MICROWAVE HEATING METHOD FOR ZNO NANOPARTICLES AS A COMPONENT IN THE PHOTOCATALYTIC PROCESS OF DEGRADATION OF DYES

• Main Author: Yehezkiel Leonardo, Kevin
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/87150
• Institution: Institut Teknologi Bandung

Even though zinc oxide (ZnO) was widely used as photocatalyst, ZnO could only use UV light due to its high bandgap (3.3 eV). Thus, it is neceesary to reduce bandgap of ZnO to increase its efficiency in utilization of sunlight. The aim of this research is to know the influence of microwave heating on crystallinity, morphology and bandgap of the obtained ZnO. In this research, five ZnO samples were prepared by sol gel method with variation as follow: (a) without heating, (b) conventional heating at 70 °C for 45 minutes, microwave heating for: (c) 30, (d) 60, dan (e) 90 second. Each sample were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and diffuse reflectance UV-Visible spectroscopy (DR UV-Vis). XRD results showed that ZnO were obtained in all samples with Full Width at Half Maximum (FWHM) value 0.54, 0.55, 0.54, 0.57, 0.64 respectively. SEM results showed that the obtained ZnO has flower-like morphology, which is expected absorption efficiency could be enhanced due to its high surface area. DR UV-Vis results showed that bandgap of five ZnO samples are 3.22 eV, 3.25 eV, 3.10 eV, 3.10 eV and 3.09 eV respectively. These results showed that microwave heating at short period could reduce bandgap of the obtained ZnO and the bandgap value tend to decrease as increasing microwave time. Hal ini menunjukkan bahwa pemanasan yang singkat dengan microwave dapat menurunkan bandgap ZnO yang dihasilkan dan bandgap ZnO yang dihasilkan cenderung semakin rendah seiring dengan lamanya pemanasan microwave.