Biosynthesis of CoCr2O4/ZnO nanocomposites using Basella alba L. leaves extracts with enhanced photocatalytic degradation of malachite green in aqueous media.

The use of chemical materials to tackle environmental concerns has undergone significant evolution, particularly in the pursuit of strategies for removing pollutants from wastewater as part of environmental remediation an increasingly crucial research topic. Employing green photocatalysts stands out as an efficient and cost-effective approach, playing a key role in promoting sustainable environmental remediation. This study introduces the modification of zinc oxide with cobalt chromite (CoCr2O4/ZnO) through a green synthesis method employing Basella alba L. leaves extract (BALE). Utilizing various characterization techniques, including FT-IR, UV-Vis DRS, XRD, SEM-EDS, and TEM, key features of ZnO, CoCr2O4, and CoCr2O4/ZnO nanocomposites were identified. The optical band gaps for ZnO, CoCr2O4, and CoCr2O4/ZnO nanocomposites were determined as 3.16, 1.71, and 2.80 eV, respectively, where it was shown that the band gap of the ZnO was reduced significantly. CoCr2O4/ZnO nanocomposites displayed a cubic shape of CoCr2O4 on the surface of ZnO, with a particle size of 23.84 ± 8.08 nm. The photocatalytic activity was assessed through the degradation of malachite green under visible light irradiation, where the CoCr2O4/ZnO nanocomposites exhibited superior photodegradation efficiency at 90.91%, surpassing ZnO alone (57.09%). This improvement in photocatalytic activity is attributed to a reduced band gap energy and a high rate constant value of 9.57 × 10-3 min-1, demonstrating pseudo-first-order reaction kinetics. In summary, this research presents the development of a ZnO-based photocatalyst with exceptional performance, especially in the visible light spectrum, making it a promising candidate for applications in wastewater removal.

Phytosynthesis of gold-198 nanoparticles for a potential therapeutic radio-photothermal agent.

We produced spherical gold-198 nanoparticles with an average size of 41 nm, good stability, and high radiochemical purity for a promising single agent of radio-photothermal therapy using Curcuma longa rhizome extract as a reducing and capping agent. The combination of in vitro treatment using gold-198 nanoparticles and irradiation of 980 nm wavelength lasers with a power output of 2 W/cm2 induced hyperthermia temperature and exhibited enhancement of the percentage dead on MDA-MB-123 cancer cells compared to gold-198 nanoparticles alone.

Chitosan Nanoparticles Modified by Anredera cordifolia (Ten.) Steenis Leaf Extract for Enhancement of Azithromycin Encapsulation Efficiency and Loading Capacity: In vitro Drug Release Study.

The encapsulation efficiency and the loading capacity of azithromycin (AZI) were succesfully enhanced by modifying chitosan nanoparticle (NCh) with Anredera cordifolia leaf extract (ACLE), as demonstrated in this study. The prominent secondary metabolites in ACLE could establish a new chemical bonds with NCh's amino groups and partly improved the hydrophobicity of NCh, which leads to excellent AZI encapsulation efficiency and loading capacity of 95.24 ± 1.30% and 55.74 ± 1.03%, respectively. TEM characterization demonstrated that the AZI-loaded ACLE-NCh nanoparticles were uniformly distributed with a particle size of 24.6 ± 2.9 nm. According to the result of in vitro drug release studies, AZI-loaded ACLE-NCh releases 1.12 ± 0.33% at a pH of 1.6 for 2 h, 82.05 ± 2.26% at a pH of 6.8 for 6 h, and 93.44 ± 1.94% at a pH of 7.4 for 24 h. It is remarkable that the encapsulation activityu of AZI-loaded ACLE-NCh is more effective due to the better interaction between NCh and AZI resulting from the increased hydrophobicity of modified NCh. Moreover, this work provides novel findings on the significant contribution of NCh modified by plant extracts, which has the potential as a carrier for azithromycin.

Green synthesis of novel YMnO3-doped TiO2 for enhanced visible-light- driven photocatalytic degradation of malachite green.

