Effect of reduced graphene oxide (rGO) on structural, optical, and dielectric properties of Mg(OH) 2 /rGO nanocomposites

Multiple phases of yttrium-doped molybdenum trioxide nanorods as efficient dye degrader and bactericidal agents with molecular docking analysis

Contaminants removal is usually becoming an exciting subject of research from water considering their environmental and ecological effects. This work provides pathways to remove organic pollutants from water via nanomaterials and is used as an antibiotic against bacteria like Escherichia coli (E. coli). In this study, molybdenum trioxide (MoO3) and yttrium (Y) doped (2 and 4%) MoO3 nanorods were synthesized by co-precipitation method. Advanced characterization techniques have been introduced to study textural structures, morphological developments, and optical characteristics of produced products. X-ray diffraction studied multiple crystalline structures of prepared samples as hexagonal, orthorhombic, and monoclinic of pure MoO3 with decrease in crystallinity and crystallite size upon Y doping. UV-visible spectroscopy unveiled a redshift (bathochromic effect) in absorption pattern attributed to band gap energy (Eg) decreases. Photoluminescence spectra examined the recombination rate of electrons (e-) and holes (h+) as charge carriers. A sufficient catalytic activity (CA) was observed against methylene blue (MB) dye in an acidic medium (99.74%) and efficient bactericidal action was studied against (E. coli) with zone of inhibition (5.20 mm) for 4% Y-doped MoO3. In addition, in silico docking demonstrated potential inhibitory effect of produced nanomaterials on FabH and FabI enzymes of fatty acid biosynthesis.

Photocatalytic Degradation of Methylene Blue and Anticancer Response of In2O3/RGO Nanocomposites Prepared by a Microwave-Assisted Hydrothermal Synthesis Process

The incorporation of graphene with metal oxide has been widely explored in various fields, including energy storage devices, optical applications, biomedical applications, and water remediation. This research aimed to assess the impact of reduced graphene oxide (RGO) doping on the photocatalytic and anticancer properties of In₂O₃ nanoparticles. Pure and In₂O₃/RGO nanocomposites were effectively synthesized using the single-step microwave hydrothermal process. XRD, TEM, SEM, EDX, XPS, Raman, UV-Vis, and PL spectroscopy were carefully utilized to characterize the prepared samples. XRD data showed that synthesized In₂O₃ nanoparticles had high crystallinity with a decreased crystal size after RGO doping. TEM and SEM images revealed that the In₂O₃ NPs were spherical and uniformly embedded onto the surface of RGO sheets. Elemental analysis of In₂O₃/RGO NC confirmed the presence of In, O, and C without impurities. Raman analysis indicated the successful fabrication of In₂O₃ onto the RGO surface. Uv-Vis analysis showed that the band gap energy was changed with RGO addition. Raman spectra confirmed that In₂O₃ nanoparticles were successfully anchored onto the RGO sheet. PL results indicated that the prepared In₂O₃/RGO NCs can be applied to enhance photocatalytic activity and biomedical applications. In the degradation experiment, In₂O₃/RGO NCs exhibited superior photocatalytic activity compared to that of pure In₂O₃. The degradation efficiency of In₂O₃/RGO NCs for MB dye was up to 90%. Biological data revealed that the cytotoxicity effect of In₂O₃/RGO NCs was higher than In₂O₃ NPs in human colorectal (HCT116) and liver (HepG2) cancer cells. Importantly, the In₂O₃/RGO NCs exhibited better biocompatibility against human normal peripheral blood mononuclear cells (PBMCs). All the results suggest that RGO addition improves the photocatalytic and anticancer activity of In₂O₃ NPs. This study highlights the potential of In₂O₃/RGO NCs as an efficient photocatalyst and therapeutic material for water remediation and biomedicine.

Antitumor Activity of PEGylated and TEGylated Phenothiazine Derivatives: Structure–Activity Relationship

The paper aims to investigate the antitumor activity of a series of phenothiazine derivatives in order to establish a structure–antitumor activity relationship. To this end, PEGylated and TEGylated phenothiazine have been functionalized with formyl units and further with sulfonamide units via dynamic imine bonds. Their antitumor activity was monitored in vitro against seven human tumors cell lines and a mouse one compared to a human normal cell line by MTS assay. In order to find the potential influence of different building blocks on antitumor activity, the antioxidant activity, the ability to inhibit farnesyltransferase and the capacity to bind amino acids relevant for tumor cell growth were investigated as well. It was established that different building blocks conferred different functionalities, inducing specific antitumor activity against the tumor cells.

Efficient Photocatalytic Dye Degradation and Bacterial Inactivation by Graphitic Carbon Nitride and Starch-Doped Magnesium Hydroxide Nanostructures

The removal of hazardous pollutants from water is becoming an increasingly interesting topic of research considering their impact on the environment and the ecosystem. This work was carried out to synthesize graphitic carbon nitride (g-C₃N₄) and starch-doped magnesium hydroxide (g-C₃N₄/St-Mg(OH)₂) nanostructures via a facile co-precipitation process. The focus of this study is to treat polluted water and bactericidal behavior with a ternary system (doping-dependent Mg(OH)₂). Different concentrations (2 and 4 wt %) of g-C₃N₄ were doped in a fixed amount of starch and Mg(OH)₂ to degrade methylene blue dye from an aqueous solution with bactericidal potential against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) pathogens. The textural structures, morphological evolutions, and optical characteristics of the as-prepared samples were analyzed using advanced characterization techniques. X-ray diffraction confirmed the hexagonal phase of Mg(OH)₂ with improved crystallinity upon doping. Fourier transform infrared spectroscopy revealed Mg(OH)₂ stretching vibrations and other functional groups. UV-visible spectroscopy exhibited a red shift (bathochromic effect) in absorption spectra representing the decrease in energy band gap (E _g). Photoluminescence patterns were recorded to study recombination of charge carriers (e^- and h⁺). A significant enhancement in photodegradation efficiency (97.62%) and efficient bactericidal actions against E. coli (14.10 mm inhibition zone) and S. aureus (7.45 mm inhibition zone) were observed for higher doped specimen 4% g-C₃N₄/St-Mg(OH)_2.

