Exclusive Solvent-Controlled Regioselective Catalytic Synthesis of Potentially Bioactive Imidazolidineiminodithiones: NMR Analysis, Computational Studies and X-ray Crystal Structures.

Herein, we describe the first consistent regiospecific reaction of isothiocyanates with a variety of substituted N-arylcyanothioformamides in a 1:1 molar ratio to generate a series of imidazolidineiminodithiones decorated with a multitude of functional groups on both aromatic rings. The reaction is carried out at room temperature using a 20 mol% catalytic amount of triethylamine with DMF as the solvent to selectively form the mentioned products with exclusive regioselectivity. The methodology features wide substrate scope, no requirement for chromatography, and good to high reaction yields. The products were isolated by simple ether/brine extraction and the structures were verified by multinuclear NMR spectroscopy and high accuracy mass measurements. The first conclusive molecular structure elucidation of the observed regioisomer was established by single-crystal X-ray diffraction analysis. Likewise, the tautomer of the N-arylcyanothioformamide reactant was proven by X-ray diffraction analysis. Density functional theory computations at the B3LYP-D4/def2-TZVP level in implicit DMF solvent were conducted to support the noted regiochemical outcome and proposed mechanism.

First X-ray Crystal Structure Characterization, Computational Studies, and Improved Synthetic Route to the Bioactive 5-Arylimino-1,3,4-thiadiazole Derivatives.

N-arylcyanothioformamides are useful coupling components for building key chemical intermediates and biologically active molecules in an expedited and efficient manner. Similarly, substituted (Z)-2-oxo-N-phenylpropanehydrazonoyl chlorides have been utilized in numerous one-step heteroannulation reactions to assemble the structural core of several different types of heterocyclic compounds. Herein, we demonstrate the effectiveness of the reaction of N-arylcyanothioformamides with various substituted (Z)-2-oxo-N-phenylpropanehydrazonoyl chlorides to produce, stereoselectively and regioselectively, a range of 5-arylimino-1,3,4-thiadiazole derivatives decorated with a multitude of functional groups on both aromatic rings. The synthetic methodology features mild room-temperature conditions, large substrate scope, wide array of functional groups on both reactants, and good to high reaction yields. The products were isolated by gravity filtration in all cases and structures were confirmed by multinuclear NMR spectroscopy and high accuracy mass spectral analysis. Proof of molecular structure of the isolated 5-arylimino-1,3,4-thiadiazole regioisomer was obtained for the first time by single-crystal X-ray diffraction analysis. Crystal-structure determination was carried out on (Z)-1-(5-((3-fluorophenyl)imino)-4-(4-iodophenyl)-4,5-dihydro-1,3,4-thiadiazol-2-yl)ethan-1-one and (Z)-1-(4-phenyl-5-(p-tolylimino)-4,5-dihydro-1,3,4-thiadiazol-2-yl)ethan-1-one. Similarly, the tautomeric structures of the N-arylcyanothioformamides and (Z)-geometries of the 2-oxo-N-phenylpropanehydrazonoyl chloride coupling partners were proven by X-ray diffraction studies. As representative examples, crystal-structure determination was carried out on (4-ethoxyphenyl)carbamothioyl cyanide and (Z)-N-(2,3-difluorophenyl)-2-oxopropanehydrazonoyl chloride. Density functional theory calculations at the B3LYP-D4/def2-TZVP level were carried out to rationalize the observed experimental findings.

In Silico Screening and Molecular Dynamics Simulation Studies in the Identification of Natural Compound Inhibitors Targeting the Human Norovirus RdRp Protein to Fight Gastroenteritis.

