Direct Z-Scheme AgBr/β-MnO2 Photocatalysts for Highly Efficient Photocatalytic and Anticancer Activity

Fe3O4/CuO/Chitosan Nanocomposites: An Ultrasound-Assisted Green Approach for Antibacterial and Photocatalytic Properties

The fundamental goal of this research was to use an environmentally friendly sonochemical method to synthesize a Fe3O4/CuO/chitosan magnetic nanocomposite. The nanocomposites featured particle sizes ranging from 50 to 90 nm, and structural characteristics were thoroughly examined. Moreover, the material displayed selective photodegradation capabilities with MB, achieving an impressive efficiency of nearly 98% within 180 min under specific conditions. Notably, the material's reusability was remarkable, maintaining an efficiency of approximately 88% even after five cycles. The possible photodegradation mechanism was proposed based on the evaluation of energy bands, along with a comprehensive analysis of the impacts on MB photodegradation. Concurrently, adsorption isotherms and kinetic models were evaluated. Additionally, this material exhibited promising antibacterial activity against Saccharomyces cerevisiae, Bacillus subtilis, and Escherichia coli. These findings suggested that the Fe3O4/CuO/chitosan material could be utilized in real-world scenarios for environmental purification due to its ability to function as a photocatalyst and antibacterial agent.

Synergistic Trimetallic Nanocomposites as Visible-NIR-Sunlight-Driven Photocatalysts for Efficient Artificial Photosynthesis

Here, we report monodispersed tricomponent MnNSs-SnO2@Pt and MnNFs-SnO2@Pt nanocomposites prepared by simultaneous SnO2 and Pt nanodot coating on Mn nanospheres (MnNSs) and Mn nanoflowers (MnNFs) for highly efficient CO2 photoreduction in visible-NIR-sunlight irradiation. MnNFs-SnO2@Pt showed higher efficiency with a quantum yield of 3.21% and a chemical yield of 5.45% for CO2 conversion under visible light irradiation for HCOOH formation with 94% selectivity. Similarly, MnNFs-SnO2@Pt displayed significant photocatalytic efficiency in NIR and sunlight irradiation for HCOOH yield. MnNFs-SnO2@Pt nanocomposites also showed robust morphology and sustained structural stability with shelf-life for at least 1 year and were utilized for at least 10 reaction cycles without losing significant photocatalytic efficiency. The high surface area (94.98 m2/g), efficient electron-hole separation, and Pt-nanodot support in MnNFs--SnO2@Pt contributed to a higher photocatalytic efficacy toward CO2 reduction.

Amoxicillin degradation by iron photonanocatalyst synthetized by green route using pumpkin (Tetsukabuto) peel extract

Amoxicillin is a pharmaceutical compound that is not degraded in wastewater treatment plants, causing harm to the environment. In this work, an iron nanoparticle (IPP) was synthesized using pumpkin (Tetsukabuto) peel extract for the degradation of amoxicillin under UV light. The IPP was characterized using scanning electron microscopy/energy dispersive x-ray spectroscopy, transmission electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, thermogravimetric analysis, and Raman spectroscopy techniques. The photocatalytic efficiency of IPP was analyzed by investigating the effect of IPP dosage (1-3 g L^-1), initial amoxicillin concentration (10-40 mg L^-1), pH (3-9), reaction time (10-60 min), and the effect of inorganic ions (1 g L^-1). The optimum conditions for the maximum photodegradation removal (≈60%) were IPP = 2.5 g L^-1, initial amoxicillin concentration = 10 mg L^-1, pH = 5.6, and irradiation time = 60 min. The results of this study showed that inorganic ions (Mg²⁺, Zn²⁺, and Ca²⁺) negatively affect the photodegradation of amoxicillin by IPP; the quenching test showed that hydroxyl radical (OH^•) is the primary reactive species of the reaction; NMR analysis revealed changes in amoxicillin molecules after photoreaction; the subproducts of photodegradation were identified by LC-MS; the proposed kinetic model demonstrated good applicability, predicting the behavior of OH^• and determining the kinetic constant, and the cost analysis based on required energy (238.5 kWh m^-3 order^-1) indicated that the amoxicillin degradation method by IPP is economically viable. This study developed a new efficient iron nanocatalyst for the removal of antibiotics from aqueous environments and provided optimal conditions and relevant information in the area of advanced oxidative processes.

Facile synthesis of hollow spherical g-C3N4@LDH/NCQDs ternary nanostructure for multifunctional antibacterial and photodegradation activities

Heterojunction nanostructure construction and morphology engineering are considered to be effective approaches to improve photocatalytic performance. Herein, ternary hierarchical hollow structures consisting of cobalt-aluminum-layered double hydroxide (CoAl-LDH) nanoplates grown on hollow carbon nitride spheres (HCNS) and decorated with N-doped carbon quantum dots (NCQDs) were prepared using a templating method and a subsequent solvothermal process. The obtained HCNS@LDH/NCQD composites presented an improved performance in photocatalytic degradation of tetracycline and inactivation of E. coli compared with pure HCNS and LDH under visible light illumination. The enhanced photocatalytic activity of the designed photocatalyst could be attributed to the following reasons: (1) A special hollow structure provides more active sites and has multiple capabilities of light reflection by helping with a high specific surface area that improves the harvesting efficiency of solar light and (2) the strong synergistic effect among the constituents, which promotes separation and transfer of charge carriers and broadens the photo-response range.

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.