Effect of the green synthesized rGO and Mg/rGO nanocomposites on the phytochemical assay, toxicity, and metabolism of Mentha longifolia in vitro cultures

Reduced graphene oxide (rGO) and Mg/rGO nanocomposites (NCs) were prepared by an eco-friendly technique using Rosa canina fruit extract. Physicochemical properties and cytotoxicity to Mentha longifolia in vitro cultures of these nanomaterials were examined by using XRD, FESEM, EDX, FT-IR, DLS/zeta potential, UV-Visible, and GC-MS techniques. The characterization techniques confirmed the synthesis of rGO and Mg/rGO NCs with particle sizes less than 20 nm (based on FESEM). In accordance to the biological measurements, rGO showed in vitro cytotoxicity to M. longifolia shoot cultures. Mg/rGO NCs showed no significant difference in the growth parameters except for a decrease in the shoot number at the concentrations of 50 and 150 mg/L and a decrease in the length of the tallest root at the concentrations of 100 and 150 mg/L, however efficiently improved the photosynthetic pigment contents. The phytochemical assay depicted that the total content of volatile compounds was increased in the treated cultures with 25, 50, and 100 mg/L of rGO and Mg/rGO NCs in comparison to the control. Generally, the more oxygenated and hydrocarbon sesquiterpenes were observed in the cultures treated with 25 and 100 mg/L of rGO and 25 and 50 mg/L of Mg/rGO NCs.

Recent Advances in MnOx/CeO2-Based Ternary Composites for Selective Catalytic Reduction of NOx by NH3: A Review

Recently, manganese oxides (MnOx)/cerium(IV) oxide (CeO2) composites have attracted widespread attention for the selective catalytic reduction (SCR) of nitrogen oxides (NOx) with ammonia (NH3), which exhibit outstanding catalytic performance owing to unique features, such as a large oxygen storage capacity, excellent low-temperature activity, and strong mechanical strength. The intimate contact between the components can effectively accelerate the charge transfer to enhance the electron–hole separation efficiency. Nevertheless, MnOx/CeO2 still reveals some deficiencies in the practical application process because of poor thermal stability, and a low reduction efficiency. Constructing MnOx/CeO2 with other semiconductors is the most effective strategy to further improve catalytic performance. In this article, we discuss progress in the field of MnOx/CeO2-based ternary composites with an emphasis on the SCR of NOx by NH3. Recent progress in their fabrication and application, including suitable examples from the relevant literature, are analyzed and summarized. In addition, the interaction mechanisms between MnOx/CeO2 catalysts and NOx pollutants are comprehensively dissected. Finally, the review provides basic insights into prospects and challenges for the advancement of MnOx/CeO2-based ternary catalysts.

Novel NiMgOH-rGO-Based Nanostructured Hybrids for Electrochemical Energy Storage Supercapacitor Applications: Effect of Reducing Agents

This paper describes the synthesis and characterization of NiMgOH-rGO nanocomposites made using a chemical co-precipitation technique with various reducing agents (e.g., NaOH and NH4OH) and reduced graphene oxide at 0.5, 1, and 1.5 percent by weight. UV-visible spectroscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, a particle size analyzer, and cyclic voltammetry were used to characterize the composite materials. The formation of the NiMgOH-rGO nanocomposite with crystallite sizes in the range of 10–40 nm was inferred by X-ray diffraction patterns of materials, which suggested interlayers of Ni(OH)2 and Mg(OH)2. The interactions between the molecules were detected using Fourier-transform infrared spectroscopy, while optical properties were studied using UV-visible spectroscopy. A uniform average particle size distribution in the range of 1–100 nm was confirmed by the particle size analyzer. Using cyclic voltammetry and galvanostatic charge/discharge measurements in a 6 M KOH solution, the electrochemical execution of NiMgOH-rGO nanocomposites was investigated. At a 1 A/g current density, the NiMgOH-rGO nanocomposites prepared with NH4OH as a reducing agent had a higher specific capacitance of 1977 F/g. The electrochemical studies confirmed that combining rGO with NiMgOH increased conductivity.

Enhanced optical properties of Cu2O anchored on reduced graphene oxide (rGO) sheets

In this report, Cu₂O and Cu₂O/rGO nanocomposites were successfully synthesized through chemical reduction method using glucose as a reducing agent for GO. The x-ray diffraction and field emission scanning electron microscope was used to investigate the phase composition and microstructure of the as-prepared materials. The presence of different functional groups in the as-synthesized sample was analyzed by Fourier transform infrared spectroscopy. Raman spectroscopy was used to confirm structural aspects such as defects of synthesized Cu₂O/rGO nanocomposites. The optical properties of the as-prepared samples were analyzed by UV-vis diffuse reflectance spectroscopy and photoluminescence spectroscopy. Urbach energy is calculated in order to find out the defects in the nanocomposites. Zeta potential analysis was done to study the surface charge and stability of the as-synthesized samples. These results show that the content of rGO introduced into nanocomposite improves the optical properties of Cu₂O thereby enhancing the utilization of visible light.