Norovirus (HNoV) is a leading cause of gastroenteritis globally, and there are currently no treatment options or vaccines available to combat it. RNA-dependent RNA polymerase (RdRp), one of the viral proteins that direct viral replication, is a feasible target for therapeutic development. Despite the discovery of a small number of HNoV RdRp inhibitors, the majority of them have been found to possess a little effect on viral replication, owing to low cell penetrability and drug-likeness. Therefore, antiviral agents that target RdRp are in high demand. For this purpose, we used in silico screening of a library of 473 natural compounds targeting the RdRp active site. The top two compounds, ZINC66112069 and ZINC69481850, were chosen based on their binding energy (BE), physicochemical and drug-likeness properties, and molecular interactions. ZINC66112069 and ZINC69481850 interacted with key residues of RdRp with BEs of -9.7, and -9.4 kcal/mol, respectively, while the positive control had a BE of -9.0 kcal/mol with RdRp. In addition, hits interacted with key residues of RdRp and shared several residues with the PPNDS, the positive control. Furthermore, the docked complexes showed good stability during the molecular dynamic simulation of 100 ns. ZINC66112069 and ZINC69481850 could be proven as potential inhibitors of the HNoV RdRp in future antiviral medication development investigations.

Computer Analysis of the Inhibition of ACE2 by Flavonoids and Identification of Their Potential Antiviral Pharmacophore Site.

In the present study, we investigated the antiviral activities of 17 flavonoids as natural products. These derivatives were evaluated for their in vitro antiviral activities against HIV and SARS-CoV-2. Their antiviral activity was evaluated for the first time based on POM (Petra/Osiris/Molispiration) theory and docking analysis. POM calculation was used to analyze the atomic charge and geometric characteristics. The side effects, drug similarities, and drug scores were also assumed for the stable structure of each compound. These results correlated with the experimental values. The bioinformatics POM analyses of the relative antiviral activities of these derivatives are reported for the first time.

Novel linezolid-based oxazolidinones as potent anticandidiasis and antitubercular agents.

The quest for new antifungal and antitubercular drugs is a need of the hour because of morbid co-pathogenesis and an increase in immunocompromised patients. One of the ways forward is to explore and repurpose the established pharmacophores for the desired application. Oxazolidinones are well-known antibacterial agents, with few investigations reported to exploit their antifungal properties. Herein, we report the design and synthesis of a series of linezolid-based oxazolidinones as potent anticandidiasis and antitubercular agents. Studies revealed that two of the novel oxazolidinones 2 and 3a exhibited excellent anticandidiasis activity against different Candida fungus strains, superior to standard drugs. Mechanistic and docking studies revealed that oxazolidinones were better inhibitors of the ergosterol biosynthesis pathway than the controls used. In addition, the oxazolidinones 2 and 3a also exhibited prominent inhibitory activity against M. tuberculosis H37Rv with MIC values of 1 and 2 µg/ml, respectively. Computational studies demonstrated the binding of the compounds to the transcriptional regulatory repressor protein, which was reinforced by the molecular dynamics simulations. The pharmacophore modeling experiments validated the molecular docking results in both the target proteins.

Structure-based designing and synthesis of 2-phenylchromone derivatives as potent tyrosinase inhibitors: In vitro and in silico studies.

The present study describes the discovery of novel inhibitors of mushroom tyrosinase enzyme. For that purpose, a series of varyingly substituted 2-phenylchromone analogues 1-28 were synthesized and characterized in detail by various spectroscopic techniques (UV-Vis, FTIR, 1H NMR, 13C NMR) and mass spectrometry. All the derivatives (1-28) were screened in vitro for their inhibitory potential against mushroom tyrosinase enzyme. Interestingly, all the synthetic compounds displayed good to excellent inhibitory activity with IC50 values ranging from 0.093 ± 0.003 µg/ml to 23.58 ± 0.94 µg/ml for brominated 3-hydroxy-2-phenylchromones and 0.22 ± 0.017 µg/ml to 22.22 ± 1.1 µg/ml for brominated 2-phenylchromones against tyrosinase in comparison to the standard kojic acid (IC50 = 1.79 ± 0.64 µg/ml). Remarkably, the bromine atoms attached on ring A attribute to increases the inhibitory potential of 2-phenylchromone moiety and anti-tyrosinase assay demonstrated that compound 10 (IC50 = 0.093 ± 0.003 µg/ml) was found almost nineteenfold, 11 (IC50 = 0.126 ± 0.015 µg/ml) fourteenfold and 26 (IC50 = 0.22 ± 0.017 µg/ml) about eightfold more active than the positive control. Notably, among the already literature reported tyrosinase inhibitors, these analogues have been found the most active inhibitors of mushroom tyrosinase with the lowest possible IC50 values. To design and develop novel tyrosinase inhibitors using 2-phenylchromone as a structural motif in the future, a limited structure-activity relationship was established. Moreover, in silico studies were carried out to rationalize the binding mode of interactions of all the targeted compounds (1-28) with the active site of enzymes. The experimental and theoretical results are in parallel with one another. In addition, molecular description was performed with the drug-likeness and bioactivity scores. Computational analysis predicted that few compounds are in a linear correlation with Lipinski's RO5 indicating superb drug-likeness and bioactivity score for drug targets.

