Being one of the foremost enticing and intriguing innovations, heterogeneous photocatalysis has also been used to effectively gather, transform, and conserve sustainable sun‘s radiation for the ...production of efficient and clean fossil energy as well as a wide range of ecological implications. The generation of solar fuel‐based water splitting and CO2 photoreduction is excellent for generating alternative resources and reducing global warming. Developing an inexpensive photocatalyst can effectively split water into hydrogen (H2), oxygen (O2) sources, and carbon dioxide (CO2) into fuel sources, which is a crucial problem in photocatalysis. The metal‐free g‐C3N4 photocatalyst has a high solar fuel generation potential. This review covers the most recent advancements in g‐C3N4 preparation, including innovative design concepts and new synthesis methods, and novel ideas for expanding the light absorption of pure g‐C3N4 for photocatalytic application. Similarly, the main issue concerning research and prospects in photocatalysts based g‐C3N4 was also discussed. The current dissertation provides an overview of comprehensive understanding of the exploitation of the extraordinary systemic and characteristics, as well as the fabrication processes and uses of g‐C3N4.
This review emphasized the composition and characteristics of recent development on g‐C3N4 based materials. Various fabrication methodologies for g‐C3N4 and g‐C3N4‐based materials were focused and evaluated in this report. Methods for enhancing the photocatalytic performance of g‐C3N4 based materials. Most important aspects were extensively explored.
Here, we report a facile route to the synthesizing of a new donor-acceptor complex, L3, using 4-{(anthracen-9-yl)meth-yl amino}-benzoic acid, L2, as donor moiety with anthraquinone as an acceptor ...moiety. The formation of donor-acceptor complex L3 was facilitated via H-bonding and characterized by single-crystal X-ray diffraction. The X-ray diffraction results confirmed the synthesized donor-acceptor complex L3 crystal belongs to the triclinic system possessing the P-1 space group. The complex L3 was also characterized by other spectral techniques, viz., FTIR and UV absorption spectroscopy, which confirmed the formation of new bonds between donor L2 moiety and acceptor anthraquinone molecule. The crystallinity and thermal stability of the newly synthesized complex L3 was confirmed by powdered XRD and TGA analysis and theoretical studies; Hirshfeld surface analysis was performed to define the type of interactions occurring in the complex L3. Interestingly, theoretical results were successfully corroborated with experimental results of FTIR and UV absorption. The density functional theory (DFT) calculations were employed for HOMO to LUMO; the energy gap (∆E) was calculated to be 3.6463 eV. The complex L3 was employed as a photocatalyst for the degradation of MB dye and was found to be quite efficient. The results showed MB dye degraded about 90% in 200 min and followed the pseudo-first-order kinetic with rate constant k = 0.0111 min
and R
= 0.9596. Additionally, molecular docking reveals that the lowest binding energy was -10.8 Kcal/mol which indicates that the L3 complex may be further studied for its biological applications.
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•Carbon dots were synthetized for the first time from V. Nilotica pods.•The acetonitrile extract of V. Nilotica pods exhibit a red fluorescence.•The aqueous extract of V. Nilotica ...used as colorimetric prob for detecting Fe3+.•The acetonitrile extract of V. Nilotica used as fluorescence probe to detect Fe3+.•Green, safe and renewable reagents were used in the proposed methods.
Principles of Green Analytical Chemistry recommended preferring using reagents from renewable sources and eliminating toxic reagents. Vachellia nilotica is a widespread plant throughout different parts of the world. In this study, using microwave energy, fluorescent carbon dots were synthesized for the first time from Vachellia nilotica pods. The morphology of the prepared carbon dots was characterized by SEM and TEM techniques, and the spectroscopic character exhibit green emission at 480 nm at λex = 386.5 nm. This fluorescence can be effectively quenched by adding Fe (III) ions (Method I). Furthermore, Vachellia nilotica pods were extracted by different solvents, including methanol, deionized water, absolute ethanol, acetone, acetonitrile, and DMF. The acetonitrile extract of Vachellia nilotica exhibited a strong red fluorescence emission at 673.9 at λex = 410 nm. Among various types of salt metals, only Fe (III) can effectively quench the fluorescence intensity of the acetonitrile extract (method II). Moreover, the bright yellow color of the aqueous extract can be changed into violet color. The absorbance of the resulted color can be spectrophotometrically measured at λ max = 530 nm (method III). The best analytical factors were optimized for the developed methods. The developed methods were applied to determine Fe (III) in different water samples.
Synthesis of photoluminescence carbon dots from red beetroot and utilizing its extract for spectrofluorimetric determination of tenoxicam.
