Synthesis and characterisation of novel Cu(ii)-anchored biopolymer complexes as reusable materials for the photocatalytic degradation of methylene blue

Novel rod-like [Cu(phen)2(OAc)]·PF6 complex for high-performance visible-light-driven photocatalytic degradation of hazardous organic dyes: DFT approach, Hirshfeld and fingerprint plot analysis

A novel octahedral distorted coordination complex was formed from a copper transition metal with a bidentate ligand (1,10-Phenanthroline) and characterized by Ultraviolet-visible spectroscopy, Ultraviolet-visible diffuse reflectance spectroscopy, Fourier-transform infrared spectroscopy, Brunauer-Emmett-Teller, Field emission scanning electron microscopy, and Single-crystal X-ray diffraction. The Hirshfeld surface and fingerprint plot analyses were conducted to determine the interactions between atoms in the Cu(II) complex. DFT calculations showed that the central copper ion and its coordinated atoms have an octahedral geometry. The Molecular electrostatic potential (MEP) map indicated that the copper (II) complex is an electrophilic compound that can interact with negatively charged macromolecules. The HOMO-LUMO analysis demonstrated the π nature charge transfer from acetate to phenanthroline. The band gap of [Cu(phen)2(OAc)]·PF6 photocatalyst was estimated to be 2.88 eV, confirming that this complex is suitable for environmental remediation. The photocatalytic degradation of erythrosine, malachite green, methylene blue, and Eriochrome Black T as model organic pollutants using the prepared complex was investigated under visible light. The [Cu(phen)2(OAc)]·PF6 photocatalyst exhibited degradation 94.7, 90.1, 82.7, and 74.3 % of malachite green, methylene blue, erythrosine, and Eriochrome Black T, respectively, under visible illumination within 70 min. The results from the Langmuir-Hinshelwood kinetic analysis demonstrated that the Cu(II) complex has a higher efficiency for the degradation of cationic pollutants than the anionic ones. This was attributed to surface charge attraction between photocatalyst and cationic dyes promoting removal efficiency. The reusability test indicated that the photocatalyst could be utilized in seven consecutive photocatalytic degradation cycles with an insignificant decrease in efficiency.

Highly efficient visible light active ZnO/Cu-DPA composite photocatalysts for the treatment of wastewater contaminated with organic dye

Industrial effluents are a leading major threat for water contamination, subsequently which results in severe health associated risks. Hence, purifying wastewater before releasing into the water resources is essential to avoid contamination. In this study, ZnO/Cu-DPA nano-composites were prepared by altering the percentage of Cu-DPA (20%, 30%, 40%, and 50% which are denoted to be ZnO/20%Cu-DPA, ZnO/30%Cu-DPA, ZnO/40%Cu-DPA and ZnO/50%Cu-DPA) using a simple mechanical grinding process. Several spectroscopic studies were employed such as electron paramagnetic analysis (EPR), powdered X-ray diffractometer (PXRD), UV-Vis absorbance spectroscopy, Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscope to characterize these nano-composites. The photo-catalytic activities of the prepared nano-composites were studied by degrading MB under visible light irradiation. ZnO, ZnO/20%Cu-DPA, ZnO/30%Cu-DPA, ZnO/40%Cu-DPA and ZnO/50%Cu-DPA degradation efficiencies were determined to be 71.8, 78.5, 77.1, and 66.1%, respectively. Among the composite catalysts, the ZnO/20%Cu-DPA coupled system are demonstrated the best efficiency (87%) for photo-degradation of MB within 80 min when exposed to visible light. The ZnO/Cu-DPA nano-composites had a greater MB photodegradation efficiency than pristine ZnO owing to p-n heterojunction in the linked system. Under visible light irradiation, the ZnO/20%Cu-DPA catalysed the conversion of dissolved O2 to hydroxyl radicals (OH·), triggering the reduction of MB. This suggests that ·OH is the primary specific active radical involved in the photo-catalytic decomposition of MB. Furthermore, EPR analysis indicates the existence of ·OH in the photo-catalytic system. The proposed nano-composites (ZnO/20%Cu-DPA) reusability was investigated across three cycles as the most efficient photo-catalyst. The results show that, the ZnO/Cu-DPA nano-catalyst is a potential candidate for the remediation of dirty water.