Heterodimerization at the dye sensitized TiO2 surface: an efficient strategy toward quick removal of water contaminants.

Sensitization of wide bandgap semiconductors with heterodimers for better solar light sensitivity has attracted widespread attention in the recent times. However, application of heterodimerization for removing soluble water pollutants from waste water is sparse in the literature. In the present study, we have utilized heterodimerization of a model pollutant methylene blue (MB) with a ruthenium based dye N719 for the removal of the pollutant. We have synthesized N719 functionalized carbonate doped TiO2 microspheres (doped MS) which act as a novel material for the detoxification of MB containing water by adsorbing at the surface and eventually killing by photoinduced reduction under visible light irradiation. The mechanism of surface adsorption and photoreduction of MB are explored using steady state and time resolved spectroscopy studies. We have fabricated two types of prototype devices (flow device and active filter) using the functionalized doped MS. Both the devices show excellent dye removal activity and recyclability. The present study would find relevance in the removal of soluble pollutants from waste water.

Sensitive Spectrofluorimetric Study of the Interaction between Europium(III) and 1,2-Phenylenebis(azan-1-yl-1-ylidene) bis(methan-1-yl-1-ylidene)diphenol Schiff Base.

A sensitive and selective spectrofluorimetric method has been developed for the rapid determination of europium(III). This method is based on the formation of nonluminous complex between Eu(III) and a Schiff base reagent N, N'-bis (salicylidene)-1,2-phenylenediamine (PABD) and measuring the fluorescence quenching of Eu(III)-PABD complex at λex/em = 390/577 nm. The fluorescence intensity complex decreased linearly by increasing the Eu(III) concentration in the range of 1.0-13.0 µM. The optimum conditions for the complex formation were determined such as a pH .0 of borate buffer. The limits of detection (LOD) and quantification (LOQ) of Eu(III) were determined and found to be 0.217 and 0.653 µM, respectively. The maximum relative standard deviation of the method for an europium(III) standard of 6.0 µM was 2.07 % (n = 6). The proposed procedures could be applied successfully for the determination of the investigated metal ion in some spiked water samples with a good precision and accuracy compared to official and reported methods as revealed by t- and F-tests.

Synthesis, Spectral Characteristics and DFT Studies of the New Dye 2,7-diacetyl-9-((dimethylamino)methylene)-9H-fluorene (DMMF) in Different Solvents.

The photophysical parameters such as electronic absorption spectra, molar absorptivity(ε), fluorescence spectra and fluorescence quantum yield (φf) of a new dye namely 2,7-diacetyl-9-((dimethylamino)methylene)-9H-fluorene (DMMF) were determined in different solvents. The electronic absorption are less sensitive to medium polarity. A bathochromic shift was observed in emission spectra(ca. 50 nm) upon increase of solvent polarity, which indicates that the singlet excited state (S1) of DMMF is more polar than the singlet ground state (So). Solid crystals of DMMF exhibit intense yellow fluorescence maximum at 550 nm with bandwidth equal 64 nm upon excitation at wavelength 365 nm. The change in dipole moment value (Δµ) was calculated by using the variation of Stokes shift with solvent polarizability (Δf) (Lippert - Mataga plot) and was found to be 7.22 and 5.5 Debye for higher and lower energy of So - S1 (π-π*) H-1 → L and So - S1 (π-π*) H → L, respectively. These results show that, the excited state is more polar than the ground state. The net photochemical quantum yields of photodecomposition of DMMF (φc) were calculated as 7.2 × 10(-5), 1.14 × 10(-4), 1.44 × 10(-4) and 2.11 × 10(-4) in different solvents such as MeOH, CH2Cl2, CHCl3 and CCl4, respectively. DFT/TD-DFT methods were used to study the geometric and electronic structures of DMMF in different solvents. A good agreement was found between the experimental and theoretical results.