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•Photoluminescence carbon dots were ...synthesized for the first time from red beetroot.•The fluorescence intensity of the carbon dots was quenched by adding tenoxicam.•The acetonitrile extract of red beetroot exhibits fluorescence activity.•The fluorescence intensity of the extract was enhanced by adding tenoxicam.•The developed methods were applied to determine tenoxicam in different dosage forms.
Tenoxicam (TNX) belongs to non-steroidal drugs that effectively treat many inflammatory disorders. In this study, luminescent carbon dots were synthesized from red beetroot as a green fluorescence probe. The synthesized carbon dots' morphology, size, and spectroscopic features were investigated and characterized by spectrophotometric, FTIR, SEM, spectrofluorimetric, and TEM techniques. The synthesized carbon dots possessed an emission at 430 nm and an excitation at 366.5 nm. Meanwhile, TNX is a yellow-colored compound with a spectrophotometric absorbance peak at 370 nm. Based on the inner filter effect mechanism, the emission fluorescence intensity of the synthesized carbon dots has been markedly quenched upon the addition of TNX. In addition, the quenching in the fluorescence intensity was quantitively related to the concentration of TNX at the linear range of 0.25 - 2.5 µg/mL (r2 = 0.9989) with a LOD of 0.08 µg/mL and LOQ of 0.24 µg/mL. The second side of this study is based on enhancing the fluorescence intensity of the acetonitrile extract of red beetroot upon the addition of TNX solution. This enhancement was recorded at a fluorescence emission of 357 nm with a fluorescence excitation of 305.5 nm. In addition, the enhancement in the fluorescence intensity was quantitively related to the concentration of TNX at the linear range of 0.5 - 8.0 µg/mL (r2 = 0.9995) with a LOD of 0.16 µg/mL and LOQ of 0.49 µg/mL. The analytical conditions were well-optimized, and the developed method was validated according to ICH guidelines. Finally, the proposed spectrofluorimetric approaches were applied to determine TNX in vials, tablets, and capsules with good recovery and accepted statistical results.
In this study, netilmicin (NTM) was selectively assessed in its dosage forms after a facile derivatization reaction. The proposed approach was based on the interaction between NTM and ...o‐phthalaldehyde/2‐mercaptoethanol (Roth's reagent). The reaction product was fluorometrically measured at λemission of 434 nm after λexcitation of 338 nm. All reaction conditions for achieving the optimum fluorescence switch‐on activity were visualized and monitored. Moreover, the method was validated under ICH guidelines, and was linear over the range 30–210 ng/ml after plotting netilmicin concentrations against the corresponding fluorescence intensity values. In addition, the selectivity of the developed method was investigated against either the co‐formulated drug (dexamethasone) or a common ophthalmic drop excipient (benzalkonium chloride) without interference from either of them. Furthermore, the developed method was applied to assay netilmicin in various samples of pharmaceutical eye drops with good recovery. Finally, multicriteria greenness and whiteness metrics were used to evaluate the sustainability, greenness, and whiteness of the approach. The applied tools were the AGREE algorithm, the RGB 12 algorithm, and HEXAGON.
Spectrofluorimetric determination of netilmicin based on its interaction with o‐phthalaldehyde/2‐mercaptoethanol.
In an acidic buffered solution, erythrosine B can react with amiodarone to form an association complex, which not only generates great enhancement in resonance Rayleigh scattering (RRS) spectrum of ...erythrosine B at 346.5 nm but also results in quenching of fluorescence spectra of erythrosine B at λemission = 550.4 nm/λexcitation = 528.5 nm. In addition, the formed erythrosine B–amiodarone complex produces a new absorbance peak at 555 nm. The spectral characteristics of the RRS, absorbance, and fluorescence spectra, as well as the optimum analytical conditions, were studied and investigated. As a result, new spectroscopic methods were developed to determine amiodarone by utilizing erythrosine B as a probe. Moreover, the ICH guidelines were used to validate the developed RRS, photometric, and fluorimetric methods. The enhancements in the absorbance and the RRS intensity and the decrease in the fluorescence intensity of the used probe were proportional to the concentration of amiodarone in ranges of 2.5–20.0, 0.2–2.5, and 0.25–1.75 μg/mL, respectively. Furthermore, limit of detection values were 0.52 ng/mL for the spectrophotometric method, 0.051 μg/mL for the RRS method, and 0.075 μg/mL for the fluorimetric method. Moreover, with good recoveries, the developed spectroscopic procedures were applied to analyze amiodarone in its commercial tablets.
Determination of amiodarone by spectrofluorimetric, scattering, and spectrophotometric methods based on its interaction with erythrosine B.
