping the other constant. The optimum reaction conditions worked out were solvent system: binary, [H2O] = 15.00 mL, [acetone] = 5.00 mL, [HEMA] = 82.217× 10-2 mol/L, [AIBN] = 3.333 × 10-2 mol/L, reaction time = 3 h, reaction temperature = 60 °C on to 1.00 g guar gum with Pg = 1694.6 and %GE = 68,704.152. Pure guar gum polymer and grafts were analyzed by several physicochemical investigation techniques like FTIR, SEM, XRD, EDX, and swelling studies. Percent swelling of the guar gum polymer and grafts was investigated at pH 2.2, 7.0, 7.4 and 9.4 concerning time. The finest yield of Ps was recorded at pH 9.4 with time 24 h for graft copolymer. Guar gum and grafted samples were explored for the sorption of toxic dye Bismarck brown Y from the aqueous solution with respect to variable contact time, pH, temperature and dye concentration so as to investigate the stimuli responsive sorption behaviour. Graft copolymers showed better results than guar gum with percent dye uptake (Du) of 97.588 % in 24 h contact time, 35 °C temperature, 9.4 pH at 150.00 ppm dye feed concentration as compared to Guar gum which only showed 85.260 % dye uptake at alike dye fed concentration. The kinetic behaviour of the polymeric samples was evaluated by applying many adsorption isotherms and kinetic models. The value of 1/n was between 0 → 1 showing that there was physisorption of the BB dye that took place on the surface of the polymers. Thermodynamics of BB Y adsorption onto hydrogels was investigated concerning the Van't Hoff equation. -∆G° values obtained from the curve proved the spontanity of the process. Within the context of adsorption efficiency, an investigation was conducted to examine the process of sorption of Bismarck brown Y dye from aqueous solutions. The graft copolymers demonstrated remarkable adsorption abilities, achieving a dye uptake (Du) of 97.588 % over a 24-h period at a temperature of 35 °C, pH level of 9.4, and a dye concentration of 150.00 ppm. The raised adsorption capacity was additionally corroborated by the application of several adsorption isotherms and kinetic models, which indicated that physisorption is the prevailing process/mechanism. Additionally, the thermodynamic research, utilising the Van't Hoff equation, validated the spontaneity of the adsorption phenomenon, as evidenced by the presence of a negative ∆G° values. The thermodynamic analysis revealed herein establishes a strong scientific foundation for the effectiveness of adsorbent composed of graft copolymers based on guar gum. The research conclude the efficiency of the guar gum based grafted copolymers for the water remediation as efficient adsorbents. The captured dye can be re-utilised and the hydrogels can be used for the same purpose in number of cycles.

A computational insight into enhancement of photovoltaic properties of non-fullerene acceptors by end-group modulations in the structural framework of INPIC molecule

Improving the open circuit voltage is a major challenge for enhancing the overall efficiency of organic solar cells. Current work has concentrated on improving open-circuit voltage by designing new molecular frameworks from an INPIC molecule having a conjugated fused core. We modulated the structure by changing the terminal groups of the reference molecule (INPIC) with seven strong electron-withdrawing units. We investigated various optoelectronic attributes, charge transfer, and photovoltaic and geometrical parameters by compiling the B3LYP/6-31G(d,p) functional of the DFT approach. The optical absorption for modulated molecules ranges from 748.51 nm to 845.96 nm while showing higher oscillation strength than INPIC. At the same time, their impressive charge transport is attributed to their smaller excitation and exciton binding energy, higher electron/hole mobility, narrower band gap, and a more than 99 % intramolecular charge transfer. The larger dipole moments help in the dense interaction of acceptors with employed donor J61 which, in turn, improves charge transfer at the donor-acceptor interface. One of the triumphs that are difficult to get in organic molecules is success in achieving a higher open circuit voltage (VOC). Our conceptualized molecular frameworks of acceptors are featured with a notable VOC improvement in the range of 1.84-2.05 eV. Thus, the results of the current investigation pave the root for architecting the acceptor molecules with impressive optoelectrical properties that may be capable of providing high photovoltaic output. Thus these acceptors can be utilized for the development of advanced organic solar cells in future.