Recently, new methods of utilizing chemistry materials to overcome environmental issues worldwide, for instance, water purification have widely evolved since it is well-aligned with the sustainable development goals 6: clean water and sanitation. These issues have become a vital research topic for researchers in the last decade, particularly, the use of green photocatalyst due to the limitation of renewable resources. Herein, we report the modification of titanium dioxide with yttrium manganite (TiO2/YMnO3) by a novel high-speed stirring technique in n-hexane-water utilizing Annona muricata L. leaf extracts (AMLE). The YMnO3 incorporation in the presence of TiO2 was introduced to accelerate the photocatalytic performance for the degradation of malachite green in aqueous media. TiO2 modification with YMnO3 presented a drastic decline of bandgap energy from 3.34 to 2.38 eV and the highest rate constant (kapp) of 2.275 × 10-2 min-1. Surprisingly, TiO2/YMnO3 exhibited an extraordinary photodegradation efficiency of 95.34%, which was 1.9-fold higher than that of TiO2 under visible light illumination. The enhanced photocatalytic activity is ascribed to the formation of a TiO2/YMnO3 heterojunction, narrower optical band gap, excellent charge carrier separation. H+ and .O2- were the major scavenger species that play a significant role in the photodegradation of malachite green. Additionally, TiO2/YMnO3 shows outstanding stability over five cycles of photocatalytic reaction without significant loss of its effectiveness. This work presents a recent understanding of the green construction of a novel TiO2-based YMnO3 photocatalyst with excellent efficiency in the visible region for environmental technology application in water purification specifically in degrading organic dyes.

SmMnO3-decorated ZnO in a hexane-water interface for enhancing visible light-driven photocatalytic degradation of malachite green.

Malachite green (MG) contributes to water contamination because its accumulation adversely impacts aquatic systems. For the first time, we prepare a high photoresponse of ZnO/SmMnO3 heterojunction via a high-speed stirring method at the nonpolar-polar interface assisted by Alstonia scholaris leaves extract (ASLE) as natural hydrolyzing and stabilizing agents. The heterojunction formation boosts the photocatalytic activity of ZnO up to 91.74% under visible light irradiation. Photoluminescence analysis confirmed that modification with SmMnO3 increases the separation of photogenerated charges and plummets the recombination rates of electron-holes, which induces high photodegradation of MG. With 3 mg of catalyst, the %TOC removal efficiency for MG degradation over ZnO/SmMnO3 was found to be 53.09%, which is higher than that over ZnO. The kinetics model for the photocatalytic reaction was a pseudo-first-order with excellent stability in four consecutive cycles with no structural change. The radical trapping experiment suggests that h+ was the major species in the MG photodegradation reaction. Additionally, morphology and elemental analyses clearly present the formation of ZnO/SmMnO3 heterojunction without any impurities. The current research demonstrates a simple and advanced technique to design heterojunction photocatalyst at the interface of hexane-water.

Investigation of crystal structure influence on spectroscopic and photoluminescent properties of terbium-picrate triethylene glycol complex.

The [Tb(Pic)(2)(H(2)O)(EO3)](Pic)·0.5(EO3) complex, for which EO3 and Pic stand for triethylene glycol and picrate anion, respectively, was successfully prepared and characterized. The Tb(III) complex was crystallized in triclinic structure with space group P1¯. The Tb(III) ion was coordinated to nine oxygen atoms from one EO3 ligand, one water molecule, and two Pic anions. The photoluminescent (PL) spectrum of the complex displayed characteristic narrow bands arising from intraconfigurational transitions of the Tb(III) ion. The strongest emission was centred at 544 nm ((5)D(4)→(7)F(5)), which was responsible for the green emission. The short acyclic chain length of the EO3 ligand, lanthanide contraction, and a bulky picrate anion affected the PL intensity, coordination environment around the Tb(III) ion, and crystal structure of the inner-sphere [Tb(Pic)(2)(H(2)O)(EO3)](+) moiety. The unique crystal structure in the Tb complex contained a half mole of triethylene glycol solvated. The complex had a high thermal stability due to the role of π-π stacking interactions of the Pic anions. The appearance of an emission from the ligands suggests that the photoluminescence of ligands cannot be quenched by coordination to the Tb(III) ion in its complex, so the intramolecular energy transfer process from the triplet state of the ligands (T(1)(L)) to the resonant emissive energy level of Tb(III) is not effective.

Interfacial aggregate growth process of Fe(II) and Fe(III) complexes with pyridylazophenol in solvent extraction system.

The complexation mechanism and aggregate formation of bis[2-(5-bromo-2-pyridylazo)-5-diethylaminophenolate] iron(II) and iron(III) complexes at the heptane-water interface were studied spectrophotometrically by the high-speed stirring method and the centrifugal liquid membrane method. Furthermore, the reduction process of the Fe(III) complex with ascorbic acid at the interface was spectrophotometrically observed. The chemical compositions of the interfacial aggregate of complexes have been proved by the X-ray photoelectron spectroscopy. The aggregation of the complex at the interface was observed as a red-shifted, very strong and narrower absorption band with respect to the absorption band of the monomer complex. The aggregate of Fe(III) complex showed more shifted spectrum than that of Fe(II) complex, which proposed the larger aggregation number of Fe(III) aggregate (n = 8) than that of Fe(II) aggregate (n = 3). The obtained rate constants of interfacial aggregation were smaller than rate constants of interfacial monomer complexation, because the formation of aggregate required the assembly of the monomers.