Impact of metal ions in porphyrin-based applied materials for visible-light photocatalysis: key information from ultrafast electronic spectroscopy.

Protoporphyrin IX-zinc oxide (PP-ZnO) nanohybrids have been synthesized for applications in photocatalytic devices. High-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and steady-state infrared, absorption, and emission spectroscopies have been used to analyze the structural details and optical properties of these nanohybrids. Time-resolved fluorescence and transient absorption techniques have been applied to study the ultrafast dynamic events that are key to photocatalytic activities. The photocatalytic efficiency under visible-light irradiation in the presence of naturally abundant iron(III) and copper(II) ions has been found to be significantly retarded in the former case, but enhanced in the latter case. More importantly, femtosecond (fs) transient absorption data have clearly demonstrated that the residence of photoexcited electrons from the sensitizer PP in the centrally located iron moiety hinders ground-state bleach recovery of the sensitizer, affecting the overall photocatalytic rate of the nanohybrid. The presence of copper(II) ions, on the other hand, offers additional stability against photobleaching and eventually enhances the efficiency of photocatalysis. In addition, we have also explored the role of UV light in the efficiency of photocatalysis and have rationalized our observations from femtosecond- to picosecond-resolved studies.

Exploring Pyrimidine-Based azo Dyes: Vibrational spectroscopic Assignments, TD-DFT Investigation, chemical Reactivity, HOMO-LUMO, ELF, LOL and NCI-RDG analysis.

Theoretical computations of pyrimidine-based azo dyes were performed by the DFT approach using the B3LYP/6 - 31G(d,p) basis set. The molecules were optimized based on the same basis set by calculating the minimum energy. FMOs, DOS and GCRD were computed for kinetic stability and chemical reactivity of the selected compounds. The MEP surface was studied to locate nucleophilic and electrophilic attack zones. The energy gap was carefully studied for pyrimidine-based azo dyes. Vibrational spectroscopy was studied in the most prominent regions with respect to PED assignments. Similarly, the UV-Vis absorption technique was calculated using the TD-DFT approach in different solvent media. The electronic structure of each atom in a molecule was examined via the electron localization function (ELF) and localized orbital locator (LOL). Non-covalent interactions were explored using reduced density gradient analysis. The combination of experimental and theoretical data allowed us to correlate the structural modifications with the observed photophysical properties, facilitating the design of azo dyes with tailored characteristics. This work contributes to the fundamental understanding of azo dyes and offers a foundation for the development of new materials with enhanced photophysical and electronic properties.

Exploring the untapped pharmacological potential of imidazopyridazines.

Imidazopyridazines are fused heterocycles, like purines, with a pyridazine ring replacing the pyrimidine ring in purines. Imidazopyridazines have been primarily studied for their kinase inhibition activity in the development of new anticancer and antimalarial agents. In addition to this, they have also been investigated for their anticonvulsant, antiallergic, antihistamine, antiviral, and antitubercular properties. Herein, we review the background and development of different imidazopyridazines as potential pharmacological agents. Moreover, the scope of this relatively less charted heterocyclic scaffold is also highlighted.

Recent highlights in the synthesis and biological significance of pyrazole derivatives.