Achieving enhanced sensitivity and accuracy in carcinoembryonic antigen (CEA) detection as an indicator of cancer monitoring using thionine/chitosan/graphene oxide nanocomposite-modified electrochemical immunosensor

The current study has focused on electrochemical immunosensing of carcinoembryonic antigen (CEA) employing an immobilized antibody on a thionine, chitosan, or graphene oxide nanocomposite modified glassy carbon electrode (anti-CEA/THi-CS-GO/GCE) as an indicator of cancer monitoring. THi-CS-GO nanocomposites were made using ultrasonication, and analyses of their morphology and crystal structure using SEM, FTIR, and XRD showed that thionine and chitosan molecules were intercalated with stacking interactions with both the top and bottom of GO nanosheets. Electrochemical experiments revealed anti-CEA, THi-CS-GO/GCE to have exceptional sensitivity and selectivity towards CEA compounds. The detection limit value was established to be 0.8 pg/mL when it was discovered that variations in the decrease peak current were directly proportional to the logarithm concentration of CEA over a wide range from 10-3 to 104 ng/mL. Results of testing the immunosensor's application capability for detecting CEA in a sample of human serum show that ELISA and DPV results are very congruent. The produced immunosensor demonstrated adequate immunosensor precision in determining CEA in prepared genuine samples of human serum and clinical applications.

Pseudomonas fluorescens and L-tryptophan application triggered the phytoremediation potential of sunflower (Heliantus annuus L.) in lead-contaminated soil

Lead, a toxic heavy metal present in soil, hampers biological activities and affects the metabolism of plants, animals, and human beings. Its higher concentration may disturb the various physio-chemical processes, which result in stunted and poor plant growth. An interactive approach of plant growth promoting rhizobacteria (PGPR) and L-tryptophan can be used to mitigate the lethal effects of lead. A pot experiment was conducted, and two weeks before sowing, the level of lead (300 mg kg-1) was maintained by spiking the PbCl2 salt. Pseudomonas fluorescens and L-tryptophan were applied individually as well as in combination to segregate the effect of both in contaminated soil under a completely Randomized Design (CRD). Statistical analysis revealed that plant growth was significantly reduced up to 22% due to lead contamination. However, the interactive approach of PGPR and L-tryptophan significantly improved the plant growth, physiology, and yield with relative productive index (RPI) under a lead-stressed environment. Moreover, integrated use of PGPR and L-tryptophan demonstrated a considerable increase (22%) in lead removal efficiency (LRE) by improving bioconcentration factor (BCF) and translocation factor (TF) for shoot without increasing the lead concentration in achenes. The reduced lead concentration in achene was due to its immobilization in shoot and root by negatively charged particles and improved the lead sequestration in vegetative parts which abridged the translocation of lead into achenes.

The chemical recognition of hydrogen fluoride via B24N24 nanocage: quantum chemical approach

CONTEXT

Ab initio calculations were employed in this investigation to scrutinize the adsorption characteristics of a linear chain (HF)n on a BN nanocage (B24N24), wherein the chain lengths varied (n = 1, 2, 3, and 4). The overarching aim was to assess the efficiency of this setup in detecting and adhering to (HF)n under both liquid and gaseous scenarios. This study encompassed an array of aspects, encompassing adsorption energy, optimal configuration determination, work function analysis, and charge exchange assessment. Furthermore, an exploration was conducted into the impact of HF linear chain dimensions on electrical attributes and adsorption energy. According to the values of adsorption energy, the dimer form of HF adsorbed onto BN nanocages displayed the highest stability.

METHODS

This scrutiny was undertaken utilizing density functional theory (DFT), employing the B3LYP functional and the 6-31 +  + G(d,p) basis set. Notably, the choice of the 6-31 +  + G(d,p) basis set is particularly apt for delving into nanostructure analyses. The HOMO-LUMO energy gap was significantly reduced by (HF)n upon adsorption onto the nanocage, falling from 6.48 to 5.43 eV and enhancing electrical conductivity as a result. Additionally, BN nanocages may be used as sensors to find (HF)n among other environmental pollutants.

