Synthesis of Titanium Dioxide/Cellulose Derived from Banana Peel for Sonocatalytic Degradation of Methylene Blue

Abstract

Banana peel was used as the source of cellulose and titanium dioxide (TiO2)/cellulose composites with different weight ratios were successfully synthesised by using sol-gel method. The composites were then characterised by using the scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The synthesised TiO2 was found to be in anatase phase. TiO2 particles were spherical in shape and consisted of both titanium (Ti) and oxygen (O) elements only. Meanwhile, the morphology of extracted cellulose was found to have a rough surface. TiO2 particles were found to be covering the cellulose surface when preparing the composite samples and clusters of agglomerated TiO2 particles on cellulose surface could be observed. FTIR results indicated that the absorption peaks intensity of cellulose slowly reduced as compared to the composite materials. The sonocatalytic degradation of methylene blue in the presence of TiO2/cellulose at weight ratio of 1:2 showed the highest degradation efficiency of 74.14 % at the optimum conditions (initial dye concentration of 10 ppm, catalyst dosage of 1.0 g/L and solution pH of 8). Study on the degradation kinetics of methylene blue at different solution pH proved that the reaction kinetics fitted well into pseudo first-order. Additionally, a chemical oxygen demand (COD) removal of 94.44 % was also achieved after 30 minutes of ultrasonic irradiation under the prescribed optimum conditions.