Aza-heterocyclic scaffolds are privileged cores in the composition of their potential therapeutic profiles and versatile synthetic intermediates. Pyrazole is one of the frequently studied compounds of "azole" family and consists of nitrogen in a 1,2 linking sequence. These motifs possess a wide-spectrum of applications in the field of pharmaceuticals, agrochemicals, polymer chemistry, cosmetics, food industries and more. In addition, functionalized pyrazole derivatives are frequently used as ligands in coordination chemistry and metal-catalysed reactions. As exemplified by numerous recent reports, pyrazoles are highly promising pharmacophores with excellent therapeutic applications. Owing to their aromaticity, the ring structures have many reactive positions, where electrophilic, nucleophilic, alkylation and oxidative reactions might occur. The structural adroitness and diversity of pyrazole cores further emanated numerous fused bicyclic skeletons with various biological applications. In this review, we highlight the recent synthetic methods developed for the preparation of functionalized pyrazole derivatives (From 2017 to present). In addition, we have also covered the notable biological activities (anti-cancer, anti-inflammatory, anti-bacterial and anti-viral) of this ubiquitous core. Herein, we emphasised the synthesis of pyrazoles from variety of precursors such as, alkynes, α,ß-unsaturated carbonyl compounds, diazo reagents, nitrile imines, diazonium salts, 1,3-dicarbonyl compounds and etc. Moreover, the recent synthetic methodologies focusing on the preparation of pyrazolines and pyrazolones and variously fused-pyrazoles are also included. Authors expect this review could significantly help the researchers in finding elegant novel tools to synthesize pyrazole skeletons and expand their biological evaluation.

Study on Regio- and Diastereoselectivity of the 1,3-Dipolar Cycloaddition Reaction of Azomethine Ylide with 2-(Benzo[d]thiazol-2-yl)-3-(aryl)acrylonitrile: Synthesis, Spectroscopic, and Computational Approach.

An unprecedented and efficient three-component 1,3-dipolar cycloaddition reaction using (E)-2-(benzo[d]thiazol-2-yl)-3-(aryl)acrylonitriles 4a-g and an in situ generated azomethine ylide 3 from isatin and N-methylglycine is described. The reaction exhibits exclusive regioselectivity, resulting in the formation of 3'-(benzo[d]thiazol-2-yl)-1'-methyl-2-oxo-4'-(aryl)spiro[indoline-3,2'-pyrrolidine]-3'-carbonitriles regioisomers through exo/endo approaches. The diastereoselectivity of the reaction is highly dependent on the substitution pattern of the phenyl ring in dipolarophiles 4a-g, leading to the formation of exo-/endo-cycloadducts in varying ratios. To understand the stereoselectivity, the transition state structures were optimized using the TS guess geometry with the QST3-based method. The reaction mechanism and regioselectivity were elucidated by evaluating global and local electrophilicity and nucleophilicity descriptors at the B3LYP/cc-pVTZ level of theory, along with considerations based on the HSAB principle. The analysis of global electron density transfer (GEDT) showed that the reactions are polar and electron density fluxes from azomethine ylide 3 toward dipolarophile 4a-g. It was found from the molecular electrostatic potential map (MESP) that at the more favorable transition state, approach of reactants locates the oppositely charged regions over each other resulting in attractive forces between the two fragments. The computational results are consistent with the experimental observations, confirming that the reactions proceed through an asynchronous one-step mechanism.

Exploring fluorine-substituted piperidines as potential therapeutics for diabetes mellitus and Alzheimer's diseases.

In the current study, a series of fluorine-substituted piperidine derivatives (1-8) has been synthesized and characterized by various spectroscopic techniques. In vitro and in vivo enzyme inhibitory studies were conducted to elucidate the efficacy of these compounds, shedding light on their potential therapeutic applications. To the best of our knowledge, for the first time, these heterocyclic structures have been investigated against α-glucosidase and cholinesterase enzymes. The antioxidant activity of the synthesized compounds was also assessed. Evaluation of synthesized compounds revealed notable inhibitory effects on α-glucosidase and cholinesterases. Remarkably, the target compounds (1-8) exhibited extraordinary α-glucosidase inhibitory activity as compared to the standard acarbose by several-fold. Subsequently, the potential antidiabetic effects of compounds 2, 4, 5, and 6 were validated using a STZ-induced diabetic rat model. Kinetic studies were also performed to understand the mechanism of inhibition, while structure-activity relationship analyses provided valuable insights into the structural features governing enzyme inhibition. Kinetic investigations revealed that compound 4 displayed a competitive mode of inhibition against α-glucosidase, whereas compound 2 demonstrated mixed-type behavior against AChE. To delve deeper into the binding interactions between the synthesized compounds and their respective enzyme targets, molecular docking studies were conducted. Overall, our findings highlight the promising potential of these densely substituted piperidines as multifunctional agents for the treatment of diseases associated with dysregulated glucose metabolism and cholinergic dysfunction.