CO2 reduction reaction on Sc-doped nanocages as catalysts

CONTEXT

The catalytic ability of Sc-doped C46 and Sc-doped Al23P23 as catalysts of CO2-RR to create the CH4 and CH3OH is investigated. The mechanisms of CO2-RR are examined by theoretical methods and ΔGreaction of reaction steps of CO2-RR mechanisms are calculated. The overpotential of CH4 and CH3OH production on Sc-doped C46 and Sc-doped Al23P23 is calculated. The Sc atoms of Sc-doped C46 and Sc-doped Al23P23 can adsorb the CO2 molecule as the first step of CO2-RR. The CH4 is produced from hydrogenation of *CH3O and the *CO → *CHO reaction step is the rate limiting step for CH4 production. The CH3OH can be formed on Sc-doped C46 and Sc-doped Al23P23 by *CO → *CHO → *CH2O → *CH3O → CH3OH mechanism and HCOOH → *CHO → *CH2O → *CH3O → CH3OH mechanism. The Sc-C46 and Sc-Al23P23 can catalyze the CO2-RR to produce the CH4 and CH3OH by acceptable mechanisms.

METHODS

Here, the structures are optimized by PW91PW91/6-311+G (2d, 2p) and M06-2X/cc-pVQZ methods in GAMESS software. The frequencies of nanocages and their complexes with species of CO2-RR are investigated by mentioned methods. The transition state of each reaction step of CO2-RR is searched by Berny method to find the CO2-RR intermediates. The ∆Eadsorption of intermediates of CO2-RR on surfaces of nanocages is calculated and the ∆Greaction of reaction steps of CO2-RR is calculated.

The iron group transition-metal (Fe, Ru, Os) coordination of Se-doped graphitic carbon (Se@g-C3N4) nanostructures for the smart therapeutic delivery of zidovudine (ZVD) as an antiretroviral drug: a theoretical calculation perspective

This study employed density functional theory (DFT) computational techniques at the ωB97XD/def2svp level of theory to comprehensively explore the electronic behavior of Fe-group transition metal (Fe, Ru, Os) coordination of Se-doped graphitic carbon (Se@g-C3N4) nanosystems in the smart delivery of zidovudine (ZVD), an antiretroviral drug. The HOMO-LUMO results of the interactions show a general reduction in energy gap values across all complexes in the following order: ZVD_Se@C3N4 < ZVD_Ru_Se@C3N4 < ZVD_Fe_Se@C3N4 < ZVD_Os_Se@C3N4. ZVD_Se@C3N4 exhibits the smallest post-interaction band gap of 3.783 eV, while ZVD_Os_Se@C3N4 presents the highest energy band gap of 5.438 eV. Results from the corrected adsorption energy (BSSE) revealed that Os_Se@C3N4 and Ru_Se@C3N4 demonstrated more negative adsorption energies of -2.67 and -2.701 eV, respectively, pointing to a more favorable interaction between ZVD and these systems, thus potentially enhancing the drug delivery efficiency. The investigation into the drug release mechanism from the adsorbents involved a comprehensive examination of the dipole moment and the influence of pH, shedding light on the controlled release of ZVD. Additionally, investigating the energy decomposition analysis (EDA) revealed that ZVD_Ru_Se@C3N4 and ZVD_Fe_Se@C3N4 exhibited the same total energy of -787.7 kJ mol-1. This intriguing similarity in their total energy levels suggested that their stability was governed by factors beyond reactivity, possibly due to intricate orbital interactions. Furthermore, analyzing the bond dissociation energies showed that all systems exhibited negative enthalpy values, indicating that these systems were exothermic at both surface and interaction levels, thus suggesting that these processes emitted heat, contributing to the surrounding thermal energy.

Sn-based materials in photocatalysis: A review

Development and the application of Sn-based materials have become more prevalent in recent years due to concerns regarding the energy crisis, environmental pollution, and the urgent need of constructing inexpensive and highly effective photocatalysis. The recent advancement in Sn-based materials for efficient photocatalysts, such as Sn alloys, Sn oxides, Sn sulfides, Sn selenides, Sn niobates, Sn tantalites, and Sn tungstates, is summarized in this study. Several design ideas for increasing the photoactivity of Sn-based materials in various photocatalytic applications are emphasized. In addition, we considered their present applications in energy generation (H2 evolution, CO2 reduction, and N2 fixation) and environmental remediation (air purification and wastewater treatment). As a result, the current review will deepen the reader's understanding of the properties and potential uses of Sn-based materials in photocatalysis. Hence, this paper will serve as a guide in promoting the domain of Sn-based materials for future photocatalytic technologies.

