Anthropogenic activities have led to environmental pollution by toxic heavy metals and dyes such as Congo red. Trimetallic nanoparticles can be used for enrichment heavy metals and photocatalytic degradation of Congo red from the environment. However, the processes used to synthesize nanoparticles can be hazardous to the environment. In the study, green synthesis of Phosphorous doped ZrO2CeO2ZnO nanoparticles were carried out using Flacourtia indica leaf aqueous extracts with phytochemicals as reducing agents. The nanoparticles were used as photocatalysts for degradation of Congo red dye and as sorbents for enrichment of selected toxic metals: lead, cadmium, arsenic and chromium. The influence of various parameters during the synthesis and solid phase extraction stages were investigated using Half, Full and Taguchi experimental designs. Interactions between factors were determined using ANOVA and response surface methodologies. The enrichment methods were validated by using spiked borehole, well, tap and effluent water samples. The P−ZrO2CeO2ZnO nanoparticles and P−ZrO2CeO2ZnO nanoparticles/alginate beads were characterized using Ultra Violet Visible spectrometry, Scanning Electron Microscope(SEM), Fourier Transform-Infra Red Spectroscopy, Transmitting Electron Microscopy (TEM), Brunauer Emmet Teller (BET) analysis, X-ray Photoelectron Spectroscopy (XPS) and X ray Diffraction (XRD). The most significant factors for P−ZrO2CeO2ZnO nanoparticle synthesis were pH, metal ion concentration and leaf extract concentration. The surface areas obtained under optimum synthesis conditions were 0.459 m2g−1 and 7.33 m2g−1for P−ZrO2CeO2ZnO nanoparticles and P−ZrO2CeO2ZnO nanoparticles/alginate beads respectively. The synthesized nanoparticles were crystalline and irregularly shaped The nanoparticles average size was 0.255 nm and the range of the size was from 0.1-4.51nm. Zn−O, Zr−O, C−O, O−H, functional groups were present in the nanoparticles from FTIR data. The optimum conditions for photocatalytic degradation of Congo red using P−ZrO2CeO2ZnO nanoparticles were 0.05 g/L catalyst dosage concentration, 10 mg/L Congo red concentration, 250 min irradiation time. The reaction followed pseudo first order kinetics with a rate constant of 0.069 min-1 and degradation efficiency of 85.85%.The reaction mechanism was explained by light, superoxide radicals and h+ holes. [...]
- Citation du texte
- Nichodimus Hokonya (Auteur), 2024, Green Synthesis of Trimetallic Nanoparticles using Flacourtia Indica (Burm.f.) Merr. Characterization and Applications, Munich, GRIN Verlag, https://www.grin.com/document/1590457