Recent developments in the synthesis and applications of terpyridine-based metal complexes: a systematic review.

Terpyridine-based metal complexes have emerged as versatile and indispensable building blocks in the realm of modern chemistry, offering a plethora of applications spanning from materials science to catalysis and beyond. This comprehensive review article delves into the multifaceted world of terpyridine complexes, presenting an overview of their synthesis, structural diversity, and coordination chemistry principles. Focusing on their diverse functionalities, we explore their pivotal roles in catalysis, supramolecular chemistry, luminescent materials, and nanoscience. Furthermore, we highlight the burgeoning applications of terpyridine complexes in sustainable energy technologies, biomimetic systems, and medicinal chemistry, underscoring their remarkable adaptability to address pressing challenges in these fields. By elucidating the pivotal role of terpyridine complexes as versatile building blocks, this review provides valuable insights into their current state-of-the-art applications and future potential, thus inspiring continued innovation and exploration in this exciting area of research.

Formation of carboxy- and amide-terminated alkyl monolayers on Silicon(111) investigated by ATR-FTIR, XPS, and X-ray scattering: construction of photoswitchable surfaces.

We have prepared high-quality, densely packed, self-assembled monolayers (SAMs) of carboxy-terminated alkyl chains on Si(111). The samples were made by thermal grafting of methyl undec-10-enoate under an inert atmosphere and subsequent cleavage of the ester functionality to disclose the carboxylic acid end-group. X-ray photoelectron spectroscopy (XPS) and grazing incidence X-ray diffraction (GIXD) indicate a surface coverage of about 50% of the initially H-terminated sites. In agreement, GIXD implies a rectangular unit mesh of 6.65 and 7.68 Å side lengths, containing two molecules in a regular zigzag-like substitution pattern for the ester- and carboxy-terminated monolayer. Hydrolysis of the remaining H-Si(111) bonds at the surface furnished HO-Si(111) groups according to XPS and attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) studies. The amide-terminated alkyl SAM on Si(111) assembled in a 2-(6-chloro-1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate (HCTU)-mediated one-pot coupling reaction under an inert atmosphere, whereby the active ester forms in situ prior to the reaction with an amino-functionalized photoswitchable fulgimide. ATR-FTIR and XPS studies of the fulgimide samples revealed closely covered amide-terminated SAMs. Reversible photoswitching of the headgroup was read out by applying XPS, ATR-FTIR, and difference absorption spectra in the mid-IR. In XPS, we observed a reversible breathing of the amide/imide C1s and N1s signals of the fulgimide. The results demonstrate the general suitability of HCTU as a reagent for amide couplings to carboxy-terminated alkyl SAMs and the on-chip functionalization toward photoswitchable Si(111) surfaces.

Highly efficient and stable AgI-CdO nanocomposites for photocatalytic and antibacterial activity.