Investigation of the structural, electronic, mechanical, and optical properties of NaXCl3 (X = Be, Mg) using density functional theory

In our pursuit of enhancing material performance, our focus is centered on the investigation of sodium-based halide perovskites, specifically NaXCl3 (where X = Be & Mg). We are utilizing first-principles methods based on density functional theory (DFT) to delve into these materials' properties and potential improvements. This investigation is executed using the WIEN2K code, aiming to uncover a deeper understanding of these materials' properties and potential enhancements. In this study, we utilize the Full Potential Linear Augmented Plane Wave (FP-LAPW) approach to analyze the structural, mechanical, electronic, and optical properties of cubic perovskite materials NaXCl3 (X = Be, Mg). We employ the Birch-Murnaghan fitting curve to assess the structural stability of these compounds, and in each case, the compound demonstrates structural stability in its optimal or ground state. The existence of real frequencies serves as confirmation of the phonon stability for both compounds. To determine the elastic characteristics, the IRelast Package is used. This involves calculating the elastic constants, which demonstrates that the compounds have anisotropic, ductile properties and demonstrate mechanical stability. We investigate the electronic properties by analyzing the density of states and the band structure. Both compounds exhibit an indirect band gap energy of 4.15 eV for NaBeCl3 and 4.16 eV for NaMgCl3. We analyze both the total and partial density of states to gain insight into the contributions of different electronic states to the band structure. Furthermore, optical characteristics, including the dielectric function, absorption coefficient, refractive index, and reflectivity, are investigated across an energy spectrum ranging from 0 to 15 eV. These findings can offer a comprehensive insight into the development of advanced electronic devices with improved efficiency and enhanced capabilities. Furthermore, they have the capacity to inspire experimental researchers to delve further into this field for subsequent explorations.

Improving the Luminescence Performance of Monolayer MoS2 by Doping Multiple Metal Elements with CVT Method

Two-dimensional (2D) transition metal dichalcogenides (TMDCs) draw much attention as critical semiconductor materials for 2D, optoelectronic, and spin electronic devices. Although controlled doping of 2D semiconductors can also be used to tune their bandgap and type of carrier and further change their electronic, optical, and catalytic properties, this remains an ongoing challenge. Here, we successfully doped a series of metal elements (including Hf, Zr, Gd, and Dy) into the monolayer MoS2 through a single-step chemical vapor transport (CVT), and the atomic embedded structure is confirmed by scanning transmission electron microscope (STEM) with a probe corrector measurement. In addition, the host crystal is well preserved, and no random atomic aggregation is observed. More importantly, adjusting the band structure of MoS2 enhanced the fluorescence and the carrier effect. This work provides a growth method for doping non-like elements into 2D MoS2 and potentially many other 2D materials to modify their properties.

MOFs as Versatile Catalysts: Synthesis Strategies and Applications in Value-Added Compound Production

Catalysts played a crucial role in advancing modern human civilization, from ancient times to the industrial revolution. Due to high cost and limited availability of traditional catalysts, there is a need to develop cost-effective, high-activity, and nonprecious metal-based electrocatalysts. Metal-organic frameworks (MOFs) have emerged as an ideal candidate for heterogeneous catalysis due to their physicochemical properties, hybrid inorganic/organic structures, uncoordinated metal sites, and accessible organic sections. MOFs are high nanoporous crystalline materials that can be used as catalysts to facilitate polymerization reactions. Their chemical and structural diversity make them effective for various reactions compared to traditional catalysts. MOFs have been applied in gas storage and separation, ion-exchange, drug delivery, luminescence, sensing, nanofilters, water purification, and catalysis. The review focuses on MOF-enabled heterogeneous catalysis for value-added compound production, including alcohol oxidation, olefin oligomerization, and polymerization reactions. MOFs offer tunable porosity, high spatial density, and single-crystal XRD control over catalyst properties. In this review, MOFs were focused on reactions of CO2 fixation, CO2 reduction, and photoelectrochemical water splitting. Overall, MOFs have great potential as versatile catalysts for diverse applications in the future.