Naftidrofuryl is a vasodilator medication used for treating cerebral and peripheral vascular diseases. In this study, two spectroscopical techniques, spectrofluorimetric and resonance Rayleigh ...scattering (RRS), were utilized to quantify naftidrofuryl in its pharmaceutical samples. The developed methodologies in this study rely on a facile process of forming an association complex between erythrosine B reagent and naftidrofuryl under acidic conditions. The fluorimetric assay is based on the ability of naftidrofuryl to quench and decrease the native fluorescence intensity of the reagent when measured at
= 550 nm (
= 526 nm). Under similar reaction conditions, the RRS method relies on the observed amplification in the RRS spectrum of the reagent at a wavelength of 577 nm following its interaction with naftidrofuryl. The methods exhibited linearity within the ranges of 0.2
1.6 μg/mL (r
= 0.999) and 0.1
1.4 μg/mL (r
= 0.9994), with LOQ values of 0.146 and 0.099 μg/mL, and LOD values of 0.048 and 0.032 μg/mL, for the fluorometric and the RRS methods, respectively. Moreover, the quenching between the dye and naftidrofuryl was studied by Stern-Volmer analysis, and the methodologies were experimentally optimized and validated. Additionally, acceptable recoveries were achieved when the procedures were applied to determine naftidrofuryl in pharmaceutical samples.
The structural alteration of carbon nitride (CN) for photocatalytic CO2 reduction is a promising research topic in the environmental and energy sectors. This work discusses the fabrication of ...photocatalyst through a heterojunction architecture obtained from the molecular engineering of electron-rich organic monomer 2,6-pyridinedicarboxylic acid (PDA) with CN precursor (CN/PDAx). The successful integration of PDA in the structure of CN served as a charge inducting entity to enhance charge separation and photocatalytic CO2 reduction under visible light (λ = 420 nm). The DFT results indicated that the upshift in the HOMO level of CN after integration of PDA in its framework was the most lawful for the charge separation and for obtaining a high reduction potential. As-synthesized photocatalysts were demonstrated for various integral analysises and after evaluating the process of photocatalytic CO2 reduction under visible light region (λ = 420 nm). The optimized sample CN/PDA10 has the most excellent photocatalytic activity producing 85.4 μmol/h of CO and 21.3 μmol/h of H2, achieving a 7.5-fold enhanced catalytic efficiency as compared to pure CN. We hope that this work will attract more attention to synthesizing efficient photocatalysts for energy production and environmental remediation.
Two novel separation methods have been presented for the concurrent assessment of flumethasone pivalate (FP) and clioquinol (CL) in their combinations in ear drop formulations or in the presence of ...phenoxyethanol preservative (PEP) in their cream formulations. The first method is an innovative thin-layer chromatographic (TLC) method. The optimal separation was accomplished via silica gel aluminum plates F254, with a mixture of benzene, ethyl acetate and formic acid (5:5:0.2, in volumes) as the mobile system. In Method II, a new ultra-high-performance liquid chromatographic method (UHPLC) with a photodiode array detector (PDA) was presented. A reversed-phase inertsil ODS 5 µm C 18 packed column (100 Å, 4.6 mm internal diameter (I.D.) × 50 mm) at 30 °C was employed. Elution was completed in 3 min. Unfortunately, greener solvents were tested as a mobile phase, but an asymmetric peak for CL was noted. In addition, the new UHPLC method has a priority over the old HPLC one by Sayed et al., 2014, in terms of quickness and avoiding interference from the PEP preservative. Concerning the TLC method, the novel TLC method has the advantage of preventing the interference of PEP. This paper represents the first analytical approach for the concurrent assay of FP and CL in the presence of the preservative phenoxyethanol in the cream formulation.
•Quantum computational and Spectroscopic studies.•FMO, UV-Vis analysis, done for charge transfer studies.•Molecular docking performed.•Molecular dynamic simulation study.
PDD (pyridine-2,6-dicarbonyl ...dichloride) has been explored both experimentally and theoretically. Pyridines and their analogues are heterocyclic nitrogenous compounds that have a wide variety of applications in the development of anticancer medicines. These synthetic sources are utilised to treat many different types of disorders, including breast cancer, myeloid leukaemia, pancreatic cancer, liver cancer, and idiopathic pulmonary fibrosis. In this study, FT-IR, 1H, 13C NMR, and UV-Vis spectra, as well as theoretical DFT calculations, were used to explore pyridine-2,6-dicarbonyl dichloride (PDD). The most stable optimized structure was found using the B3LYP/6-311++G(d,p) basis set, which was subsequently studied using FT-IR and NMR. Hirshfeld's surface analysis were presented and discussed. Chemical reactivity investigations, MEP maps, and surface area maps were also carried out. The vibrational assignments were completed using individual vibrational modes, which were then compared to experimental data. The docking studies were used to look into how the ligand PDD interacted with specific protein targets. In order to better visualise binding locations and the influence of the ligand on 4LB4 conformation, this system was also subjected to molecular dynamic simulations.
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