For the last several decades, semiconducting materials and nanocomposites have received a lot of interest in generating highly efficient photocatalysts to destroy organic pollutants and eradicate bacteria. This study uses a simple deposition and precipitation approach at ambient temperature to create a unique and efficient AgI-CdO heterojunction. DRS, IR, SEM, EDS, XRD, EIS, and TEM were utilized to identify the material. SEM and TEM investigation depict the completely spherical, hexagonal forms and zigzag cubes for synthesized AgI-CdO. The EDX spectra reveal the presence of Ag, I, Cd, and O elements without impurity peaks showing that the prepared samples are highly pure. The activity of the synthesized materials was tested by degrading two different chromophoric dyes and a drug derivative (paracetamol) in an aqueous suspension under visible light. In addition, the activity of the most active catalyst was compared with Degussa P25, Fenton's reagent, and under sunlight for degradation of MB and RhB under similar conditions. Photolysis of paracetamol was also looked at using HPLC to identify intermediates formed in the photo-oxidation process. In addition, antibacterial activity was also investigated with the synthesized CdO-AgI nanocomposite in vitro against human pathogenic bacterial strains and compared with that of pure materials like AgI and standard ampicillin. The results showed excellent activity with the composite material, which could be due to the higher surface areas and the interactions between AgI and CdO nanoparticles. Quenching investigations revealed O2˙- and holes are principal reactive species. A viable photocatalytic degradation mechanism for organic pollutant elimination over the AgI-CdO nanocomposite has been sketched out based on the obtained results.

Novel Type-II Heterojunction Binary Composite (CdS/AgI) with Outstanding Visible Light-Driven Photocatalytic Performances toward Methyl Orange and Tetracycline Hydrochloride.

In this study, an effective type-II heterojunction CdS/AgI binary composite was constructed by an in situ precipitation approach. To validate the successful formation of heterojunction between AgI and CdS photocatalysts, the synthesized binary composites were characterized by various analytical techniques. UV-vis diffuse-reflectance spectroscopy (UV-vis DRS) revealed that heterojunction formation led to a red shift in the absorbance spectra of the CdS/AgI binary composite. The optimized 20AgI/CdS binary composite showed a least intense photoluminescence (PL) peak indicating highly improved charge carrier (e-/h+ pairs) separation efficiency. The photocatalytic efficiency of the synthesized materials was assessed based on the degradation of methyl orange (MO) and tetracycline hydrochloride (TCH) in the presence of visible light. Compared to bare photocatalysts and other binary composites, the 20AgI/CdS binary composite showed the highest photocatalytic degradation performances. Additionally, the trapping studies showed that superoxide radical anion (O2•-) was the most dominant active species involved in photodegradation processes. Based on the results of active species trapping studies, a mechanism was proposed to describe the formation of type-II heterojunctions for CdS/AgI binary composite. Overall, the synthesized binary composite has tremendous promise for environmental remediation due to its straightforward synthesis approach and excellent photocatalytic efficacy.

Fabrication of Direct Z-Scheme CoNiWO4/Ph-gC3N4 Heterocomposites: Enhanced Photodegradation of Bisphenol A and Anticancer Activity.

Photocatalysis is realized by the design of a visible-light-active catalyst with robust redox capacity and broad absorption. In this study, a series of novel Z-scheme CoNiWO4/Ph-gC3N4 photocatalysts are synthesized to improve their redox property and photocatalytic activity toward broad visible light absorption. An intimate stable heterojunction is made between cobalt-nickel tungstate (CoNiWO4) and phenyl-doped graphitic carbon nitride (Ph-gC3N4), and its physicochemical properties are studied. The bifunctional properties of all of the synthesized materials were assessed by studying the decomposition of bisphenol A (BPA) and methyl orange (MO) dye as model pollutants, followed by an evaluation of their anticancer activity on human lung cancer cell lines. The photocatalyst with 20 wt % CoNiWO4 heterocomposite showed an enhanced response toward the removal of cancerous cells. The synthesized pristine CoNiWO4 and Ph-gC3N4 exhibit well-matched band structures and, hence, make it easier to create a Z-scheme heterocomposite. This may increase the lifetime of photoinduced charge carriers with a high redox power, thereby improving their photocatalytic and anticancer activity. An extensive analysis of the mechanism demonstrates that hydroxyl radicals (•OH) and superoxide radical anions (•O2-) are responsible for the degradation of organic compounds via Z-scheme charge transfer approach. These findings point toward a new route for creating effective Co-Ni tungstate-based direct Z-scheme photocatalysts for various redox processes, particularly the mineralization of resistant organic molecules.