Effect of Selected Crosslinking and Stabilization Methods on the Properties of Porous Chitosan Composites Dedicated for Medical Applications

Chitosan is one of the most commonly employed natural polymers for biomedical applications. However, in order to obtain stable chitosan biomaterials with appropriate strength properties, it is necessary to subject it to crosslinking or stabilization. Composites based on chitosan and bioglass were prepared using the lyophilization method. In the experimental design, six different methods were used to obtain stable, porous chitosan/bioglass biocomposite materials. This study compared the crosslinking/stabilization of chitosan/bioglass composites with ethanol, thermal dehydration, sodium tripolyphosphate, vanillin, genipin, and sodium β-glycerophosphate. The physicochemical, mechanical, and biological properties of the obtained materials were compared. The results showed that all the selected crosslinking methods allow the production of stable, non-cytotoxic porous composites of chitosan/bioglass. The composite with genipin stood out with the best of the compared properties, taking into account biological and mechanical characteristics. The composite stabilized with ethanol is distinct in terms of its thermal properties and swelling stability, and it also promotes cell proliferation. Regarding the specific surface area, the highest value exposes the composite stabilized by the thermal dehydration method.

Synthesis of novel chitosan Schiff base and its ZnO nanocomposite for removal of synthetic dye, antimicrobial, and cytotoxicity activity

In this work, a novel chitosan Schiff base 4-(2-Hydroxyaniline)pent-3-en-2-one chitosan (2-HyA-CS) and its ZnO nanocomposite (2-HyA-CS/ZnO) were sensitized and characterized by appropriate methods; FTIR, XRD, Elemental analysis, SEM, TEM and TGA. The result of characterization methods confirms the preparation of 2-HyA-CS and 2-HyA-CS/ZnO. The SEM images reveal that chitosan, 2-HyA-CS, and 2-HyA-CS/ZnO have a varied roughness and porous surfaces. The reason for this difference was attributed to the formation of Schiff base 2-HyA-CS and the presence of ZnO nanoparticles in 2-HyA-CS/ZnO. The patterns of XRD and FTIR confirm the formation of 2-HyA-CS and 2-HyA-CS/ZnO. The degree of substitution (DS) of modified chitosan 2-HyA-CS was calculated using Elemental analysis and FTIR.ATR, it was found to be 74%. The adsorption efficiency of the produced adsorbents was compared with pure chitosan to remove of Remazol Brilliant Blue R (RBBR) from an aqueous medium and antimicrobial activity. The removal percentage of RBBR by chitosan, 2-HyA-CS, and 2-HyA-CS/ZnO are 47.12%, 91.9%, and 96.56%, respectively with the following order: 2-HyA-CS/ZnO > 2-HyA-CS > chitosan. Their antimicrobial activities were studied against two Gram negative bacteria ( E. coli and P. aeruginosa), two Gram positive bacteria ( S. aureus and B. cereus) and ( C. albicans) as a yeast strain, the inhibitory zone measurements revealed that the activity of 2-HyA-CS/ZnO is excellent and higher than 2-HyA-CS and pure chitosan. The cytotoxicity of the prepared compound 2-HyA-CS and 2-HyA-CS/ZnO along with pure chitosan was estimated against two human cancer cells MCF-7 cells and HepG-2 cells, the result indicates that 2-HyA-CS/ZnO having higher Inhibitory activity against both MCF-7 and HepG-2 cells with 53.5 ± 2.86 and 27.4 ± 1.23 µg/mL respectively and 2-HyA-CS possessing moderate Inhibitory activity against both MCF-7 and HepG-2 cancer cells with IC50 = 216.5 ± 7.48 and 135.6 ± 6.49 µg/ml respectively.

Unraveling the Pharmaceutical Benefits of Freshly Prepared Amino Acid-Based Schiff Bases Via DFT, In Silico Molecular Docking and ADMET

A series of amino acid-based Schiff bases have been synthesized using a facile condensation between benzil (a diketone) and amino acid in the presence of a base. The formation of Schiff base compounds has been ensured by elemental analysis, FT-IR, ¹H-NMR, ¹³C-NMR and UV-Vis. spectra. Density Functional Theory (DFT) calculations have been explored in order to get intuition into the molecular structure and chemical reactivity of the compounds. The DFT, optimized structure of the compounds, has been used to attain the molecular docking studies with DNA structure to find the favorable mode of interaction. In silico ADME/Tox profile of the compounds has been predicted using pkCSM web tools, exhibiting suitable values of absorption, distribution, and metabolism. These obtained parameters are connected to bioavailability. In addition, toxicity, skin sensitization and cardiotoxicity (hERG) analysis have been performed for evaluating the drug-like character of the prepared Schiff bases. The findings obtained from this study may find applications in the field focusing on the production of efficient and harmless pharmacological drugs.

