Synthesis of efficient composite photocatalysts from solid solution Bi3O4Cl0.5Br0.5 and Ag-AgI/AgCl for decomposition the oil field pollutants of phenol and acrylamide

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.

Toxicity of acrylamide after degradation by conjugated (UV/H2O2) photolysis in microalgae

Acrylamide (AA) is routinely used in laboratories and industries, and its disposal is always a problem; consequently, offering an alternative for their treatment contributes to conducting research in a responsible way. Therefore, in this work, acrylamide solutions were degraded by ultraviolet radiation and hydrogen peroxide (H₂O₂), and their toxicity was evaluated using a Desmodesmus quadricauda microalgae growth assay. The AA solutions were exposed to different dosages of H₂O₂ and different exposure times to UV radiation. The degradation was evaluated by liquid chromatography, which allowed the identification of the acrylamide peak and subsequent by-product peaks. A 100% degradation of the 1.5 mg L^-1 AA solution with UV/H₂O₂ (0.034 g L^-1) was achieved in just 10 min. The by-products formed did not inhibit the growth of D. quadricauda microalgae. The number of D. quadricauda individuals that grew in acrylamide solutions exposed to 20 and 30 min of UV radiation, with 0.034 g L^-1 of H₂O₂, was very similar to the number of individuals that grew in the control solution. Thus, the treatment proposed in this work using H₂O₂ combined with ultraviolet radiation degraded acrylamide into by-products with reduced toxicity.

Synthesis of a BiPO4/Bi4O5I2 heterostructure for efficient degradation of oil field pollutants

In this research, composite photocatalysts were found to have a superior photocatalytic performance.