Fe3O4@ABA-aniline-CuI nanocomposite as a highly efficient and reusable nanocatalyst for the synthesis of benzothiazole-sulfide aryls and heteroaryls

Studying diaryl sulfides and benzothiazoles is important in organic synthesis because numerous natural and medicinal products contain these scaffolds. Over the past few years, research on the synthesis of compounds containing benzothiazole-sulfide aryls, as important biological molecules, has received significant attention. Multicomponent reactions are the most popular strategy for performing difficult reactions and the synthesis of complexed molecules such as benzothiazole-sulfide aryls. In this work, CuI was successfully immobilized on the surface of magnetic Fe₃O₄ nanoparticles modified with aniline and 4-aminobenzoic acid [Fe₃O₄@ABA-Aniline-CuI nanocomposite] and its catalytic activity was investigated in the preparation of a broad range of benzothiazole-sulfide aryls and heteroaryls through the one-pot three-component reactions of 2-iodoaniline with carbon disulfide and aryl or heteroaryl iodides in the presence of KOAc as base in PEG-400 as solvent. TEM and SEM images revealed that the shape of the Fe₃O₄@ABA-Aniline-CuI particles is spherical and the size of the particles is approximately between 12-25 nanometers.

Luminescent Properties and Charge Compensator Effects of SrMo0.5W0.5O4:Eu3+ for White Light LEDs

The high-temperature solid-phase approach was used to synthesize Eu3+-doped SrMo0.5W0.5O4 phosphors, whose morphological structure and luminescence properties were then characterized by XRD, SEM, FT-IR, excitation spectra, emission spectra, and fluorescence decay curves. The results reveal that the best phosphor synthesis temperature was 900 °C and that the doping of Eu3+ and charge compensators (K+, Li+, Na+, NH4+) had no effect on the crystal phase change. SrMo0.5W0.5O4:Eu3+ has major excitation peaks at 273 nm, 397 nm, and 464 nm, and a main emission peak at 615 nm, making it a potential red fluorescent material to be used as a down converter in UV LEDs (273 nm and 397 nm) and blue light LEDs (464 nm) to achieve Red emission. The emission spectra of Sr1−yMo0.5W0.5O4:yEu3+(y = 0.005, 0.01, 0.02, 0.05, 0.07) excited at 273 were depicted, with the Eu3+ concentration increasing the luminescence intensity first increases and then decreases, the emission peak intensity of SrMo0.5W0.5O4:Eu3+ achieves its maximum when the doping concentration of Eu3+ is 1%, and the critical transfer distance is calculated as 25.57 Å. When various charge compensators such as K+, Li+, Na+, and NH4+ are added to SrMo0.5W0.5O4:Eu3+, the NH4+ shows the best effect with the optimal doping concentration of 3wt%. The SrMo0.5W0.5O4:Eu3+,NH4+ color coordinate is (0.656,0.343), which is close to that of the ideal red light (0.670,0.333).

Novel Materials for Urban Farming

Scarcity of natural resources, shifting demographics, climate change, and increasing waste are four major challenges in the quest to feed the exploding world population. These challenges serve as the impetus to harness novel technologies to improve agriculture, productivity, and sustainability. Urban farming has several advantages over conventional farming: higher productivity, improved sustainability, and the ability to provide fresh food all year round. Novel materials are key to accelerating the evolution of urban farming - with their ability to facilitate controlled release of nutrients and pesticides, improved seed health, substrates with better water retention capability, more efficient recycling of agricultural waste, and precise plant health monitoring. Materials science enables environmental sustainability and higher harvest yields in urban farms. Here, Singapore is used as an example of a land-scarce city where urban farming may be the solution for future food production. Potential research directions and challenges in urban farming are highlighted, and how material optimization and innovation drive the development of urban farming to meet national and global food demands is briefly discussed. This review serves as a guide for researchers and a reference for stakeholders of urban farms, policy makers, and other interested parties.