Dye Removal Ability of Pure and Doped Graphitic Carbon Nitride

Background:

Rapid escalation in textile, paper, pesticides, pharmaceuticals and several other chemical based manufacturing industries due to amplification in human requirements have proportionately contributed to the extreme contamination of water ecosystem, resulted from the discharge of toxic pollutants from industries. Effluents from textile industries are comprised of coloured dyes like Rhodamine B, Methyl Orange, Methylene Blue and phenolic compounds which deserve special mention owing to their non-biodegradable, carcinogenic and severe detrimental nature. Urgent needs to ameliorate this fast declining environmental situation are of immense necessity in current scenario.

Objectives:

Objectives: In this regard, graphitic carbon nitride (GCN) is a distinguished material for water purification-based applications because of its exclusive characteristics making it highly prospective for degradation of toxic dyes from water by catalysis and adsorption techniques. GCN has been a material of conspicuous interest in recent times owing to its two dimensional sheets like structure with favourable surface area, and cost-effective synthesis approaches along with high production yield. This article presents a detail study of different aspects of GCN as a material of potential for water purification. Through extensive literature survey it has been shown that GCN is an effective material to be used in the fields of application. Several effective procedures like catalysis or adsorption for removal of dyes from water have been discussed with their basic science behind.

Conclusions:

This systematic effort shows that GCN can be considered to be one of the most efficient water purifier with further advantages arising from its easy and cost effective large scale synthesis.

Review on Methylene Blue: Its Properties, Uses, Toxicity and Photodegradation

The unavailability of clean drinking water is one of the significant health issues in modern times. Industrial dyes are one of the dominant chemicals that make water unfit for drinking. Among these dyes, methylene blue (MB) is toxic, carcinogenic, and non-biodegradable and can cause a severe threat to human health and environmental safety. It is usually released in natural water sources, which becomes a health threat to human beings and living organisms. Hence, there is a need to develop an environmentally friendly, efficient technology for removing MB from wastewater. Photodegradation is an advanced oxidation process widely used for MB removal. It has the advantages of complete mineralization of dye into simple and nontoxic species with the potential to decrease the processing cost. This review provides a tutorial basis for the readers working in the dye degradation research area. We not only covered the basic principles of the process but also provided a wide range of previously published work on advanced photocatalytic systems (single-component and multi-component photocatalysts). Our study has focused on critical parameters that can affect the photodegradation rate of MB, such as photocatalyst type and loading, irradiation reaction time, pH of reaction media, initial concentration of dye, radical scavengers and oxidising agents. The photodegradation mechanism, reaction pathways, intermediate products, and final products of MB are also summarized. An overview of the future perspectives to utilize MB at an industrial scale is also provided. This paper identifies strategies for the development of effective MB photodegradation systems.

Mechanistic insight into the photocatalytic degradation of organic pollutants and electrochemical behavior of modified MWCNTs/Cu–Co3O4 nanocomposites

The present work reported the physical, chemical and electrical properties of Cu doped Co3O4.

Yttrium(iii) coordination polymer micro/nanospheres with single ligand and dual ligands

In this work, yttrium(iii) coordination polymer (Y-CP) ball-flower-shaped microparticles with diameters ranging from 5 μm to 10 μm were synthesized using vanillin and asparagine as ligands under solvothermal conditions at 150 °C for 24 h. Then, we investigated the reaction influencing factors such as the concentration of reactants (involving vanillin, asparagine, and rare earth), reaction temperature, and reaction time. Both uniform and sphere-like nanoparticles with an average size of ∼50 nm were obtained using vanillin as a ligand at 120 °C for 12 h. Furthermore, the products were characterized and the results of cytotoxicity research demonstrated that the nanoparticles had low cytotoxicity and the coordination polymer nanospheres were perfectly biocompatible.

Designing novel morphologies of l-cysteine surface capped 2D covellite (CuS) nanoplates to study the effect of CuS morphologies on dye degradation rate under visible light

Novel CuS@l-Cys NPs are designed by a hydrothermal route. The effects of synthetic parameters on the morphologies of CuS@l-Cys NPs were investigated. CuS@l-Cys NPs exhibit an enhanced dye degradation rate under visible light.