Preparation of Magnetite/Silica Composite with Polypropylene Carbon Nanodots (PP-CNs) from Commercial Polypropylene Plastic Waste for Photocatalytic Degradation of Methylene Blue

KATTY FEBRILIANI RAHAYU, Prof. Dr. Bambang Rusdiarso, DEA. dan Indriana Kartini, S.Si., M.Si., Ph.D.

2021 | Skripsi | S1 KIMIA

Research on the preparation of magnetite/silica composite with carbon nanodots for photocatalytic degradation of methylene blue has been done. This research was initiated by synthesizing carbon nanodots from polypropylene plastic waste (PP-CNs) using a solvothermal method with H2SO4 as a solvent, KMnO4 and H2O2 as the oxidizing agents. PP-CNs were extracted from the resulted viscous liquid using ethyl acetate, then separated by chromatography column. Anhydrous sodium sulfate was used for purification. Characterization for PP-CNs was performed by FTIR spectrophotometer, HR-TEM with EDS and SAED, UV-Vis and fluorescence spectrophotometer. PP-CNs were modified into powder by preparing composite with Fe3O4/SiO2. The resulted powder, namely Fe3O4/SiO2/PP-CNs, was characterized using an FTIR spectrophotometer and XRD. The photocatalytic activity of Fe3O4/SiO2/PP-CNs was tested for methylene blue degradation with the variation of irradiation time and photocatalyst weight. The percentage of degradation was determined by using the UV-Visible method. The results showed that PP-CNs having an average particle size of 2.07 nm and a blue fluorescence color in the UV light were successfully synthesized. Fe3O4/SiO2/PP-CNs as a photocatalyst can increase the percentage of methylene blue 10 mg/L (20 mL) degradation by up to 28.20% under UV irradiation which the effect of light showed optimum irradiation time is 90 minutes. Meanwhile, the effect of photocatalyst weight with UV light showed that the optimum photocatalyst weight is 20 mg with the uncorrected percentage degradation of methylene blue 10 mg/L (20 mL) by up to 61.80%.

Research on the preparation of magnetite/silica composite with carbon nanodots for photocatalytic degradation of methylene blue has been done. This research was initiated by synthesizing carbon nanodots from polypropylene plastic waste (PP-CNs) using a solvothermal method with H2SO4 as a solvent, KMnO4 and H2O2 as the oxidizing agents. PP-CNs were extracted from the resulted viscous liquid using ethyl acetate, then separated by chromatography column. Anhydrous sodium sulfate was used for purification. Characterization for PP-CNs was performed by FTIR spectrophotometer, HR-TEM with EDS and SAED, UV-Vis and fluorescence spectrophotometer. PP-CNs were modified into powder by preparing composite with Fe3O4/SiO2. The resulted powder, namely Fe3O4/SiO2/PP-CNs, was characterized using an FTIR spectrophotometer and XRD. The photocatalytic activity of Fe3O4/SiO2/PP-CNs was tested for methylene blue degradation with the variation of irradiation time and photocatalyst weight. The percentage of degradation was determined by using the UV-Visible method. The results showed that PP-CNs having an average particle size of 2.07 nm and a blue fluorescence color in the UV light were successfully synthesized. Fe3O4/SiO2/PP-CNs as a photocatalyst can increase the percentage of methylene blue 10 mg/L (20 mL) degradation by up to 28.20% under UV irradiation which the effect of light showed optimum irradiation time is 90 minutes. Meanwhile, the effect of photocatalyst weight with UV light showed that the optimum photocatalyst weight is 20 mg with the uncorrected percentage degradation of methylene blue 10 mg/L (20 mL) by up to 61.80%.

Kata Kunci : Fe3O4/SiO2/PP-CNs, methylene blue, photocatalyst, solvothermal