Research on the quantum confinement effect and enhanced luminescence of red-emitting P5+-doped CaAl12O19:Mn4+,Mg2+ phosphors

Mn⁴⁺-activated oxide red phosphors are always a hot topic in the luminescent material field to solve the lack of red light components in white-light-emitting diodes (WLEDs). Herein, a series of novel deep red-emitting CaAl_12-mP_mO_19+m:0.01Mn⁴⁺,0.2Mg²⁺ (m = 0-0.15) phosphors were synthesized and their crystal structure, luminescence properties and thermal stability were investigated in detail. The high-valence P⁵⁺ is used to replace low-valence Al³⁺ in the luminescent host CaAl₁₂O₁₉ to improve the photoluminescence quantum yield (PLQY) of phosphors. The doping of P⁵⁺ does not change the crystal phase structure of phosphors, and the luminescence intensity and PLQY are significantly enhanced. The analysis of the photocurrent and fluorescence lifetime shows that an electron trap with a quantum-confinement structure is formed in the phosphor host, which plays a key role in buffering photogenerated electrons. Therefore, the PLQY of the P⁵⁺-doped CaAl_11.90P_0.1O_19.10:0.01Mn⁴⁺,0.2Mg²⁺ phosphor increased from 9.8% (P⁵⁺-undoped) to 70.2%, and the mechanism of PLQY enhancement is proposed based on the analysis of the crystal structure. Furthermore, the phosphor has superior thermal stability and color purity (96.8%). Overall, this work provides new insights and ideas on quantum confinement effects for improving the quantum yield of Mn⁴⁺-activated luminescent materials.

A Novel Red-Emitting Na2NbOF5:Mn4+ Phosphor with Ultrahigh Color Purity for Warm White Lighting and Wide-Gamut Backlight Displays

In this work, a novel red-emitting oxyfluoride phosphor Na₂NbOF₅:Mn⁴⁺ with an ultra-intense zero-phonon line (ZPL) was successfully synthesized by hydrothermal method. The phase composition and luminescent properties of Na₂NbOF₅:Mn⁴⁺ were studied in detail. The photoluminescence excitation spectrum contains two intense excitation bands centered at 369 and 470 nm, which match well with commercial UV and blue light-emitting diode (LED) chips. When excited by 470 nm blue light, Na₂NbOF₅:Mn⁴⁺ exhibits red light emission dominated by ZPL. Notably, the color purity of the Na₂NbOF₅:Mn⁴⁺ red phosphor can reach 99.9%. Meanwhile, the Na₂NbOF₅:Mn⁴⁺ phosphor has a shorter fluorescence decay time than commercial K₂SiF₆:Mn⁴⁺, which is conducive to fast switching of images in display applications. Profiting from the intense ZPL, white light-emitting diode (WLED) with high color rendering index of Ra = 86.2 and low correlated color temperature of T_c = 3133 K is realized using yellow YAG:Ce³⁺ and red Na₂NbOF₅:Mn⁴⁺ phosphor. The WLED fabricated using CsPbBr₃ quantum dots (QDs) and red Na₂NbOF₅:Mn⁴⁺ phosphor shows a wide color gamut of 127.56% NTSC (National Television Standard Committee). The results show that red-emitting Na₂NbOF₅:Mn⁴⁺ phosphor has potential application prospects in WLED lighting and display backlight.

A review on the structural dependent optical properties and energy transfer of Mn4+ and multiple ion-codoped complex oxide phosphors

The tetravalent manganese Mn4+ ions with a 3d3 electron configuration as luminescence centers in solid-state inorganic compounds have been widely investigated because they emit bright light in the red to far-red region when they are excited by light with a wavelength in the UV to blue light region. Herein, we present an overview of the recent developments of Mn4+ and multiple ion such as Bi3+ and rare earth ion Dy3+, Nd3+, Yb3+, Er3+, Ho3+, and Tm3+ codoped complex oxide phosphors. Most of the specified host lattices of these complex oxide phosphors possess multiple metallic cations, which provide possible substitutions with different codopants and form various luminescence centers with diverse spectra. The luminescence of Mn4+ and multiple ion-codoped materials spans almost the whole visible light to near infrared (NIR) region. The crystal structures of complex oxide phosphors, the spectroscopic properties of Mn4+, and the energy transfer between Mn4+ and multiple ions are introduced and summarized in detail with regard to their practical applications. This review provides an insight into the optical properties of Mn4+ and the energy transfer process in multiple ion-codoped luminescence materials, which will be helpful in the development of novel excellent materials for applications in the lighting industry.